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Sample records for bovine adrenomedullary chromaffin

  1. Phosphorylation of myosin light chain from adrenomedullary chromaffin cells in culture.

    PubMed Central

    Gutierrez, L M; Hidalgo, M J; Palmero, M; Ballesta, J J; Reig, J A; Garcia, A G; Viniegra, S

    1989-01-01

    The myosin-light-chain (MLC) phosphorylation accompanying catecholamine release in chromaffin cells was investigated with the objective of assessing the possible role of this contractile protein in catecholamine secretion. The electrophoretic characteristics of adrenomedullary MLC were determined by immunochemical techniques using two different specific antibodies. The identified 22 kDa phosphoprotein was mainly present in the cytosol, as demonstrated by ultracentrifugation and immunocytochemical analysis. A part of this protein was located on, or close to, the plasma membrane. Cell stimulation by secretagogues resulted in a Ca2(+)-dependent 32P incorporation into MLC, the time course of this process being related to catecholamine release. These findings were supported by a two-dimensional gel-electrophoretic analysis by which means this protein was resolved into two acidic forms. A role for Ca2(+)-calmodulin and Ca2(+)-phospholipid kinases in adrenomedullary MLC phosphorylation is reported. The results obtained suggest a regulatory role for such a protein in the underlying exocytotic event. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 6. PMID:2481449

  2. Adenoviral Gene Transfer in Bovine Adrenomedullary and Murine Pheochromocytoma Cells: Potential Clinical and Therapeutic Relevance

    PubMed Central

    Alesci, Salvatore; Perera, Shiromi M.; Lai, Edwin W.; Kukura, Christina; Abu-Asab, Mones; Tsokos, Maria; Morris, John C.; Pacak, Karel

    2008-01-01

    Recombinant adenoviruses (rAd) have been widely used as gene transfer vectors both in the laboratory and in human clinical trials. In the present study, we investigated the effects of adenoviral-mediated gene transfer in primary bovine adrenal chromaffin cells (BACC) and a murine pheochromocytoma cell line (MPC). Cells were infected with one of three nonreplicating E1/E3-deleted (E1-/E3-) rAd vectors: Ad.GFP, expressing a green fluorescent protein (GFP); Ad.null, expressing no transgene; or Ad.C2.TK, expressing the herpes simplex virus-1 thymidine kinase gene (TK). Forty-eight hours after exposure to Ad.GFP, the percentage of GFP-expressing BACC ranged from 23.5-97% in a dose-dependent manner and similarly from 1.06 - 84.4% in the MPC, indicating that adrenomedullary cells are a potentially valuable target for adenoviral-mediated gene transfer. Ultrastructural analysis, however, revealed profound changes in the nucleus and mitochondria of cells infected with rAd. Furthermore, infection of BACC with Ad.null was accompanied by a time- and dose-dependent decrease in cell survival due to the vector alone. Specific whole-cell norepinephrine uptake was also decreased in a time- and dose-dependent fashion in BACC. Infection of MPC cells with the Ad.C2.TK vector sensitized them to the cytotoxic effect of the antiviral drug ganciclovir, in direct proportion to the fraction of cells infected with the virus. We conclude that rAd may alter the structural and functional integrity of adrenomedullary cells, potentially interfering with the normal stress response. At the same time, in light of their ability to effectively deliver and express genes in pheochromocytoma cells, they may be applicable to the gene therapy of adrenomedullary tumors. PMID:17525127

  3. Adenoviral gene transfer in bovine adrenomedullary and murine pheochromocytoma cells: potential clinical and therapeutic relevance.

    PubMed

    Alesci, Salvatore; Perera, Shiromi M; Lai, Edwin W; Kukura, Christina; Abu-Asab, Mones; Tsokos, Maria; Morris, John C; Pacak, Karel

    2007-08-01

    Recombinant adenoviruses (rAd) have been widely used as gene transfer vectors both in the laboratory and in human clinical trials. In the present study, we investigated the effects of adenoviral-mediated gene transfer in primary bovine adrenal chromaffin cells (BACC) and a murine pheochromocytoma cell line (MPC). Cells were infected with one of three nonreplicating E1/E3-deleted (E1(-)/E3(-)) rAd vectors: Ad.GFP, expressing a green fluorescent protein (GFP); Ad.null, expressing no transgene; or Ad.C2.TK, expressing the herpes simplex virus-1 thymidine kinase gene (TK). Forty-eight hours after exposure to Ad.GFP, the percentage of GFP-expressing BACC ranged from 23.5-97% in a dose-dependent manner and similarly from 1.06-84.4% in the MPC, indicating that adrenomedullary cells are a potentially valuable target for adenoviral-mediated gene transfer. Ultrastructural analysis, however, revealed profound changes in the nucleus and mitochondria of cells infected with rAd. Furthermore, infection of BACC with Ad.null was accompanied by a time- and dose-dependent decrease in cell survival due to the vector alone. Specific whole-cell norepinephrine uptake was also decreased in a time- and dose-dependent fashion in BACC. Infection of MPC cells with the Ad.C2.TK vector sensitized them to the cytotoxic effect of the antiviral drug ganciclovir, in direct proportion to the fraction of cells infected with the virus. We conclude that rAd may alter the structural and functional integrity of adrenomedullary cells, potentially interfering with the normal stress response. At the same time, in light of their ability to effectively deliver and express genes in pheochromocytoma cells, they may be applicable to the gene therapy of adrenomedullary tumors.

  4. A defined, controlled culture system for primary bovine chromaffin progenitors reveals novel biomarkers and modulators.

    PubMed

    Masjkur, Jimmy; Levenfus, Ian; Lange, Sven; Arps-Forker, Carina; Poser, Steve; Qin, Nan; Vukicevic, Vladimir; Chavakis, Triantafyllos; Eisenhofer, Graeme; Bornstein, Stefan R; Ehrhart-Bornstein, Monika; Androutsellis-Theotokis, Andreas

    2014-07-01

    We present a method to efficiently culture primary chromaffin progenitors from the adult bovine adrenal medulla in a defined, serum-free monolayer system. Tissue is dissociated and plated for expansion under support by the mitogen basic fibroblast growth factor (bFGF). The cultures, although not homogenous, contain a subpopulation of cells expressing the neural stem cell marker Hes3 that also propagate. In addition, Hes3 is also expressed in the adult adrenal medulla from where the tissue is taken. Differentiation is induced by bFGF withdrawal and switching to Neurobasal medium containing B27. Following differentiation, Hes3 expression is lost, and cells acquire morphologies and biomarker expression patterns of chromaffin cells and dopaminergic neurons. We tested the effect of different treatments that we previously showed regulate Hes3 expression and cell number in cultures of fetal and adult rodent neural stem cells. Treatment of the cultures with a combination of Delta4, Angiopoietin2, and a Janus kinase inhibitor increases cell number during the expansion phase without significantly affecting catecholamine content levels. Treatment with cholera toxin does not significantly affect cell number but reduces the ratio of epinephrine to norepinephrine content and increases the dopamine content relative to total catecholamines. These data suggest that this defined culture system can be used for target identification in drug discovery programs and that the transcription factor Hes3 may serve as a new biomarker of putative adrenomedullary chromaffin progenitor cells.

  5. Glucosensing in an immortalized adrenomedullary chromaffin cell line: role of ATP-sensitive K+ channels.

    PubMed

    Piskuric, Nikol A; Brown, Stephen T; Zhang, Min; Nurse, Colin A

    2008-11-07

    Using an immortalized adrenal chromaffin cell line (MAH cells), we investigated the cellular mechanisms underlying sensitivity to glucose-free solution (aglycemia) using ratiometric Ca2+ imaging and whole-cell recording. Though few cells (< 15%) responded to aglycemia with an increase in intracellular-free Ca2+ concentration ([Ca2+]i), in most cells (approximately 75%), aglycemia caused > 50% suppression of the Delta[Ca2+]i induced by the depolarizing stimulus, high (10 mM) K+. Moreover, in normal K+, the average aglycemia-induced rise in Cai2+ as well as the proportion of aglycemia-responsive cells increased in the presence of the K(ATP) channel blocker, glibenclamide. During membrane potential (Vm) measurements, aglycemia induced either hyperpolarization (6/20), depolarization (4/20) or no change in Vm. RT-PCR and Western blotting confirmed the presence of K(ATP) channel subunits Kir6.2 and SUR1 in MAH cells. These findings suggest a dual inhibitory and excitatory action of aglycemia in MAH cells, where activation of K(ATP) channels effectively inhibits or blunts the Delta[Ca2+]i due to the excitatory effect. Thus, this cell line appears as an attractive model for studying the molecular mechanisms of glucosensing.

  6. The protein phosphatase inhibitor calyculin-A affects catecholamine secretion and granular distribution in cultured adrenomedullary chromaffin cells.

    PubMed

    Gutierrez, L M; Quintanar, J L; Rueda, J; Viniegra, S; Reig, J A

    1995-09-01

    Calyculin-A, a potent inhibitor of types 1 and 2A protein phosphatases, increases basal catecholamine secretion in cultured chromaffin cells with a maximum effect observed at 100 nM. This effect was increased by forskolin and the calmodulin antagonist W7, but was modified neither by phorbol esters nor the protein kinase inhibitor, H7. The effect of the toxin, calyculin-A, on basal secretion was completely prevented by the protein kinase inhibitor K252a. In digitonin-permeabilized cells calyculin-A induced an increase in basal release, but, in contrast, it partially reduced calcium-induced secretion. Analysis of total proteins revealed that calyculin-A treatment of the cells increased the level of phosphorylation of different protein bands. Examination of the Triton X-100-insoluble fraction revealed a clear increase in the phosphorylation level of various proteins, including vimentin. Calyculin-A provoked a rapid morphological change in chromaffin cells in the same range of concentration (50-300 nM). Cells became rounder and were partially detached from the substratum forming clusters, this effect was also blocked by K252a. Transmission electron microscopy of calyculin-A-treated cells showed an increase in the proportion of chromaffin granules located closer to the membrane. These results suggest that calyculin-A induces changes both in the catecholamine secretory response and in the cytoskeletal elements of chromaffin cells by protein phosphorylation.

  7. Calcium dynamics in bovine adrenal medulla chromaffin cell secretory granules.

    PubMed

    Santodomingo, Jaime; Vay, Laura; Camacho, Marcial; Hernández-Sanmiguel, Esther; Fonteriz, Rosalba I; Lobatón, Carmen D; Montero, Mayte; Moreno, Alfredo; Alvarez, Javier

    2008-10-01

    The secretory granules constitute one of the less well-known compartments in terms of Ca2+ dynamics. They contain large amounts of total Ca2+, but the free intragranular [Ca2+] ([Ca2+]SG), the mechanisms for Ca2+ uptake and release from the granules and their physiological significance regarding exocytosis are still matters of debate. We used in the present work an aequorin chimera targeted to the granules to investigate [Ca2+]SG homeostasis in bovine adrenal chromaffin cells. We found that most of the intracellular aequorin chimera is present in a compartment with 50-100 microM Ca2+. Ca2+ accumulation into this compartment takes place mainly through an ATP-dependent mechanism, namely, a thapsigargin-sensitive Ca2+-ATPase. In addition, fast Ca2+ release was observed in permeabilized cells after addition of inositol 1,4,5-trisphosphate (InsP3) or caffeine, suggesting the presence of InsP3 and ryanodine receptors in the vesicular membrane. Stimulation of intact cells with the InsP3-producing agonist histamine or with caffeine also induced Ca2+ release from the vesicles, whereas acetylcholine or high-[K+] depolarization induced biphasic changes in vesicular[Ca2+], suggesting heterogeneous responses of different vesicle populations, some of them releasing and some taking up Ca2+during stimulation. In conclusion, our data show that chromaffin cell secretory granules have the machinery required for rapid uptake and release of Ca2+, and this strongly supports the hypothesis that granular Ca2+ may contribute to its own secretion.

  8. Mobile and immobile calcium buffers in bovine adrenal chromaffin cells.

    PubMed Central

    Zhou, Z; Neher, E

    1993-01-01

    1. The calcium binding capacity (kappa S) of bovine chromaffin cells preloaded with fura-2 was measured during nystatin-perforated-patch recordings. 2. Subsequently, the perforated patch was ruptured to obtain a whole-cell recording situation, and the time course of kappa S was monitored during periods of up to one hour. 3. No rapid change (within 10-20 s) of kappa S was observed upon transition to whole-cell recording, as would be expected, if highly mobile organic anions contributed significantly to calcium buffering. However, approximately half of the cells investigated displayed a drop in kappa S within 2-5 min, indicative of the loss of soluble Ca2+ binding proteins in the range of 7-20 kDa. 4. The average Ca2+ binding capacity (differential ratio of bound calcium over free calcium) was 9 +/- 7 (mean +/- S.E.M.) for the poorly mobile component and 31 +/- 10 for the fixed component. It was concluded that a contribution of 7 from highly mobile buffer would have been detected, if present. Thus, this value can be considered as an upper bound to highly mobile Ca2+ buffer. 5. Both mobile and fixed calcium binding capacity appeared to have relatively low Ca2+ affinity, since kappa S did not change in the range of Ca2+ concentrations between 0.1 and 3 microM. 6. It was found that cellular autofluorescence and contributions to fluorescence of non-hydrolysed or compartmentalized dye contribute a serious error in estimation of kappa S. 'Balanced loading', a degree of fura-2 loading such that the calcium binding capacity of fura-2 equals cellular calcium binding capacity, minimizes these errors. Also, changes in kappa S at the transition from perforated-patch to whole-cell recording can be most faithfully recorded for similar degrees of loading in both situations. 7. Nystatin was found unable to make pores from inside of the plasma membrane of chromaffin cells. With careful preparation and storage the diluted nystatin solution maintained its high activity of membrane

  9. The mechanism of calcium channel facilitation in bovine chromaffin cells.

    PubMed Central

    Albillos, A; Gandía, L; Michelena, P; Gilabert, J A; del Valle, M; Carbone, E; García, A G

    1996-01-01

    1. This study was planned to clarify the mechanism of Ca2+ channel facilitation by depolarizing prepulses given to voltage-clamped bovine chromaffin cells. The hypothesis for an autocrine modulation of such channels was tested by studying the effects of a soluble vesicle lysate (SVL) on whole-cell Ba2+ currents (IBa). 2. SVL was prepared from a bovine adrenal medullary homogenate. The ATP content in this concentrated SVL amounted to 3.18 +/- 0.12 mM (n = 4). The concentration of noradrenaline and adrenaline present in the SVL was 11.2 +/- 0.97 and 15.2 +/- 2 mM, respectively (n = 5). A 1:1000 dilution of SVL in the external solution halved the magnitude of IBa and produced a 7-fold slowing of its activation kinetics. The blocking effects of SVL were concentration dependent and quickly reversed upon washout. 3. Inhibition and slowing of the kinetics of IBa by SVL could be partially reversed by strong depolarizing prepulses (+90 mV, 45 ms). This reversal of inhibition, called Ca2+ channel facilitation, persisted in the presence of 3 microM nifedipine. 4. Intracellular dialysis of GDP-beta-S (0.5 mM) or pretreatment of the cells with pertussis toxin (100 ng ml-1 for 18-24 h) prevented the reduction in peak current caused by a 1:100 dilution of SVL; no prepulse facilitation could be observed under these conditions. 5. The receptor blockers naloxone (10 microM) or suramin (100 microM) and PPADS (100 microM) largely antagonized the effects of SVL. Treatment of SVL with alkaline phosphatase or dialysis against a saline buffer to remove low molecular mass materials (< 10 kDa) considerably reduced the activity of SVL. 6. Stopping the flow of the external solution (10 mM Ba2+) gradually reduced the size, and slowed down the activation phase, of the current. Prepulse facilitation of IBa was absent or weak in a superfused cell, but was massive upon flow-stop conditions in the presence or absence of 3 microM nifedipine. 7. Our experiments suggest that facilitation by prepulses

  10. Specific insulin binding in bovine chromaffin cells; demonstration of preferential binding to adrenalin-storing cells

    SciTech Connect

    Serck-Hanssen, G.; Soevik, O.

    1987-12-28

    Insulin binding was studied in subpopulations of bovine chromaffin cells enriched in adrenalin-producing cells (A-cells) or noradrenalin-producing cells (NA-cells). Binding of /sup 125/I-insulin was carried out at 15/sup 0/C for 3 hrs in the absence or presence of excess unlabeled hormone. Four fractions of cells were obtained by centrifugation on a stepwise bovine serum albumin gradient. The four fractions were all shown to bind insulin in a specific manner and the highest binding was measured in the cell layers of higher densities, containing mainly A-cells. The difference in binding of insulin to the four subpopulations of chromaffin cells seemed to be related to differences in numbers of receptors as opposed to receptor affinities. The authors conclude that bovine chromaffin cells possess high affinity binding sites for insulin and that these binding sites are mainly confined to A-cells. 24 references, 2 figures, 1 table.

  11. Monolayer co-culture of rat heart cells and bovine adrenal chromaffin paraneurons.

    PubMed

    Trifaró, J M; Tang, R; Novas, M L

    1990-04-01

    This paper describes a method for the preparation of co-cultures of rat heart cells and bovine adrenal chromaffin paraneurons. The most suitable condition for heart cell isolation was when a combination of trypsin-DNAse I in Locke's solution was used for digestion. The best co-culture conditions were obtained when 10(6) heart cells were plated on 7- to 8-d-old adrenal chromaffin paraneuron cultures containing 0.5 x 10(6) cells per 35-mm diameter culture dishes. Measurements of DNA (heart cells and chromaffin paraneurons), monitoring of beating frequency (heart cells), and catecholamine (chromaffin paraneurons) levels and release indicated that both cell types remain viable and functional for several weeks. Heart cells started their characteristic contractile activity 24 h earlier when plated either on viable or lysed chromaffin paraneurons, an effect apparently due to faster surface adhesion of heart cells. The beating frequency of heart cells increased after treatment of co-cultures with either noradrenaline or nicotine, with the latter agent acting indirectly through the release of chromaffin paraneuron catecholamines. Propranolol produced a dose-related inhibition of the responses to either noradrenaline or nicotine, thus suggesting that the increase in myocyte's beating activity was mediated through beta-receptors. Anti-myosin and anti-dopamine-beta-hydroxylase immunostaining was used for cell type identification and for the demonstration of body-to-body and process-to-process contacts between adrenal chromaffin paraneurons and heart cells. This co-culture system will serve as a starting point of further studies directed to understand a) the influence of a cell type on the development and on the phenotypic characteristics of a second cell type and b) the interaction of cells derived from different organs and species.

  12. Analgesia Induced by Isolated Bovine Chromaffin Cells Implanted in Rat Spinal Cord

    NASA Astrophysics Data System (ADS)

    Sagen, Jacqueline; Pappas, George D.; Pollard, Harvey B.

    1986-10-01

    Chromaffin cells synthesize and secrete several neuroactive substances, including catecholamines and opioid peptides, that, when injected into the spinal cord, induce analgesia. Moreover, the release of these substances from the cells can be stimulated by nicotine. Since chromaffin cells from one species have been shown to survive when transplanted to the central nervous system of another species, these cells are ideal candidates for transplantation to alter pain sensitivity. Bovine chromaffin cells were implanted into the subarachnoid space of the lumbar spinal region in adult rats. Pain sensitivity and response to nicotine stimulation was determined at various intervals following cell implantation. Low doses of nicotine were able to induce potent analgesia in implanted animals as early as one day following their introduction into the host spinal cord. This response could be elicited at least through the 4 months the animals were tested. The induction of analgesia by nicotine in implanted animals was dose related. This analgesia was blocked by the opiate antagonist naloxone and partially attenuated by the adrenergic antagonist phentolamine. These results suggest that the analgesia is due to the stimulated release of opioid peptides and catecholamines from the implanted bovine chromaffin cells and may provide a new therapeutic approach for the relief of pain.

  13. PACAP controls adrenomedullary catecholamine secretion and expression of catecholamine biosynthetic enzymes at high splanchnic nerve firing rates characteristic of stress transduction in male mice.

    PubMed

    Stroth, N; Kuri, B A; Mustafa, T; Chan, S-A; Smith, C B; Eiden, L E

    2013-01-01

    The neuropeptide PACAP (pituitary adenylate cyclase-activating polypeptide) is a cotransmitter of acetylcholine at the adrenomedullary synapse, where autonomic regulation of hormone secretion occurs. We have previously reported that survival of prolonged metabolic stress in mice requires PACAP-dependent biosynthesis and secretion of adrenomedullary catecholamines (CAs). In the present experiments, we show that CA secretion evoked by direct high-frequency stimulation of the splanchnic nerve is abolished in native adrenal slices from male PACAP-deficient mice. Further, we demonstrate that PACAP is both necessary and sufficient for CA secretion ex vivo during stimulation protocols designed to mimic stress. In vivo, up-regulation of transcripts encoding adrenomedullary CA-synthesizing enzymes (tyrosine hydroxylase, phenylethanolamine N-methyltransferase) in response to both psychogenic and metabolic stressors (restraint and hypoglycemia) is PACAP-dependent. Stressor-induced alteration of the adrenomedullary secretory cocktail also appears to require PACAP, because up-regulation of galanin mRNA is abrogated in male PACAP-deficient mice. We further show that hypoglycemia-induced corticosterone secretion is not PACAP-dependent, ruling out the possibility that glucocorticoids are the main mediators of the aforementioned effects. Instead, experiments with bovine chromaffin cells suggest that PACAP acts directly at the level of the adrenal medulla. By integrating prolonged CA secretion, expression of biosynthetic enzymes and production of modulatory neuropeptides such as galanin, PACAP is crucial for adrenomedullary function. Importantly, our results show that PACAP is the dominant adrenomedullary neurotransmitter during conditions of enhanced secretory demand.

  14. Mixed nicotinic and muscarinic features of cholinergic receptor coupled to secretion in bovine chromaffin cells

    SciTech Connect

    Shirvan, M.H.; Pollard, H.B.; Heldman, E. )

    1991-06-01

    Acetylcholine evokes release from cultured bovine chromaffin cells by a mechanism that is believed to be classically nicotinic. However, the authors found that the full muscarinic agonist oxotremorine-M (Oxo-M) induced a robust catecholamine (CA) secretion. By contrast, muscarine, pilocarpine, bethanechol, and McN-A-343 did not elicit any secretory response. Desensitization of the response to nicotine by Oxo-M and desensitization of the response to Oxo-M by nicotine suggest that both nicotine and Oxo-M were acting at the same receptor. Additional experiments supporting this conclusion show that nicotine-induced secretion and Oxo-M-induced secretion were similarly blocked by various muscarinic and nicotinic antagonists. Moreover, secretion induced by nicotine and Oxo-M were Ca{sup 2+} dependent, and both agonists induced {sup 45}Ca{sup 2+} uptake. Equilibrium binding studies showed that ({sup 3}H)Oxo-M bound to chromaffin cell membranes with a K{sub d} value of 3.08 {times} 10{sup {minus}8}M and a Hill coefficient of 1.00, suggesting one binding site for this ligand. Nicotine inhibited Oxo-M binding in a noncompetitive manner, suggesting that both ligands bind at two different sites on the same receptor. They propose that the receptor on bovine chromaffin cells that is coupled to secretion represents an unusual cholinergic receptor that has both nicotinic and muscarinic features.

  15. Calcium requirements for secretion in bovine chromaffin cells.

    PubMed Central

    Augustine, G J; Neher, E

    1992-01-01

    1. Measurements of membrane capacitance and intracellular Ca2+ concentration, [Ca2+]i, were used to examine the Ca2+ dependence of secretion in single adrenal chromaffin cells. 2. Intracellular dialysis of Ca2+, through a patch pipette, promoted secretion; the rate of secretion increased monotonically as [Ca2+]i was elevated, while the total amount of secretion reached a maximum at 1.5 microM-Ca2+ and declined at high [Ca2+]i. 3. Release of Ca2+ from internal stores, using bradykinin or ionomycin, transiently elevated [Ca2+]i and the rate of secretion. 4. Considering responses to both Ca2+ dialysis and release from internal stores, it appears that the rate of secretion increases over a range of [Ca2+]i levels above 0.2 microM and saturates at concentrations greater than 10 microM, if at all. Secretion appears to have a Hill coefficient for Ca2+ of about 2. At [Ca2+]i greater than 1-2 microM, prolonged elevation of [Ca2+]i, via dialysis, produced lower rates of secretion than transient elevation of [Ca2+]i caused by release from internal stores. This may have been caused by a depletion of readily releasable chromaffin granules during prolonged elevation of [Ca2+]i. 5. Brief depolarizing pulses produced transient rises in both [Ca2+]i and the rate of secretion. The ability of these pulses to evoke secretion 'washed out' during prolonged intracellular dialysis, due to both reduced Ca2+ influx and a diminished ability of the cell to secrete in response to a given Ca2+ load. 6. The kinetics of the secretory response depended upon the size of the depolarization-induced Ca2+ load; small rises in [Ca2+]i increased membrane capacitance only during the depolarization, while larger rises in [Ca2+]i produced increases both during and following the depolarization. The secretory responses that outlasted the depolarization appeared to be due to persistent elevation of [Ca2+]i. Secretory responses were sometimes followed by a slower decline in membrane capacitance, probably due to

  16. Calcium gradients and exocytosis in bovine adrenal chromaffin cells.

    PubMed

    Marengo, Fernando D

    2005-08-01

    The relationship between the localized Ca(2+) concentration and depolarization-induced exocytosis was studied in patch-clamped adrenal chromaffin cells using pulsed-laser Ca(2+) imaging and membrane capacitance measurements. Short depolarizing voltage steps induced Ca(2+) gradients and small "synchronous" increases in capacitance during the pulses. Longer pulses increased the capacitance changes, which saturated at 16 fF, suggesting the presence of a small immediately releasable pool of fusion-ready vesicles. A Hill plot of the capacitance changes versus the estimated Ca(2+) concentration in a thin (100 nm) shell beneath the membrane gave n = 2.3 and K(d) = 1.4 microM. Repetitive stimulation elicited a more complex pattern of exocytosis: early pulses induced synchronous capacitance increases, but after five or more pulses there was facilitation of the synchronous responses and gradual increases in capacitance continued between pulses (asynchronous exocytosis) as the steep submembrane Ca(2+) gradients collapsed. Raising the pipette Ca(2+) concentration led to early facilitation of the synchronous response and early appearance of asynchronous exocytosis. We used this data to develop a kinetic model of depolarization-induced exocytosis, where Ca(2+)-dependent fusion of vesicles occurs from a small immediately releasable pool with an affinity of 1-2 microM and vesicles are mobilized to this pool in a Ca(2+)-dependent manner.

  17. Differential effects of the neuroprotectant lubeluzole on bovine and mouse chromaffin cell calcium channel subtypes

    PubMed Central

    Hernández-Guijo, Jesús M; Gandía, Luis; de Pascual, Ricardo; García, Antonio G

    1997-01-01

    The effects of lubeluzole (a neuroprotective benzothiazole derivative) and its (−) enantiomer R91154 on whole-cell currents through Ca2+ channels, with 10 mM Ba2+ as charge carrier (IBa), have been studied in bovine and mouse voltage-clamped adrenal chromaffin cells. Currents generated by applying 50 ms depolarizing test pulses to 0 mV, from a holding potential of −80 mV, at 10 s intervals had an average magnitude of 1 nA. Lubeluzole and R91154 blocked the peak IBa of bovine chromaffin cells in a time and concentration-dependent manner; their IC50s were 1.94 μM for lubeluzole and 2.54 μM for R91154. In a current-voltage protocol, lubeluzole (3 μM) inhibited peak IBa at all test potentials. However, no obvious shifts of the I-V curve were detected. After 10 min exposure to 3 μM lubeluzole, the late current (measured at the end of the pulse) was inhibited more than the peak current. Upon wash out of the drug, the inactivation reversed first and then the peak current recovered. Blockade of peak current was greater at more depolarizing holding potentials (i.e. 35% at −110 mV and 87% at −50 mV, after 10 min superfusion with lubeluzole). Inactivation of the current was pronounced at −110 mV, decreased at −80 mV and did not occur at −50 mV. Intracellular dialysis of bovine voltage-clamped chromaffin cells with 3 μM lubeluzole caused neither blockade nor inactivation of IBa. The external application of 3 μM lubeluzole to those dialysed cells produced inhibition as well as inactivation of IBa. The effects of lubeluzole (3 μM) on IBa in mouse chromaffin cells were similar to those in bovine chromaffin cells. At −80 mV holding potential, a pronounced inactivation of the current led to greater blockade of the late IBa (66%) as compared with peak IBa (46% after 10 min superfusion with lubeluzole). In mouse chromaffin cells approximately half of the whole-cell IBa was sensitive to 3 μM nifedipine (L-type Ca2

  18. Electrophysiological and morphological features underlying neurotransmission efficacy at the splanchnic nerve-chromaffin cell synapse of bovine adrenal medulla.

    PubMed

    de Diego, Antonio M G

    2010-02-01

    The ability of adrenal chromaffin cells to fast-release catecholamines relies on their capacity to fire action potentials (APs). However, little attention has been paid to the requirements needed to evoke the controlled firing of APs. Few data are available in rodents and none on the bovine chromaffin cell, a model extensively used by researchers. The aim of this work was to clarify this issue. Short puffs of acetylcholine (ACh) were fast perifused to current-clamped chromaffin cells and produced the firing of single APs. Based on the currents generated by such ACh applications and previous literature, current waveforms that efficiently elicited APs at frequencies up to 20 Hz were generated. Complex waveforms were also generated by adding simple waveforms with different delays; these waveforms aimed at modeling the stimulation patterns that a chromaffin cell would conceivably undergo upon strong synaptic stimulation. Cholinergic innervation was assessed using the acetylcholinesterase staining technique on the supposition that the innervation pattern is a determinant of the kind of stimuli chromaffin cells can receive. It is concluded that 1) a reliable method to produce frequency-controlled APs by applying defined current injection waveforms is achieved; 2) the APs thus generated have essentially the same features as those spontaneously emitted by the cell and those elicited by fast-ACh perifusion; 3) the higher frequencies attainable peak at around 30 Hz; and 4) the bovine adrenal medulla shows abundant cholinergic innervation, and chromaffin cells show strong acetylcholinesterase staining, consistent with a tight cholinergic presynaptic control of firing frequency.

  19. Muscarinic receptor-mediated inositol tetrakisphosphate response in bovine adrenal chromaffin cells

    SciTech Connect

    Sanborn, B.B.; Schneider, A.S. )

    1990-01-01

    Inositol trisphosphate (IP{sub 3}), a product of the phosphoinositide cycle, mobilizes intracellular Ca{sup 2+} in many cell types. New evidence suggests that inositol tetrakisphosphate (IP{sub 4}), an IP{sub 3} derivative, may act as another second messenger to further alter calcium homeostasis. However, the function and mechanism of action of IP{sub 4} are presently unresolved. We now report evidence of muscarinic receptor-mediated accumulation of IP{sub 4} in bovine adrenal chromaffin cells, a classic neurosecretory system in which calcium movements have been well studied. Muscarine stimulated an increase in ({sup 3}H)IP{sub 4} and ({sup 3}H)IP{sub 3} accumulation in chromaffin cells and this effect was completely blocked by atropine. ({sup 3}H)IP{sub 4} accumulation was detectable within 15 sec, increased to a maximum by 30 sec and thereafter declined. 2,3-diphosphoglycerate, an inhibitor of IP{sub 3} and IP{sub 4} hydrolysis, enhanced accumulation of these inositol polyphosphates. The results provide the first evidence of a rapid inositol tetrakisphosphate response in adrenal chromaffin cells, which should facilitate the future resolution of the relationship between IP{sub 4} and calcium homeostasis.

  20. Association of the GTP-binding protein Rab3A with bovine adrenal chromaffin granules

    SciTech Connect

    Darchen, F.; Hammel, F.; Monteils, M.P.; Scherman, D. ); Zahraoui, A.; Tavitian, A. )

    1990-08-01

    The Rab3A protein belongs to a large family of small GTP-binding proteins that are present in eukaryotic cells and that share amino acid identities with the Ras proteins (products of the ras protooncogenes). Rab3A, which is specifically located in nervous and endocrine tissues, is suspected to play a key role in secretion. Its localization was investigated in bovine adrenal gland by using a polyclonal antibody. Rab3A was detected in adrenal medulla but not in adrenal cortex. In cultured adrenal medulla cells, Rab3A was specifically expressed in the catecholamine-secreting chromaffin cells. Subcellular fractionation suggested that Rab3A is about 30% cytosolic and that particulate Rab3A is associated with the membrane of chromaffin granules (the catecholamine storage organelles) and with a second compartment likely to be the plasma membrane. The Rab3A localization on chromaffin granule membranes was confirmed by immunoadsorption with an antibody against dopamine {beta}-hydroxylase. Rab3A was not extracted from this membrane by NaCl or KBr but was partially extracted by urea and totally solubilized by Triton X-100, suggesting either an interaction with an intrinsic protein or a membrane association through fatty acid acylation. This study suggests that Rab3A, which may also be located on other secretory vesicles containing noncharacterized small GTP-binding proteins, is involved in their biogenesis or in the regulated secretion process.

  1. Effect of quinine on the release of catecholamines from bovine cultured chromaffin cells.

    PubMed Central

    Tang, R.; Novas, M. L.; Glavinovic, M. I.; Trifaró, J. M.

    1990-01-01

    1. The effects of quinine on catecholamine release from cultured bovine chromaffin cells were studied. 2. Quinine (25-400 microM) produced a dose-related inhibition of catecholamine release in response to depolarizing concentrations (12.5-50 mM) of K+. 3. The inhibition of the secretory response to high K+ produced by quinine decreased with the increase in the extracellular concentration of Ca2+. 4. Stimulation of cultured chromaffin cells with 50 mM K+ produced a significant increase in Ca2+ influx. In the presence of 100 microM quinine a 54% inhibition of the K(+)-induced Ca2+ influx was observed. 5. Quinine treatment of chromaffin cell cultures produced a small but significant decrease in membrane resting potential and a less pronounced depolarization in response to 50 mM K+. 6. The results suggest that the inhibition of the K(+)-evoked release of catecholamines produced by quinine is at least partly due to a decrease in Ca2+ influx. Ca2+ influx is lower because quinine reduces the sensitivity of the membrane potential to changes in extracellular K+ but direct effects of quinine on Ca2+ channels cannot be excluded. PMID:2158846

  2. Bovine chromaffin cells in culture show carboxylesterase activities sensitive to organophosphorus compounds.

    PubMed

    Sogorb, M A; Vilanova, E; Quintanar, J L; Viniegra, S

    1996-09-01

    Carboxylesterase activities are widely distributed in a great variety of tissues; however, the biological function of these enzymes remains unclear. Some organophosphorus compounds induce a neurodegenarative syndrome related to the covalent modification of a carboxylesterase known as neuropathy target esterase. We investigated the expression of neuropathy target esterase and related carboxylesterase in bovine chromaffin cells with the aim of developing a potential in vitro model for studying the cellular function of carboxylesterase enzymes and toxic effects of organophosphorus compounds. Total phenyl valerate esterase exhibited an activity of 1.27 +/- 0.19 mU/10(5) cells (SD, n = 15). From the phenyl valerate esterase paraoxon and mipafox inhibition curves the following activities have been determined: B-activity (resistant to 40 microM paraoxon), 1.05 +/- 0.08 mU/10(5) cells (n = 8); C-activity (resistant to 40 microM paraoxon plus 250 microM mipafox), 0.12 +/- 0.05 mU/10(5) cells (n = 8); and neuropathy target esterase, calculated by the difference between B- and C-activities, 0.93 +/- 0.08 mU/10(5) cells (n = 8). All of these activities increased linearly with the number of cells and time of incubation with the substrate. Most of the phenol product of the reaction was released and detected in the extracellular medium. None of the components of the reaction were shown to affect cell viability when assessed by trypan blue exclusion. The study shows that bovine chromaffin cells possess carboxylesterase activities and respond to inhibition by paraoxon and mipafox, thus facilitating the discrimination of neuropathy target esterase. In conclusion, bovine chromaffin cells are appropriate as an in vitro cell model for studying toxic effects of organophosphorus compounds.

  3. Angiotensin II binding to cultured bovine adrenal chromaffin cells: identification of angiotensin II receptors

    SciTech Connect

    Boyd, V.L.; Printz, M.P.

    1986-03-05

    Physiological experiments have provided evidence that angiotensin II stimulates catecholamine secretion from the adrenal gland. Their laboratory and others have now shown by receptor autoradiography the presence of angiotensin II receptors (AIIR) in bovine and rat adrenal medulla. In order to extend these studies they have undertaken to define AIIR on cultured bovine adrenal chromaffin cells. Cells were isolated using the method of Levitt including cell enrichment with Percoll gradient centrifugation. Primary cultures of bovine adrenal medullary cells were maintained in DME/F12 medium containing 10% FCS. Cells were characterized by immunocytochemistry for Met- and Leu-enkephalin, PNMT, DBH and Chromagranin A. Cultured cells bind with high affinity and specificity (/sup 125/I)-ANG II yielding a K/sub D/ of 0.74 nM and B/sub max/ of 24,350 sites/cell. After Percoll treatment values of .77 nm and 34,500 sites/cell are obtained. K/sub D/ values are in close agreement with that obtained in adrenal slices by Healy. Competition studies identify a rank order of binding by this receptor similar to that of other tissues. They conclude that cultured chromaffin cells provide a suitable model system for the investigation and characterization of the ANG II receptor and for cellular studies of its functional significance.

  4. Tetrodotoxin-insensitive Na+ channel activator palytoxin inhibits tyrosine uptake into cultured bovine adrenal chromaffin cells

    SciTech Connect

    Morita, K.; Teraoka, K.; Azuma, M.; Oka, M.; Hamano, S. )

    1991-07-01

    The effects of the tetrodotoxin-insensitive Na+ channel activator palytoxin on both the secretion of endogenous catecholamines and the formation of 14C-catecholamines from (14C)tyrosine were examined using cultured bovine adrenal chromaffin cells. Palytoxin was shown to cause the stimulation of catecholamine secretion in a concentration-dependent manner. However, this toxin caused the reduction rather than the stimulation of 14C-catecholamine formation at the same concentrations. Palytoxin failed to cause any alteration in the activity of tyrosine hydroxylase prepared from bovine adrenal medulla. Furthermore, the uptake of (14C)tyrosine into the cells was shown to be inhibited by this toxin under the conditions in which the suppression of 14C-catecholamine formation was observed, and this inhibitory action on tyrosine uptake was closely correlated with that on catecholamine formation. The inhibitory action of palytoxin on tyrosine uptake into the cells was observed to be noncompetitive, and this effect was not altered by the removal of Na+ from the incubation mixture. These results suggest that palytoxin may be able to inhibit the uptake of (14C)tyrosine into the cells, resulting in the suppression of 14C-catecholamine formation, probably through its direct action on the plasma membranes of bovine adrenal chromaffin cells.

  5. Otilonium: a potent blocker of neuronal nicotinic ACh receptors in bovine chromaffin cells.

    PubMed

    Gandía, L; Villarroya, M; Lara, B; Olmos, V; Gilabert, J A; López, M G; Martínez-Sierra, R; Borges, R; García, A G

    1996-02-01

    1. Otilonium, a clinically useful spasmolytic, behaves as a potent blocker of neuronal nicotinic acetylcholine receptors (AChR) as well as a mild wide-spectrum Ca2+ channel blocker in bovine adrenal chromaffin cells. 2. 45Ca2+ uptake into chromaffin cells stimulated with high K+ (70 mM, 1 min) was blocked by otilonium with an IC50 of 7.6 microM. The drug inhibited the 45Ca2+ uptake stimulated by the nicotinic AChR agonist, dimethylphenylpiperazinium (DMPP) with a 79 fold higher potency (IC50 = 0.096 microM). 3. Whole-cell Ba2+ currents (IBa) through Ca2+ channels of voltage-clamped chromaffin cells were blocked by otilonium with an IC50 of 6.4 microM, very close to that of K(+)-evoked 45Ca2+ uptake. Blockade developed in 10-20 s, almost as a single step and was rapidly and almost fully reversible. 4. Whole-cell nicotinic AChR-mediated currents (250 ms pulses of 100 microM DMPP) applied at 30 s intervals were blocked by otilonium in a concentration-dependent manner, showing an IC50 of 0.36 microM. Blockade was induced in a step-wise manner. Wash out of otilonium allowed a slow recovery of the current, also in discrete steps. 5. In experiments with recordings in the same cells of whole-cell IDMPP, Na+ currents (INa) and Ca2+ currents (ICa), 1 microM otilonium blocked 87% IDMPP, 7% INa and 13% ICa. 6. Otilonium inhibited the K(+)-evoked catecholamine secretory response of superfused bovine chromaffin cells with an IC50 of 10 microM, very close to the IC50 for blockade of K(+)-induced 45Ca2+ uptake and IBa. 7. Otilonium inhibited the secretory responses induced by 10 s pulses of 50 microM DMPP with an IC50 of 7.4 nM. Hexamethonium blocked the DMPP-evoked responses with an IC50 of 29.8 microM, 4,000 fold higher than that of otilonium. 8. In conclusion, otilonium is a potent blocker of nicotinic AChR-mediated responses. The drugs also blocked various subtypes of neuronal voltage-dependent Ca2+ channels at a considerably lower potency. Na+ channels were unaffected by

  6. Otilonium: a potent blocker of neuronal nicotinic ACh receptors in bovine chromaffin cells.

    PubMed Central

    Gandía, L.; Villarroya, M.; Lara, B.; Olmos, V.; Gilabert, J. A.; López, M. G.; Martínez-Sierra, R.; Borges, R.; García, A. G.

    1996-01-01

    1. Otilonium, a clinically useful spasmolytic, behaves as a potent blocker of neuronal nicotinic acetylcholine receptors (AChR) as well as a mild wide-spectrum Ca2+ channel blocker in bovine adrenal chromaffin cells. 2. 45Ca2+ uptake into chromaffin cells stimulated with high K+ (70 mM, 1 min) was blocked by otilonium with an IC50 of 7.6 microM. The drug inhibited the 45Ca2+ uptake stimulated by the nicotinic AChR agonist, dimethylphenylpiperazinium (DMPP) with a 79 fold higher potency (IC50 = 0.096 microM). 3. Whole-cell Ba2+ currents (IBa) through Ca2+ channels of voltage-clamped chromaffin cells were blocked by otilonium with an IC50 of 6.4 microM, very close to that of K(+)-evoked 45Ca2+ uptake. Blockade developed in 10-20 s, almost as a single step and was rapidly and almost fully reversible. 4. Whole-cell nicotinic AChR-mediated currents (250 ms pulses of 100 microM DMPP) applied at 30 s intervals were blocked by otilonium in a concentration-dependent manner, showing an IC50 of 0.36 microM. Blockade was induced in a step-wise manner. Wash out of otilonium allowed a slow recovery of the current, also in discrete steps. 5. In experiments with recordings in the same cells of whole-cell IDMPP, Na+ currents (INa) and Ca2+ currents (ICa), 1 microM otilonium blocked 87% IDMPP, 7% INa and 13% ICa. 6. Otilonium inhibited the K(+)-evoked catecholamine secretory response of superfused bovine chromaffin cells with an IC50 of 10 microM, very close to the IC50 for blockade of K(+)-induced 45Ca2+ uptake and IBa. 7. Otilonium inhibited the secretory responses induced by 10 s pulses of 50 microM DMPP with an IC50 of 7.4 nM. Hexamethonium blocked the DMPP-evoked responses with an IC50 of 29.8 microM, 4,000 fold higher than that of otilonium. 8. In conclusion, otilonium is a potent blocker of nicotinic AChR-mediated responses. The drugs also blocked various subtypes of neuronal voltage-dependent Ca2+ channels at a considerably lower potency. Na+ channels were unaffected by

  7. Subcellular compartmentalization of 1-methyl-4-phenylpyridinium with catecholamines in adrenal medullary chromaffin vesicles may explain the lack of toxicity to adrenal chromaffin cells.

    PubMed

    Reinhard, J F; Diliberto, E J; Viveros, O H; Daniels, A J

    1987-11-01

    Cultures of bovine adrenomedullary chromaffin cells accumulated 1-methyl-4-phenylpyridinium (MPP+) in a time- and concentration-dependent manner by a process that was prevented by desmethylimipramine. The subcellular localization of the incorporated [methyl-3H]MPP+ was examined by differential centrifugation and sucrose density gradient fractionation and was found to be predominantly colocalized with catecholamines in chromaffin vesicles, and negligible amounts were detected within the mitochondrial fraction. When chromaffin cell membranes were made permeable with the detergent digitonin in the absence of calcium, there was no increase in the release of [3H]MPP+, indicating that there is negligible accumulation of the neurotoxin in the cytosol. Simultaneous exposure to digitonin and calcium induced cosecretion of MPP+ and catecholamines. Stimulation of the cells with nicotine released both catecholamines and MPP+ at identical rates and percentages of cellular content in a calcium-dependent manner. Last, when cells were incubated with MPP+ in the presence of tetrabenazine (an inhibitor of vesicular uptake), the chromaffin cell toxicity of MPP+ was potentiated. We submit that the ability of the chromaffin cells to take up and store MPP+ in the chromaffin vesicle prevents the toxin's interaction with other structures and, thus, prevents cell damage. As an extension of this hypothesis, the relative resistance of some brain monoaminergic neurons to the toxic actions of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine may result from the subcellular sequestration of MPP+ in the storage vesicle.

  8. Deciphering dead-end docking of large dense core vesicles in bovine chromaffin cells.

    PubMed

    Hugo, Sandra; Dembla, Ekta; Halimani, Mahantappa; Matti, Ulf; Rettig, Jens; Becherer, Ute

    2013-10-23

    Large dense core vesicle (LDCV) exocytosis in chromaffin cells follows a well characterized process consisting of docking, priming, and fusion. Total internal reflection fluorescence microscopy (TIRFM) studies suggest that some LDCVs, although being able to dock, are resistant to calcium-triggered release. This phenomenon termed dead-end docking has not been investigated until now. We characterized dead-end vesicles using a combination of membrane capacitance measurement and visualization of LDCVs with TIRFM. Stimulation of bovine chromaffin cells for 5 min with 6 μm free intracellular Ca2+ induced strong secretion and a large reduction of the LDCV density at the plasma membrane. Approximately 15% of the LDCVs were visible at the plasma membrane throughout experiments, indicating they were permanently docked dead-end vesicles. Overexpression of Munc18-2 or SNAP-25 reduced the fraction of dead-end vesicles. Conversely, expressing open-syntaxin increased the fraction of dead-end vesicles. These results indicate the existence of the unproductive target soluble N-ethylmaleimide-sensitive factor attachment protein receptor acceptor complex composed of 2:1 syntaxin-SNAP-25 in vivo. More importantly, they define a novel function for this acceptor complex in mediating dead-end docking.

  9. Inhibitory effect of strychnine on acetylcholine receptor activation in bovine adrenal medullary chromaffin cells.

    PubMed Central

    Kuijpers, G A; Vergara, L A; Calvo, S; Yadid, G

    1994-01-01

    1. Strychnine, which is known as a potent and selective antagonist of the inhibitory glycine receptor in the central nervous system, inhibits the nicotinic stimulation of catecholamine release from bovine cultured adrenal chromaffin cells in a concentration-dependent (1-100 microM) manner. At 10 microM nicotine, the IC50 value for strychnine is approximately 30 microM. Strychnine also inhibits the nicotine-induced membrane depolarization and increase in intracellular Ca2+ concentration. 2. The inhibitory action of strychnine is reversible and is selective for nicotinic stimulation, with no effect observed on secretion elicited by a high external K+ concentration, histamine or angiotensin II. 3. Strychnine competes with nicotine in its effect, but not modify the apparent positive cooperatively of the nicotine binding sites. In the absence of nicotine, strychnine has no effect on catecholamine release. Glycine does not affect catecholamine release nor the inhibitory action of strychnine on this release. 4. These results suggest that strychnine interacts with the agonist binding site of the nicotinic acetylcholine receptor in chromaffin cells, thus exerting a pharmacological effect independently of the glycine receptor. PMID:7834198

  10. [Study on relationship of dose-effect and time-effect of APA microencapsulated bovine chromaffin cells on pain treatment].

    PubMed

    Hui, Jianfeng; Li, Tao; Du, Zhi; Song, Jichang

    2011-12-01

    This study was to investigate the relationship of dose-effect and time-effect of Alginate-Polylysine-Alginate (APA) microencapsulated bovine chromaffin cells on the treatment of pain model rats. Using a rat model of painful peripheral neuropathy, the antinociceptive effects of APA microencapsulated bovine cells transplanted into the subarachnoid space was evaluated by cold allodynia test and hot hyperalgesia test. Compared with control group, the withdrawal difference with cell number 50 thousands groups, 100 thousands groups and 200 thousands groups was reduced (P < 0.05), and the difference decreased with the cells increases, indicating a significant analgesic effect. There was no significant difference between 400 thousands groups and 200 thousands groups. This analgesic effect maintained longer than 12 weeks. There was a positive correlation between the analgesic effect and the quantity of APA microencapsulated bovine chromaffin cells which were transplanted to treat pain model rats, and the effective antinociception remained longer than 12 weeks.

  11. Identification and characterization of an angiotensin II receptor on cultured bovine adrenal chromaffin cells

    SciTech Connect

    Boyd, V.L.

    1987-01-01

    The presence of an angiotensin II receptor on cultured bovine adrenal chromaffin cells was demonstrated by radioligand binding. A single class of finding sites with a K/sub D/ of 0.7 nM was characterized. The use of radioligands also allows the localization of receptors by autoradiography. Autoradiography demonstrated that approximately 50% of the isolated cells bound angiotensin II. It was of interest to see if angiotensin II bound to a cell that possessed a certain phenotype. In order to evaluate this possibility a technique was developed that combined autoradiography and immunocytochemistry. Results indicated that angiotensin II binding sites were not localized preferentially to either norepinephrine or epinephrine cells. Binding of angiotensin II was associated with the release of intracellular catecholamine stores. Cells were pre-loaded with /sup 3/H-norepinephrine and secretion was monitored by following radioactivity released into the supernatant. Alternatively, release of endogenous catecholamines was determined by fluorometric assay.

  12. Effect of high hydrostatic pressure on the BK channel in bovine chromaffin cells.

    PubMed Central

    Macdonald, A G

    1997-01-01

    The activity of the BK channel of bovine chromaffin cells was studied at high hydrostatic pressure, using inside-out patches in symmetrical KCl solution, Ca2+-free and at V(H) = -60 to -40 mV. Pressure increased the probability of channels being open (900 atm increasing the probability 30-fold), and it increased the minimum number of channels apparent in the patches. The pressure activation of the channel was reversed on decompression. Channel conductance was unaffected. It was shown that pressure did not act by raising the temperature, or by affecting [Ca] or pH, or the order of the membrane bilayer, and it was concluded that pressure most likely acted directly on the channel proteins and/or their modulating reactions. PMID:9336182

  13. Enhancement by GABA of the stimulation-evoked catecholamine release from cultured bovine adrenal chromaffin cells.

    PubMed

    Kitayama, S; Morita, K; Dohi, T; Tsujimoto, A

    1990-05-01

    The possible involvement of GABAergic mechanisms in the catecholamine (CA) release from adrenal medulla was investigated in a primary culture of bovine adrenal chromaffin cells. GABA elicited CA release and enhanced acetylcholine (ACh)-, excess K(+)- and veratridine-evoked CA release. Muscimol, a selective GABAA receptor agonist, mimicked the action of GABA on CA release. On the other hand, baclofen, a GABAB receptor agonist, failed to affect basal or evoked CA release. Furthermore, bicuculline and picrotoxin blocked the enhancement by GABA of veratridine-evoked CA release without affecting basal CA release and CA release evoked by veratridine. In Ca2(+)-free medium, GABA failed to affect basal and caffeine-evoked CA release. ACh-evoked CA release was slightly reduced by bicuculline, whereas excess K(+)-evoked CA release was not, suggesting the involvement of endogenous GABA in CA release evoked by ACh. These results suggest a facilitatory modulation by GABA of basal and evoked release of CA from bovine adrenal medulla through GABAA receptor-mediated mechanisms.

  14. Inhibition of nicotinic receptor-mediated responses in bovine chromaffin cells by diltiazem.

    PubMed

    Gandía, L; Villarroya, M; Sala, F; Reig, J A; Viniegra, S; Quintanar, J L; García, A G; Gutiérrez, L M

    1996-07-01

    1. The effects of diltiazem on various functional parameters were studied in bovine cultured adrenal chromaffin cells stimulated with the nicotinic receptor agonist dimethylphenylpiperazinium (DMPP) or with depolarizing Krebs-HEPES solutions containing high K+ concentrations. 2. The release of [3H]-noradrenaline induced by DMPP (100 microM for 5 min) was gradually and fully inhibited by increasing concentrations of diltiazem (IC50 = 1.3 microM). In contrast, the highest concentration of diltiazem used (10 microM) inhibited the response to high K+ (59 mM for 5 min) by only 25%. 3. 45Ca2+ uptake into cells stimulated with DMPP (100 microM for 1 min) was also blocked by diltiazem in a concentration-dependent manner (IC50 = 0.4 microM). Again, diltiazem blocked the K(+)-evoked 45Ca2+ uptake (70 mM K+ for 1 min) only by 20%. In contrast, the N-P-Q-type Ca2+ channel blocker omega-conotoxin MVIIC depressed the K+ signal by 70%. In the presence of this toxin, diltiazem exhibited an additional small inhibitory effect, indicating that the compound was acting on L-type Ca2+ channels. 4. Whole-cell Ba2+ currents through Ca2+ channels in voltage-clamped chromaffin cells were inhibited by 3-10 microM diltiazem by 20-25%. The inhibition was readily reversed upon washout of the drug. 5. The whole-cell currents elicited by 100 microM DMPP (IDMPP) were inhibited in a concentration-dependent and reversible manner by diltiazem. Maximal effects were found at 10 microM, which reduced the peak IDMPP by 70%. The area of each curve represented by total current (QDMPP) was reduced more than the peak current. At 10 microM, the inhibition amounted to 80%; the IC50 for QDMPP inhibition was 0.73 microM, a figure close to the IC50 for 45Ca2+ uptake (0.4 microM) and [3H]-noradrenaline release (1.3 microM). The blocking effects of diltiazem developed very quickly and did not exhibit use-dependence; thus the drug blocked the channel in its closed state. The blocking effects of 1 microM diltiazem on

  15. Processing of enkephalin-containing peptides in isolated bovine adrenal chromaffin granules.

    PubMed Central

    Fleminger, G; Ezra, E; Kilpatrick, D L; Udenfriend, S

    1983-01-01

    Intact chromaffin granules isolated from bovine adrenal medulla were incubated at 37 degrees C for up to 22 hr. Processing of enkephalin-containing (EC) peptides in the granules was followed by the change in their size distribution as shown by chromatography on Sephadex G-75 columns. A gradual shift toward lower molecular weight EC peptides was observed during the incubation, indicating processing of the higher molecular weight to lower molecular weight EC peptides. The total amount of [Met]-enkephalin, free and in peptide linkage, remained constant indicating that little or no nonspecific degradation occurred during the experiment. HPLC resolution of the fraction containing the low molecular weight EC peptides showed that free enkephalins as well as [Met]enkephalin-Arg6-Phe7 and [Met]enkephalin-Arg6-Gly7-Leu8 accumulated while [Met]enkephalin-Arg6 and [Met]enkephalin-Lys6 disappeared. All the above data indicate the presence of an atypical trypsin activity and the presence of a carboxypeptidase B-like activity within the granules. From the rates of accumulation of the low molecular weight EC peptides and the disappearance of the higher molecular weight EC peptides, a processing rate of 65-70 pmol/g tissue per hr was estimated, which calculates to a lifetime of 6-8 days for EC peptides in the granules. Under steady-state conditions this rate of processing appears to be too low to produce significant amounts of free enkephalins from larger EC peptides. This is well in accord with previous observations that relatively small amounts of free enkephalins are found in bovine adrenal medulla. PMID:6578517

  16. GABAA and GABAB receptors are functionally active in the regulation of catecholamine secretion by bovine chromaffin cells.

    PubMed

    Castro, E; Oset-Gasque, M J; González, M P

    1989-07-01

    GABA stimulates the basal catecholamine release from adrenal bovine chromaffin cells in a calcium-dependent manner. This release represents about 70% of that obtained by similar doses of nicotine under similar experimental conditions. This effect is mediated by GABAA receptor sites present in chromaffin cells, since it was mimicked by muscimol and reversed by bicuculline. In addition, GABA, through its GABAA receptors, increases the catecholamine release evoked by submaximal doses of nicotine, but it has no effect on nicotine-evoked secretion of catecholamines when nicotine was given at maximal doses. These results seem to indicate that both nicotine and GABA release catecholamines from the same intracellular pool. In contrast, baclofen, a GABAB receptor agonist, depressed both basal and nicotine-evoked catecholamine release; this result indicates that in addition to GABAA control of catecholamine secretion by chromaffin cells, there is a GABAB control of this function. These results support the existence of a dual regulation of catecholamine secretion by both the GABAA and GABAB receptors in a similar way as that proposed for muscarinic and nicotinic cholinergic receptors.

  17. Interleukin-6-mediated signaling in adrenal medullary chromaffin cells.

    PubMed

    Jenkins, Danielle E; Sreenivasan, Dharshini; Carman, Fiona; Samal, Babru; Eiden, Lee E; Bunn, Stephen J

    2016-12-01

    The pro-inflammatory cytokines, tumor necrosis factor-α, and interleukin-1β/α modulate catecholamine secretion, and long-term gene regulation, in chromaffin cells of the adrenal medulla. Since interleukin-6 (IL6) also plays a key integrative role during inflammation, we have examined its ability to affect both tyrosine hydroxylase activity and adrenomedullary gene transcription in cultured bovine chromaffin cells. IL6 caused acute tyrosine/threonine phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2), and serine/tyrosine phosphorylation of signal transducer and activator of transcription 3 (STAT3). Consistent with ERK1/2 activation, IL6 rapidly increased tyrosine hydroxylase phosphorylation (serine-31) and activity, as well as up-regulated genes, encoding secreted proteins including galanin, vasoactive intestinal peptide, gastrin-releasing peptide, and parathyroid hormone-like hormone. The effects of IL6 on the entire bovine chromaffin cell transcriptome were compared to those generated by G-protein-coupled receptor (GPCR) agonists (histamine and pituitary adenylate cyclase-activating polypeptide) and the cytokine receptor agonists (interferon-α and tumor necrosis factor-α). Of 90 genes up-regulated by IL6, only 16 are known targets of IL6 in the immune system. Those remaining likely represent a combination of novel IL6/STAT3 targets, ERK1/2 targets and, potentially, IL6-dependent genes activated by IL6-induced transcription factors, such as hypoxia-inducible factor 1α. Notably, genes induced by IL6 include both neuroendocrine-specific genes activated by GPCR agonists, and transcripts also activated by the cytokines. These results suggest an integrative role for IL6 in the fine-tuning of the chromaffin cell response to a wide range of physiological and paraphysiological stressors, particularly when immune and endocrine stimuli converge. © 2016 International Society for Neurochemistry.

  18. Subcellular compartmentalization of 1-methyl-4-phenylpyridinium with catecholamines in adrenal medullary chromaffin vesicles may explain the lack of toxicity to adrenal chromaffin cells

    SciTech Connect

    Reinhard, J.F. Jr.; Diliberto, E.J. Jr.; Viveros, O.H.; Daniels, A.J.

    1987-11-01

    Cultures of bovine adrenomedullary chromaffin cells accumulated 1-methyl-4-phenylpyridinium (MPP/sup +/) in a time- and concentration-dependent manner by a process that was prevented by desmethylimipramine. The subcellular localization of the incorporated (methyl-/sup 3/H)MPP/sup +/ was examined by differential centrifugation and sucrose density gradient fractionation and was found to be predominantly colocalized with catecholamines in chromaffin vesicles, and negligible amounts were detected within the mitochondrial fraction. When chromaffin cell membranes were made permeable with the detergent digitonin the absence of calcium, there was no increase in the release of (/sup 3/H)MPP/sup +/, indicating that there is negligible accumulation of the neurotoxin in the cytosol. Simultaneous exposure to digitonin and calcium induced cosecretion of MPP/sup +/ and catecholamines. Stimulation of the cells with nicotine released both catecholamines and MPP/sup +/ at identical rates and percentages of cellular content in a calcium-dependent manner. Last, when cells were incubated with MPP/sup +/ in the presence of tetrabenazine (an inhibitor of vesicular uptake), the chromaffin cell toxicity of MPP/sup +/ was potentiated. The authors submit that the ability of the chromaffin cells to take up and store MPP/sup +/ in the chromaffin vesicle prevents the toxin's interaction with other structures and, thus, prevents cell damage. As an extension of this hypothesis, the relative resistance of some brain monoaminergic neurons to the toxic actions of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine may result from the subcellular sequestration of MPP/sup +/ in the storage vesicle.

  19. The mechanism by which procaine inhibits catecholamine secretion from bovine chromaffin cells.

    PubMed Central

    Charlesworth, P.; Jacobson, I.; Pocock, G.; Richards, C. D.

    1992-01-01

    1. We have investigated the action of procaine on stimulus-secretion coupling in bovine adrenal chromaffin cells. 2. Procaine inhibited the catecholamine secretion evoked by 500 microM carbachol (CCh) with an IC50 of 35 microM and the associated calcium influx (IC50 60 microM). It inhibited the catecholamine secretion evoked by depolarization with high potassium by less than 20% even at the highest concentrations tested (3.2 mM). 3. The secretion evoked by CCh was associated with an increase in sodium influx. This evoked influx was also inhibited by procaine (IC50 80 microM). 4. This selective action of procaine on the CCh-evoked catecholamine secretion was investigated further by patch-clamp techniques. 5. In agreement with the ion flux studies, procaine inhibited the inward current evoked by CCh. Procaine also altered the spectral characteristics of the noise associated with the agonist-induced current by adding an additional high frequency component. The amplitude of this component showed an e-fold increase for a 55 mV membrane hyperpolarization. 6. Data from cell-attached patches showed that increasing concentrations of procaine produced a progressive fall in the mean channel open time and an increase in mean blocked time. This combination led to a decrease in mean burst length. In addition, Popen was reduced by 50 microM procaine. These changes in channel conducting time were sufficient to account for the reduction in inward current. A limited study of the action of procaine on nicotinic channels in outside-out patches gave similar results. 7. The data were considered in relation to various schemes of anaesthetic-channel interactions. The data did not fit the sequential blocking model or the extended channel block model but could be fitted to a modified sequential blocking model in which the rate constant for channel reopening after block was itself subject to modulation by the anaesthetic and the blocked channel could close without passing through the open

  20. Stimulation of catecholamine synthesis through unique estrogen receptors in the bovine adrenomedullary plasma membrane by 17{beta}-estradiol

    SciTech Connect

    Yanagihara, Nobuyuki . E-mail: yanagin@med.uoeh-u.ac.jp; Liu, Minhui; Toyohira, Yumiko; Tsutsui, Masato; Ueno, Susumu; Shinohara, Yuko; Takahashi, Kojiro; Tanaka, Kazumi

    2006-01-13

    Incubation of cultured bovine adrenal medullary cells with 17{beta}-estradiol (E{sub 2}) (0.3-100 nM) or membrane-impermeable E{sub 2}-bovine serum albumin (100 nM) acutely increased {sup 14}C-catecholamine synthesis from [{sup 14}C]tyrosine. The stimulatory effect of E{sub 2} was not inhibited by ICI182,780, a nuclear estrogen receptor inhibitor. E{sub 2} also increased tyrosine hydroxylase activity and p44/42MAPK phosphorylation, the former of which was attenuated by U0126, an inhibitor of p44/42MAPK kinase. The plasma membrane isolated from the gland showed two classes of specific binding sites of [{sup 3}H]E{sub 2} with apparent K {sub d}s of 3.2 and 106 nM, and B {sub max}s of 0.44 and 8.5 pmol/mg protein, respectively. The high-affinity binding of [{sup 3}H]E{sub 2} was most strongly inhibited by E{sub 2} and phytoestrogens, and to lesser extents by other steroid hormones, while it was enhanced by ICI182,780 and environmental estrogenic pollutants. These findings suggest that E{sub 2} acutely stimulates catecholamine synthesis via activation of p44/42MAPK through unique estrogen receptors in the plasma membrane of bovine adrenal medulla.

  1. Catecholamine release from cultured bovine adrenal medullary chromaffin cells in the presence of 60-Hz magnetic fields.

    PubMed

    Craviso, Gale L; Chatterjee, Indira; Publicover, Nelson G

    2003-04-01

    Effects of powerline frequency (50/60 Hz) electric and magnetic fields on the central nervous system may involve altered neurotransmitter release. This possibility was addressed by determining whether 60-Hz linearly polarized sinusoidal magnetic fields (MFs) alter the release of catecholamines from cultured bovine adrenal chromaffin cells, a well-characterized model of neural-type cells. Dishes of cells were placed in the center of each of two four-coil Merritt exposure systems that were enclosed within mu-metal chambers in matched incubators for simultaneous sham and MF exposure. Following 15-min MF exposure of the cells to flux densities of 0.01, 0.1, 1.0 or 2 mT, norepinephrine and epinephrine release were quantified by high-performance liquid chromatography (HPLC) coupled with electrochemical detection. No significant differences in the release of either norepinephrine or epinephrine were detected between sham-exposed cells and cells exposed to MFs in either the absence or presence of Bay K-8644 (2 microM) or dimethylphenylpiperazinium (DMPP, 10 microM). Consistent with these null findings is the lack of effect of MF exposure on calcium influx. We conclude that catecholamine release from chromaffin cells is not sensitive to 60-Hz MFs at magnetic flux densities in the 0.01-2 mT range.

  2. Direct visualization of secretion from single bovine adrenal chromaffin cells by laser-induced native fluorescence imaging microscopy

    SciTech Connect

    Tong, W.; Yeung, E.S.

    1998-03-01

    Direct visualization of the secretion process of individual bovine adrenal chromaffin cells was achieved with laser-induced native fluorescence imaging microscopy. By monitoring the native fluorescence of catecholamines excited by the 275 nm laser line with an intensified charge-coupled-device (CCD) camera, we obtained good temporal and spatial resolution simultaneously without using additional fluorescent probes. Large variations were found among individual cells in terms of the amounts of catecholamines secreted and the rates of secretion. Different regions of a cell also behave differently during the secretion process. However, the degree of this local heterogeneity is smaller than in neurons and neuralgia. The influence of deep-ultraviolet (UV) laser excitation on cells is also discussed. This quantitative imaging technique provides a useful noninvasive approach for the study of dynamic cellular changes and the understanding of the molecular mechanisms of secretory processes. {copyright} {ital 1998} {ital Society for Applied Spectroscopy}

  3. Brain RVD-haemopressin, a haemoglobin-derived peptide, inhibits bombesin-induced central activation of adrenomedullary outflow in the rat.

    PubMed

    Tanaka, Kenjiro; Shimizu, Takahiro; Yanagita, Toshihiko; Nemoto, Takayuki; Nakamura, Kumiko; Taniuchi, Keisuke; Dimitriadis, Fotios; Yokotani, Kunihiko; Saito, Motoaki

    2014-01-01

    Haemopressin and RVD-haemopressin, derived from the haemoglobin α-chain, are bioactive peptides found in brain and are ligands for cannabinoid CB1 receptors. Activation of brain CB1 receptors inhibited the secretion of adrenal catecholamines (noradrenaline and adrenaline) induced by i.c.v. bombesin in the rat. Here, we investigated the effects of two haemoglobin-derived peptides on this bombesin-induced response Anaesthetised male Wistar rats were pretreated with either haemoglobin-derived peptide, given i.c.v., 30 min before i.c.v. bombesin and plasma catecholamines were subsequently measured electrochemically after HPLC. Direct effects of bombesin on secretion of adrenal catecholamines were examined using bovine adrenal chromaffin cells. Furthermore, activation of haemoglobin α-positive spinally projecting neurons in the rat hypothalamic paraventricular nucleus (PVN, a regulatory centre of central adrenomedullary outflow) after i.c.v. bombesin was assessed by immunohistochemical techniques. Bombesin given i.c.v. dose-dependently elevated plasma catecholamines whereas incubation with bombesin had no effect on spontaneous and nicotine-induced secretion of catecholamines from chromaffin cells. The bombesin-induced increase in catecholamines was inhibited by pretreatment with i.c.v. RVD-haemopressin (CB1 receptor agonist) but not after pretreatment with haemopressin (CB1 receptor inverse agonist). Bombesin activated haemoglobin α-positive spinally projecting neurons in the PVN. The haemoglobin-derived peptide RVD-haemopressin in the brain plays an inhibitory role in bombesin-induced activation of central adrenomedullary outflow via brain CB1 receptors in the rat. These findings provide basic information for the therapeutic use of haemoglobin-derived peptides in the modulation of central adrenomedullary outflow. © 2013 The British Pharmacological Society.

  4. Brain RVD-haemopressin, a haemoglobin-derived peptide, inhibits bombesin-induced central activation of adrenomedullary outflow in the rat

    PubMed Central

    Tanaka, Kenjiro; Shimizu, Takahiro; Yanagita, Toshihiko; Nemoto, Takayuki; Nakamura, Kumiko; Taniuchi, Keisuke; Dimitriadis, Fotios; Yokotani, Kunihiko; Saito, Motoaki

    2014-01-01

    BACKGROUND AND PURPOSE Haemopressin and RVD-haemopressin, derived from the haemoglobin α-chain, are bioactive peptides found in brain and are ligands for cannabinoid CB1 receptors. Activation of brain CB1 receptors inhibited the secretion of adrenal catecholamines (noradrenaline and adrenaline) induced by i.c.v. bombesin in the rat. Here, we investigated the effects of two haemoglobin-derived peptides on this bombesin-induced response EXPERIMENTAL APPROACH Anaesthetised male Wistar rats were pretreated with either haemoglobin-derived peptide, given i.c.v., 30 min before i.c.v. bombesin and plasma catecholamines were subsequently measured electrochemically after HPLC. Direct effects of bombesin on secretion of adrenal catecholamines were examined using bovine adrenal chromaffin cells. Furthermore, activation of haemoglobin α-positive spinally projecting neurons in the rat hypothalamic paraventricular nucleus (PVN, a regulatory centre of central adrenomedullary outflow) after i.c.v. bombesin was assessed by immunohistochemical techniques. KEY RESULTS Bombesin given i.c.v. dose-dependently elevated plasma catecholamines whereas incubation with bombesin had no effect on spontaneous and nicotine-induced secretion of catecholamines from chromaffin cells. The bombesin-induced increase in catecholamines was inhibited by pretreatment with i.c.v. RVD-haemopressin (CB1 receptor agonist) but not after pretreatment with haemopressin (CB1 receptor inverse agonist). Bombesin activated haemoglobin α-positive spinally projecting neurons in the PVN. CONCLUSIONS AND IMPLICATIONS The haemoglobin-derived peptide RVD-haemopressin in the brain plays an inhibitory role in bombesin-induced activation of central adrenomedullary outflow via brain CB1 receptors in the rat. These findings provide basic information for the therapeutic use of haemoglobin-derived peptides in the modulation of central adrenomedullary outflow. PMID:24138638

  5. Stimulatory actions of bioflavenoids on tyrosine uptake into cultured bovine adrenal chromaffin cells

    SciTech Connect

    Morita, K.; Hamano, S.; Oka, M.; Teraoka, K. )

    1990-09-28

    The effects of flavenoids on L-({sup 14}C)tyrosine uptake into cultured adrenal chromaffin cells were examined. Flavone markedly stimulated tyrosine uptake into these cells in a manner dependent on its concentration. Apigenin also caused a moderate stimulatory action, but quercetin had no significant effect on the uptake. Flavone also stimulated the uptake of histidine, but did not affect the uptake of serine, lysine, or glutamic acid. These results are considered to propose the possibility that flavonoids may be able to stimulate the precursor uptake into the cells, resulting in an enhancement of the biogenic amine production.

  6. A study of the bovine adrenal chromaffin nicotinic receptor using patch clamp and concentration-jump techniques.

    PubMed Central

    Maconochie, D J; Knight, D E

    1992-01-01

    1. Voltage clamp records have been obtained from bovine adrenal chromaffin cells in the outside-out and whole-cell configurations, in response to step changes of acetylcholine (ACh) concentration. The concentrations used ranged from 50 nM to 20 mM. 2. At high acetylcholine concentrations, the activation and desensitization kinetics of the nicotinic receptor, as observed in outside-out patches, may be described by a model incorporating a single, fast agonist binding step, and relatively slow isomerization to the open state. The affinity of the closed receptor for ACh is 310 microM, the channel opening rate constant is 460 s-1, and the closing rate constant is 29 s-1. 3. Single channel events, observed when nanomolar ACh concentrations are applied to whole cells, have two distinct channel lifetimes: 0.6 ms and 11-15 ms. The variation of the frequencies of the events with ACh concentration, suggests that the short lifetimes are openings of a singly liganded receptor and the longer lifetimes are openings of a doubly liganded receptor. 4. Only a single exponential associated with receptor desensitization is seen with outside-out patches, but two are seen with whole cells. It is postulated that there are two nicotinic receptor types present on adrenal chromaffin cells. 5. The rate of desensitization (9 s-1 and 26 s-1, whole cells; 24 s-1, patches), is fast enough to be significant in determining the open channel lifetime. 6. A sudden increase in current (rebound) is observed when a high concentration of ACh is abruptly removed from outside-out patches. This is evidence for a blocked state. The affinity of the blocking site for ACh is 1400 microM (outside-out patches). 7. The total number of activatable nicotinic channels per whole cell is estimated to be 2600. PMID:1282154

  7. The Differential Organization of F-Actin Alters the Distribution of Organelles in Cultured When Compared to Native Chromaffin Cells.

    PubMed

    Gimenez-Molina, Yolanda; Villanueva, José; Nanclares, Carmen; Lopez-Font, Inmaculada; Viniegra, Salvador; Francés, Maria Del Mar; Gandia, Luis; Gil, Amparo; Gutiérrez, Luis M

    2017-01-01

    Cultured bovine chromaffin cells have been used extensively as a neuroendocrine model to study regulated secretion. In order to extend such experimental findings to the physiological situation, it is necessary to study mayor cellular structures affecting secretion in cultured cells with their counterparts present in the adrenomedullary tissue. F-actin concentrates in a peripheral ring in cultured cells, as witnessed by phalloidin-rodhamine labeling, while extends throughout the cytoplasm in native cells. This result is also confirmed when studying the localization of α-fodrin, a F-actin-associated protein. Furthermore, as a consequence of this redistribution of F-actin, we observed that chromaffin granules and mitochondria located into two different cortical and internal populations in cultured cells, whereas they are homogeneously distributed throughout the cytoplasm in the adrenomedullary tissue. Nevertheless, secretion from isolated cells and adrenal gland pieces is remarkably similar when measured by amperometry. Finally, we generate mathematical models to consider how the distribution of organelles affects the secretory kinetics of intact and cultured cells. Our results imply that we have to consider F-actin structural changes to interpret functional data obtained in cultured neuroendocrine cells.

  8. The Differential Organization of F-Actin Alters the Distribution of Organelles in Cultured When Compared to Native Chromaffin Cells

    PubMed Central

    Gimenez-Molina, Yolanda; Villanueva, José; Nanclares, Carmen; Lopez-Font, Inmaculada; Viniegra, Salvador; Francés, Maria del Mar; Gandia, Luis; Gil, Amparo; Gutiérrez, Luis M.

    2017-01-01

    Cultured bovine chromaffin cells have been used extensively as a neuroendocrine model to study regulated secretion. In order to extend such experimental findings to the physiological situation, it is necessary to study mayor cellular structures affecting secretion in cultured cells with their counterparts present in the adrenomedullary tissue. F-actin concentrates in a peripheral ring in cultured cells, as witnessed by phalloidin–rodhamine labeling, while extends throughout the cytoplasm in native cells. This result is also confirmed when studying the localization of α-fodrin, a F-actin-associated protein. Furthermore, as a consequence of this redistribution of F-actin, we observed that chromaffin granules and mitochondria located into two different cortical and internal populations in cultured cells, whereas they are homogeneously distributed throughout the cytoplasm in the adrenomedullary tissue. Nevertheless, secretion from isolated cells and adrenal gland pieces is remarkably similar when measured by amperometry. Finally, we generate mathematical models to consider how the distribution of organelles affects the secretory kinetics of intact and cultured cells. Our results imply that we have to consider F-actin structural changes to interpret functional data obtained in cultured neuroendocrine cells. PMID:28522964

  9. Munc18-1 phosphorylation by protein kinase C potentiates vesicle pool replenishment in bovine chromaffin cells.

    PubMed

    Nili, U; de Wit, H; Gulyas-Kovacs, A; Toonen, R F; Sørensen, J B; Verhage, M; Ashery, U

    2006-12-01

    Activation of protein kinase C (PKC) after robust stimulation is necessary for vesicle pool replenishment in secretory cells. Here we studied the contribution of a prominent downstream PKC target, Munc18-1, to this process in bovine chromaffin cells. In these cells, both activation of endogenous PKC and overexpressing of Munc18-1 promote vesicle pool replenishment after an extensive stimulation. In order to study the physiological relevance of PKC-dependent Munc18-1 phosphorylation, we generated two Munc18-1 phospho-mutants; one that mimics a constitutively PKC-phosphorylated Munc18-1 (i.e. a phosphomimetic mutant; Munc18-1(S313D)) and a second that cannot be PKC-phosphorylated (Munc18-1(3A)). Overexpression of Munc18-1(3A) caused a significant decrease in vesicle pool replenishment following a depleting stimulation, while Munc18-1(S313D) caused a significant increase in vesicle pool replenishment. These findings suggested that the phosphorylation of Munc18-1 by PKC potentiates vesicle pool replenishment. This hypothesis was further strengthened by the finding that overexpression of wild type Munc18-1 in the presence of a PKC inhibitor caused a significant reduction in vesicle pool replenishment, similar to that observed with Munc18-1(3A). Moreover, overexpression of Munc18-1(S313D) in the presence of the PKC inhibitor partly alleviated this attenuation, elucidating Munc18-1's unique contribution to vesicle pool replenishment. Finally, we demonstrate that Munc18-1 promotes vesicle docking in a phosphorylation-independent manner. This is deduced from the findings that both the wild type and the two Munc18-1 phospho-mutants enhanced docking to the same extent in bovine chromaffin cells. We conclude that Munc18-1 facilitates docking in a PKC phosphorylation-independent manner, and that its phosphorylation by PKC potentiates vesicle pool replenishment following a depleting stimulation, at a post-docking stage.

  10. Compensatory and excess retrieval: two types of endocytosis following single step depolarizations in bovine adrenal chromaffin cells

    PubMed Central

    Engisch, Kathrin L; Nowycky, Martha C

    1998-01-01

    Endocytosis following exocytosis evoked by single step depolarizations was examined in bovine adrenal chromaffin cells using high resolution capacitance measurements in perforated-patch voltage clamp recordings. Endocytosis was detected as a smooth exponential decline in membrane capacitance to either the pre-stimulus level (‘compensatory retrieval’) or far below the pre-stimulus level (‘excess retrieval’). During excess retrieval, > 10 % of the cell surface could be internalized in under 5 s. Compensatory retrieval was equal in magnitude to stimulus-evoked exocytosis for membrane additions > 100 fF (about fifty large dense-cored vesicles). In contrast, excess retrieval surpassed both the stimulus-evoked exocytosis, and the initial capacitance level recorded at the onset of phase-tracking measurements. Cell capacitance was not maintained at the level achieved by excess retrieval but slowly returned to pre-stimulus levels, even in the absence of stimulation. A large percentage of capacitance increases < 100 fF, usually evoked by 40 ms depolarizations, were not accompanied by membrane retrieval. Compensatory retrieval could occur with any amount of Ca2+ entry, but excess retrieval was never triggered below a threshold Ca2+ current integral of 70 pC. The kinetics of compensatory and excess retrieval differed by an order of magnitude. Compensatory retrieval was usually fitted with a single exponential function that had a median time constant of 5.7 s. Excess retrieval usually occurred with double exponential kinetics that had an extremely fast first time constant (median, 670 ms) and a second time constant indistinguishable from that of compensatory retrieval. The speed of compensatory retrieval was Ca2+ dependent: the largest mono-exponential time constants occurred for the smallest amounts of Ca2+ entry and decreased with increasing Ca2+ entry. The Ca2+ dependence of mono-exponential time constants was disrupted by cyclosporin A (CsA), an inhibitor of the Ca2

  11. Brevenal Inhibits Pacific Ciguatoxin-1B-Induced Neurosecretion from Bovine Chromaffin Cells

    PubMed Central

    Mattei, César; Alvarez, Martha; Benoit, Evelyne; Bourdelais, Andrea J.; Lewis, Richard J.; Baden, Daniel G.; Molgó, Jordi; Meunier, Frédéric A.

    2008-01-01

    Ciguatoxins and brevetoxins are neurotoxic cyclic polyether compounds produced by dinoflagellates, which are responsible for ciguatera and neurotoxic shellfish poisoning (NSP) respectively. Recently, brevenal, a natural compound was found to specifically inhibit brevetoxin action and to have a beneficial effect in NSP. Considering that brevetoxin and ciguatoxin specifically activate voltage-sensitive Na+ channels through the same binding site, brevenal has therefore a good potential for the treatment of ciguatera. Pacific ciguatoxin-1B (P-CTX-1B) activates voltage-sensitive Na+ channels and promotes an increase in neurotransmitter release believed to underpin the symptoms associated with ciguatera. However, the mechanism through which slow Na+ influx promotes neurosecretion is not fully understood. In the present study, we used chromaffin cells as a model to reconstitute the sequence of events culminating in ciguatoxin-evoked neurosecretion. We show that P-CTX-1B induces a tetrodotoxin-sensitive rise in intracellular Na+, closely followed by an increase in cytosolic Ca2+ responsible for promoting SNARE-dependent catecholamine secretion. Our results reveal that brevenal and β-naphtoyl-brevetoxin prevent P-CTX-1B secretagogue activity without affecting nicotine or barium-induced catecholamine secretion. Brevenal is therefore a potent inhibitor of ciguatoxin-induced neurotoxic effect and a potential treatment for ciguatera. PMID:18941627

  12. Adrenomedullary and glycemic alterations following diverse stress in soft-shelled turtles Lissemys punctata punctata Bonnoterre.

    PubMed

    Ray, Prajna Paramita; Sarkar, Supriti; Chaudhuri-Sengupta, Santasri; Maiti, B R

    2008-01-01

    The objective of the current investigation was to study adrenomedullary and glycemic responses to stress in soft-shelled turtles, Lissemys p. punctata. Dehydration (7 days) and formalin (formaldehyde 1%, 0.1 mL/100 g body wt. daily for 7 days) stress-stimulated adrenomedullary activity at histological (by increasing the nuclear diameter and degranulation of chromaffin cells) and hormonal levels (by elevations of norepinephrine and epinephrine concentrations) with hyperglycemia in turtles. But salt loading (NaCl: 1%, 1 mL/100 g body wt. daily for 7 days) had no significant effect on adrenomedullary activity or glycemia presumably owing to the nonresponsiveness of adrenocortical activity to salt stress in turtles. It is suggested that dehydration and formalin stresses might have exerted their actions through the hypothalamo (CRF)-hypophysial (ACTH)-adrenocortical axis in turtles.

  13. Inhibition of adrenomedullary catecholamine release by propranolol isomers and clonidine involving mechanisms unrelated to adrenoceptors.

    PubMed Central

    Orts, A.; Orellana, C.; Cantó, T.; Ceña, V.; González-García, C.; García, A. G.

    1987-01-01

    1 Transmural electrical stimulation (10 Hz, 40 V, 1 ms for 60s) increased total catecholamine secretion from perfused cat adrenal glands; this response was enhanced by neostigmine and inhibited by mecamylamine, suggesting that release of acetylcholine from splanchnic nerve terminals was stimulating nicotinic receptors and enhancing catecholamine secretion. 2 Isoprenaline, (-)-propranolol and (+)-propranolol (10(-7)-10(-5)M) inhibited the electrically-evoked secretory response by 40-70%; similar reductions were obtained with clonidine and yohimbine. Neither, (+)-propranolol nor (-)-propranolol inhibited K-evoked secretion from cat adrenals; in contrast, nimodipine potently inhibited it (IC50 = 24 nM). 3 Either, racemic propranolol or the (+)- or (-)-isomers (1-10 microM) equally inhibited [3H]-noradrenaline release evoked by nicotine or acetylcholine from cultured bovine adrenal chromaffin cells; clonidine (10 microM) inhibited secretion by 50% and yohimbine or isoprenaline did not affect it. 4 The results indicate that adrenomedullary catecholamine release evoked by splanchnic nerve stimulation is not modulated by alpha- or beta-adrenoceptors and suggest that propranolol may inhibit secretion by blocking ion fluxes through the acetylcholine receptor ionophore. Clonidine may inhibit secretion by this same mechanism, and/or by interfering with some intracellular event in the secretory mechanism. PMID:2827826

  14. Anti-syntaxin antibodies inhibit calcium-dependent catecholamine secretion from permeabilized chromaffin cells.

    PubMed

    Gutierrez, L M; Quintanar, J L; Viniegra, S; Salinas, E; Moya, F; Reig, J A

    1995-01-05

    Adrenomedullary chromaffin cells release catecholamines in response to the intracellular calcium rise upon stimulation by different secretagogues. The presence of syntaxin 1, a protein presumably involved in docking of synaptic vesicles to presynaptic membranes, has been investigated in chromaffin cells. The study using two different monoclonal antibodies shows that syntaxin 1 is present in the chromaffin cell membrane fraction. Functional experiments demonstrate that anti-syntaxin antibodies inhibit calcium-dependent secretion in permeabilized cells. These results suggest that syntaxin 1 is an important component of the secretory machinery in chromaffin cells.

  15. Bovine chromaffin cells have insulin-like growth factor-I (IGF-I) receptors: IGF-I enhances catecholamine secretion.

    PubMed

    Dahmer, M K; Perlman, R L

    1988-07-01

    The binding of 125I-insulin-like growth factor-I (125I-IGF-I) to bovine chromaffin cells was measured. Chromaffin cell cultures contained 111,000 +/- 40,000 IGF-I binding sites/cell. These sites bound IGF-I with a KD of 1.1 +/- 0.3 nM and had a much lower affinity for insulin. Cross-linking studies showed that 125I-IGF-I bound to a protein that had an Mr of approximately 125,000, similar to the Mr of the alpha subunit of the IGF-I receptor in other tissues. Cells cultured with IGF-I (10 nM) for 4 days exhibited an almost twofold increase in high K+-evoked catecholamine secretion. Insulin was much less potent than IGF-I in enhancing catecholamine secretion. These data indicate that binding of IGF-I to its receptors on chromaffin cells can modulate the function of these cells.

  16. Characterization of a novel, hydrophilic dihydropyridine, NKY-722, as a Ca2+ antagonist in bovine cultured adrenal chromaffin cells.

    PubMed Central

    Ohue, T.; Lee, K.; Koshimura, K.; Miwa, S.

    1991-01-01

    1. To characterize NKY-722, a novel hydrophilic dihydropyridine derivative, as a Ca2+ antagonist, we examined its effects on 45Ca2+ influx, intracellular free Ca2+ concentrations [( Ca2+]i), and release of noradrenaline and adrenaline in bovine cultured adrenal chromaffin cells. 2. NKY-722 had little effect on basal 45Ca2+ influx into the resting cells, but inhibited high K+ (35.9 mM)-evoked 45Ca2+ influx in a concentration-dependent manner with an IC50 value of 5.2 nM. 3. NKY-722 inhibited high K(+)-evoked increases in [Ca2+]i in a concentration-dependent manner without effect on the resting [Ca2+]i. 4. NKY-722 had little effect on basal release of noradrenaline and adrenaline but inhibited high K(+)-evoked release of noradrenaline and adrenaline in a concentration-dependent manner with IC50 values of 5.0 nM and 4.8 nM, respectively. 5. Nicardipine, a prototype of NKY-722, also inhibited high K(+)-evoked 45Ca2+ influx and release of noradrenaline and adrenaline in a concentration-dependent manner: the IC50 value for high K(+)-evoked 45Ca2+ influx was 51 nM, and the values for high K(+)-evoked release of noradrenaline and adrenaline were 52 nM and 50 nM, respectively. 6. These results show that NKY-722 is a hydrophilic Ca2+ antagonist ten times more potent than nicardipine. PMID:1912977

  17. Spontaneous and electrically-evoked catecholamine secretion from long-term cultures of bovine adrenal chromaffin cells.

    PubMed

    Noga, Brian R; Pinzon, Alberto

    2013-09-05

    Catecholamine release was measured from bovine adrenal medullary chromaffin cell (CC) cultures maintained over a period of three months. Cells were plated over simple biocompatible cell platforms with electrical stimulation capability and at specified times transferred to an acrylic superfusion chamber designed to allow controlled flow of superfusate over the culture. Catecholamine release was measured from the superfusates using fast cyclic voltammetry before, during and after electrical stimulation of the cells. Immunocytochemical staining of CC cultures revealed that they were composed of epinephrine (EP) and/or norepinephrine (NE) type cells. Both spontaneous and evoked-release of catecholamines from CCs were observed throughout the testing period. EP predominated during spontaneous release, whereas NE was more prevalent during electrically-evoked release. Electrical stimulation for 20 s, increased total catecholamine release by 60-130% (measured over a period of 500 s) compared to that observed for an equivalent 20 s period of spontaneous release. Stimulus intensity was correlated with the amount of evoked release, up to a plateau which was observed near the highest intensities. Shorter intervals between stimulation trials did not significantly affect the initial amount of release, and the amount of evoked release was relatively stable over time and did not decrease significantly with age of the culture. The present study demonstrates long-term survival of CC cultures in vitro and describes a technique useful for rapid assessment of cell functionality and release properties of cultured monoaminergic cell types that later can be transplanted for neurotransmitter replacement following injury or disease. Copyright © 2013 Elsevier B.V. All rights reserved.

  18. Effects of nonylphenol on the calcium signal and catecholamine secretion coupled with nicotinic acetylcholine receptors in bovine adrenal chromaffin cells.

    PubMed

    Liu, Pei-Shan; Liu, Ging-Hui; Chao, Wei-Liang

    2008-02-03

    Nonylphenol (NP) is the most critical metabolite of alkylphenol polyethoxylate detergents. NP is known as an endocrine disruptor with estrogenic activities and as an inhibitor of endoplasmic reticulum Ca(2+)-ATPase. Estrogen has modulatory roles on ligand-gated ion channels, such as nicotinic acetylcholine receptors (nAChRs). Ca(2+)-ATPase inhibitors can modulate the cytosolic calcium concentration ([Ca(2+)](c)]) and thus can affect the calcium signaling coupled with nAChRs. Therefore, NP is predicted to have complex effects on the Ca(2+) signaling and secretion coupled with nAChRs. This study investigated these effects using bovine adrenal chromaffin cells. The results show that NP suppressed the Ca(2+) signaling coupled with nAChRs and voltage-operated Ca(2+) channels in a dose-dependent manner, with IC(50)s of 1 and 5.9 microM, respectively. Estradiol exhibits similar suppression but much lower inhibitory potencies. NP alone induced a transient rise in [Ca(2+)](c) in the presence or absence of extracellular calcium. Thapsigargin, an endoplasmic reticulum Ca(2+)-ATPase inhibitor, partially suppressed the [Ca(2+)](c) rise induced by NP, but NP totally blocked the [Ca(2+)](c) rise induced by thapsigargin. This illustrates that NP can cause Ca(2+) release from thapsigargin-insensitive pools. Thapsigargin suppressed the Ca(2+) signaling coupled with nAChRs but increased that coupled with voltage-operated Ca(2+) channels. We propose that three routes are responsible for the effects of NP on nAChRs: named receptor channels, voltage-gated Ca(2+) channels, and Ca(2+)-induced Ca(2+) release. Three routes are related to the characteristics of NP as steroid-like compounds and Ca(2+)-ATPase inhibitor.

  19. Correlation between catecholamine secretion from bovine isolated chromaffin cells and [3H]-ouabain binding to plasma membranes

    PubMed Central

    Aunis, Dominique; García, Antonio G.

    1981-01-01

    1 Secretion of catecholamines (CA) evoked by ouabain, chlormadinone acetate (CMA), phenoxybenzamine (Pbz) and vanadate, four agents known to inhibit Na+, K+-dependent Mg2+-activated adenosine triphosphatase (ATPase) activity has been studied in suspensions of bovine isolated adrenal medullary cells. 2 Acetylcholine (ACh) evoked a 5 fold increase of the basal CA secretion from isolated cells suspended in oxygenated Krebs-bicarbonate solution kept at 27°C. Secretion was antagonized by Ca2+-deprivation or hexamethonium, indicating good functional viability of the cells. 3 Ouabain (10-7 to 10-4 M) evoked a progressive, dose-dependent release of CA from cell suspensions. Study of the time course of the secretory response for 2 h allowed the separation of two components in the secretory response at all doses studied: a slow initial component (0.011 pg/min CA) and a second faster component (0.032 pg/min CA). 4 CMA evoked a clear-cut CA secretory response. The ED50 for CMA was 10-4 M, as compared to 3 × 10-6 M for ouabain. Pbz and vanadate did not induce CA release. 5 [3H]-ouabain was taken up and bound to intact isolated cells by a non-saturable binding process. However, in semi-purified plasma membranes from bovine adrenal medulla a saturable specific [3H]-ouabain binding process was observed with a KD of 8.1 nM. Binding to the membranes was ATP-dependent and antagonized by K+. 6 [3H]-ouabain specific binding to membranes was antagonized by ouabain and CMA, but not by Pbz or vanadate; the ID50 for ouabain and CMA were 10-6 and 10-5 M respectively. 7 Ouabain partially inhibited, in a dose-dependent manner, Na+, K+-Mg2+ ATPase activity of the semi-purified plasma membranes. 8 The results demonstrate a good correlation between the ability of different drugs, known to inhibit ATPase activity, to displace [3H]-ouabain binding to adreno—medullary plasma membranes and their capacity to evoke a CA secretory response from isolated chromaffin cells. The data also suggest that

  20. Simultaneous monitoring of monoamines, amino acids, nucleotides and neuropeptides by liquid chromatography-tandem mass spectrometry and its application to neurosecretion in bovine chromaffin cells.

    PubMed

    Wojnicz, Aneta; Avendaño-Ortiz, José; de Pascual, Ricardo; Ruiz-Pascual, Lucía; García, Antonio G; Ruiz-Nuño, Ana

    2016-08-01

    The primary functions of adrenal medullary chromaffin cells are the synthesis and storage in their chromaffin vesicles of the catecholamines noradrenaline (NA) and adrenaline (AD), and their subsequent release into the bloodstream by Ca(2+) -dependent exocytosis under conditions of fear or stress (fight or flight response). Several monoamines, nucleotides and opiates, such as leucine-enkephalin (LENK) and methionine-enkephalin (MENK), are also co-stored and co-released with the catecholamines. However, other neurotransmitters have not been studied in depth. Here, we present a novel high-resolution liquid chromatography-tandem mass spectrometry approach for the simultaneous monitoring of 14 compounds stored and released in bovine chromaffin cells (BCCs). We validated the analytical method according to the recommendations of the EMA and FDA by testing matrix effect, selectivity, sensitivity, precision, accuracy, stability and carry-over. After testing on six batches of BCCs from different cultures, the method enabled simultaneous quantitative determination of monoamines (AD, NA, dopamine, serotonin, 5-hydroxyindoleacetic acid, histamine and metanephrine), amino acids (L-glutamic acid, γ-aminobutyric acid), nucleotides (adenosine 5'-diphosphate, adenosine 5'-monophosphate, cyclic adenosine 5'-monophosphate) and neuropeptides (LENK and MENK) in the intracellular content, basal secretion and acetylcholine induced secretion of BBCs. The high-resolution approach used here enabled us to determine the levels of 14 compounds in the same BCC batch in only 16 min. This novel approach will make it possible to study the regulatory mechanisms of Ca(2+) signaling, exocytosis and endocytosis using different neurotrophic factors and/or secretagogues as stimuli in primary BCC cultures. Our method is actually being applied to human plasma samples of different therapeutic areas where sympathoadrenal axis is involved in stress situations such as Alzheimer's disease, migraine or

  1. Drastic facilitation by alpha-latrotoxin of bovine chromaffin cell exocytosis without measurable enhancement of Ca2+ entry or [Ca2+]i.

    PubMed Central

    Michelena, P; de la Fuente, M T; Vega, T; Lara, B; López, M G; Gandía, L; García, A G

    1997-01-01

    1. Latrotoxin (LTX, 1-3 nM) caused a gradual increase of the spontaneous catecholamine release rate in bovine adrenal chromaffin cells superfused with normal Krebs-Hepes solution containing 2.5 mM Ca2+. Ca2+ removal abolished this effect. LTX enhanced also the secretory responses to high K+ (35 or 70 mM) and to acetylcholine (ACh, 30 microM). 2. The application of Ca2+ pulses to cells previously superfused with a 0 Ca2+ solution (Krebs-Hepes deprived of CaCl2) induced secretory responses that gradually reached 400-800 nA of catecholamines, provided that LTX was present. The responses to ACh or 35 mM K+ pulses (in the presence of Ca2+) were also enhanced by LTX, from around 100-200 nA to over 1000 nA. Though such enhancement remained in the presence of Ca2+ channel blockers, it disappeared upon the lowering of [Na+]o or in electroporated cells. 3. Using protocols similar to those of secretion, LTX did not enhance basal 45Ca2+ uptake, whole-cell Ca2+ currents or basal [Ca2+]i. In fact, LTX attenuated the K(+)- or ACh-evoked increases in 45Ca2+ uptake and [Ca2+]i. 4. It is proposed that the secretory response to brief periods of Ca2+ reintroductions is triggered by local subplasmalemmal Ca2+i transients, produced by the Na(+)-Ca2+ exchanger of the plasma membrane working in the reverse mode. This situation might be physiologically reproduced during ACh stimulation of chromaffin cells, which is followed by the firing of Na(+)-dependent action potentials. Images Figure 12 PMID:9279802

  2. Kinetics of Ca2+ binding to parvalbumin in bovine chromaffin cells: implications for [Ca2+] transients of neuronal dendrites

    PubMed Central

    Lee, Suk-Ho; Schwaller, Beat; Neher, Erwin

    2000-01-01

    The effect of parvalbumin (PV) on [Ca2+] transients was investigated by perfusing adrenal chromaffin cells with fura-2 and fluorescein isothiocyanate (FITC)-labelled PV. As PV diffused into cells, the decay of [Ca2+] transients was transformed from monophasic into biphasic. The proportion of the initial fast decay phase increased in parallel with the fluorescence intensity of FITC, indicating that PV is responsible for the initial fast decay phase.The relationship between the fast decay phase and the [Ca2+] level was investigated using depolarizing trains of stimuli. Within a train the relative amplitude of the fast decay phase was inversely dependent on the [Ca2+] level preceding a given stimulus.Based on these observations, we estimated the Ca2+ binding ratio of PV (κP), the apparent dissociation constant of PV for Ca2+ (Kdc,app), and the unbinding rate constant of Ca2+ from PV (kc-) in the cytosol of chromaffin cells. Assuming free [Mg2+] to be 0.14 mm, we obtained values of 51.4 ± 2.0 nm (n = 3) and 0.95 ± 0.026 s−1 (n = 3), for Kdc,app and kc-, respectively.With the parameters obtained in the perfusion study, we simulated [Ca2+] transients, using two different Ca2+ extrusion rates (γ) – 20 and 300 s−1– which represent typical values for chromaffin cells and neuronal dendrites, respectively. The simulation indicated that Ca2+ is pumped out before it is equilibrated with PV, when γ is comparable to the equilibration rates between PV and Ca2+, resulting in the fast decay phase of a biexponential [Ca2+] transient.From these results we conclude that Ca2+ buffers with slow kinetics, such as PV, may cause biexponential decays in [Ca2+] transients, thereby complicating the analysis of endogenous Ca2+ binding ratios (κS) based on time constants. Nevertheless, estimates of κS based on Ca2+ increments provide reasonable estimates for Ca2+ binding ratios before equilibration with PV. PMID:10835044

  3. Calcium signalling mediated through α7 and non-α7 nAChR stimulation is differentially regulated in bovine chromaffin cells to induce catecholamine release

    PubMed Central

    del Barrio, Laura; Egea, Javier; León, Rafael; Romero, Alejandro; Ruiz, Ana; Montero, Mayte; Álvarez, Javier; López, Manuela G

    2011-01-01

    BACKGROUND AND PURPOSE Ca2+ signalling and exocytosis mediated by nicotinic receptor (nAChR) subtypes, especially the α7 nAChR, in bovine chromaffin cells are still matters of debate. EXPERIMENTAL APPROACH We have used chromaffin cell cultures loaded with Fluo-4 or transfected with aequorins directed to the cytosol or mitochondria, several nAChR agonists (nicotine, 5-iodo-A-85380, PNU282987 and choline), and the α7 nAChR allosteric modulator PNU120596. KEY RESULTS Minimal [Ca2+]c transients, induced by low concentrations of selective α7 nAChR agonists and nicotine, were markedly increased by the α7 nAChR allosteric modulator PNU120596. These potentiated responses were completely blocked by the α7 nAChR antagonist α-bungarotoxin (α7-modulated-response). Conversely, high concentrations of the α7 nAChR agonists, nicotine or 5-iodo-A-85380 induced larger [Ca2+]c transients, that were blocked by mecamylamine but were unaffected by α-bungarotoxin (non-α7 response). [Ca2+]c increases mediated by α7 nAChR were related to Ca2+ entry through non-L-type Ca2+ channels, whereas non-α7 nAChR-mediated signals were related to L-type Ca2+ channels; Ca2+-induced Ca2+-release contributed to both responses. Mitochondrial involvement in the control of [Ca2+]c transients, mediated by either receptor, was minimal. Catecholamine release coupled to α7 nAChRs was more efficient in terms of catecholamine released/[Ca2+]c. CONCLUSIONS AND IMPLICATIONS [Ca2+]c and catecholamine release mediated by α7 nAChRs required an allosteric modulator and low doses of the agonist. At higher agonist concentrations, the α7 nAChR response was lost and the non-α7 nAChRs were activated. Catecholamine release might therefore be regulated by different nAChR subtypes, depending on agonist concentrations and the presence of allosteric modulators of α7 nAChRs. PMID:20840468

  4. GRK2 Up-Regulation Creates a Positive Feedback Loop for Catecholamine Production in Chromaffin Cells.

    PubMed

    Jafferjee, Malika; Reyes Valero, Thairy; Marrero, Christine; McCrink, Katie A; Brill, Ava; Lymperopoulos, Anastasios

    2016-03-01

    Elevated sympathetic nervous system (SNS) activity aggravates several diseases, including heart failure. The molecular cause(s) underlying this SNS hyperactivity are not known. We have previously uncovered a neurohormonal mechanism, operating in adrenomedullary chromaffin cells, by which circulating catecholamine (CA) levels increase in heart failure: severe dysfunction of the adrenal α2-adrenergic receptors (ARs) due to the up-regulation of G protein-coupled receptor-kinase (GRK)-2, the kinase that desensitizes them. Herein we looked at the potential signaling mechanisms that bring about this GRK2 elevation in chromaffin cells. We found that chronic CA treatment of either PC12 or rat primary chromaffin cells can in itself result in GRK2 transcriptional up-regulation through α2ARs-Gi/o proteins-Src-ERK1/2. The resultant GRK2 increase severely enhances the α2AR desensitization/down-regulation elevating not only CA release but also CA biosynthesis, as evidenced by tyrosine hydroxylase up-regulation. Finally, GRK2 knockdown leads to enhanced apoptosis of PC12 cells, indicating an essential role for GRK2 in chromaffin cell homeostasis/survival. In conclusion, chromaffin cell GRK2 mediates a positive feedback loop that feeds into CA secretion, thereby enabling the adrenomedullary component of the SNS to turn itself on.

  5. Nitric oxide inhibits neuroendocrine CaV1 L-channel gating via cGMP-dependent protein kinase in cell-attached patches of bovine chromaffin cells

    PubMed Central

    Carabelli, Valentina; D'Ascenzo, Marcello; Carbone, Emilio; Grassi, Claudio

    2002-01-01

    Nitric oxide (NO) regulates the release of catecholamines from the adrenal medulla but the molecular targets of its action are not yet well identified. Here we show that the NO donor sodium nitroprusside (SNP, 200 μM) causes a marked depression of the single CaV1 L-channel activity in cell-attached patches of bovine chromaffin cells. SNP action was complete within 3-5 min of cell superfusion. In multichannel patches the open probability (NPo) decreased by ∼60 % between 0 and +20 mV. Averaged currents over a number of traces were proportionally reduced and showed no drastic changes to their time course. In single-channel patches the open probability (Po) at +10 mV decreased by the same amount as that of multichannel patches (∼61 %). Such a reduction was mainly associated with an increased probability of null sweeps and a prolongation of mean shut times, while first latency, mean open time and single-channel conductance were not significantly affected. Addition of the NO scavenger carboxy-PTIO or cell treatment with the guanylate cyclase inhibitor ODQ prevented the SNP-induced inhibition. 8-Bromo-cyclicGMP (8-Br-cGMP; 400 μM) mimicked the action of the NO donor and the protein kinase G blocker KT-5823 prevented this effect. The depressive action of SNP was preserved after blocking the cAMP-dependent up-regulatory pathway with the protein kinase A inhibitor H89. Similarly, the inhibitory action of 8-Br-cGMP proceeded regardless of the elevation of cAMP levels, suggesting that cGMP/PKG and cAMP/PKA act independently on L-channel gating. The inhibitory action of 8-Br-cGMP was also independent of the G protein-induced inhibition of L-channels mediated by purinergic and opiodergic autoreceptors. Since Ca2+ channels contribute critically to both the local production of NO and catecholamine release, the NO/PKG-mediated inhibition of neuroendocrine L-channels described here may represent an important autocrine signalling mechanism for controlling the rate of

  6. Nonreutilizaton of adrenal chromaffin granule membranes following secretion

    SciTech Connect

    Nobiletti, J.B.

    1985-01-01

    The intracellular postexocytotic fate of the adrenal chromaffin granule membrane (reutilization vs. nonreutilization) was addressed through two experimental approaches. First, (/sup 3/H) leucine pulse-chase labeling experiments were conducted in two systems - the isolated retrograde perfused cat adrenal gland and cultured bovine adrenal chromaffin cells to compare chromaffin granule soluble dopamine-B-hydroxylase (DBH) turnover (marker for granule soluble content turnover) to that of membrane-bound DBH (marker for granule membrane turnover). Experiments in cat adrenal glands showed that at all chase periods the granule distribution of radiolabeled DBH was in agreement with the DBH activity distribution (73% membrane-bound/27% soluble) - a result consistent with parallel turnover of soluble and membrane-bound DBH. Experiments in cultured bovine cells showed that labeled soluble and membrane-bound DBH had parallel turnover patterns and at all chase period, the distribution of radiolabeled DBH between the soluble contents and membranes was similar to the DBH activity distribution (50% soluble/50% membrane-bound). The above experiments showed that the soluble contents and membranes turnover in parallel and are consistent with nonreutilization of chromaffin granule membranes following exocytosis. Isolated retrograde perfused bovine adrenal glands were subjected to repetitive acetylcholine stimulation to induce exocytosis and then the dense and less-dense chromaffin granule fractions were isolated. Since both approaches gave results consistent with membrane nonreutilization, the authors conclude that once a chromaffin granule is involved in exocytosis, its membrane is not reutilized for the further synthesis, storage, and secretion of catecholamines.

  7. Voltage inactivation of Ca2+ entry and secretion associated with N- and P/Q-type but not L-type Ca2+ channels of bovine chromaffin cells

    PubMed Central

    Villarroya, Mercedes; Olivares, Román; Ruíz, Ana; Cano-Abad, María F; de Pascual, Ricardo; Lomax, Richard B; López, Manuela G; Mayorgas, Inés; Gandía, Luis; García, Antonio G

    1999-01-01

    In this study we pose the question of why the bovine adrenal medullary chromaffin cell needs various subtypes (L, N, P, Q) of the neuronal high-voltage activated Ca2+ channels to control a given physiological function, i.e. the exocytotic release of catecholamines. One plausible hypothesis is that Ca2+ channel subtypes undergo different patterns of inactivation during cell depolarization. The net Ca2+ uptake (measured using 45Ca2+) into hyperpolarized cells (bathed in a nominally Ca2+-free solution containing 1·2 mM K+) after application of a Ca2+ pulse (5 s exposure to 100 mM K+ and 2 mM Ca2+), amounted to 0·65 ± 0·02 fmol cell−1; in depolarized cells (bathed in nominally Ca2+-free solution containing 100 mM K+) the net Ca2+ uptake was 0·16 ± 0·01 fmol cell−1. This was paralleled by a dramatic reduction of the increase in the cytosolic Ca2+ concentration, [Ca2+]i, caused by Ca2+ pulses applied to fura-2-loaded single cells, from 1181 ± 104 nM in hyperpolarized cells to 115 ± 9 nM in depolarized cells. A similar decrease was observed when studying catecholamine release. Secretion was decreased when K+ concentration was increased from 1·2 to 100 mM; the Ca2+ pulse caused, when comparing the extreme conditions, the secretion of 807 ± 35 nA of catecholamines in hyperpolarized cells and 220 ± 19 nA in depolarized cells. The inactivation by depolarization of Ca2+ entry and secretion occluded the blocking effects of combined ω-conotoxin GVIA (1 μM) and ω-agatoxin IVA (2 μM), thus suggesting that depolarization caused a selective inactivation of the N- and P/Q-type Ca2+ channels. This was strengthened by two additional findings: (i) nifedipine (3 μM), an L-type Ca2+ channel blocker, suppressed the fraction of Ca2+ entry (24 %) and secretion (27 %) left unblocked by depolarization; (ii) FPL64176 (3 μM), an L-type Ca2+ channel ‘activator’, dramatically enhanced the entry of Ca2+ and the secretory response in depolarized cells. In voltage

  8. Acetylcholine nicotinic receptor subtypes in chromaffin cells.

    PubMed

    Criado, Manuel

    2017-08-08

    In the adrenal gland, acetylcholine released on stimulation of the sympathetic splanchnic nerve activates neuronal-type nicotinic receptors (nAChRs) in chromaffin cells and triggers catecholamine secretion. At least two subtypes of nAChRs have been described in bovine chromaffin cells. The main subtype, a heteromeric assembly of α3, β4 and perhaps α5 subunits, is involved in the activation step of the catecholamine secretion process and is not blocked by the snake toxin α-bungarotoxin. The other is α-bungarotoxin-sensitive, and its functional role has not yet been well defined. The α7 subunit conforms the homomeric structure of this subtype. All nAChR subunits share the same molecular organization and structural data at atomic resolution level are now available for some homomeric and heteromeric ensembles. The α3, β4 and α5 subunits are clustered in genomes of different species, with the transcription factor Sp1 playing a co-ordinating role in the transcriptional regulation of these three subunits. The transcription factor Egr-1 controls the differential expression of α7 nAChR in adrenergic chromaffin cells, as happens with the enzyme phenylethanolamine N-methyl transferase. For unknown reasons, whole cell currents observed in bovine chromaffin cells clearly differ of the ones observed when different combinations of subunit RNAs are injected in oocytes. In addition to the typical nicotinic ligands, a variety of unrelated substances with clinical relevance can target nAChRs in chromaffin cells and, therefore, affect catecholamine secretion. They can act as agonists, antagonists or allosteric modulators.

  9. Exocytotic dynamics in human chromaffin cells: experiments and modeling.

    PubMed

    Albillos, Almudena; Gil, Amparo; González-Vélez, Virginia; Pérez-Álvarez, Alberto; Segura, Javier; Hernández-Vivanco, Alicia; Caba-González, José Carlos

    2013-02-01

    Chromaffin cells have been widely used to study neurosecretion since they exhibit similar calcium dependence of several exocytotic steps as synaptic terminals do, but having the enormous advantage of being neither as small or fast as neurons, nor as slow as endocrine cells. In the present study, secretion associated to experimental measurements of the exocytotic dynamics in human chromaffin cells of the adrenal gland was simulated by using a model that combines stochastic and deterministic approaches for short and longer depolarizing pulses, respectively. Experimental data were recorded from human chromaffin cells, obtained from healthy organ donors, using the perforated patch configuration of the patch-clamp technique. We have found that in human chromaffin cells, secretion would be mainly managed by small pools of non-equally fusion competent vesicles, slowly refilled over time. Fast secretion evoked by brief pulses can be predicted only when 75% of one of these pools (the "ready releasable pool" of vesicles, abbreviated as RRP) are co-localized to Ca²⁺ channels, indicating an immediately releasable pool in the range reported for isolated cells of bovine and rat (Álvarez and Marengo, J Neurochem 116:155-163, 2011). The need for spatial correlation and close proximity of vesicles to Ca²⁺ channels suggests that in human chromaffin cells there is a tight control of those releasable vesicles available for fast secretion.

  10. Mouse Adrenal Chromaffin Cell Isolation

    PubMed Central

    Kolski-Andreaco, Aaron; Cai, Haijiang; Currle, D. Spencer; Chandy, K. George; Chow, Robert H.

    2007-01-01

    Adrenal medullary chromaffin cell culture systems are extremely useful for the study of excitation-secretion coupling in an in vitro setting. This protocol illustrates the method used to dissect the adrenals and then isolate the medullary region by stripping away the adrenal cortex. The digestion of the medulla into single chromaffin cells is then demonstrated. PMID:18830430

  11. The presence of lysophosphatidylcholine in chromaffin granules

    PubMed Central

    Arthur, Gilbert; Sheltawy, Ayman

    1980-01-01

    Lysophosphatidylcholine is thought to be a characteristic component of the chromaffin granules in adrenal glands. By the use of a t.l.c. system that resolves minor phospholipids satisfactorily, this subcellular location was confirmed in the present study in bovine glands. However, phospholipid degradation was demonstrated in homogenates of the adrenal medulla and cortex under conditions similar to those of subcellular fractionation (incubation at 4°C for 90min). Phosphatidylethanolamine and cardiolipin were hydrolysed, but the concentration of lysophosphatidylcholine did not change, indicating that the latter was present in the medulla before this treatment. Attempts were made to decrease the time between death of the animal and the extraction of lipids. Lysophosphatidylcholine was easily demonstrable in lipid extracts of the dissected medulla and even in those of the whole bovine gland. For practical reasons it is not possible to decrease further the time lapse before extraction in the case of this animal. Adrenal glands were obtained from anaesthetized and untreated rabbits. These were frozen immediately in liquid N2 and the lipids were extracted. In a control experiment, the glands from rabbit were dissected and treated in the same manner as with those of ox, and then the lipids were extracted. No lysophosphatidylcholine was detected in the extracts from glands frozen in liquid N2 but lysophosphatidylcholine was observed in the controls. These results suggest that lysophosphatidylcholine is not a component of chromaffin granules, but is produced if the period between death of the animal and lipid extraction is unduly prolonged. To discover whether lysophosphatidylcholine affected the permeability barrier properties of chromaffin granules, sonicated liposomes of egg phosphatidylcholine alone or with lysophosphatidylcholine (15mol/100mol) were prepared. Both types were shown by electron microscopy to be largely made up of single bilayer vesicles. The exchange

  12. Vimentin in cultured chromaffin cells: an immunofluorescent, biochemical and functional study.

    PubMed

    Quintanar, J L

    2000-01-01

    In tile present study we seek the presence and possible function of the intermediate filament protein vimentin in adrenomedullary chromaffin cells. Vimentin which is not present in the adrenal medulla was clearly showed up after collagenase digestion of the gland in the cultured chromaffin cells by using an immunofluorescent analysis with double cell labeling with monoclonal antibodies against vimentin and dopamine-beta-hydroxylase. Vimentin was also shown to be phosphorylated in a calcium-dependent manner by acetylcholine. The specific protein phosphatase inhibitor calyculin-A, that has been previously shown to increase vimentin phosphorylation, caused a change in the distribution of vimentin which moved from the Triton X-100 insoluble cytoskeletal preparation to the detergent soluble fraction probably as a result of modifications in filament integrity. The possible role of vimentin in secretion was in addition investigated using digitonin-permeabilized cells, in which the specific antibody for vimentin partially inhibited calcium-induced catecholamine release. These results demonstrate the induction of vimentin expression after collagenase digestion in cultured chromaffin cells and suggest that in these conditions this protein is possibly implicated in the regulation of the secretory process through a phosphorylation-dependent mechanism.

  13. Chromaffin cells as a model to evaluate mechanisms of cell death and neuroprotective compounds.

    PubMed

    de Los Rios, Cristobal; Cano-Abad, Maria F; Villarroya, Mercedes; López, Manuela G

    2017-08-19

    In this review, we show how chromaffin cells have contributed to evaluate neuroprotective compounds with diverse mechanisms of action. Chromaffin cells are considered paraneurons, as they share many common features with neurons: (i) they synthesize, store, and release neurotransmitters upon stimulation and (ii) they express voltage-dependent calcium, sodium, and potassium channels, in addition to a wide variety of receptors. All these characteristics, together with the fact that primary cultures from bovine adrenal glands or chromaffin cells from the tumor pheochromocytoma cell line PC12 are easy to culture, make them an ideal model to study neurotoxic mechanisms and neuroprotective drugs. In the first part of this review, we will analyze the different cytotoxicity models related to calcium dyshomeostasis and neurodegenerative disorders like Alzheimer's or Parkinson's. Along the second part of the review, we describe how different classes of drugs have been evaluated in chromaffin cells to determine their neuroprotective profile in different neurodegenerative-related models.

  14. Synaptotagmin isoforms confer distinct activation kinetics and dynamics to chromaffin cell granules.

    PubMed

    Rao, Tejeshwar C; Santana Rodriguez, Zuleirys; Bradberry, Mazdak M; Ranski, Alexandra H; Dahl, Peter J; Schmidtke, Michael W; Jenkins, Paul M; Axelrod, Daniel; Chapman, Edwin R; Giovannucci, David R; Anantharam, Arun

    2017-08-07

    Adrenomedullary chromaffin cells respond to sympathetic nervous system activation by secreting a cocktail of potent neuropeptides and hormones into the circulation. The distinct phases of the chromaffin cell secretory response have been attributed to the progressive fusion of distinct populations of dense core granules with different activation kinetics. However, it has been difficult to define what distinguishes these populations at the molecular level. Functional segregation of granule pools may depend on selective sorting of synaptotagmin-1 (Syt-1) and synaptotagmin-7 (Syt-7), which our previous work showed are rarely cosorted to the same granule. Here we assess the consequences of selective sorting of Syt isoforms in chromaffin cells, particularly with respect to granule dynamics and activation kinetics. Upon depolarization of cells expressing fluorescent Syt isoforms using elevated K(+), we find that Syt-7 granules fuse with faster kinetics than Syt-1 granules, irrespective of stimulation strength. Pharmacological blockade of Ca(2+) channels reveals differential dependence of Syt-1 versus Syt-7 granule exocytosis on Ca(2+) channel subtypes. Syt-7 granules also show a greater tendency to fuse in clusters than Syt-1 granules, and granules harboring Syt-1 travel a greater distance before fusion than those with Syt-7, suggesting that there is spatial and fusion-site heterogeneity among the two granule populations. However, the greatest functional difference between granule populations is their responsiveness to Ca(2+) Upon introduction of Ca(2+) into permeabilized cells, Syt-7 granules fuse with fast kinetics and high efficacy, even at low Ca(2+) levels (e.g., when cells are weakly stimulated). Conversely, Syt-1 granules require a comparatively larger increase in intracellular Ca(2+) for activation. At Ca(2+) concentrations above 30 µM, activation kinetics are faster for Syt-1 granules than for Syt-7 granules. Our study provides evidence for functional

  15. Further characteristics of the ATP-stimulated uptake of calcium into chromaffin granules.

    PubMed

    Burger, A; Niedermaier, W; Langer, R; Bode, U

    1984-09-01

    The ATP-stimulated uptake of 45Ca2+ [and [3H](-)-noradrenaline ([3H]NA)] into chromaffin granules and that into mitochondria are driven by a protonic gradient delta mu H+, composed of the components delta pH (concentration gradient of protons) and delta psi (electrical potential difference). The granular ATPase pumps protons into the matrix (delta pH inside acid, delta psi positive), but the mitochondrial ATPase ejects protons from the matrix (delta pH alkaline, delta psi negative inside). To show different driving forces of uptake, the rate of the ATP-stimulated uptake of 45Ca2+ (and [3H]NA) into chromaffin granules was compared with the rate of the ATP-stimulated uptake of 45Ca2+ into mitochondria (adrenomedullary or rat liver). In the presence of nitrate, the rate of the ATP-stimulated uptake of 45Ca2+ into chromaffin granules is higher than in the presence of acetate, because the lyotropic anion nitrate stimulates the granular ATPase and increases delta pH (acid inside). Compared with nitrate, the rate of the ATP-stimulated uptake of 45Ca2+ into mitochondria is higher in the presence of the proton-carrying anion acetate, which, after permeation, provides protons for ejection by the ATPase. In the absence of ATP, a valinomycin-mediated potassium influx (delta psi inside positive) stimulates the granular uptake of [3H]NA, which has an electrogenic component, but not the granular uptake of 45Ca2+, which is electroneutral. The electrogenic uptake of 45Ca2+ into mitochondria is stimulated by a valinomycin-mediated potassium efflux (delta psi negative inside). The ATP-stimulated uptake of 45Ca2+ into chromaffin granules is sensitive to ruthenium red, suggesting a carrier-mediated mechanism of uptake, and it is sensitive to atractyloside, indicating the simultaneous uptake of ATP. After collapse of delta pH by ammonia, the ATP-stimulated uptake of 45Ca2+ into chromaffin granules is abolished, but not that into mitochondria. In the presence of ammonia, the rate of the

  16. An osmotic mechanism for exocytosis from dissociated chromaffin cells.

    PubMed

    Pollard, H B; Pazoles, C J; Creutz, C E; Scott, J H; Zinder, O; Hotchkiss, A

    1984-01-25

    Dissociated chromaffin cells from bovine adrenal medulla were stimulated to secrete epinephrine and dopamine beta-hydroxylase with a variety of secretagogues in a study designed to test the hypothesis that the chemiosmotic lysis reaction of isolated chromaffin granules might in some way be related to the mechanism of release during exocytosis. Increasing the osmotic strength of the incubation medium with either NaCl or sucrose led to suppression of secretion of epinephrine from the cells regardless of whether secretion was induced with veratridine or acetylcholine. Suppression of secretion was approximately exponential with respect to osmotic strength. Epinephrine secretion occurred only if the medium contained a permeant anion such as chloride, and secretion induced by veratridine was suppressed when Na isethionate replaced NaCl in the medium. In an extensive study with different monovalent anions veratridine supported epinephrine secretion according to the following activity series: Br-, I-, NO3- greater than methylsulfate, SCN- greater than Cl greater than acetate much greater than isethionate. A similar series, except for the potency of NO3-, was observed with A23187 as agonist. In general, the anion series for granule lysis was analogous. However, there was a poor quantitative correlation between the anion dependence of chemiosmotic granule lysis and the anion dependence of cell secretion. Anion transport inhibitors such as probenecid and pyridoxal phosphate also inhibited secretion while the stilbene disulfonates were inactive. The ineffectiveness of the stilbene disulfonates further distinguished chemiosmotic granule lysis from cell secretion. Secretion of catecholamines, induced by veratridine or nicotine, a cholinergic agonist, was suppressed when NaCl in the medium was replaced by isosmotic sucrose and unexpectedly low levels of dopamine beta-hydroxylase were observed in some cases. In sum, these properties of secreting chromaffin cells resembled some

  17. Phosphatidylinositol kinase. A component of the chromaffin-granule membrane

    PubMed Central

    Phillips, John H.

    1973-01-01

    Phosphorylation of bovine chromaffin granules by ATP leads to the formation of diphosphoinositide in the granule membrane. Both phosphatidylinositol kinase and its substrate are components of this membrane, and triphosphoinositide is not formed under the conditions of the assay. The reaction is Mg2+-dependent and is stimulated by Mn2+ and F− ions. The initial reaction is rapid, with a broad pH profile and a `transition' temperature for its activation energy at 27°C. The apparent Km for ATP is 5μm. ATP, N-ethylmaleimide, Cu2+ ions and NaIO4 are inhibitory. The phospholipids of chromaffin-granule membranes have been analysed: 6.8% of the lipid P is found in phosphatidylinositol, and only 2–3% in phosphatidylserine. Comparison of the rate of phosphorylation of intact and lysed granules suggests that the sites for phosphorylation are on the outer (cytoplasmic) surface of the granules, and diphosphoinositide may therefore make an important contribution to the charge of the chromaffin granule in vivo. PMID:4360713

  18. Effect of heart failure on catecholamine granule morphology and storage in chromaffin cells

    PubMed Central

    Mahata, Sushil K; Zheng, Hong; Mahata, Sumana; Liu, Xuefei

    2016-01-01

    One of the key mechanisms involved in sympathoexcitation in chronic heart failure (HF) is the activation of the adrenal glands. Impact of the elevated catecholamines on the hemodynamic parameters has been previously demonstrated. However, studies linking the structural effects of such overactivation with secretory performance and cell metabolism in the adrenomedullary chromaffin cells in vivo have not been previously reported. In this study, HF was induced in male Sprague-Dawley rats by ligation of the left coronary artery. Five weeks after surgery, cardiac function was assessed by ventricular hemodynamics. HF rats showed increased adrenal weight and adrenal catecholamine levels (norepinephrine, epinephrine and dopamine) compared with sham-operated rats. Rats with HF demonstrated increased small synaptic and dense core vesicle in splanchnic–adrenal synapses indicating trans-synaptic activation of catecholamine biosynthetic enzymes, increased endoplasmic reticulum and Golgi lumen width to meet the demand of increased catecholamine synthesis and release, and more mitochondria with dilated cristae and glycogen to accommodate for the increased energy demand for the increased biogenesis and exocytosis of catecholamines from the adrenal medulla. These findings suggest that increased trans-synaptic activation of the chromaffin cells within the adrenal medulla may lead to increased catecholamines in the circulation which in turn contributes to the enhanced neurohumoral drive, providing a unique mechanistic insight for enhanced catecholamine levels in plasma commonly observed in chronic HF condition. PMID:27402067

  19. Effect of heart failure on catecholamine granule morphology and storage in chromaffin cells.

    PubMed

    Mahata, Sushil K; Zheng, Hong; Mahata, Sumana; Liu, Xuefei; Patel, Kaushik P

    2016-09-01

    One of the key mechanisms involved in sympathoexcitation in chronic heart failure (HF) is the activation of the adrenal glands. Impact of the elevated catecholamines on the hemodynamic parameters has been previously demonstrated. However, studies linking the structural effects of such overactivation with secretory performance and cell metabolism in the adrenomedullary chromaffin cells in vivo have not been previously reported. In this study, HF was induced in male Sprague-Dawley rats by ligation of the left coronary artery. Five weeks after surgery, cardiac function was assessed by ventricular hemodynamics. HF rats showed increased adrenal weight and adrenal catecholamine levels (norepinephrine, epinephrine and dopamine) compared with sham-operated rats. Rats with HF demonstrated increased small synaptic and dense core vesicle in splanchnic-adrenal synapses indicating trans-synaptic activation of catecholamine biosynthetic enzymes, increased endoplasmic reticulum and Golgi lumen width to meet the demand of increased catecholamine synthesis and release, and more mitochondria with dilated cristae and glycogen to accommodate for the increased energy demand for the increased biogenesis and exocytosis of catecholamines from the adrenal medulla. These findings suggest that increased trans-synaptic activation of the chromaffin cells within the adrenal medulla may lead to increased catecholamines in the circulation which in turn contributes to the enhanced neurohumoral drive, providing a unique mechanistic insight for enhanced catecholamine levels in plasma commonly observed in chronic HF condition.

  20. Differential distribution of synaptotagmin-1, -4, -7, and -9 in rat adrenal chromaffin cells.

    PubMed

    Matsuoka, Hidetada; Harada, Keita; Nakamura, Jun; Fukuda, Mitsunori; Inoue, Masumi

    2011-04-01

    Neurons and certain kinds of endocrine cells, such as adrenal chromaffin cells, have large dense-core vesicles (LDCVs) and synaptic vesicles or synaptic-like microvesicles (SLMVs). These secretory vesicles exhibit differences in Ca(2+) sensitivity and contain diverse signaling substances. The present work was undertaken to identify the synaptotagmin (Syt) isoforms present in secretory vesicles. Fractionation analysis of lysates of the bovine adrenal medulla and immunocytochemistry in rat chromaffin cells indicated that Syt 1 was localized in LDCVs and SLMVs, whereas Syt 7 was the predominant isoform present in LDCVs. In contrast to PC12 cells and the pancreatic β cell line INS-1, Syt 9 was not immunodetected in LDCVs in rat chromaffin cells. Double-staining revealed that Syt 9-like immunoreactivity was nearly identical with fluorescent thapsigargin binding, suggesting the presence of Syt 9 in the endoplasmic reticulum (ER).The exogenous expression of Syt 1-GFP in INS-1 cells, which had a negligible level of endogenous Syt 1, resulted in an increase in the amount of Syt 9 in the ER, suggesting that Syt 9 competes with Syt 1 for trafficking from the ER to the Golgi complex. We conclude that LDCVs mainly contain Syt 7, whereas SLMVs contain Syt 1, but not Syt 7, in rat and bovine chromaffin cells.

  1. Enhanced BDNF signalling following chronic hypoxia potentiates catecholamine release from cultured rat adrenal chromaffin cells

    PubMed Central

    Scott, Angela L; Zhang, Min; Nurse, Colin A

    2015-01-01

    Environmental stressors, including chronic hypoxia, enhance the ability of adrenomedullary chromaffin cells (AMCs) to secrete catecholamines; however, the underlying molecular mechanisms remain unclear. Here, we investigated the role of brain-derived neurotrophic factor (BDNF) signalling in rat AMCs exposed to chronic hypoxia. In rat adrenal glands, BDNF and its tropomyosin-related kinase B (TrkB) receptor are highly expressed in the cortex and medulla, respectively. Exposure of AMCs to chronic hypoxia (2% O2; 48 h) in vitro caused a significant increase to TrkB mRNA expression. A similar increase was observed in an immortalized chromaffin cell line (MAH cells); however, it was absent in MAH cells deficient in the transcription factor HIF-2α. A specific TrkB agonist, 7,8-dihydroxyflavone (7,8-DHF), stimulated quantal catecholamine secretion from chronically hypoxic (CHox; 2% O2) AMCs to a greater extent than normoxic (Nox; 21% O2) controls. Activation of TrkB by BDNF or 7,8-DHF increased intracellular Ca2+ ([Ca2+]i), an effect that was significantly larger in CHox cells. The 7,8-DHF-induced [Ca2+]i rise was sensitive to the tyrosine kinase inhibitor K252a and nickel (2 mm), but not the Ca2+ store-depleting agent cyclopiazonic acid. Blockade of T-type calcium channels with TTA-P2 (1 μm) or voltage-gated Na+ channels with TTX inhibited BDNF-induced [Ca2+]i increases. BDNF also induced a dose-dependent enhancement of action potential firing in CHox cells. These data demonstrate that during chronic hypoxia, enhancement of BDNF-TrkB signalling increases voltage-dependent Ca2+ influx and catecholamine secretion in chromaffin cells, and that T-type Ca2+ channels play a key role in the signalling pathway. Key points We investigated the role of the neurotrophin BDNF signalling via the TrkB receptor in rat adrenomedullary chromaffin cells (AMCs) exposed to normoxia (Nox; 21% O2) and chronic hypoxia (CHox; 2% O2) in vitro for ∼48 h. TrkB receptor expression was

  2. Effect of weightlessness on sympathetic-adrenomedullary activity of rats

    NASA Astrophysics Data System (ADS)

    Kvetňanský, R.; Torda, T.; Macho, L.; Tigranian, R. A.; Serova, L.; Genin, A. M.

    Three cosmic experiments were performed in which rats spent 18-20 days in space on board the biosatellites "COSMOS 782", "COSMOS 936" and "COSMOS 1129". The following indicators of the sympathetic-adrenomedullary system (SAS) activity were measured: tissue and plasma catecholamines (CA), CA-synthesizing enzymes—tyrosine hydroxylase (TH), dopamine-β-hydroxylase (DBH), phenylethanolamine-N-methyltransferase (PNMT)—as well as CA-degrading enzymes—monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). Adrenal epinephrine (EPI) and norepinephrine (NE) as well as CA-synthesizing and degrading enzymes were not significantly changed in the animals after flight on COSMOS 782. On the other hand, a significant increase was found in heart CA, the indicator which is usually decreased after stress. 26 days after landing all values were at control levels. The results obtained, compared to our previous stress experiments on Earth, suggest that prolonged weightlessness does not appear to be a pronounced stressful stimulus for the SAS. Heart and plasma CA, mainly NE, were increased both in the group living in the state of weightlessness and the group living in a centrifuge and exposed to artificial gravitation 1 g (COSMOS 936), suggesting again that prolonged weightlessness is not an intensive stressful stimulus for the SAS. The animals exposed after space flight on COSMOS 1129 to repeated immobilization stress on Earth showed a significant decrease of adrenal EPI and an expressive increase of adrenal TH activity compared to stressed animals which were not in space. Thus, the results corroborate that prolonged state of weightlessness during space flight though not representing by itself an intensive stressful stimulus for the sympathetic-adrenomedullary system, was found to potentiate the response of "cosmic rats" to stress exposure after return to Earth.

  3. Ultrastructural evidence of a vesicle-mediated mode of cell degranulation in chicken chromaffin cells during the late phase of embryonic development

    PubMed Central

    Crivellato, Enrico; Nico, Beatrice; Travan, Luciana; Isola, Miriam; Ribatti, Domenico

    2009-01-01

    In the present investigation, we attempted to determine whether ultrastructural features indicative of a vesicle-mediated mode of cell secretion were detectable in chick chromaffin cells during embryo development. The adrenal anlagen of domestic fowls were examined at embryonic days (E) 12, 15, 19 and 21 by electron microscopy quantitative analysis. Morphometric evaluation revealed a series of granule and cytoplasmic changes highly specific for piecemeal degranulation (PMD), a secretory process based on vesicular transport of cargoes from within granules for extracellular release. At E19 and E21 we found a significant peak in the percentage of granules exhibiting changes indicative of progressive release of secretory materials, i.e. granules with lucent areas in their cores, reduced electron density, disassembled matrices, residual cores and membrane empty containers. A dramatic raise in the density of 30–80-nm-diameter, membrane-bound, electron-dense and electron-lucent vesicles – which were located either next to granules or close to the plasma membrane – was recognizable at E19, that is, during the prehatching phase. The cytoplasmic burst of dense and clear vesicles was paralleled by the appearance of chromaffin granules showing outpouches or protrusions of their profiles (‘budding features’). These ultrastructural data are indicative of an augmented vesicle-mediated transport of chromaffin granule products for extracellular release in chick embryo chromaffin cells during the prehatching stage. In conclusion, this study provides new data on the fine structure of chromaffin cell organelles during organ development and suggests that PMD may be part of an adrenomedullary secretory response that occurs towards the end of chicken embryogenesis. From an evolutionary point of view, this study lends support to the concept that PMD is a secretory mechanism highly conserved throughout vertebrate classes. PMID:19245498

  4. Dotarizine versus flunarizine as calcium antagonists in chromaffin cells.

    PubMed Central

    Villarroya, M; Gandía, L; Lara, B; Albillos, A; López, M G; García, A G

    1995-01-01

    1. Dotarizine is a novel piperazine derivative structurally related to flunarizine that is currently being evaluated in clinical trials for its antimigraine and antivertigo effects. This clinical profile may be related to its Ca2+ antagonist properties. Therefore, the actions of both compounds as calcium antagonists were compared in bovine chromaffin cells. 2. Dotarizine and flunarizine blocked 45Ca2+ uptake into K+ depolarized chromaffin cells (70 mM K+/0.5 mM Ca2+ for 60 s) in a concentration-dependent manner, with IC50s of 4.8 and 6.7 microM, respectively. 3. Dotarizine and flunarizine also inhibited the whole-cell Ca2+ and Ba2+ currents (ICa, IBa) in voltage-clamped chromaffin cells, induced by depolarizing test pulses to 0 mV, during 50 ms, from a holding potential of -80 mV. Blockade exhibited IC50s of 4 microM for dotarizine and 2.2 microM for flunarizine. Dotarizine increased the rate of inactivation of ICa and IBa; inhibition of whole-cell currents was use-dependent. 4. Transient increases of the cytosolic Ca2+ concentration, [Ca2+]i, produced by K+ stimulation (70 mM K+ for 5 s) of single fura-2-loaded chromaffin cells, were also inhibited by dotarizine and flunarizine with IC50s of 1.2 and 0.6 microM, respectively. Upon washout of dotarizine, the [Ca2+]i increases recovered fully after 5-10 min. In contrast, the responses remained largely inhibited 10 min after washing out flunarizine. 5. Catecholamine release induced by K+ stimulation (10-s pulses of 70 mM) was inhibited by dotarizine with an IC50 of 2.6 microM and by flunarizine with an IC50 of 1.2 microM. The blocking effects of both compounds developed slowly, and was fully established after 20-30 min of superfusion.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7881736

  5. Ontogeny of O2 and CO2//H+ chemosensitivity in adrenal chromaffin cells: role of innervation.

    PubMed

    Salman, Shaima; Buttigieg, Josef; Nurse, Colin A

    2014-03-01

    The adrenal medulla plays a key role in the physiological responses of developing and mature mammals by releasing catecholamines (CAT) during stress. In rodents and humans, the innervation of CAT-producing, adrenomedullary chromaffin cells (AMCs) is immature or absent during early postnatal life, when these cells possess 'direct' hypoxia- and CO2/H(+)-chemosensing mechanisms. During asphyxial stressors at birth, these mechanisms contribute to a CAT surge that is critical for adaptation to extra-uterine life. These direct chemosensing mechanisms regress postnatally, in parallel with maturation of splanchnic innervation. Here, we review the evidence that neurotransmitters released from the splanchnic nerve during innervation activate signaling cascades that ultimately cause regression of direct AMC chemosensitivity to hypoxia and hypercapnia. In particular, we consider the roles of cholinergic and opioid receptor signaling, given that splanchnic nerves release acetylcholine and opiate peptides onto their respective postsynaptic nicotinic and opioid receptors on AMCs. Recent in vivo and in vitro studies in the rat suggest that interactions involving α7 nicotinic acetylcholine receptors (nAChRs), the hypoxia inducible factor (HIF)-2α signaling pathway, protein kinases and ATP-sensitive K(+) (KATP) channels contribute to the selective suppression of hypoxic chemosensitivity. In contrast, interactions involving μ- and/or δ-opiod receptor signaling pathways contribute to the suppression of both hypoxic and hypercapnic chemosensitivity, via regulation of the expression of KATP channels and carbonic anhydrase (CA I and II), respectively. These data suggest that the ontogeny of O2 and CO2/H(+) chemosensitivity in chromaffin cells can be regulated by the tonic release of presynaptic neurotransmitters.

  6. Neonatal intermittent hypoxia impairs neuronal nicotinic receptor expression and function in adrenal chromaffin cells

    PubMed Central

    Souvannakitti, Dangjai; Kuri, Barbara; Yuan, Guoxiang; Pawar, Anita; Kumar, Ganesh K.; Smith, Corey; Fox, Aaron P.

    2010-01-01

    We recently reported that adrenomedullary chromaffin cells (AMC) from neonatal rats treated with intermittent hypoxia (IH) exhibit enhanced catecholamine secretion by hypoxia (Souvannakitti D, Kumar GK, Fox A, Prabhakar NR. J Neurophysiol 101: 2837–2846, 2009). In the present study, we examined whether neonatal IH also facilitate AMC responses to nicotine, a potent stimulus to chromaffin cells. Experiments were performed on rats exposed to either IH (15-s hypoxia-5-min normoxia; 8 h/day) or to room air (normoxia; controls) from ages postnatal day 0 (P0) to P5. Quantitative RT-PCR analysis revealed expression of mRNAs encoding α3-, α5-, α7-, and β2- and β4-nicotinic acetylcholine receptor (nAChR) subunits in adrenal medullae from control P5 rats. Nicotine-elevated intracellular Ca2+ concentration ([Ca2+]i) in AMC and nAChR antagonists prevented this response, suggesting that nAChRs are functional in neonatal AMC. In IH-treated rats, nAChR mRNAs were downregulated in AMC, which resulted in a markedly attenuated nicotine-evoked elevation in [Ca2+]i and subsequent catecholamine secretion. Systemic administration of antioxidant prevented IH-evoked downregulation of nAChR expression and function. P35 rats treated with neonatal IH exhibited reduced nAChR mRNA expression in adrenal medullae, attenuated AMC responses to nicotine, and impaired neurogenic catecholamine secretion. Thus the response to neonatal IH lasts for at least 30 days. These observations demonstrate that neonatal IH downregulates nAChR expression and function in AMC via reactive oxygen species signaling, and the effects of neonatal IH persist at least into juvenile life, leading to impaired neurogenic catecholamine secretion from AMC. PMID:20664070

  7. Insulin-like growth factor I enhances proenkephalin synthesis and dopamine. beta. -hydroxylase activity in adrenal chromaffin cells

    SciTech Connect

    Wilson, S.P. )

    1991-01-01

    Insulin-like growth factor I (IGF-I) increased both the contents of proenkephalin derived enkephalin-containing peptides and the activity of dopamine {beta}-hydroxylase in bovine adrenal chromaffin cells. These increases in dopamine {beta}-hydroxylase and enkephalin-containing peptides continued for at least 8 days. The half-maximal IGF-I concentration for these effects was {approximately} 1 nM, with maximal effects observed at 10-30 nM. In contrast, insulin was 1,000-fold less potent. Pretreatment of chromaffin cells with IGF-I increased the rate of ({sup 35}S)proenkephalin synthesis 4-fold compared to untreated cells. Total protein synthesis increased only 1.5-fold under these conditions. These results suggest that IGF-I may be a normal regulator of chromaffin cell function.

  8. Adrenomedullary response to hypoglycemia in first-degree relatives of patients with rheumatoid arthritis.

    PubMed

    Rovensky, J; Imrich, R; Penesova, A; Radikova, Z; Scipova, A; Vlcek, M; Vigas, M

    2008-12-01

    Our recent studies showed blunted adrenomedullary responses to insulin-induced hypoglycemia in premenopausal females with rheumatoid arthritis (RA) and systemic sclerosis, suggesting dysregulation of the adrenomedullary hormonal system (AMHS). Since no relationship has been found between degree of AMHS dysfunction and clinical or inflammatory parameters in those patients, we hypothesize the presence of an inherited perturbation of the AMHS. To test this hypothesis, we evaluated adrenomedullary responses to insulin-induced hypoglycemia (0.1 IU/kg) in premenopausal female subjects: 17 glucocorticoid-naïve RA patients, 15 healthy first-degree family members (FDR), and 18 age- and body mass index-matched healthy controls. Our results demonstrate that when compared to controls, RA patients had lower baseline epinephrine levels (P= 0.01) and lower area under response curve (AUC) levels of norepinephrine (P < 0.001) and epinephrine (P < 0.003). In contrast, FDR had lower (P= 0.001) AUC levels of norepinephrine compared to controls and higher (P= 0.033) AUC levels of epinephrine compared to RA patients. There were no significant differences in epinephrine response between FDR and controls. Although we found lower norepinephrine responses to hypoglycemia in FDR of RA patients, adrenomedullary responses to hypoglycemia does not appear to be altered to the degree found in RA patients.

  9. Biological amine transport in chromaffin ghosts. Coupling to the transmembrane proton and potential gradients.

    PubMed

    Johnson, R G; Pfister, D; Carty, S E; Scarpa, A

    1979-11-10

    The effect of the transmembrane proton gradient (delta pH) and potential gradient (delta psi) upon the rate and extent of amine accumulation was investigated in chromaffin ghosts. The chromaffin ghosts were formed by hypo-osmotic lysis of isolated bovine chromaffin granules and extensive dialysis in order to remove intragranular binding components and dissipate the endogenous electrochemical gradients. Upon ATP addition to suspensions of chromaffin ghosts, a transmembrane proton gradient alone, a transmembrane gradient alone, or both, could be established, depending upon the compositions of the media in which the ghosts were formed and resuspended. When chloride was present in the medium, addition of ATP resulted in the generation of a transmembrane proton gradient, acidic inside of 1 pH unit (measured by [14C]methylamine distribution), and no transmembrane potential (measured by [14C]-thiocyanate distribution). When ATP was added to chromaffin ghosts suspended in a medium in which chloride was substituted by isethionate, a transmembrane potential, inside positive, of 45 mV and no transmembrane proton gradient, was measured. In each medium, the addition of agents known to affect proton or potential gradients, respectively, exerted a predictable mechanism of action. Accumulation of [14C]epinephrine or [14C]5-hydroxytryptamine was over 1 order of magnitude greater in the presence of the transmembrane proton gradient or the transmembrane potential than in the absence of any gradient and, moreover, was related to the magnitude of the proton or potential gradient in a dose-dependent manner. When ghosts were added to a medium containing chloride and isethionate, both a delta pH and delta psi could be generated upon addition of ATP. In this preparation, the maximal rate of amine accumulation was observed. The results indicate that amine accumulation into chromaffin ghosts can occur in the presence of either a transmembrane proton gradient, or a transmembrane potential

  10. Isolation of neural crest derived chromaffin progenitors from adult adrenal medulla.

    PubMed

    Chung, Kuei-Fang; Sicard, Flavie; Vukicevic, Vladimir; Hermann, Andreas; Storch, Alexander; Huttner, Wieland B; Bornstein, Stefan R; Ehrhart-Bornstein, Monika

    2009-10-01

    Chromaffin cells of the adrenal medulla are neural crest-derived cells of the sympathoadrenal lineage. Unlike the closely-related sympathetic neurons, a subpopulation of proliferation-competent cells exists even in the adult. Here, we describe the isolation, expansion, and in vitro characterization of proliferation-competent progenitor cells from the bovine adrenal medulla. Similar to neurospheres, these cells, when prevented from adherence to the culture dish, grew in spheres, which we named chromospheres. These chromospheres were devoid of mRNA specific for smooth muscle cells (MYH11) or endothelial cells (PECAM1). During sphere formation, markers for differentiated chromaffin cells, such as phenylethanolamine-N-methyl transferase, were downregulated while neural progenitor markers nestin, vimentin, musashi 1, and nerve growth factor receptor, as well as markers of neural crest progenitor cells such as Sox1 and Sox9, were upregulated. Clonal analysis and bromo-2'-deoxyuridine-incorporation analysis demonstrated the self-renewing capacity of chromosphere cells. Differentiation protocols using NGF and BMP4 or dexamethasone induced neuronal or endocrine differentiation, respectively. Electrophysiological analyses of neural cells derived from chromospheres revealed functional properties of mature nerve cells, such as tetrodotoxin-sensitive sodium channels and action potentials. Our study provides evidence that proliferation and differentiation competent chromaffin progenitor cells can be isolated from adult adrenal medulla and that these cells might harbor the potential for the treatment of neurodegenerative diseases, such as Parkinson's disease.

  11. Adrenomedullary hormonal and glycemic modulation following gonadotropin and sex hormone administration in the soft-shelled turtle Lissemys punctata punctata.

    PubMed

    Ray, Prajna Paramita; Chaudhuri, Santasri; Maiti, B R

    2002-01-01

    The aim of the current investigation was to ascertain whether gonadotropins and sex hormones can modulate adrenomedullary and glycemic functions in turtles. Exogenous FSH (3.0 microg/100 gm body wt daily for 10 days) stimulated adrenomedullary activity by increasing nuclear diameter and cytoplasmic degranulation, and elevating adrenal norepinephrine and epinephrine, and blood glycemic levels in turtles. LH (3.0 microg/100 gm body wt daily for 10 days) had no significant effect and the combined treatment of FSH and LH (3.0 microg each/100 gm body wt daily for 10 days) failed to show further adrenomedullary stimulation and hyperglycemia beyond that of FSH alone. Estrogen treatment in low dose (25 microg/100 gm body wt daily for 10 days) had no significant effect on adrenomedullary activity or glycemia, but at higher doses (50 microg or 100 microg/100 gm body wt daily for 10 days) showed dose-dependent adrenomedullary stimulation by inducing the same manifestations as those of FSH. Progesterone in low dose (25 microg/100 gm body wt daily for 10 days) had no perceptible effect, but in other doses (50 microg/100 microg per 100 gm body wt daily for 10 days), suppressed dose-dependent adrenomedullary activity by reversing the changes to those of estrogen. Simultaneous treatment with estrogen and progesterone (50 microg each/100 gm body wt daily for 10 days) failed to show further changes beyond that of estrogen alone.

  12. Adrenomedullary progenitor cells: Isolation and characterization of a multi-potent progenitor cell population.

    PubMed

    Vukicevic, Vladimir; Rubin de Celis, Maria Fernandez; Pellegata, Natalia S; Bornstein, Stefan R; Androutsellis-Theotokis, Andreas; Ehrhart-Bornstein, Monika

    2015-06-15

    The adrenal is a highly plastic organ with the ability to adjust to physiological needs by adapting hormone production but also by generating and regenerating both adrenocortical and adrenomedullary tissue. It is now apparent that many adult tissues maintain stem and progenitor cells that contribute to their maintenance and adaptation. Research from the last years has proven the existence of stem and progenitor cells also in the adult adrenal medulla throughout life. These cells maintain some neural crest properties and have the potential to differentiate to the endocrine and neural lineages. In this article, we discuss the evidence for the existence of adrenomedullary multi potent progenitor cells, their isolation and characterization, their differentiation potential as well as their clinical potential in transplantation therapies but also in pathophysiology.

  13. Adrenomedullary Response to Glucagon in Patients with Primary Sjögren’s Syndrome

    PubMed Central

    Imrich, Richard; Nikolov, Nikolay P.; Bebris, Lolita; Alevizos, Ilias; Goldstein, David S.; Holmes, Courtney S.; Illei, Gabor G.

    2012-01-01

    Several studies showed signs of autonomic dysfunction in patients with primary Sjögren's syndrome (pSS). Adrenomedullary function might be of importance for pSS pathogenesis by affecting salivary gland functions and modulating immune responses. The aim of the study was to evaluate the adrenomedullary hormonal system in patients with pSS. The glucagon test (1 mg i.v.) was performed in 18 pSS patients and 13 control subjects. During the testing each patient had electrocardiographic and impedance cardiographic monitoring. Plasma epinephrine and norepinephrine were assayed by liquid chromatography with electrochemical detection after batch alumina extraction. Baseline concentrations of epinephrine and norepinephrine were comparable between pSS and controls. Glucagon administration induced a significant increase in systolic blood pressure, diastolic blood pressure, heart rate, cardiac output (p < 0.01), stroke volume; however the changes were comparable between pSS and controls. Epinephrine levels increased (p < 0.01) in response to glucagon administration while norepinephrine concentration did not change. There was no significant difference in neurochemical responses to glucagon between pSS and controls. In conclusion, the present results suggest normal adrenomedullary function in pSS. PMID:22350211

  14. Passive ion permeability of the chromaffin-granule membrane.

    PubMed

    Phillips, J H

    1977-11-15

    'Ghosts' of bovine chromaffin granules, in which the complex mixture of proteins and solutes normally found in the granule matrix is replaced by buffered sucrose are osmotically sensitive. They shrink when the osmotic pressure of the suspension medium is increased, and swell if solute entry is facilitated by the addition of ionophores. Swelling in the presence of ionophores has been used to investigate the passive ion permeability of these membranes. They have a very low permeability to K+ ions (of the order of 10(-10) cm/s); their permeability to protons, Na+ and choline ions is too low to be detected by these methods. Their passive permeability to anions decreases in the order: CNS- greater than I- greater than CCl3CO2- greater than Br- greater than Cl- greater than SO4(2)- greater than CH3CO2-, HCO3-, F-, PO4(3)- the permeability to hiocyanate being of the order of 10(-7) cm/s. Coupled proton and anion entry is extremely slow, except for weak acids. Fluoride, unexpectedly, also appears to enter rapidly when proton/K+ exchange is facilitated by nigericin. In the presence of K+ salts, nigericin, like valinomycin, induces lysis of intact granules, an effect that is not dependent on the presence of a permeant anion, but is dependent on the pH gradient across the membrane.

  15. Adrenomedullary hormonal and glycemic responses to high ambient temperature in the soft-shelled turtle, Lissemys punctata punctata.

    PubMed

    Ray, P P; Maiti, B R

    2001-04-01

    The aim of the investigation was to study the influence of high ambient temperature on adrenomedullary activity and blood glucose levels in adult female soft-shelled turtles (Lissemys punctata punctata). Experiments were carried out at 25 degrees, 35 degrees, and 38 degrees, and one group was exposed to 38 degrees for 15 days and then maintained at 25 degrees for another 15 days. Exposure to a low ambient temperature of 25 degrees had no clear effect on adrenomedullary function with respect to histology (nuclear diameter), epinephrine and norepinephrine concentrations, and blood glucose level of turtles, but higher temperatures of 35 degrees and 38 degrees stimulated adrenomedullary activity as well as blood glucose level in turtles compared with controls (30 degrees ). The extent of these changes was greater at 38 degrees than that at 35 degrees, and withdrawal from high ambient temperature reversed the effect in turtles. Copyright 2001 Academic Press.

  16. Tensile Strength of the Chromaffin Granule Membrane

    PubMed Central

    Hiram, Yael; Nir, Avinoam; Zinder, Oren

    1982-01-01

    Catecholamine release from chromaffin granules, suspended in sucrose solutions of various osmotic strengths, was determined at different temperatures between 2° and 44°C. Dynamic measurements showed that steady state is achieved within 15 min of incubation at all temperatures. The effect of temperature on the release was established in terms of the median granular fragility (MGF) defined as the concentration of sucrose solution causing 50% lysis. The MGF was determined as the inflection point of the Gaussian distribution of granular fragility. The MGF was found to decrease with fall in temperature implying a corresponding increase of the tensile strength of the vesicle membrane. Critical resultant forces at lysis were calculated and found to vary from 8.2 dyn/cm at 2°C to 4.2 dyn/cm at 44°C. These compare well with tensions at lysis found earlier for erythrocytes. PMID:7104452

  17. The organization of the secretory machinery in chromaffin cells as a major factor in modeling exocytosis

    PubMed Central

    Villanueva, José; Torregrosa-Hetland, Cristina J.; Gil, Amparo; González-Vélez, Virginia; Segura, Javier; Viniegra, Salvador; Gutiérrez, Luis M.

    2010-01-01

    The organization of cytoplasm in excitable cells was a largely ignored factor when mathematical models were developed to understand intracellular calcium and secretory behavior. Here we employed a combination of fluorescent evanescent and transmitted light microscopy to explore the F-actin cytoskeletal organization in the vicinity of secretory sites in cultured bovine chromaffin cells. This technique and confocal fluorescent microscopy show chromaffin granules associated with the borders of cortical cytoskeletal cages forming an intricate tridimensional network. Furthermore, the overexpression of SNAP-25 in these cells also reveals the association of secretory machinery clusters with the borders of these cytoskeletal cages. The importance of these F-actin cage borders is stressed when granules appear to interact and remain associated during exocytosis visualized in acridin orange loaded vesicles. These results will prompt us to propose a model of cytoskeletal cages, where the secretory machinery is associated with its borders. Both the calcium level and the secretory response are enhanced in this geometrical arrangement when compared with a random distribution of the secretory machinery that is not restricted to the borders of the cage. PMID:20885775

  18. A cell-semiconductor synapse: transistor recording of vesicle release in chromaffin cells.

    PubMed

    Lichtenberger, Janosch; Fromherz, Peter

    2007-03-15

    The release of dense-core vesicles in bovine chromaffin cells is a model for the presynaptic process in neurons. It is usually studied by microamperometry of catecholamines with carbon fibers. Here we introduce transistor recording as a tool to study vesicle release. When we stimulate a chromaffin cell placed on a field-effect transistor, the gate voltage exhibits peaks that correlate with a simultaneously performed amperometric recording. We attribute the transistor signal to a release of protons from the extruded matrix of vesicles that lowers the extracellular pH and changes the electrical surface potential of the gate oxide. The rise time of the transistor signals is similar to that of amperometric responses, whereas their duration is distinctly longer. In a model computation, the rise time is identified with the extrusion of vesicle matrix into the narrow extracellular space between cell and gate oxide, and the decay time is attributed to pH equilibration through slow diffusion in the extruded matrix. Because the transistor recording relies on protons, it can be applied to acidic vesicles with electrochemically inactive hormones or transmitters.

  19. A Cell-Semiconductor Synapse: Transistor Recording of Vesicle Release in Chromaffin Cells

    PubMed Central

    Lichtenberger, Janosch; Fromherz, Peter

    2007-01-01

    The release of dense-core vesicles in bovine chromaffin cells is a model for the presynaptic process in neurons. It is usually studied by microamperometry of catecholamines with carbon fibers. Here we introduce transistor recording as a tool to study vesicle release. When we stimulate a chromaffin cell placed on a field-effect transistor, the gate voltage exhibits peaks that correlate with a simultaneously performed amperometric recording. We attribute the transistor signal to a release of protons from the extruded matrix of vesicles that lowers the extracellular pH and changes the electrical surface potential of the gate oxide. The rise time of the transistor signals is similar to that of amperometric responses, whereas their duration is distinctly longer. In a model computation, the rise time is identified with the extrusion of vesicle matrix into the narrow extracellular space between cell and gate oxide, and the decay time is attributed to pH equilibration through slow diffusion in the extruded matrix. Because the transistor recording relies on protons, it can be applied to acidic vesicles with electrochemically inactive hormones or transmitters. PMID:17189317

  20. Role of a transmembrane pH gradient in epinephrine transport by chromaffin granule membrane vesicles.

    PubMed

    Schuldiner, S; Fishkes, H; Kanner, B I

    1978-08-01

    ATP-driven transport and accumulation of epinephrine in chromaffin granule membrane vesicles isolated from bovine adrenal medulla is inhibited by the proton ionophores carbonylcyanide p-trifluoromethoxyphenylhydrazone and nigericin, but not by valinomycin. Moreover, an artificially imposed pH gradient (interior acid) is able to drive this reserpine-sensitive transport system in the absence of ATP. Dicyclohexylcarbodiimide, an inactivator of the chromaffin granule membrane-bound ATPase, completely inhibits ATP-dependent epinephrine accumulation, but has much less effect when an imposed pH gradient is the driving force for epinephrine transport. The findings provide a strong indication that a pH gradient (interior acid) is the immediate driving force for epinephrine uptake in these storage granules and suggest that ATP-driven epinephrine transport is the result of two processes: (i) generation of a proton electrochemical gradient (interior acid and positive) by the membrane-bound, proton-translocating ATPase; and (ii) pH gradient-driven accumulation of the catecholamine.

  1. Role of a transmembrane pH gradient in epinephrine transport by chromaffin granule membrane vesicles.

    PubMed Central

    Schuldiner, S; Fishkes, H; Kanner, B I

    1978-01-01

    ATP-driven transport and accumulation of epinephrine in chromaffin granule membrane vesicles isolated from bovine adrenal medulla is inhibited by the proton ionophores carbonylcyanide p-trifluoromethoxyphenylhydrazone and nigericin, but not by valinomycin. Moreover, an artificially imposed pH gradient (interior acid) is able to drive this reserpine-sensitive transport system in the absence of ATP. Dicyclohexylcarbodiimide, an inactivator of the chromaffin granule membrane-bound ATPase, completely inhibits ATP-dependent epinephrine accumulation, but has much less effect when an imposed pH gradient is the driving force for epinephrine transport. The findings provide a strong indication that a pH gradient (interior acid) is the immediate driving force for epinephrine uptake in these storage granules and suggest that ATP-driven epinephrine transport is the result of two processes: (i) generation of a proton electrochemical gradient (interior acid and positive) by the membrane-bound, proton-translocating ATPase; and (ii) pH gradient-driven accumulation of the catecholamine. PMID:29292

  2. Uptake of [3H]-nicotine and [3H]-noradrenaline by cultured chromaffin cells.

    PubMed Central

    Ceña, V.; García, A. G.; Montiel, C.; Sánchez-García, P.

    1984-01-01

    Three day-old cultured bovine adrenal chromaffin cells incubated at room temperature with Krebs-HEPES solution containing different concentrations of [3H]-nicotine, took up and retained increasing amounts of the drug by a mechanism that did not saturate. Concentrations of cold nicotine as high as 100 microM did not alter the amount of [3H]-nicotine retained by cells. Imipramine, cocaine, tetracaine or mecamylamine, at concentrations (10 microM) that blocked the catecholamine secretory effects of nicotine completely, did not modify the uptake of [3H]-nicotine. Both imipramine and cocaine drastically inhibited [3H]-noradrenaline uptake by cells in a concentration-dependent manner (IC50S of 0.08 and 1 microM, respectively). These data indicate that the secretory effects of nicotine are not coupled to its previous uptake into cells, and are evidence in favour of a site of action for nicotine located in or at the surface of the chromaffin cell membrane. PMID:6704577

  3. Computing the chromaffin cell: a research-community curator/user approach to biocomputation for chromaffin cell biology.

    PubMed

    Eiden, Lee E; Hirsch, Michael D

    2002-10-01

    Exocytosis, stimulus-secretion coupling, real-time measurements of neurosecretion, and stimulus-secretion-synthesis coupling (stimulus-transcription coupling) were all initially proposed and verified in the chromaffin cell. Detailed analysis of the molecules and pathways responsible for secretion and transsynaptic regulation of gene expression patterns in neuroendoccrine cells have been very fruitfully explored in chromaffin cells and the related PC12 pheochromocytoma cell line, using modern molecular biologcal, cellular imaging, and expression profiling techniques. The time is clearly at hand for a concerted bioinformatics approach to acquiring and synthesizing electrophysiological, biochemical, and proteomic/genomic data on the chromaffin cell. Accelerating this process will fully realize the unique attributes of the chromaffin cell as a homogeneous, accessible, fully functional model of the posttmitotic neuroendocrine cell.

  4. Activity of the sympathetic-adrenomedullary system in rats after space flight on the COSMOS biosatellites

    NASA Astrophysics Data System (ADS)

    Kvetňanský, R.; Vigaš, M.; Németh, Š.; Macho, L.; Tigranyan, R. A.

    The indicators of adrenomedullary activity (catecholamine content (CA) and the activity of the catecholamine-synthesizing enzymes tyrosine hydroxylase (TH) and dopamine-β-hydroxylase (DBH)) were measured in the adrenal glands of rats living in a state of weightlessness for 18.5-19.5 days on board the biosatellites COSMOS 936 and COSMOS 1129. None of these indicators was significantly changed by space flight, neither in the group living in a state of weightlessness nor in the group living in a centrifuge on board the spacecraft and exposed to artificial gravity of 1 g (COSMOS 936). Animals exposed after space flight to repeated immobilization stress on Earth showed a significant decrease of adrenal adrenaline and an appreciable increase in adrenal TH activity compared to stressed animals which were not in space. These results suggest that a prolonged state of weightlessness during space flight does not by itself represent an intensive stressful stimulus for the adrenomedullary system but potentiates the response of cosmonauts to stress after return to Earth.

  5. Studies on the adrenomedullary dependence of kappa-opioid agonist-induced diuresis in conscious rats.

    PubMed Central

    Borkowski, K. R.

    1989-01-01

    1. The dependence of kappa-opioid agonist-induced diuresis, upon an intact and functional adrenal medulla in conscious rats, was investigated in order to test the hypothesis that the diuresis is mediated by a blood-borne 'diuretic factor', of adrenomedullary origin, released by kappa-opioid receptor stimulation. 2. Confirming previous observations, adrenal demedullation significantly attenuated diuretic responses to the kappa-opioid agonists U50488H, ethylketocyclazocine (EKC) and tifluadom, but did not affect basal urine output, furosemide-induced diuresis or the antidiuretic response to the mu-opioid agonist, buprenorphine. Naloxone abolished U50488H-induced diuresis, confirming an involvement of opioid receptors. 3. Transfusion studies established that blood, from intact rats treated with U50488H, induced diuresis in intact and demedullated recipient rats, whether or not the recipients had been pretreated with naloxone. However, blood from demedullated rats treated with U50448H was unable to induce diuresis when administered to intact or demedullated recipients. 4. It is concluded that kappa-opioid agonist-induced diuresis is dependent upon an intact and functional adrenal medulla and appears to be mediated by a blood-borne 'diuretic factor' of adrenomedullary origin. PMID:2558758

  6. A major role for calcium-dependent potassium current in action potential repolarization in adrenal chromaffin cells.

    PubMed

    Pancrazio, J J; Johnson, P A; Lynch, C

    1994-12-30

    To determine the extent which Ca dependent K current (IKCa) contributes during an action potential (AP), bovine chromaffin cells were voltage-clamped using a pre-recorded AP as the command voltage waveform. Based on (1) differential sensitivity of IKCa and Ca-independent K current (IK) to tetraethylammonium; (2) measurements of AP currents under conditions where Ca activation of IKCa had been abolished; and (3) blockade by charybdotoxin, IKCa comprised 70-90% of the outward K current during AP repolarization. In addition, observations are made concerning the form of AP-evoked Ca current.

  7. Unmasking the functions of the chromaffin cell α7 nicotinic receptor by using short pulses of acetylcholine and selective blockers

    PubMed Central

    López, Manuela G.; Montiel, Carmen; Herrero, Carlos J.; García-Palomero, Esther; Mayorgas, Inés; Hernández-Guijo, Jesús M.; Villarroya, M.; Olivares, Román; Gandía, Luis; McIntosh, J. Michael; Olivera, Baldomero M.; García, Antonio G.

    1998-01-01

    Methyllycaconitine (MLA), α-conotoxin ImI, and α-bungarotoxin inhibited the release of catecholamines triggered by brief pulses of acetylcholine (ACh) (100 μM, 5 s) applied to fast-superfused bovine adrenal chromaffin cells, with IC50s of 100 nM for MLA and 300 nM for α-conotoxin ImI and α-bungarotoxin. MLA (100 nM), α-conotoxin ImI (1 μM), and α-bungarotoxin (1 μM) halved the entry of 45Ca2+ stimulated by 5-s pulses of 300 μM ACh applied to incubated cells. These supramaximal concentrations of α7 nicotinic receptor blockers depressed by 30% (MLA), 25% (α-bungarotoxin), and 50% (α-conotoxin ImI) the inward current generated by 1-s pulses of 100 μM ACh, applied to voltage-clamped chromaffin cells. In Xenopus oocytes expressing rat brain α7 neuronal nicotinic receptor for acetylcholine nAChR, the current generated by 1-s pulses of ACh was blocked by MLA, α-conotoxin ImI, and α-bungarotoxin with IC50s of 0.1 nM, 100 nM, and 1.6 nM, respectively; the current through α3β4 nAChR was unaffected by α-conotoxin ImI and α-bungarotoxin, and weakly blocked by MLA (IC50 = 1 μM). The functions of controlling the electrical activity, the entry of Ca2+, and the ensuing exocytotic response of chromaffin cells were until now exclusively attributed to α3β4 nAChR; the present results constitute the first evidence to support a prominent role of α7 nAChR in controlling such functions, specially under the more physiological conditions used here to stimulate chromaffin cells with brief pulses of ACh. PMID:9826675

  8. PC12 Cells Differentiate into Chromaffin Cell-Like Phenotype in Coculture with Adrenal Medullary Endothelial Cells

    NASA Astrophysics Data System (ADS)

    Mizrachi, Yaffa; Naranjo, Jose R.; Levi, Ben-Zion; Pollard, Harvey B.; Lelkes, Peter I.

    1990-08-01

    Previously we described specific in vitro interactions between PC12 cells, a cloned, catecholamine-secreting pheochromocytoma cell line derived from the rat adrenal medulla, and bovine adrenal medullary endothelial cells. We now demonstrate that these interactions induce the PC12 cells to acquire physical and biochemical characteristics reminiscent of chromaffin cells. Under coculture conditions involving direct cell-cell contact, the endothelial cells and the PC12 cells reduced their rates of proliferation; upon prolonged coculture PC12 cells clustered into nests of cells similar to the organization of chromaffin cells seen in vivo. Within 3 days in coculture with endothelial cells, but not with unrelated control cells, PC12 cells synthesized increased levels of [Met]enkephalin. In addition, PC12 cells, growing on confluent endothelial monolayers, failed to extend neurites in response to nerve growth factor. Neither medium conditioned by endothelial cells nor fixed endothelial cells could by themselves induce all of these different phenomena in the PC12 cells. These results suggest that under coculture conditions PC12 cells change their state of differentiation toward a chromaffin cell-like phenotype. The rapid, transient increase in the expression of the protooncogene c-fos suggests that the mechanism(s) inducing the change in the state of differentiation in PC12 cells in coculture with the endothelial cells may be distinct from that described for the differentiation of PC12 cells--e.g., by glucocorticoids. We propose that similar interactions between endothelial cells and chromaffin cell precursors may occur during embryonic development and that these interactions might be instrumental for the organ-specific differentiation of the adrenal medulla in vivo.

  9. Evidence for a paracrine role of endogenous adrenomedullary galanin in the regulation of glucocorticoid secretion in the rat adrenal gland.

    PubMed

    Andreis, Paola G; Tortorella, Cinzia; Ziolkowska, Agnieska; Spinazzi, Raffaella; Malendowicz, Ludwik K; Neri, Giuliano; Nussdorfer, Gastone G

    2007-03-01

    Previous investigations have shown that rat adrenocortical cells are provided with galanin receptors, and galanin stimulates glucocorticoid secretion from dispersed cells. The present study aimed to clarify the possible role of galanin in the physiological regulation of rat adrenal secretory activity. Reverse transcription-polymerase chain reaction detected galanin mRNA expression in the adrenal medulla, but not in the cortex. Sizeable concentrations of galanin-immunoreactivity were measured by radioimmune assay only in the adrenomedullary tissue. Galanin raised norepinephrine, but not epinephrine, release from adrenomedullary tissue. Galanin immunoneutralization (obtained with concentrations of anti-galanin antibody able to block the galanin glucocorticoid secretagogue effect on dispersed adrenocortical cells) decreased basal corticosterone production from adrenal slices containing adrenomedullary tissue, without affecting that from dispersed adrenocortical cells. The beta-adrenoceptor antagonist l-alprenolol partially prevented galanin-stimulated corticosterone secretion from adrenal slices, without per se altering basal secretion. Taken together, our findings allow us to conclude that endogenous galanin, produced in adrenal medulla, is involved in the regulation of adrenocortical glucocorticoid secretion acting via a two-fold paracrine mechanism: i) direct activation of adrenocortical galanin receptors; and ii) stimulation of adrenomedullary release of catecholamines, which in turn activate beta-adrenoceptors located on adrenocortical cells.

  10. Adrenomedullary and glycemic responses to ACTH, corticosterone, aldosterone, epinephrine and norepinephrine administrations in the soft-shelled turtle.

    PubMed

    Ray, Prajna P; Chaudhuri-Sengupta, S; Maiti, B R

    2004-01-01

    The aim of the current investigation was to ascertain the role of ACTH and adrenal hormones on adrenomedullary and glycemic functions in soft-shelled turtles, Lissemys punctata punctata. All the experiments were carried out on sexually immature animals. Findings revealed that: (1) ACTH administration (0.5 IU/1.0 IU/2.0 IU per 100 g body wt. daily for 10 days) in all doses stimulated adrenomedullary function by increasing medullary cell nuclear diameter with elevations of norepinephrine, epinephrine and blood sugar levels. Only moderate and higher doses (50 microg/100 microg per 100 g body wt. daily for 10 days) of dexamethasone suppressed adrenomedullary activity and blood sugar level by reversing the changes to those of ACTH; the responses were dose-dependent. But these changes were no longer observed after ACTH treatment in dexamethasone (DMS) recipients (DMS: 100 microg/ 100 g body wt daily for the first 10 days and ACTH: 0.5 IU / 100 g body wt daily for the next 10 days); (2) Only moderate and higher doses (50 microg/100 microg per 100 g body wt daily for 10 days) of corticosterone increased adrenomedullary activity and blood sugar level and the responses were also dose-dependent. But aldosterone treatment in all doses (same as for corticosterone) had no significant effect on the adrenal medulla or blood sugar level; (3) Only moderate and higher doses of norepinephrine or epinephrine (same as for corticosterone) caused adrenomedullary atrophy with depletions of norepinephrine and epinephrine levels but elevated the glycemic level. The findings are briefly discussed.

  11. Mapping Organelle Motion Reveals a Vesicular Conveyor Belt Spatially Replenishing Secretory Vesicles in Stimulated Chromaffin Cells

    PubMed Central

    Maucort, Guillaume; Kasula, Ravikiran; Papadopulos, Andreas; Nieminen, Timo A.; Rubinsztein-Dunlop, Halina; Meunier, Frederic A.

    2014-01-01

    How neurosecretory cells spatially adjust their secretory vesicle pools to replenish those that have fused and released their hormonal content is currently unknown. Here we designed a novel set of image analyses to map the probability of tracked organelles undergoing a specific type of movement (free, caged or directed). We then applied our analysis to time-lapse z-stack confocal imaging of secretory vesicles from bovine Chromaffin cells to map the global changes in vesicle motion and directionality occurring upon secretagogue stimulation. We report a defined region abutting the cortical actin network that actively transports secretory vesicles and is dissipated by actin and microtubule depolymerizing drugs. The directionality of this “conveyor belt” towards the cell surface is activated by stimulation. Actin and microtubule networks therefore cooperatively probe the microenvironment to transport secretory vesicles to the periphery, providing a mechanism whereby cells globally adjust their vesicle pools in response to secretagogue stimulation. PMID:24489879

  12. Glucose transporters in isolated chromaffin cells. Effects of insulin and secretagogues.

    PubMed Central

    Delicado, E G; Miras Portugal, M T

    1987-01-01

    1. Isolated chromaffin cells from bovine adrenal medulla were used to study glucose transport in a homogeneous neural tissue. 2. The affinity of glucose transporters was 1.20 +/- 0.52 mM by the infinite-cis technique and 1.02 +/- 0.09 mM by the direct transport experiments. 3. The affinity for 2-deoxyglucose of these transporters was 2.3 mM. 4. The glucose transporters, quantified by [3H]cytochalasin B binding, were 419,532 +/- 120,740 receptors/cell, which corresponds to about 7.2 +/- 2 pmol/mg of protein, with KD = 0.1 microM. 5. High-affinity insulin receptors with KD = 3.95 nM were present at a density of 68,400 +/- 7500 per cell. 6. Insulin and secretagogues increased glucose transport, raising the transporter number at the plasma membrane without changes in the affinity. PMID:2820386

  13. Mapping organelle motion reveals a vesicular conveyor belt spatially replenishing secretory vesicles in stimulated chromaffin cells.

    PubMed

    Maucort, Guillaume; Kasula, Ravikiran; Papadopulos, Andreas; Nieminen, Timo A; Rubinsztein-Dunlop, Halina; Meunier, Frederic A

    2014-01-01

    How neurosecretory cells spatially adjust their secretory vesicle pools to replenish those that have fused and released their hormonal content is currently unknown. Here we designed a novel set of image analyses to map the probability of tracked organelles undergoing a specific type of movement (free, caged or directed). We then applied our analysis to time-lapse z-stack confocal imaging of secretory vesicles from bovine Chromaffin cells to map the global changes in vesicle motion and directionality occurring upon secretagogue stimulation. We report a defined region abutting the cortical actin network that actively transports secretory vesicles and is dissipated by actin and microtubule depolymerizing drugs. The directionality of this "conveyor belt" towards the cell surface is activated by stimulation. Actin and microtubule networks therefore cooperatively probe the microenvironment to transport secretory vesicles to the periphery, providing a mechanism whereby cells globally adjust their vesicle pools in response to secretagogue stimulation.

  14. Chronic opioids regulate KATP channel subunit Kir6.2 and carbonic anhydrase I and II expression in rat adrenal chromaffin cells via HIF-2α and protein kinase A

    PubMed Central

    Salman, Shaima; Holloway, Alison C.

    2014-01-01

    At birth, asphyxial stressors such as hypoxia and hypercapnia are important physiological stimuli for adrenal catecholamine release that is critical for the proper transition to extrauterine life. We recently showed that chronic opioids blunt chemosensitivity of neonatal rat adrenomedullary chromaffin cells (AMCs) to hypoxia and hypercapnia. This blunting was attributable to increased ATP-sensitive K+ (KATP) channel and decreased carbonic anhydrase (CA) I and II expression, respectively, and involved μ- and δ-opioid receptor signaling pathways. To address underlying molecular mechanisms, we first exposed an O2- and CO2-sensitive, immortalized rat chromaffin cell line (MAH cells) to combined μ {[d-Arg2,Ly4]dermorphin-(1–4)-amide}- and δ ([d-Pen2,5,P-Cl-Phe4]enkephalin)-opioid agonists (2 μM) for ∼7 days. Western blot and quantitative real-time PCR analysis revealed that chronic opioids increased KATP channel subunit Kir6.2 and decreased CAII expression; both effects were blocked by naloxone and were absent in hypoxia-inducible factor (HIF)-2α-deficient MAH cells. Chronic opioids also stimulated HIF-2α accumulation along a time course similar to Kir6.2. Chromatin immunoprecipitation assays on opioid-treated cells revealed the binding of HIF-2α to a hypoxia response element in the promoter region of the Kir6.2 gene. The opioid-induced regulation of Kir6.2 and CAII was dependent on protein kinase A, but not protein kinase C or calmodulin kinase, activity. Interestingly, a similar pattern of HIF-2α, Kir6.2, and CAII regulation (including downregulation of CAI) was replicated in chromaffin tissue obtained from rat pups born to dams exposed to morphine throughout gestation. Collectively, these data reveal novel mechanisms by which chronic opioids blunt asphyxial chemosensitivity in AMCs, thereby contributing to abnormal arousal responses in the offspring of opiate-addicted mothers. PMID:24898587

  15. How does the stimulus define exocytosis in adrenal chromaffin cells?

    PubMed

    Marengo, Fernando D; Cárdenas, Ana M

    2017-08-29

    The extent and type of hormones and active peptides secreted by the chromaffin cells of the adrenal medulla have to be adjusted to physiological requirements. The chromaffin cell secretory activity is controlled by the splanchnic nerve firing frequency, which goes from approximately 0.5 Hz in basal conditions to more than 15 Hz in stress. Thus, these neuroendocrine cells maintain a tonic release of catecholamines under resting conditions, massively discharge intravesicular transmitters in response to stress, or adequately respond to moderate stimuli. In order to adjust the secretory response to the stimulus, the adrenal chromaffin cells have an appropriate organization of Ca(2+) channels, secretory granules pools, and sets of proteins dedicated to selectively control different steps of the secretion process, such as the traffic, docking, priming and fusion of the chromaffin granules. Among the molecules implicated in such events are the soluble N-ethylmaleimide-sensitive factor attachment protein receptor (SNARE) proteins, Ca(2+) sensors like Munc13 and synaptotagmin-1, chaperon proteins such as Munc18, and the actomyosin complex. In the present review, we discuss how these different actors contribute to the extent and maintenance of the stimulus-dependent exocytosis in the adrenal chromaffin cells.

  16. Brain histamine mediates the bombesin-induced central activation of sympatho-adrenomedullary outflow.

    PubMed

    Okuma, Y; Yokotani, K; Murakami, Y; Osumi, Y

    1997-01-01

    Intracerebroventricular (i.c.v.) administration of bombesin (0.3 nmol) increased plasma levels of both adrenaline and noradrenaline in urethane anesthetized rats. These bombesin-induced increases were inhibited by i.c.v. pretreatment with pyrilamine, an H1-receptor antagonist. Ranitidine, an H2-receptor antagonist also inhibited the increase of adrenaline, however, its effective dose was much larger than that of pyrilamine. Furthermore, the bombesin-induced increase of noradrenaline was not effectively inhibited by ranitidine. In the next series, turnover of histamine was assessed by measuring accumulation of tele-methylhistamine (t-MH), a major metabolite of brain histamine. I.c.v. administration of bombesin (0.3-3 nmol) increased turnover of hypothalamic histamine, while its intravenous administration was without effect. The present results suggest that the bombesin-induced central activation of sympatho-adrenomedullary outflow is probably, at least in part, mediated through brain histaminergic neurons.

  17. Vesicle Pools: Lessons from Adrenal Chromaffin Cells

    PubMed Central

    Stevens, David R.; Schirra, Claudia; Becherer, Ute; Rettig, Jens

    2011-01-01

    The adrenal chromaffin cell serves as a model system to study fast Ca2+-dependent exocytosis. Membrane capacitance measurements in combination with Ca2+ uncaging offers a temporal resolution in the millisecond range and reveals that catecholamine release occurs in three distinct phases. Release of a readily releasable (RRP) and a slowly releasable (SRP) pool are followed by sustained release, due to maturation, and release of vesicles which were not release-ready at the start of the stimulus. Trains of depolarizations, a more physiological stimulus, induce release from a small immediately releasable pool of vesicles residing adjacent to calcium channels, as well as from the RRP. The SRP is poorly activated by depolarization. A sequential model, in which non-releasable docked vesicles are primed to a slowly releasable state, and then further mature to the readily releasable state, has been proposed. The docked state, dependent on membrane proximity, requires SNAP-25, synaptotagmin, and syntaxin. The ablation or modification of SNAP-25 and syntaxin, components of the SNARE complex, as well as of synaptotagmin, the calcium sensor, and modulators such complexins and Snapin alter the properties and/or magnitudes of different phases of release, and in particular can ablate the RRP. These results indicate that the composition of the SNARE complex and its interaction with modulatory molecules drives priming and provides a molecular basis for different pools of releasable vesicles. PMID:21423410

  18. Inhibitory effects of tramadol on nicotinic acetylcholine receptors in adrenal chromaffin cells and in Xenopus oocytes expressing alpha 7 receptors.

    PubMed

    Shiraishi, Munehiro; Minami, Kouichiro; Uezono, Yasuhito; Yanagihara, Nobuyuki; Shigematsu, Akio; Shibuya, Izumi

    2002-05-01

    1. Tramadol has been used clinically as an analgesic; however, the mechanism of its analgesic effects is still unknown. 2. We used bovine adrenal chromaffin cells to investigate effects of tramadol on catecholamine secretion, nicotine-induced cytosolic Ca(2+) concentration ([Ca(2+)](i)) increases and membrane current changes. We also investigated effects of tramadol on alpha7 nicotinic acetylcholine receptors (AChRs) expressed in Xenopus oocytes. 3. Tramadol concentration-dependently suppressed carbachol-induced catecholamine secretion to 60% and 27% of the control at the concentration of 10 and 100 microM, respectively, whereas it had little effect on veratridine- or high K(+)-induced catecholamine secretion. 4. Tramadol also suppressed nicotine-induced ([Ca(2+)](i)) increases in a concentration-dependent manner. Tramadol inhibited nicotine-induced inward currents, and the inhibition was unaffected by the opioid receptor antagonist naloxone. 5. Tramadol inhibited nicotinic currents carried by alpha7 receptors expressed in Xenopus oocytes. 6. Tramadol inhibited both alpha-bungarotoxin-sensitive and -insensitive nicotinic currents in bovine adrenal chromaffin cells. 7. In conclusion, tramadol inhibits catecholamine secretion partly by inhibiting nicotinic AChR functions in a naloxone-insensitive manner and alpha7 receptors are one of those inhibited by tramadol.

  19. Chromaffin cell transplants: from the lab to the clinic.

    PubMed

    Ambriz-Tututi, Mónica; Monjaraz-Fuentes, Fernanda; Drucker-Colín, René

    2012-12-17

    Chromaffin cell transplants have been explored since the early 1980s as a promising alternative in different pathological states, mainly Parkinson's disease and chronic pain. Advances are significant since transplants have been performed in humans. The general mechanism of these transplants relies in the capacity of chromaffin cells to act as mini-pumps that release amines and peptides. Different strategies are being used to improve the efficacy of transplants. However, a remaining hurdle is to determine the viability across time and the interaction with the microenvironment of the graft. We analyzed previous and current results finding that although there is a lot of positive evidence, there is also a lack of molecular studies that support behavioral results. The present review gives an update on recent advances of chromaffin cell transplants and their future in the clinic.

  20. Plasma metanephrine levels are decreased in type 1 diabetic patients with a severely impaired epinephrine response to hypoglycemia, indicating reduced adrenomedullary stores of epinephrine.

    PubMed

    De Galan, Bastiaan E; Tack, Cees J; Willemsen, Jacques J; Sweep, C G J Fred; Smits, Paul; Lenders, Jacques W M

    2004-05-01

    A defective epinephrine response to hypoglycemia is a common disorder in type 1 diabetes. We assessed the role of the adrenomedullary capacity to secrete epinephrine in this disorder by measuring plasma metanephrine levels in affected type 1 diabetic patients compared with those in matched nondiabetic controls. Metanephrine is formed from epinephrine that leaks from adrenomedullary storage vesicles by catechol-O-methyl transferase (COMT) and is continuously released into the circulation. Thus, plasma metanephrine levels reflect adrenomedullary epinephrine content and, provided there is normal COMT activity, the adrenomedullary capacity to secrete epinephrine. Diabetic patients had approximately 25% lower plasma metanephrine levels than controls (0.18 +/- 0.09 vs. 0.24 +/- 0.02 nmol/liter; P = 0.012), whereas plasma epinephrine, norepinephrine, and normetanephrine levels were comparable between patients and controls. In response to hypoglycemia, the increments in plasma epinephrine and plasma metanephrine levels were both significantly lower in diabetic patients than in controls (P < 0.001), but the increase in plasma metanephrine as a percentage of the increase in plasma epinephrine was identical, indicating similar COMT activity. We conclude that type 1 diabetic patients with an impaired epinephrine response to hypoglycemia have lower plasma metanephrine levels than matched controls, reflecting decreased adrenomedullary stores of epinephrine and indicating reduced adrenomedullary capacity to secrete epinephrine.

  1. Exocytosis: the chromaffin cell as a model system.

    PubMed

    Bader, Marie-France; Holz, Ronald W; Kumakura, Konosuke; Vitale, Nicolas

    2002-10-01

    Neurons and neuroendocrine cells release transmitters and hormones by exocytosis of secrctory vesicles or granules. Among the cell models that have provided insight into the molecular machinery underlying the successive steps of exocytosis, adrenal chromaffin cells have taken a prominent place. Thus, most of the molecular players that orchestrate the formation, targeting, docking, and fusion of secrctory granules have been identified in chromaffin cells. By offering the opportunity to combine the use of recent biophysical techniques allowing single-vesicle resolution and specific biochemical modifications in the protein machinery involved in exocytosis, chromaffn cells remain a powerful model to address new and still open questions in the field of secretion.

  2. Vesicle Motion during Sustained Exocytosis in Chromaffin Cells: Numerical Model Based on Amperometric Measurements

    PubMed Central

    Jarukanont, Daungruthai; Bonifas Arredondo, Imelda; Femat, Ricardo; Garcia, Martin E.

    2015-01-01

    Chromaffin cells release catecholamines by exocytosis, a process that includes vesicle docking, priming and fusion. Although all these steps have been intensively studied, some aspects of their mechanisms, particularly those regarding vesicle transport to the active sites situated at the membrane, are still unclear. In this work, we show that it is possible to extract information on vesicle motion in Chromaffin cells from the combination of Langevin simulations and amperometric measurements. We developed a numerical model based on Langevin simulations of vesicle motion towards the cell membrane and on the statistical analysis of vesicle arrival times. We also performed amperometric experiments in bovine-adrenal Chromaffin cells under Ba2+ stimulation to capture neurotransmitter releases during sustained exocytosis. In the sustained phase, each amperometric peak can be related to a single release from a new vesicle arriving at the active site. The amperometric signal can then be mapped into a spike-series of release events. We normalized the spike-series resulting from the current peaks using a time-rescaling transformation, thus making signals coming from different cells comparable. We discuss why the obtained spike-series may contain information about the motion of all vesicles leading to release of catecholamines. We show that the release statistics in our experiments considerably deviate from Poisson processes. Moreover, the interspike-time probability is reasonably well described by two-parameter gamma distributions. In order to interpret this result we computed the vesicles’ arrival statistics from our Langevin simulations. As expected, assuming purely diffusive vesicle motion we obtain Poisson statistics. However, if we assume that all vesicles are guided toward the membrane by an attractive harmonic potential, simulations also lead to gamma distributions of the interspike-time probability, in remarkably good agreement with experiment. We also show that

  3. Comparative morphology, cytochemistry and innervation of chromaffin tissue in vertebrates.

    PubMed Central

    Scheuermann, D W

    1993-01-01

    Chromaffin cells were observed singly or in clusters in the heart and sympathetic cord of 2 genera of dipnoan fish, Protopterus and Lepidosiren. They were invariably found in close association with the autonomic sympathetic nervous system and at sites where chromaffin cells or their precursors are situated in mammals during ontogenetic development. X-ray microanalysis demonstrated that they contained a primary catecholamine which was identified microspectrofluorometrically as dopamine. The chromaffin cells were innervated by efferent axons with typical preganglionic sympathetic terminals which were acetylcholinesterase-positive. Although the general morphology and cytochemistry agree with those of developing intra-adrenal chromaffin cells in mammals, the morphological characteristics implicate them as active secretory gland cells. The dopamine transmitter phenotype seems to be determined by the maintenance throughout life of the separate and distant location of steroidogenic interrenal tissue from suprarenal elements. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 14 PMID:8300420

  4. Platelet Granule Exocytosis: A Comparison with Chromaffin Cells

    PubMed Central

    Fitch-Tewfik, Jennifer L.; Flaumenhaft, Robert

    2013-01-01

    The rapid secretion of bioactive amines from chromaffin cells constitutes an important component of the fight or flight response of mammals to stress. Platelets respond to stresses within the vasculature by rapidly secreting cargo at sites of injury, inflammation, or infection. Although chromaffin cells derive from the neural crest and platelets from bone marrow megakaryocytes, both have evolved a heterogeneous assemblage of granule types and a mechanism for efficient release. This article will provide an overview of granule formation and exocytosis in platelets with an emphasis on areas in which the study of chromaffin cells has influenced that of platelets and on similarities between the two secretory systems. Commonalities include the use of transporters to concentrate bioactive amines and other cargos into granules, the role of cytoskeletal remodeling in granule exocytosis, and the use of granules to provide membrane for cytoplasmic projections. The SNAREs and SNARE accessory proteins used by each cell type will also be considered. Finally, we will discuss the newly appreciated role of dynamin family proteins in regulated fusion pore formation. This evaluation of the comparative cell biology of regulated exocytosis in platelets and chromaffin cells demonstrates a convergence of mechanisms between two disparate cell types both tasked with responding rapidly to physiological stimuli. PMID:23805129

  5. The innervation of the chromaffin cells in the head kidney of the carp, Cyprinus carpio; regional differences of the connections between nerve endings and chromaffin cells.

    PubMed

    Imagawa, T; Kitagawa, H; Uehara, M

    1996-02-01

    Nerve fibres and their connections with chromaffin cells in the carp head kidney were studied by light and electron microscopy. Some nerve bundles entered the head kidney from the dorsal aspect along veins. Many unmyelinated axons emerged from the nerve bundles to invade the clusters of chromaffin cells, the distribution of which was restricted to the neighbourhood of the venous trunks and their tributaries. Most of the nerve endings were attached to a chromaffin cell by synaptic junctions and were generally invaginated into the cell. Some nerve endings were flattened in shape and connected with two chromaffin cells. Occasional exocytotic figures of synaptic vesicles opening into the intercellular space, or synaptic junctions along the course of the nerve fibre were observed. The percentage of the chromaffin cells supplied by nerve endings in the head kidney as a whole was similar to that in primitive amphibians. The distribution of the chromaffin cells and the frequency of their innervation suggest that carp chromaffin cells are phylogenetically similar to those of amphibians. The frequencies of synaptic connections in the carp head kidney showed regional differences. The number in dorsal portion was significantly higher than that in two ventral portions. It is suggested that chromaffin cells in the head kidney are separable into two populations: one (in the dorsal portion) shows closer and the other (in the ventral portions) less contact with nerve fibres. The fine structure of the nerve endings indicates that catecholamine secretion of carp chromaffin cells is partially modulated by nerve fibres (probably preganglionic cholinergic fibres). However, the low frequency of synaptic connections on the chromaffin cells and their distribution suggest that carp chromaffin cells are mainly modulated by the endocrine system via the bloodstream.

  6. Novel antimigraineur dotarizine releases Ca2+ from caffeine-sensitive Ca2+ stores of chromaffin cells

    PubMed Central

    Novalbos, Jesús; Abad-Santos, Francisco; Zapater, Pedro; Alvarez, Javier; Alonso, María Teresa; Montero, Mayte; García, Antonio G

    1999-01-01

    The novel antimigraineur, dotarizine (30 μM), increased cytosolic Ca2+ concentration, [Ca2+]c, in fura-2-loaded bovine adrenal chromaffin cells. This increase was transient, reached a peak in about 2–5 min (0.53±0.07 μM; n=19) and then declined to basal levels over a further 5 min period.This transient rise of [Ca2+]c was mimicked by 1 μM thapsigargin and by 30 μM cyclopiazonic acid (CPA), but not by 30 μM flunarizine. Both thapsigargin and CPA occluded the effects of dotarizine and vice versa.All three compounds suppressed the transient [Ca2+]c rises induced by caffeine (10 mM, 10 s); blockade induced by thapsigargin was irreversible and that induced by CPA and dotarizine was reversible.Of the three compounds, only dotarizine blocked reversibly the [Ca2+]c spikes induced by short pulses of high K+ (70 mM, 5 s), suggesting that dotarizine blocks voltage-dependent Ca2+ channels but CPA and thapsigargin do not.Dotarizine caused a gradual and reversible depletion of endoplasmic reticulum (ER) Ca2+ in chromaffin cells transfected with ER-targeted aequorin. CPA had a similar effect.These data show that dotarizine shares with thapsigargin and CPA the ability to deplete Ca2+ in the ER; this novel action of dotarizine could be relevant to its prophylactic effects in migraine. Unlike thapsigargin and CPA, however, dotarizine additionally and reversibly blocks Ca2+ entry through voltage-dependent Ca2+ channels. PMID:10516641

  7. GABA Signaling and Neuroactive Steroids in Adrenal Medullary Chromaffin Cells

    PubMed Central

    Harada, Keita; Matsuoka, Hidetada; Fujihara, Hiroaki; Ueta, Yoichi; Yanagawa, Yuchio; Inoue, Masumi

    2016-01-01

    Gamma-aminobutyric acid (GABA) is produced not only in the brain, but also in endocrine cells by the two isoforms of glutamic acid decarboxylase (GAD), GAD65 and GAD67. In rat adrenal medullary chromaffin cells only GAD67 is expressed, and GABA is stored in large dense core vesicles (LDCVs), but not synaptic-like microvesicles (SLMVs). The α3β2/3γ2 complex represents the majority of GABAA receptors expressed in rat and guinea pig chromaffin cells, whereas PC12 cells, an immortalized rat chromaffin cell line, express the α1 subunit as well as the α3. The expression of α3, but not α1, in PC12 cells is enhanced by glucocorticoid activity, which may be mediated by both the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR). GABA has two actions mediated by GABAA receptors in chromaffin cells: it induces catecholamine secretion by itself and produces an inhibition of synaptically evoked secretion by a shunt effect. Allopregnanolone, a neuroactive steroid which is secreted from the adrenal cortex, produces a marked facilitation of GABAA receptor channel activity. Since there are no GABAergic nerve fibers in the adrenal medulla, GABA may function as a para/autocrine factor in the chromaffin cells. This function of GABA may be facilitated by expression of the immature isoforms of GAD and GABAA receptors and the lack of expression of plasma membrane GABA transporters (GATs). In this review, we will consider how the para/autocrine function of GABA is achieved, focusing on the structural and molecular mechanisms for GABA signaling. PMID:27147972

  8. Effects of phorbol esters and secretagogues on nitrobenzylthioinosine binding to nucleoside transporters and nucleoside uptake in cultured chromaffin cells.

    PubMed Central

    Delicado, E G; Sen, R P; Miras-Portugal, M T

    1991-01-01

    Secretagogues inhibited adenosine uptake in chromaffin cells without causing apparent changes in the uptake affinity. The inhibition caused by carbachol, nicotine and acetylcholine reached 50%. This inhibition was reproduced by the action of protein kinase C activators such as phorbol 12-myristate 13-acetate (PMA; 100 nM), phorbol 12,13-dibutyrate (PDBu; 100 nM), dicaproin (10 micrograms/ml) and tricaprylin (10 micrograms/ml), with inhibitions of Vmax. of 18, 20, 37 and 47% respectively. No changes in the affinity of uptake were observed with these effectors. Down-regulation of protein kinase C by phorbol esters decreased the inhibitory effects of carbachol on adenosine uptake. Binding studies with nitrobenzylthioinosine (NBTI) showed a similar decrease in the number of transporters when chromaffin cells were treated with the same effectors used for the uptake studies. The high-affinity dissociation constants showed minor changes with respect to the control. The ratio between maximal uptake capacity and the transporter number per cell was not significantly modified by the action of secretagogues or direct effectors of protein kinase C. The number of high-affinity binding sites for NBTI was decreased in cellular homogenates by the direct action of protein kinase C activators, with staurosporine able to reverse this action. Protein kinase C from bovine brain in the presence of ATP and effectors, decreased the number of high-affinity NBTI-binding sites in purified chromaffin cell plasma membranes. These data suggest the possibility of a molecular modification at the transporter level. PMID:1953658

  9. Ca2+-induced Ca2+ Release in Chromaffin Cells Seen from inside the ER with Targeted Aequorin

    PubMed Central

    Alonso, Maria Teresa; Barrero, Maria José; Michelena, Pedro; Carnicero, Estela; Cuchillo, Inmaculada; García, Antonio G.; García-Sancho, Javier; Montero, Mayte; Alvarez, Javier

    1999-01-01

    The presence and physiological role of Ca2+-induced Ca2+ release (CICR) in nonmuscle excitable cells has been investigated only indirectly through measurements of cytosolic [Ca2+] ([Ca2+]c). Using targeted aequorin, we have directly monitored [Ca2+] changes inside the ER ([Ca2+]ER) in bovine adrenal chromaffin cells. Ca2+ entry induced by cell depolarization triggered a transient Ca2+ release from the ER that was highly dependent on [Ca2+]ER and sensitized by low concentrations of caffeine. Caffeine-induced Ca2+ release was quantal in nature due to modulation by [Ca2+]ER. Whereas caffeine released essentially all the Ca2+ from the ER, inositol 1,4,5-trisphosphate (InsP3)- producing agonists released only 60–80%. Both InsP3 and caffeine emptied completely the ER in digitonin-permeabilized cells whereas cyclic ADP-ribose had no effect. Ryanodine induced permanent emptying of the Ca2+ stores in a use-dependent manner after activation by caffeine. Fast confocal [Ca2+]c measurements showed that the wave of [Ca2+]c induced by 100-ms depolarizing pulses in voltage-clamped cells was delayed and reduced in intensity in ryanodine-treated cells. Our results indicate that the ER of chromaffin cells behaves mostly as a single homogeneous thapsigargin-sensitive Ca2+ pool that can release Ca2+ both via InsP3 receptors or CICR. PMID:9922451

  10. Dynamin-2 Regulates Fusion Pore Expansion and Quantal Release through a Mechanism that Involves Actin Dynamics in Neuroendocrine Chromaffin Cells

    PubMed Central

    González-Jamett, Arlek M.; Momboisse, Fanny; Guerra, María José; Ory, Stéphane; Báez-Matus, Ximena; Barraza, Natalia; Calco, Valerie; Houy, Sébastien; Couve, Eduardo; Neely, Alan; Martínez, Agustín D.; Gasman, Stéphane; Cárdenas, Ana M.

    2013-01-01

    Over the past years, dynamin has been implicated in tuning the amount and nature of transmitter released during exocytosis. However, the mechanism involved remains poorly understood. Here, using bovine adrenal chromaffin cells, we investigated whether this mechanism rely on dynamin’s ability to remodel actin cytoskeleton. According to this idea, inhibition of dynamin GTPase activity suppressed the calcium-dependent de novo cortical actin and altered the cortical actin network. Similarly, expression of a small interfering RNA directed against dynamin-2, an isoform highly expressed in chromaffin cells, changed the cortical actin network pattern. Disruption of dynamin-2 function, as well as the pharmacological inhibition of actin polymerization with cytochalasine-D, slowed down fusion pore expansion and increased the quantal size of individual exocytotic events. The effects of cytochalasine-D and dynamin-2 disruption were not additive indicating that dynamin-2 and F-actin regulate the late steps of exocytosis by a common mechanism. Together our data support a model in which dynamin-2 directs actin polymerization at the exocytosis site where both, in concert, adjust the hormone quantal release to efficiently respond to physiological demands. PMID:23940613

  11. Permissive effect of dexamethasone on the increase of proenkephalin mRNA induced by depolarization of chromaffin cells

    SciTech Connect

    Naranjo, J.R.; Mocchetti, I.; Schwartz, J.P.; Costa, E.

    1986-03-01

    In cultured bovine chromaffin cells, changes in the dynamic state of enkephalin stores elicited experimentally were studied by measuring cellular proenkephalin mRNA, as well as enkephalin precursors and authentic enkephalin content of cells and culture media. In parallel, tyrosine hydroxylase mRNA and catecholamine cell content were also determined. Low concentrations (0.5-100 pM) of dexamethasone increased the cell contents of proenkephalin mRNA and enkephalin-containing peptides. High concentrations of the hormone(1 ..mu..M) were required to increase the cell contents of tyrosine hydroxylase mRNA and catecholamines. Depolarization of the cells with 10 ..mu..M veratridine resulted in a depletion of enkephalin and catecholamine stores after 24 hr. The enkephalin, but not the catecholamine, content was restored by 48 hr. An increase in proenkephalin mRNA content might account for the recovery; this increase was curtailed by tetrodotoxin and enhanced by 10 pM dexamethasone. Tyrosine hydroxylase mRNA content was not significantly modified by depolarization, even in the presence of 1 ..mu..M dexamethasone. Aldosterone, progesterone, testosterone, or estradiol (1 ..mu..M) failed to change proenkephalin mRNA. Hence, dexamethasone appears to exert a specific permissive action on the stimulation of the proenkephalin gene elicited by depolarization. Though the catecholamines and enkephalins are localized in the same chromaffin granules and are coreleased by depolarization, the genes coding for the processes that are rate limiting in the production of these neuromodulators can be differentially regulated.

  12. Immunohistochemical demonstration of syntaxin and SNAP-25 in chromaffin cells of the frog adrenal gland.

    PubMed

    Quintanar, J L; Salinas, E; Reig, J A

    1998-08-01

    The release of catecholamines from chromaffin cells involves specific proteins such as synaptobrevin present in the secretory vesicles as well as syntaxin and synaptosomal-associated protein of 25 kDa (SNAP-25), both present in the plasma membrane. We have found syntaxin and SNAP-25 in chromaffin cells of the frog adrenal gland by immunohistochemistry. This result suggests that the secretion of catecholamines from chromaffin cells involves these proteins in the frog.

  13. Chromaffin cell grafts to rat cerebral cortex reverse lesion-induced memory deficits.

    PubMed

    Welner, S A; Koty, Z C; Boksa, P

    1990-09-10

    Adrenal chromaffin cells were isolated from donor adult rats and transplanted to the cerebral cortex of bilaterally nucleus basalis magnocellularis-lesioned rats. Chromaffin cell grafts to lesioned animals completely reversed the spatial memory deficit seen in lesioned alone animals on a T-maze alternation task. Although chromaffin cell grafts have been used previously to reverse motor abnormalities arising from defective nigro-striatal aminergic transmission, the present report is the first evidence that chromaffin cell transplants can reverse deficits in memory function. Grafts also enhanced cortical acetylcholinesterase staining.

  14. The study of adrenal chromaffin of fish, Carassius auratus (Toleostei).

    PubMed

    Sampour, M

    2008-04-01

    In C. auratus the adrenal chramaffin tissue is situated around the posterior cardinal veins, in the head kidney. Chromaffin tissue consists of two types of cells containing secretory granules, adrenaline and nor adrenaline cells. The cells produced catecholamine hormones. Adrenaline cell contains electron-lucent granules, whereas nor adrenaline cells possesses electron-dense granules. Cholinergic fibers embedded in the head kidney innervated the chromaffin cell. Two types of secretory structures, synaptic vesicles and secretory granules are found within the presynaptic terminal. Secretory granules discharge their contests, as neuropeptide in non synaptic area of nerve terminal by exocytosis, whereas synaptic vesicles discharge their contents as neurotransmitters at the synaptic thickening (active zone) in the presynaptic terminal by exocytosis.

  15. Chronic nicotine blunts hypoxic sensitivity in perinatal rat adrenal chromaffin cells via upregulation of KATP channels: role of alpha7 nicotinic acetylcholine receptor and hypoxia-inducible factor-2alpha.

    PubMed

    Buttigieg, Josef; Brown, Stephen; Holloway, Alison C; Nurse, Colin A

    2009-06-03

    Fetal nicotine exposure blunts hypoxia-induced catecholamine secretion from neonatal adrenomedullary chromaffin cells (AMCs), providing a link between maternal smoking, abnormal arousal responses, and risk of sudden infant death syndrome. Here, we show that the mechanism is attributable to upregulation of K(ATP) channels via stimulation of alpha7 nicotinic ACh receptors (AChRs). These K(ATP) channels open during hypoxia, thereby suppressing membrane excitability. After in utero exposure to chronic nicotine, neonatal AMCs show a blunted hypoxic sensitivity as determined by inhibition of outward K(+) current, membrane depolarization, rise in cytosolic Ca(2+), and catecholamine secretion. However, hypoxic sensitivity could be unmasked in nicotine-exposed AMCs when glibenclamide, a blocker of K(ATP) channels, was present. Both K(ATP) current density and K(ATP) channel subunit (Kir 6.2) expression were significantly enhanced in nicotine-exposed cells relative to controls. The entire sequence could be reproduced in culture by exposing neonatal rat AMCs or immortalized fetal chromaffin (MAH) cells to nicotine for approximately 1 week, and was prevented by coincubation with selective blockers of alpha7 nicotinic AChRs. Additionally, coincubation with inhibitors of protein kinase C and CaM kinase, but not protein kinase A, prevented the effects of chronic nicotine in vitro. Interestingly, chronic nicotine failed to blunt hypoxia-evoked responses in MAH cells bearing short hairpin knockdown (>90%) of the transcription factor, hypoxia-inducible factor-2alpha (HIF-2alpha), suggesting involvement of the HIF pathway. The therapeutic potential of K(ATP) channel blockers was validated in experiments in which hypoxia-induced neonatal mortality in nicotine-exposed pups was significantly reduced after pretreatment with glibenclamide.

  16. Heterogeneous distribution of exocytotic microdomains in adrenal chromaffin cells resolved by high-density diamond ultra-microelectrode arrays

    PubMed Central

    Gosso, Sara; Turturici, Marco; Franchino, Claudio; Colombo, Elisabetta; Pasquarelli, Alberto; Carbone, Emilio; Carabelli, Valentina

    2014-01-01

    Here we describe the ability of a high-density diamond microelectrode array targeted to resolve multi-site detection of fast exocytotic events from single cells. The array consists of nine boron-doped nanocrystalline diamond ultra-microelectrodes (9-Ch NCD-UMEA) radially distributed within a circular area of the dimensions of a single cell. The device can be operated in voltammetric or chronoamperometric configuration. Sensitivity to catecholamines, tested by dose–response calibrations, set the lowest detectable concentration of adrenaline to ∼5 μm. Catecholamine release from bovine or mouse chromaffin cells could be triggered by electrical stimulation or external KCl-enriched solutions. Spikes detected from the cell apex using carbon fibre microelectrodes showed an excellent correspondence with events measured at the bottom of the cell by the 9-Ch NCD-UMEA, confirming the ability of the array to resolve single quantal secretory events. Subcellular localization of exocytosis was provided by assigning each quantal event to one of the nine channels based on its location. The resulting mapping highlights the heterogeneous distribution of secretory activity in cell microdomains of 12–27 μm2. In bovine chromaffin cells, secretion was highly heterogeneous with zones of high and medium activity in 54% of the cell surface and zones of low or no activity in the remainder. The ‘non-active’ (‘silent’) zones covered 24% of the total and persisted for 6–8 min, indicating stable location. The 9-Ch NCD-UMEA therefore appears suitable for investigating the microdomain organization of neurosecretion with high spatial resolution. PMID:24879870

  17. Anoxia differentially modulates multiple K+ currents and depolarizes neonatal rat adrenal chromaffin cells

    PubMed Central

    Thompson, Roger J; Nurse, Colin A

    1998-01-01

    Using perforated-patch, whole cell recording, we investigated the membrane mechanisms underlying O2 chemosensitivity in neonatal rat adrenomedullary chromaffin cells (AMC) bathed in extracellular solution containing tetrodotoxin (TTX; 0.5–1 μm), with or without blockers of calcium entry. Under voltage clamp, low PO2 (0–15 mmHg) caused a graded and reversible suppression in macroscopic outward K+ current. The suppression during anoxia (PO2 = 0 mmHg) was ∼35% (voltage step from −60 to +30 mV) and was due to a combination of several factors: (i) suppression of a cadmium-sensitive, Ca2+-dependent K+ current, IK(CaO2); (ii) suppression of a Ca2+-insensitive, delayed rectifier type K+ current, IK(VO2); (iii) activation of a glibenclamide- (and Ca2+)-sensitive current, IK(ATP). During normoxia (PO2 = 150 mmHg), application of pinacidil (100 μm), an ATP-sensitive potassium channel (KATP) activator, increased outward current density by 45.0 ± 7.0 pA pF−1 (step from −60 to + 30 mV), whereas the KATP blocker glibenclamide (50 μm) caused only a small suppression by 6.3 ± 4.0 pA pF−1. In contrast, during anoxia the presence of glibenclamide resulted in a substantial reduction in outward current density by 24.9 ± 7.9 pA pF−1, which far exceeded that seen in its absence. Thus, activation of IK(ATP) by anoxia appears to reduce the overall K+ current suppression attributable to the combined effects of IK(CaO2) and IK(VO2). Pharmacological tests revealed that IK(CaO2) was carried predominantly by maxi-K+ or BK potassium channels, sensitive to 50–100 nm iberiotoxin; this current also accounted for the major portion (∼60%) of the anoxic suppression of outward current. Tetraethylammonium (TEA; 10–20 mm) blocked all of the anoxia-sensitive K+ currents recorded under voltage clamp, i.e. IK(CaO2), IK(VO2) and IK(ATP). Under current clamp, anoxia depolarized neonatal AMC by 10–15 mV from a resting potential of ∼-55 mV. At least part of this depolarization

  18. Novel synthetic sulfoglycolipid IG20 facilitates exocytosis in chromaffin cells through the regulation of sodium channels.

    PubMed

    Crespo-Castrillo, Andrea; Punzón, Eva; de Pascual, Ricardo; Maroto, Marcos; Padín, Juan Fernando; García-Álvarez, Isabel; Nanclares, Carmen; Ruiz-Pascual, Lucía; Gandía, Luis; Fernández-Mayoralas, Alfonso; García, Antonio G

    2015-12-01

    In search of druggable synthetic lipids that function as potential modulators of synaptic transmission and plasticity, we synthesized sulfoglycolipid IG20, which stimulates neuritic outgrowth. Here, we have explored its effects on ion channels and exocytosis in bovine chromaffin cells. IG20 augmented the rate of basal catecholamine release. Such effect did not depend on Ca(2+) mobilization from intracellular stores; rather, IG20-elicited secretion entirely dependent on Ca(2+) entry through L-subtype voltage-activated Ca(2+) channels. Those channels were recruited by cell depolarization mediated by IG20 likely through its ability to enhance the recruitment of Na(+) channels at more hyperpolarizing potentials. Confocal imaging with fluorescent derivative IG20-NBD revealed its rapid incorporation and confinement into the plasmalemma, supporting the idea that IG20 effects are exerted through a plasmalemmal-delimited mechanism. Thus, synthetic IG20 seems to mimic several physiological effects of endogenous lipids such as regulation of ion channels, Ca(2+) signaling, and exocytosis. Therefore, sulfoglycolipid IG20 may become a pharmacological tool for investigating the role of the lipid environment on neuronal excitability, ion channels, neurotransmitter release, synaptic efficacy, and neuronal plasticity. It may also inspire the synthesis of druggable sulfoglycolipids aimed at increasing synaptic plasticity and efficacy in neurodegenerative diseases and traumatic brain-spinal cord injury. The novel synthetic sulfoglycolipid IG20 mimics several physiological effects of endogenous lipids such as regulation of ion channels, Ca(2+) signaling, and exocytosis. This profile may eventually drive enhanced synaptic plasticity and efficacy.

  19. Release of chromaffin granule glycoproteins and proteoglycans from potassium-stimulated PC12 pheochromocytoma cells.

    PubMed

    Salton, S R; Margolis, R U; Margolis, R K

    1983-10-01

    Cultured PC12 pheochromocytoma cells were labeled with [3H]glucosamine, and the glycoproteins and proteoglycans released following potassium-induced depolarization were fractionated and characterized. Exposure of PC12 cells for 20 min to a high concentration of potassium (51.5 mM in Krebs-Ringers-HEPES buffer) results in an approximately sixfold increase in the release of labeled glycoproteins and proteoglycans, compared to incubation in physiological levels of potassium (6 mM). The released complex carbohydrates include chromogranins, dopamine beta-hydroxylase, and two chondroitin sulfate/heparan sulfate proteoglycan fractions, which together account for 7.4% of the soluble cell radioactivity. The chromogranins contained galactosyl(beta 1 leads to 3)N-acetylgalactosamine, as well as several mono- and disialyl O-glycosidically-linked oligosaccharides, and the tetrasaccharide AcNeu(alpha 2 leads to 3)Gal(beta 1 leads to 3)[AcNeu(alpha 2 leads to 6)] GalNAcol, obtained by alkaline borohydride treatment of the chromogranin glycopeptides, accounted for almost half of the total chromogranin labeling. The proteoglycan fractions varied in their relative proportions of chondroitin sulfate (23-68%), heparan sulfate (16-23%), and glycoprotein oligosaccharides (16-54%), which are of the tri- and tetraantennary and O-glycosidic types. As previously found in the case of proteoglycans from bovine chromaffin granules, the more acidic species has a considerably higher proportion of carbohydrate in the form of sulfated glycosaminoglycans.

  20. Estrogen reduces aldosterone, upregulates adrenal angiotensin II AT2 receptors and normalizes adrenomedullary Fra-2 in ovariectomized rats.

    PubMed

    Macova, Miroslava; Armando, Ines; Zhou, Jin; Baiardi, Gustavo; Tyurmin, Dmitri; Larrayoz-Roldan, Ignacio M; Saavedra, Juan M

    2008-01-01

    We studied the effect of ovariectomy and estrogen replacement on expression of adrenal angiotensin II AT1 and AT2 receptors, aldosterone content, catecholamine synthesis, and the transcription factor Fos-related antigen 2 (Fra-2). Ovariectomy increased AT1 receptor expression in the adrenal zona glomerulosa and medulla, and decreased adrenomedullary catecholamine content and Fra-2 expression when compared to intact female rats. In the zona glomerulosa, estrogen replacement normalized AT1 receptor expression, decreased AT1B receptor mRNA, and increased AT2 receptor expression and mRNA. Estrogen treatment decreased adrenal aldosterone content. In the adrenal medulla, the effects of estrogen replacement were: normalized AT1 receptor expression, increased AT2 receptor expression, AT2 receptor mRNA, and tyrosine hydroxylase mRNA, and normalized Fra-2 expression and catecholamine content. We demonstrate that the constitutive adrenal expression of AT1 receptors, catecholamine synthesis and Fra-2 expression are partially under the control of reproductive hormones. Our results suggest that estrogen treatment decreases aldosterone production through AT1 receptor downregulation and AT2 receptor upregulation. AT2 receptor upregulation and modulation of Fra-2 expression may participate in the estrogen-dependent normalization of adrenomedullary catecholamine synthesis in ovariectomized rats. The AT2 receptor upregulation and the decrease in AT1 receptor function and in the production of the fluid-retentive, pro-inflammatory hormone aldosterone partially explain the protective effects of estrogen therapy. Copyright 2008 S. Karger AG, Basel.

  1. Histogenesis of the human adrenal medulla. An evaluation of the ontogeny of chromaffin and nonchromaffin lineages.

    PubMed

    Cooper, M J; Hutchins, G M; Israel, M A

    1990-09-01

    The authors previously evaluated the expression of a panel of chromaffin-related genes during histogenesis of the human adrenal medulla. In these studies, chromaffin and nonchromaffin adrenal neuroblasts were identified. To better characterize these nonchromaffin neuroblasts, the authors evaluated two additional markers: HNK-1, an antibody recognizing the migratory neural crest cell; and S-100, a protein expressed by sustentacular cells of the adrenal medulla. HNK-1 immunoreactivity was found in both chromaffin and nonchromaffin cell types at different times during development, marking the nonchromaffin lineage during the second trimester of gestation as well as the chromaffin lineage in the neonatal period. In addition, S-100 expression was noted in some nonchromaffin neuroblasts, and sustentacular cells were first identified at approximately 28 weeks of gestational age. These data suggest a model of human adrenal medullary histogenesis that incorporates the chromaffin, ganglionic, and sustentacular lineages known to constitute the adult adrenal medulla.

  2. Characterization of diadenosine polyphosphate transport into chromaffin granules from adrenal medulla.

    PubMed

    Gualix, J; Fideu, M D; Pintor, J; Rotllán, P; García-Carmona, F; Miras-Portugal, M T

    1997-10-01

    The transport of diadenosine polyphosphates into chromaffin granules from bovine adrenal medulla has been studied by using the radiolabeled substrate [3H]Ap5A and the fluorescent substrate analog di(1,N6-ethenoadenosine)polyphosphate, epsilon-(Ap(n)A) (n=3-5). The vesicular concentration increase was time dependent and the substrates were not metabolized to any extent during the transport experiments. The saturation curve indicates the existence of kinetic and allosteric cooperativity during Ap(n)A (diadenosine polyphosphates) transport and could be the result of the presence of various affinity states of the transporter with K values of 16 +/- 1 microM and 75 +/- 6 microM, and corresponding Hill numbers of 2 and 4, when epsilon-(Ap4A) was the substrate. The saturation studies for [3H]Ap5A were performed in a broader concentration range; in this case a three-step curve was obtained with K values of 16 +/- 2 microM, 125 +/- 9 microM, and 545 +/- 11 microM; the corresponding Hill numbers were 2, 4, and 6. This kinetic behavior can be explained on the basis of a mnemonic model, as already demonstrated for the vesicular transport of ATP. The nonhydrolyzable adenine nucleotide analogs, ATPgammaS and ADPbetaS, inhibited the diadenosine polyphosphate transport at concentrations in the millimolar range. Ap(n)A transport was also inhibited by the P2 receptor antagonist suramin, the mitochondrial ATP/ADP exchange inhibitor atractyloside, the proton translocator FCCP, and N-ethylmaleimide.

  3. Regulation by L channels of Ca(2+)-evoked secretory responses in ouabain-treated chromaffin cells.

    PubMed

    De Pascual, Ricardo; Colmena, Inés; Ruiz-Pascual, Lucía; Baraibar, Andrés Mateo; Egea, Javier; Gandía, Luis; García, Antonio G

    2016-10-01

    It is known that the sustained depolarisation of adrenal medullary bovine chromaffin cells (BCCs) with high K(+) concentrations produces an initial sharp catecholamine release that subsequently fades off in spite depolarisation persists. Here, we have recreated a sustained depolarisation condition of BCCs by treating them with the Na(+)/K(+) ATPase blocker ouabain; in doing so, we searched experimental conditions that permitted the development of a sustained long-term catecholamine release response that could be relevant during prolonged stress. BCCs were perifused with nominal 0Ca(2+) solution, and secretion responses were elicited by intermittent application of short 2Ca(2+) pulses (Krebs-HEPES containing 2 mM Ca(2+)). These pulses elicited a biphasic secretory pattern with an initial 30-min period with secretory responses of increasing amplitude and a second 30-min period with steady-state, non-inactivating responses. The initial phase was not due to gradual depolarisation neither to gradual increases of the cytosolic calcium transients ([Ca(2+)]c) elicited by 2Ca(2+) pulses in BBCs exposed to ouabain; both parameters increased soon after ouabain addition. Νifedipine blocked these responses, and FPL64176 potentiated them, suggesting that they were triggered by Ca(2+) entry through non-inactivating L-type calcium channels. This was corroborated by nifedipine-evoked blockade of the L-type Ca(2+) channel current and the [Ca(2+)]c transients elicited by 2Ca(2+) pulses. Furthermore, the plasmalemmal Na(+)/Ca(2+) exchanger (NCX) blocker SEA0400 caused a mild inhibition followed by a large rebound increase of the steady-state secretory responses. We conclude that these two phases of secretion are mostly contributed by Ca(2+) entry through L calcium channels, with a minor contribution of Ca(2+) entry through the reverse mode of the NCX.

  4. Synaptotagmin-1 and -7 are functionally overlapping Ca2+ sensors for exocytosis in adrenal chromaffin cells.

    PubMed

    Schonn, Jean-Sébastien; Maximov, Anton; Lao, Ye; Südhof, Thomas C; Sørensen, Jakob B

    2008-03-11

    Synaptotagmin-1, the canonical isoform of the synaptotagmin family, is a Ca(2+) sensor for fast synchronous neurotransmitter release in forebrain neurons and chromaffin cells. Even though deletion of synaptotagmin-1 abolishes fast exocytosis in chromaffin cells, it reduces overall secretion by only 20% because of the persistence of slow exocytosis. Therefore, another Ca(2+) sensor dominates release in these cells. Synaptotagmin-7 has a higher Ca(2+) affinity and slower binding kinetics than synaptotagmin-1, matching the proposed properties for the second, slower Ca(2+) sensor. Here, we examined Ca(2+)-triggered exocytosis in chromaffin cells from KO mice lacking synaptotagmin-7, and from knockin mice containing normal levels of a mutant synaptotagmin-7 whose C(2)B domain does not bind Ca(2+). In both types of mutant chromaffin cells, Ca(2+)-triggered exocytosis was decreased dramatically. Moreover, in chromaffin cells lacking both synaptotagmin-1 and -7, only a very slow release component, accounting for approximately 30% of WT exocytosis, persisted. These data establish synaptotagmin-7 as a major Ca(2+) sensor for exocytosis in chromaffin cells, which, together with synaptotagmin-1, mediates almost all of the Ca(2+) triggering of exocytosis in these cells, a surprising result, considering the lack of a role of synaptotagmin-7 in synaptic vesicle exocytosis.

  5. Synaptotagmin-1 and -7 are functionally overlapping Ca2+ sensors for exocytosis in adrenal chromaffin cells

    PubMed Central

    Schonn, Jean-Sébastien; Maximov, Anton; Lao, Ye; Südhof, Thomas C.; Sørensen, Jakob B.

    2008-01-01

    Synaptotagmin-1, the canonical isoform of the synaptotagmin family, is a Ca2+ sensor for fast synchronous neurotransmitter release in forebrain neurons and chromaffin cells. Even though deletion of synaptotagmin-1 abolishes fast exocytosis in chromaffin cells, it reduces overall secretion by only 20% because of the persistence of slow exocytosis. Therefore, another Ca2+ sensor dominates release in these cells. Synaptotagmin-7 has a higher Ca2+ affinity and slower binding kinetics than synaptotagmin-1, matching the proposed properties for the second, slower Ca2+ sensor. Here, we examined Ca2+-triggered exocytosis in chromaffin cells from KO mice lacking synaptotagmin-7, and from knockin mice containing normal levels of a mutant synaptotagmin-7 whose C2B domain does not bind Ca2+. In both types of mutant chromaffin cells, Ca2+-triggered exocytosis was decreased dramatically. Moreover, in chromaffin cells lacking both synaptotagmin-1 and -7, only a very slow release component, accounting for ≈30% of WT exocytosis, persisted. These data establish synaptotagmin-7 as a major Ca2+ sensor for exocytosis in chromaffin cells, which, together with synaptotagmin-1, mediates almost all of the Ca2+ triggering of exocytosis in these cells, a surprising result, considering the lack of a role of synaptotagmin-7 in synaptic vesicle exocytosis. PMID:18308932

  6. New functional imaging modalities for chromaffin tumors, neuroblastomas and ganglioneuromas.

    PubMed

    Ilias, Ioannis; Shulkin, Barry; Pacak, Karel

    2005-03-01

    Nuclear medicine modalities use radiolabeled ligands that either follow metabolic pathways or act on cellular receptors. Thus, they permit functional imaging of physiological processes and help to localize sites such as tumors that harbor pathological events. The application of positron emission tomography (PET) ligands to the specific pathways of synthesis, metabolism and inactivation of catecholamines found in chromaffin tumors, neuroblastomas and ganglioneuromas can be used to provide a more thorough localization of these types of tumor. Recent advances have been made in functional imaging to localize pheochromocytomas, paragangliomas, neuroblastomas and ganglioneuromas, including approaches based on PET with [(18)F]fluorodopamine, [(18)F]fluorohydroxyphenylalanine, [(11)C]epinephrine or [(11)C]hydroxyephedrine. Such functional imaging can complement computed tomography or magnetic resonance imaging and other scintigraphic techniques to localize these tumors before surgical or medical therapeutic approaches are considered.

  7. Effect of MPTP on primate chromaffin cells in vitro: relevance for adrenal medullary cell transplantation.

    PubMed

    Notter, M F; Kaniuki, M; Felten, S Y; Hansen, J T; Gash, D M

    1991-01-01

    Primate adrenal medullary cells were exposed to l-methyl-4-phenyl-l,2,3,6-tetrahydropyridine (MPTP) in vitro to examine the effect of this neurotoxic agent on chromaffin cells. Chromaffin cells from monkey and humans were cultured in the presence of 100 ng/ml nerve growth factor for 1 week and then exposed to 150 μM MPTP or its active metabolite methylpyridinium ion (MPP+) for an additional week. Cells which had extended neurites in the presence of NGF showed no morphological effect in response to MPTP or MPP+ at the light microscopic level. However, there was a significant loss in catecholamines as seen by histofluorescence and high performance liquid chromotography (HPLC). Electron microscopy revealed a depletion in dense-core vesicles in chromaffin cells after chronic exposure to MPTP while the mitochondria appeared similar to those observed in control cells. Replacement of MPTP medium with standard medium stimulated restoration of catecholamine histofluorescence after 7 days. An acute 15 min pretreatment of chromaffin cells with MPTP or MPP+ induced secretion of catecholamines over a 1 h pulse, with MPP+ producing the maximum and more rapid secretion as determined by HPLC. These data indicate that MPTP induces a dramatic loss in catecholamines in primate chromaffin cells in vitro after both acute and chronic exposures; however, removal of the toxic agent permits restoration of catecholamines without permanent effect on the integrity of these cells.

  8. Chromaffin granules in the rat adrenal medulla release their secretory content in a particulate fashion.

    PubMed

    Crivellato, Enrico; Belloni, Anna; Nico, Beatrice; Nussdorfer, Gastone G; Ribatti, Domenico

    2004-03-01

    Exocytosis is considered the main route of granule discharge in chromaffin cells. We recently provided ultrastructural evidence suggesting that piecemeal degranulation (PMD) occurs in mouse adrenal chromaffin cells. In the present study, we processed rat adrenal glands for transmission electron microscopy (TEM), and examined chromaffin cells for changes characteristic of PMD. Both adrenaline (A)- and noradrenaline (NA)-storing cells express ultrastructural features suggestive of a slow and particulate mode of granule discharge. In adrenaline-containing cells, some granules present enlarged dimensions accompanied by eroded or dissolved matrices. Likewise, a number of granules in NA-releasing cells show content reduction with variably expanded granule chambers. Dilated, empty granule containers are recognizable in the cytoplasm of both cell types. Characteristically, altered granules and empty containers are seen intermingled with normal, resting granules. In addition, chromaffin granules often show irregular profiles, with budding or tail-like projections of their limiting membranes. Thirty 150-nm-diameter membrane-bound vesicles with a moderately electron-dense or -lucent internal structure are observable in the cytoplasm of both cell types. These vesicles are seen among the granules and some of them are fused with the perigranule membranes in the process of attachment to or budding from the granules. These data add further support to the concept that PMD may be an alternative secretory pathway in adrenal chromaffin cells.

  9. A sodium/proton antiporter in chromaffin-granule membranes.

    PubMed Central

    Haigh, J R; Phillips, J H

    1989-01-01

    Chromaffin granules, the secretory vesicles of the adrenal medulla, have a Na+/H+ exchange activity in their membranes which brings their proton gradient into equilibrium with a Na+ gradient. This explains why Na+ is mildly inhibitory to amine transport (which is driven by the H+ gradient) The activity can be demonstrated by using accumulation of 22Na+ in response to a pH gradient that is either imposed by diluting membrane 'ghosts' into alkaline media, or generated by ATP hydrolysis. It can also be monitored indirectly by fluorescence measurements in which the pH inside 'ghost' is monitored by quenching of a fluorescent weak base. This method has been used to monitor Na+ entry into acid-loaded 'ghosts' of H+ entry into methylamine accumulation. The exchanger appears to be reversible and non-electrogenic, with a stoichiometry of 1:1. Using an indirect assay we measured an apparent Km for Na+ of 4.7 mM, and a Ki for amiloride, a competitive inhibitor, of 0.26 mM. Direct assays using 22Na+ suggested a higher Km. Ethylisopropylamiloride was not inhibitory. PMID:2539089

  10. Lack of an adrenal cortex in Sf1 mutant mice is compatible with the generation and differentiation of chromaffin cells.

    PubMed

    Gut, Philipp; Huber, Katrin; Lohr, Jennifer; Brühl, Barbara; Oberle, Stephan; Treier, Mathias; Ernsberger, Uwe; Kalcheim, Chaya; Unsicker, Klaus

    2005-10-01

    The diversification of neural-crest-derived sympathoadrenal (SA) progenitor cells into sympathetic neurons and neuroendocrine adrenal chromaffin cells was thought to be largely understood. In-vitro studies with isolated SA progenitor cells had suggested that chromaffin cell differentiation depends crucially on glucocorticoids provided by adrenal cortical cells. However, analysis of mice lacking the glucocorticoid receptor gene had revealed that adrenal chromaffin cells develop mostly normally in these mice. Alternative cues from the adrenal cortex that may promote chromaffin cell determination and differentiation have not been identified. We therefore investigated whether the chromaffin cell phenotype can develop in the absence of an adrenal cortex, using mice deficient for the nuclear orphan receptor steroidogenic factor-1 (SF1), which lack adrenal cortical cells and gonads. We show that in Sf1-/- mice typical chromaffin cells assemble correctly in the suprarenal region adjacent to the suprarenal sympathetic ganglion. The cells display most features of chromaffin cells, including the typical large chromaffin granules. Sf1-/- chromaffin cells are numerically reduced by about 50% compared with the wild type at embryonic day (E) 13.5 and E17.5. This phenotype is not accounted for by reduced survival or cell proliferation beyond E12.5. However, already at E12.5 the 'adrenal' region in Sf1-/- mice is occupied by fewer PHOX2B+ and TH+ SA cells as well as SOX10+ neural crest cells. Our results suggest that cortical cues are not essential for determining chromaffin cell fate, but may be required for proper migration of SA progenitors to and/or colonization of the adrenal anlage.

  11. Are Cav1.3 pacemaker channels in chromaffin cells?

    PubMed Central

    Striessnig, Joerg

    2011-01-01

    Mouse and rat chromaffin cells (MCCs, RCCs) fire spontaneously at rest and their activity is mainly supported by the two L-type Ca2+ channels expressed in these cells (Cav1.2 and Cav1.3). Using Cav1.3−/− KO MCCs we have shown that Cav1.3 possess all the prerequisites for carrying subthreshold currents that sustain low frequency cell firing near resting (0.5 to 2 Hz at −50 mV):1 low-threshold and steep voltage dependence of activation, slow and incomplete inactivation during pulses of several hundreds of milliseconds. Cav1.2 contributes also to pacemaking MCCs and possibly even Na+ channels may participate in the firing of a small percentage of cells. We now show that at potentials near resting (−50 mV), Cav1.3 carries equal amounts of Ca2+ current to Cav1.2 but activates at 9 mV more negative potentials. MCCs express only TTX-sensitive Nav1 channels that activate at 24 mV more positive potentials than Cav1.3 and are fully inactivating. Their blockade prevents the firing only in a small percentage of cells (13%). This suggests that the order of importance with regard to pacemaking MCCs is: Cav1.3, Cav1.2 and Nav1. The above conclusions, however, rely on the proper use of DHPs, whose blocking potency is strongly holding potential dependent. We also show that small increases of KCl concentration steadily depolarize the MCCs causing abnormally increased firing frequencies, lowered and broadened AP waveforms and an increased facility of switching “non-firing” into “firing” cells that may lead to erroneous conclusions about the role of Cav1.3 and Cav1.2 as pacemaker channels in MCCs.2 PMID:21406973

  12. Neuropeptide Y immunohistochemistry and ultrastructure of developing chromaffin tissue in the cloudy dogfish, Scyliorhinus torazame (Chondrichthyes, Elasmobranchii).

    PubMed

    Chiba, A

    2001-02-01

    Ontogenetic changes in neuropeptide Y-like immunoreactivity (NPY-LI) were studied in chromaffin tissue of the cloudy dogfish, Scyliorhinus torazame. In adults and post-hatching juveniles, NPY-LI was demonstrated in chromaffin cells, but not in ganglion cells and supporting cells. Immunoreactive fibers were also found in the axillary body (the major chromaffin tissue) of the adult fish. During the embryonic period, NPY-LI was found at first in chromaffin tissue in the 34-mm stage. In this stage, cells in the periphery of the tissue were positive for NPY. Afterwards, changes were not observed in the topography and relative dominance of labelled cells in the tissue. Transmission electron microscopy of chromaffin tissue of the 26-mm stage showed an early phase of histogenesis in rudimental cell clusters composed of agranular cells and a few granular cells, i.e. pheochromoblasts. In the 43-mm stage, differentiation of the chromaffin tissue enabled ultrastructural classification of adrenalin-producing cells, noradrenalin-producing cells, ganglion cells, supporting cells, and unmyelinated nerve fibers. These results suggest that in the dogfish the appearance of NPY-LI in the developing sympathoadrenal system is related to differentiation of chromaffin cells.

  13. Chromogranin A deficiency in transgenic mice leads to aberrant chromaffin granule biogenesis.

    PubMed

    Kim, Taeyoon; Zhang, Chun-fa; Sun, Ziqing; Wu, Heling; Loh, Y Peng

    2005-07-27

    The biogenesis of dense-core secretory granules (DCGs), organelles responsible for the storage and secretion of neurotransmitters and neuropeptides in chromaffin cells, is poorly understood. Chromogranin A (CgA), which binds catecholamines for storage in the lumen of chromaffin granules, has been shown to be involved in DCG biogenesis in neuroendocrine PC12 cells. Here, we report that downregulation of CgA expression in vivo by expressing antisense RNA against CgA in transgenic mice led to a significant reduction in DCG formation in adrenal chromaffin cells. The number of DCGs formed in CgA antisense transgenic mice was directly correlated with the amount of CgA present in adrenal medulla. In addition, DCGs showed an increase in size, with enlargement in the volume around the dense core, a phenomenon that occurs to maintain constant "free" catecholamine concentration in the lumen of these granules. The extent of DCG swelling was inversely correlated with the number of DCGs formed, as well as the amount of CgA present in the adrenal glands of CgA antisense transgenic mice. These data indicate an essential role of CgA in regulating chromaffin DCG biogenesis and catecholamine storage in vivo.

  14. Cell therapy of pain: Characterization of human fetal chromaffin cells at early adrenal medulla development.

    PubMed

    Zhou, H; Aziza, J; Sol, J C; Courtade-Saïdi, M; Chatelin, S; Evra, C; Parant, O; Lazorthes, Y; Jozan, S

    2006-04-01

    Adult adrenal chromaffin cells are being utilized for therapeutic transplantation. With the prospect of using fetal chromaffin cells in pain therapy, we studied their phenotype, proliferative power, function, and growth in vitro and in situ in order to determine the optimal time for implantation. Between 7 and 10 gestational weeks (GW), we isolated, in vitro, two types of chromaffin cells with a noradrenergic phenotype akin to that observed, in situ. Among the adherent chromaffin cells first observed in vitro, only a few samples expressed met-enkephalin, whereas almost all the neurosphere-like colonies, which appeared later, expressed it. However, neither of the two types of populations expressed an adrenergic phenotype in line with that observed in situ. At the upper limits of the voluntary abortion period authorized in France, this phenotype (12 GW) and met-enkephalin expression (13 GW) were evidenced in situ. For the first time in man, we demonstrate the secretion of noradrenaline in vitro by the two populations of cells. Consistent with this result, we also noted dopamine beta hydroxylase (DbetaH) mRNA expression in vitro and in situ within this period. These observations on the expression of these biological factors indicate that 9-10 GW would be the best stage for sampling these cells for preclinical transplantation experiments.

  15. [Effects of NGF on chromaffin adrenaline-containing cells of adrenal medulla of rabbits transplanted into brains of mice].

    PubMed

    Jousselin-Hosaja, M; Derbin, C

    1993-01-01

    The graft of chromaffin adrenaline-containing (A) cells of rabbit adrenal medulla implanted to mouse brain and treated with NGF contains more survived cells 1 month after grafting than adrenal medulla alone. The cells developed either an intermediate (e.g. chromaffin cell and neuron) or a neuron-like phenotypes accompanied with a decrease in an immunoreactivity for PNMT (phenyletanolamine-N-methyltransferase). A gap junctions and attached plaques were found between grafted cells. The grafts received a synaptic input. The NGF influence on the fate of chromaffin A-containing cells is discussed.

  16. [Evaluation of clinical utility of 123I-MIBG scintigraphy in localization of tumors of sympathetic and adrenomedullary origin--a report of multicenter phase III clinical trials].

    PubMed

    Ishii, K; Kubo, A; Kusakabe, K; Murata, H; Masaki, H; Horiike, S; Hayashi, A; Hara, Y

    2000-01-01

    Phase III clinical study was performed to evaluate clinical utility of 123I-MIBG in the localization of tumors in 48 patients with tumors of sympathetic and adrenomedullary origin, diagnosed or strongly suspected. Sixteen patients had pheochromocytoma, 23 had neuroblastoma, 7 had medullary carcinoma of the thyroid, and 2 had Sipple syndrome. In 3 out of 48 patients, 123I-MIBG scintigraphy was performed twice. The clinical utility of 123I-MIBG was evaluated in 50 cases. Out of 140 lesions, 123I-MIBG scintigraphy demonstrated 51 true positive, 79 true negative, 1 false positive, and 2 false negative. Seven lesions were not evaluable. Sensitivity was 96.2%, Specificity was 98.8%, and Accuracy was 97.7%. An acquisition between 4 hrs and a day after injection was adequate for tumor detection. Neither adverse reactions nor abnormal laboratory findings were noted in relation to 123I-MIBG injections. Our study indicates that 123I-MIBG is a safe and useful radiotracer for visualization and localization of tumors of sympathetic and adrenomedullary origin.

  17. Roles of brain phosphatidylinositol-specific phospholipase C and diacylglycerol lipase in centrally administered histamine-induced adrenomedullary outflow in rats.

    PubMed

    Shimizu, Takahiro; Yamaguchi, Naoko; Okada, Shoshiro; Lu, Lianyi; Sasaki, Tsuyoshi; Yokotani, Kunihiko

    2007-10-01

    Recently, we reported that intracerebroventricularly (i.c.v.) administered histamine evokes the secretion of noradrenaline and adrenaline from adrenal medulla by brain cyclooxygenase-1- and thromboxane A2-mediated mechanisms in rats. These results suggest the involvement of brain arachidonic acid cascade in the histamine-induced activation of the central adrenomedullary outflow. Arachidonic acid is released mainly by phospholipase A2 (PLA2)-dependent pathway or phospholipase C (PLC)/diacylglycerol lipase-dependent pathway. In the present study, histamine (27 nmol/animal, i.c.v.) -induced elevation of plasma noradrenaline and adrenaline was dose-dependently reduced by U-73122 (PLC inhibitor) (10 and 100 nmol/animal, i.c.v.), ET-18-OCH3 (phosphatidylinositol-specific PLC inhibitor) (10 and 30 nmol/animal, i.c.v.) and RHC-80267 (diacylglycerol lipase inhibitor) (1.3 and 2.6 micromol/animal, i.c.v.). However, mepacrine (PLA2 inhibitor) (1.1 and 2.2 micromol/animal, i.c.v.) and D609 (phosphatidylcholine-specific PLC inhibitor) (30, 100 and 300 nmol/animal, i.c.v.) had no effect. These results suggest the involvement of brain phosphatidylinositol-specific PLC and diacylglycerol lipase in the centrally administered histamine-induced activation of the adrenomedullary outflow in rats.

  18. Human fetal chromaffin cells: a potential tool for cell pain therapy.

    PubMed

    Jozan, Suzanne; Aziza, Jacqueline; Châtelin, Sophie; Evra, Corinne; Courtade-Saïdi, Monique; Parant, Olivier; Sol, Jean Christophe; Zhou, Huafang; Lazorthes, Yves

    2007-06-01

    Transplantation of adrenal medulla cells has been proposed in the treatment of various conditions. Indeed, these cells possess a bipotentiality: neural and neuroendocrine, which could be exploited for brain repair or pain therapy. In a previous study, we characterized these human cells in vitro over 7-10 gestational weeks (GW) [Zhou, H., Aziza, J., Sol, J.C., Courtade-Saidi, M., Chatelin, S., Evra, C., Parant, O., Lazorthes, Y., and Jozan, S., 2006. Cell therapy of pain: Characterization of human fetal chromaffin cells at early adrenal medulla development. Exp. Neurol. 198, 370-381]. We report here our results on the extension to 23 GW. This developmental period can be split into three stages. During the first stage (7-10 GW), we observed in situ that extra-adrenal surrounding cells display the same morphology and phenotype as the intra-adrenal chromaffin cells. We also found that the intra-adrenal chromaffin cells could be committed in vitro towards an adrenergic phenotype using differentiating agents. During the second stage (11 to 15-16 GW), two types of cells (Type 1 and Type 2 cells) were identified morphologically both inside and outside the gland. Interestingly, we noted that the Type 2 cells stem from the Type 1 cells. However, during this developmental period only the intra-adrenal Type 2 cells will evolve towards an adrenergic phenotype. In the third stage (17-23 GW), we observed the ultimate location of the medulla gland. Both the in situ results and the in vitro experiments indicate that particular procedures need to be implemented prior transplantation of chromaffin cells. First, in order to obtain a large number of immature chromaffin cells, they must be isolated from the intra and extra-adrenal gland and should then be committed towards an adrenergic phenotype in vitro for subsequent use in pain therapy. This strategy is under investigation in our laboratory.

  19. F-actin cytoskeleton and the fate of organelles in chromaffin cells.

    PubMed

    Villanueva, José; Gimenez-Molina, Yolanda; Viniegra, Salvador; Gutiérrez, Luis M

    2016-06-01

    In addition to playing a fundamental structural role, the F-actin cytoskeleton in neuroendocrine chromaffin cells has a prominent influence on governing the molecular mechanism and regulating the secretory process. Performing such roles, the F-actin network might be essential to first transport, and later locate the cellular organelles participating in the secretory cycle. Chromaffin granules are transported from the internal cytosolic regions to the cell periphery along microtubular and F-actin structures. Once in the cortical region, they are embedded in the F-actin network where these vesicles experience restrictions in motility. Similarly, mitochondria transport is affected by both microtubule and F-actin inhibitors and suffers increasing motion restrictions when they are located in the cortical region. Therefore, the F-actin cortex is a key factor in defining the existence of two populations of cortical and perinuclear granules and mitochondria which could be distinguished by their different location and mobility. Interestingly, other important organelles for controlling intracellular calcium levels, such as the endoplasmic reticulum network, present clear differences in distribution and much lower mobility than chromaffin vesicles and mitochondria. Nevertheless, both mitochondria and the endoplasmic reticulum appear to distribute in the proximity of secretory sites to fulfill a pivotal role, forming triads with calcium channels ensuring the fine tuning of the secretory response. This review presents the contributions that provide the basis for our current view regarding the influence that F-actin has on the distribution of organelles participating in the release of catecholamines in chromaffin cells, and summarizes this knowledge in simple models. In chromaffin cells, organelles such as granules and mitochondria distribute forming cortical and perinuclear populations whereas others like the ER present homogenous distributions. In the present review we discuss

  20. Isolation of a membrane protein by chromatofocusing: cytochrome b-561 of the adrenal chromaffin granule.

    PubMed

    Wakefield, L M; Cass, A E; Radda, G K

    1984-09-01

    Chromatofocusing, a form of ion-exchange chromatography in which proteins are separated on the basis of their differing isoelectric points, has been adapted for use with membrane proteins, solubilized by the non-ionic detergent Nonidet P-40. Using a two-step detergent extraction followed by chromatofocusing under high pressure, the highly hydrophobic protein cytochrome b-561 was isolated from chromaffin granule membranes and purified to near homogeneity in a functionally active form, in less than 5 h. Chromatofocusing conditions were optimized empirically since the behaviour of the chromaffin granule membrane proteins conformed less to the theory than that of soluble proteins, and the various factors affecting yield and resolution are discussed. The speed, high resolution and focusing effect could make this method particularly suitable for rapid isolation in a functionally active form of the many membrane proteins that are unstable in dilute solution and when removed from their lipid environment.

  1. Fluctuation analysis of nonselective cation currents induced by AIF complex in guinea-pig chromaffin cells.

    PubMed

    Inoue, M; Imanaga, I

    1996-11-11

    Properties of aluminium fluoride (AIF) complex-activated nonselective cation (NS) channels in guinea-pig chromaffin cells were investigated using the patch clamp technique. As the membrane potential was hyperpolarized from the holding potential of -55 mV, the AIF-induced nonselective cation current (INS) diminished progressively. With hyperpolarizations to -100 mV or more negative potentials, the AIF.INS almost instantaneously disappeared. The apparent unit conductance of AIF INS was estimated to be 3 pS by fluctuation analysis. The open state probability of AIF-activated NS channels became large with a decrease in concentration of free Mg2+ ions inside the cell and was less than 0.5 at 12 microM Mg2+. It is concluded that NS channels in the chromaffin cell apparently differ from those in smooth muscle cells.

  2. F-actin and myosin II accelerate catecholamine release from chromaffin granules

    PubMed Central

    Berberian, Khajak; Torres, Alexis J; Fang, Qinghua; Kisler, Kassandra

    2009-01-01

    The roles of non-muscle myosin II and cortical actin filaments in chromaffin granule exocytosis were studied by confocal fluorescence microscopy, amperometry, and cell-attached capacitance measurements. Fluorescence imaging indicated decreased mobility of granules near the plasma membrane following inhibition of myosin II function with Blebbistatin. Slower fusion pore expansion rates and longer fusion pore lifetimes were observed after inhibition of actin polymerization using Cytochalasin-D. Amperometric recordings revealed increased amperometric spike half-widths without change in quantal size after either myosin II inhibition or actin disruption. These results suggest that actin and myosin II facilitate release from individual chromaffin granules by accelerating dissociation of catecholamines from the intragranular matrix possibly through generation of mechanical forces. PMID:19158310

  3. Pannexin 1 channels: new actors in the regulation of catecholamine release from adrenal chromaffin cells

    PubMed Central

    Momboisse, Fanny; Olivares, María José; Báez-Matus, Ximena; Guerra, María José; Flores-Muñoz, Carolina; Sáez, Juan C.; Martínez, Agustín D.; Cárdenas, Ana M.

    2014-01-01

    Chromaffin cells of the adrenal gland medulla synthesize and store hormones and peptides, which are released into the blood circulation in response to stress. Among them, adrenaline is critical for the fight-or-flight response. This neurosecretory process is highly regulated and depends on cytosolic [Ca2+]. By forming channels at the plasma membrane, pannexin-1 (Panx1) is a protein involved in many physiological and pathological processes amplifying ATP release and/or Ca2+ signals. Here, we show that Panx1 is expressed in the adrenal gland where it plays a role by regulating the release of catecholamines. In fact, inhibitors of Panx1 channels, such as carbenoxolone (Cbx) and probenecid, reduced the secretory activity induced with the nicotinic agonist 1,1-dimethyl-4-phenyl-piperazinium (DMPP, 50 μM) in whole adrenal glands. A similar inhibitory effect was observed in single chromaffin cells using Cbx or 10Panx1 peptide, another Panx1 channel inhibitors. Given that the secretory response depends on cytosolic [Ca2+] and Panx1 channels are permeable to Ca2+, we studied the possible implication of Panx1 channels in the Ca2+ signaling occurring during the secretory process. In support of this possibility, Panx1 channel inhibitors significantly reduced the Ca2+ signals evoked by DMPP in single chromaffin cells. However, the Ca2+ signals induced by caffeine in the absence of extracellular Ca2+ was not affected by Panx1 channel inhibitors, suggesting that this mechanism does not involve Ca2+ release from the endoplasmic reticulum. Conversely, Panx1 inhibitors significantly blocked the DMPP-induce dye uptake, supporting the idea that Panx1 forms functional channels at the plasma membrane. These findings indicate that Panx1 channels participate in the control the Ca2+ signal that triggers the secretory response of adrenal chromaffin cells. This mechanism could have physiological implications during the response to stress. PMID:25237296

  4. Blocking effects of otilonium on Ca2+ channels and secretion in rat chromaffin cells.

    PubMed

    Gandía, L; López, M G; Villarroya, M; Gilabert, J A; Cárdenas, A; García, A G; Borges, R

    1996-03-07

    We describe here the effects of otilonium bromide (an anticholinergic agent widely used as an intestinal spasmolytic) on whole-cell currents through Ca2+ channels (IBa) and catecholamine secretion in rat adrenal glands and isolated rat chromaffin cells. Otilonium blocked the peak IBa current in voltage-clamped chromaffin cells in a concentration-dependent manner; the IC50 to block IBa was 4.7 microM. Blockade was not accompanied by a significant shift in the I-V relationship for IBa, suggesting that such blockade was not affecting a specific subtype of Ca2+ channel. When given intracellularly through the patch pipette, otilonium (10 microM) did not block IBa. However, its external application to the same cell (10 microM) reversibly reduced IBa by 70%. Otilonium caused a concentration-dependent blockade of catecholamine release from perfused rat adrenal glands intermittently stimulated with methacholine, high K+ or histamine. The IC50 to block secretion after a 5 min incubation with otilonium was 0.02, 0.7 and 3 microM, respectively, for methacholine, K+ and histamine. The blocking effects of otilonium were fully reversible at concentrations below 10 microM. The Ca2+ channel agonist Bay K 8644 (methyl-1,4-dihydro-2,6-dimethyl-3-nitro-4-(2-trifluoromethylphenyl)-pyr idine-5- carboxylate) partially antagonized the effects of otilonium on K(+)-evoked secretion and accelerated the time course of recovery from inhibition. The results are compatible with the idea that otilonium blocks Ca2+ entry into chromaffin cells by blocking voltage-dependent Ca2+ channels. This would lead to a limitation in the rise in cytosolic Ca2+ at secretory sites and to inhibition of catecholamine release in response to stimulation of chromaffin cells.

  5. Monkey Adrenal Chromaffin Cells Express α6β4* Nicotinic Acetylcholine Receptors

    PubMed Central

    Scadden, Mick´l; Carmona-Hidalgo, Beatriz; McIntosh, J. Michael; Albillos, Almudena

    2014-01-01

    Nicotinic acetylcholine receptors (nAChRs) that contain α6 and β4 subunits have been demonstrated functionally in human adrenal chromaffin cells, rat dorsal root ganglion neurons, and on noradrenergic terminals in the hippocampus of adolescent mice. In human adrenal chromaffin cells, α6β4* nAChRs (the asterisk denotes the possible presence of additional subunits) are the predominant subtype whereas in rodents, the predominant nAChR is the α3β4* subtype. Here we present molecular and pharmacological evidence that chromaffin cells from monkey (Macaca mulatta) also express α6β4* receptors. PCR was used to show the presence of transcripts for α6 and β4 subunits and pharmacological characterization was performed using patch-clamp electrophysiology in combination with α-conotoxins that target the α6β4* subtype. Acetylcholine-evoked currents were sensitive to inhibition by BuIA[T5A,P6O] and MII[H9A,L15A]; α-conotoxins that inhibit α6-containing nAChRs. Two additional agonists were used to probe for the expression of α7 and β2-containing nAChRs. Cells with currents evoked by acetylcholine were relatively unresponsive to the α7-selctive agonist choline but responded to the agonist 5-I-A-85380. These studies provide further insights into the properties of natively expressed α6β4* nAChRs. PMID:24727685

  6. Adrenal chromaffin cells do not swell when exposed to nanosecond electric pulses.

    PubMed

    Craviso, Gale L; Fisher, Christa; Chatterjee, Indira; Vernier, P Thomas

    2015-06-01

    High intensity, nanosecond duration electric pulses (NEPs) permeabilize plasma membranes causing osmotic cell swelling that can elicit a wide variety of cellular effects. This study examined the possibility that cell swelling is the mechanism by which 5 ns NEPs trigger the release of catecholamines from neuroendocrine adrenal chromaffin cells. Swelling was assessed by comparing measurements of cell area obtained from bright field images of the cells before and at 10s intervals following exposure of the cells to 5 ns pulses at a field intensity of 5-6 MV/m. The results indicated that chromaffin cells do not swell in response to a single pulse or a train of ten pulses delivered at repetition frequencies of 10 Hz and 1 kHz. Swelling was also not observed in response to a train of 50 pulses whereas Jurkat T lymphoblast cell area increased 15% on average under the same NEP exposure conditions. These results demonstrating that chromaffin cells do not undergo swelling when exposed to 5 ns NEPs have important implications regarding the mechanism by which these pulses stimulate the release of catecholamines from these cells, namely that catecholamine secretion is most likely not caused by cell swelling.

  7. Monkey adrenal chromaffin cells express α6β4* nicotinic acetylcholine receptors.

    PubMed

    Hernández-Vivanco, Alicia; Hone, Arik J; Scadden, Mick L; Carmona-Hidalgo, Beatriz; McIntosh, J Michael; Albillos, Almudena

    2014-01-01

    Nicotinic acetylcholine receptors (nAChRs) that contain α6 and β4 subunits have been demonstrated functionally in human adrenal chromaffin cells, rat dorsal root ganglion neurons, and on noradrenergic terminals in the hippocampus of adolescent mice. In human adrenal chromaffin cells, α6β4* nAChRs (the asterisk denotes the possible presence of additional subunits) are the predominant subtype whereas in rodents, the predominant nAChR is the α3β4* subtype. Here we present molecular and pharmacological evidence that chromaffin cells from monkey (Macaca mulatta) also express α6β4* receptors. PCR was used to show the presence of transcripts for α6 and β4 subunits and pharmacological characterization was performed using patch-clamp electrophysiology in combination with α-conotoxins that target the α6β4* subtype. Acetylcholine-evoked currents were sensitive to inhibition by BuIA[T5A,P6O] and MII[H9A,L15A]; α-conotoxins that inhibit α6-containing nAChRs. Two additional agonists were used to probe for the expression of α7 and β2-containing nAChRs. Cells with currents evoked by acetylcholine were relatively unresponsive to the α7-selctive agonist choline but responded to the agonist 5-I-A-85380. These studies provide further insights into the properties of natively expressed α6β4* nAChRs.

  8. Osmotic pressures of solutions of ATP and catecholamines relating to storage in chromaffin granules.

    PubMed

    Kopell, W N; Westhead, E W

    1982-05-25

    The chromaffin granule, which is the catecholamine storage organelle of the adrenal medulla, contains at least 0.73 M ions, yet it is isotonic with 0.3 osM solutions. One hypothesis which accounts for this disparity is formation of a complex between major constituents of the granule: the catecholamines, the proteins, and the ATP. In this paper we show by vapor pressure osmometry, which affords a direct measure of colligative properties, that ATP-catecholamine mixtures form highly nonideal solutions. At 37 degrees C, solutions containing 0.6 M epinephrine and 0.15 M ATP show an effective osmotic pressure of only 0.25 osM. The existence of polymeric complexes is implied by the fact that the increase of osmotic pressure with increasing concentrations of ATP and catecholamine falls off substantially at concentrations approaching those in the chromaffin granules. Neither inorganic ions nor calcium chelators cause regain of ideal colligative behavior. Osmotic measurements on model compounds suggest that the primary interaction is between the phosphate and amino groups. There is also evidence that the effects are not wholly due to the formation of discrete complexes; factors of nonideal solution behavior also play a role in lowering the osmotic pressure. These observations show that the stability of the chromaffin granule in situ can be accounted for, perhaps entirely, by spontaneous interactions among nucleotides and catecholamines.

  9. Maternal perinatal undernutrition impairs chromaffin cells proliferation in the postnatal rat.

    PubMed

    Molendi-Coste, O; Mairesse, J; Aubert, N; Ghzili, H; Abbadie, C; Vaudry, H; Gonzalez, B; Anouar, Y; Vieau, D; Breton, C; Laborie, C

    2008-06-01

    Numerous data show that malnutrition during early life programs chronic diseases in adulthood. Many of these disorders may result from alterations in the development of neuroendocrine systems, such as the hypothalamo-pituitary-adrenal axis and the sympathoadrenal system. We have previously reported that maternal 50% food restriction during late pregnancy and lactation reduces adrenal weight and impairs chromaffin cell differentiation in male rats at weaning. In addition, maternal undernutrition modifies the expression of several genes involved in proliferation and apoptosis. This study therefore investigated the impact of maternal food restriction on adrenal cell growth in the late postnatal rat. Histological analysis showed that the number of proliferating chromaffin cells assessed by nuclear labelling with BrdU was reduced by 45%, whereas the level of apoptosis visualised by caspase-3 immunoreactivity was increased by 340% in adrenal medulla of offspring from undernourished mothers. In contrast, maternal food restriction did not affect proliferation and apoptosis in cortical cells of rats. These developmental changes were associated with overexpression of TGFbeta2. These data show that perinatal undernutrition impairs the balance between chromaffin cell proliferation and apoptosis. These modifications may lead to "malprogramming" of adrenal medulla development, which could contribute to the pathogenesis of chronic diseases in adulthood.

  10. Kidney-Tonifying Recipe Can Repair Alterations in Adrenal Medullary Chromaffin Cells in Asthmatic Rats

    PubMed Central

    Hu, Cheng-Ping; Zou, Jun-Tao; Zou, Ye-Qiang; Li, Xiao-Zhao; Feng, Jun-Tao

    2012-01-01

    Traditional Chinese medicine suggests that renal deficiency is a causative factor of asthma, and tonifying kidney drugs are believed to be an appropriate and beneficial treatment. The adrenal medullary chromaffin cells (AMCC) transition to the neuronal phenotype is known to occur in asthma, as evidenced by degranulation of chromaffin granules, decline of epinephrine (EPI) and phenylethanolamine-n-methyl transferase (PNMT), and obvious alterations in cellular architecture. In this study, rats were sensitized and challenged with ovalbumin, then treated with Kidney-Tonifying Recipe (KTR) to evaluate the therapeutic effect. Tissues were evaluated for changes in pathology and EPI, PNMT, and peripherin expression. Degranulation of chromaffin granules and appearance of neurite-like process were found in AMCC from asthmatic rats, and these changes were corrected by KTR treatment. EPI and PNMT expressions were decreased in asthmatic rats and increased by KTR treatment. Peripherin expression was increased in asthmatic rats and decreased in the KTR-treated group. Morphological changes and decreases in EPI were observed when cultured AMCC were exposed to sera from asthmatic rats in vitro, and these changes were attenuated with the addition of sera from KRT-treated rats. These results suggest that the Kidney-Tonifying Recipe is capable of repairing asthma-associated alterations in endocrine function and the ultrastructure of AMCC. PMID:22474509

  11. Isolation of ATPase I, the proton pump of chromaffin-granule membranes.

    PubMed Central

    Percy, J M; Pryde, J G; Apps, D K

    1985-01-01

    Chromaffin-granule membranes contain two ATPases, which can be separated by (NH4)2SO4 fractionation after solubilization with detergents, or by phase segregation in Triton X-114. ATPase I (Mr 400000) is inhibited by trialkyltin, quercetin and alkylating agents, and hydrolyses both ATP and ITP. It contains up to five types of subunit, including a low-Mr hydrophobic polypeptide that reacts with dicyclohexylcarbodi-imide; these subunits are unrelated to those of mitochondrial F1F0-ATPase, as judged by size and reaction with antibodies. ATPase II (Mr 140000) is inhibited by vanadate, and is specific for ATP; it has not been extensively purified. Proton translocation by resealed chromaffin-granule 'ghosts', measured by uptake of methylamine or by quenching of the fluorescence of 9-amino-6-chloro-2-methoxyacridine, is supported by the hydrolysis of ATP or ITP, and inhibited by quercetin or alkylating agents, but not by vanadate. ATPase I must therefore be the proton translocator involved in the uptake of catecholamines and possibly of other components of the chromaffin-granule matrix, whereas ATPase II does not translocate protons. Images Fig. 1. PMID:3000354

  12. Purification of N-ethylmaleimide-sensitive ATPase from chromaffin granule membranes

    SciTech Connect

    Cidon, S.; Nelson, N.

    1986-07-15

    An N-ethylmaleimide-sensitive ATPase was purified 100-fold from chromaffin granule membranes. The purification procedure included solubilization with polyoxyethylene 9 lauryl ether, chromatography on hydroxylapatite and DEAE-cellulose columns, and glycerol gradient centrifugations. Inclusion of phosphatidylserine and a mixture of protease inhibitors during the purification procedure was necessary to maintain the activity of the preparation. The purified preparation contained four major polypeptides with molecular masses of about 115, 72, 57, and 39 kDa, which were copurified with the ATPase activity. The 115-kDa subunit binds (/sup 14/C)dicyclohexylcarbodiimide and the subunits of 115 and 39 kDa bind (/sup 14/C)N-ethylmaleimide. The ATP-dependent proton uptake activity of chromaffin granule membranes is inhibited 50% with about 20 microM N-ethylmaleimide, while over 5 mM concentrations of the inhibitor were required to block the ATPase activity of the membranes. The ATPase activity of the purified enzyme was inhibited via two different affinities: a high affinity site with a Ki in the microM range and a low affinity site in the mM range, each contributing to about 50% inhibition of the enzyme. It is concluded that the proton-ATPase of chromaffin granule membranes contains at least four subunits with the 115-kDa polypeptide being the main subunit having the active site for the ATPase activity of the enzyme.

  13. Membrane Toxicity of Abnormal Prion Protein in Adrenal Chromaffin Cells of Scrapie Infected Sheep

    PubMed Central

    McGovern, Gillian; Jeffrey, Martin

    2013-01-01

    Transmissible spongiform encephalopathies (TSEs) or prion diseases are associated with accumulations of disease specific PrP (PrPd) in the central nervous system (CNS) and often the lymphoreticular system (LRS). Accumulations have additionally been recorded in other tissues including the peripheral nervous system and adrenal gland. Here we investigate the effect of sheep scrapie on the morphology and the accumulation of PrPd in the adrenal medulla of scrapie affected sheep using light and electron microscopy. Using immunogold electron microscopy, non-fibrillar forms of PrPd were shown to accumulate mainly in association with chromaffin cells, occasional nerve endings and macrophages. PrPd accumulation was associated with distinctive membrane changes of chromaffin cells including increased electron density, abnormal linearity and invaginations. Internalisation of PrPd from the chromaffin cell plasma membrane occurred in association with granule recycling following hormone exocytosis. PrPd accumulation and internalisation from membranes is similarly associated with perturbations of membrane structure and trafficking in CNS neurons and tingible body macrophages of the LRS. These data suggest that a major toxic effect of PrPd is at the level of plasma membranes. However, the precise nature of PrPd-membrane toxicity is tissue and cell specific suggesting that the normal protein may act as a multi-functional scaffolding molecule. We further suggest that the co-localisation of PrPd with exocytic granules of the hormone trafficking system may provide an additional source of infectivity in blood. PMID:23469286

  14. Effects of the neuroprotectant lubeluzole on the cytotoxic actions of veratridine, barium, ouabain and 6-hydroxydopamine in chromaffin cells

    PubMed Central

    Cano-Abad, María F; López, Manuela G; Hernández-Guijo, Jesús M; Zapater, Pedro; Gandía, Luis; Sánchez-García, Pedro; García, Antonio G

    1998-01-01

    Incubation of bovine adrenal chromaffin cells with veratridine (10–100 μM) during 24 h, caused a concentration-dependent release of the cytosolic lactate dehydrogenase (LDH) into the bathing medium, an indicator of cell death. Lubeluzole or its R(−) enantiomer, R91154, did not enhance LDH release. Both lubeluzole and R91154 (0.3–10 μM) decreased the veratridine-induced LDH release. Penfluridol did not increase LDH release at concentrations 0.003–1 μM; 3–10 μM increased LDH release to 50–60%, after 24 h exposure. Penfluridol (0.03–0.3 μM) did not protect against the cytotoxic effects of veratridine; at 1 μM, 15% protection was produced. Higher concentrations (3–10 μM) enhanced the cytotoxic effects of veratridine. Ba2+ ions caused a concentration-dependent increase of LDH release. This cytotoxic effect was partially prevented by 3 μM lubeluzole and fully counteracted by 1 μM penfluridol. R91154 was less potent than lubeluzole and only protected against the lesion induced by 0.5 mM Ba2+. Ouabain (10 μM during 24 h) increased LDH release to about 30%. Both lubeluzole (0.3–10 μM) and the lower concentrations of penfluridol (0.003–0.3 μM) prevented the ouabain cytotoxic effects. At higher concentrations (3 μM), penfluridol increased drastically the ouabain cytotoxic effects. 6-Hydroxydopamine (6-OHDA) caused significant cytotoxic effects at 30 and 100 μM. Lubeluzole (3–10 μM) or penfluridol (0.03–0.3 μM) had no cytoprotective effects against 6-OHDA. Lubeluzole (3 μM), R91154 (3 μM) and penfluridol (1 μM) blocked the current through Na+ channels in voltage-clamped chromaffin cells (INa) by around 20–30%. Ca2+ current through Ca2+ channels (ICa) was inhibited 57% by lubeluzole and R91154 and 50% by penfluridol. The effects of penfluridol were not washed out, but those of lubeluzole and R91154 were readily reversible. Lubeluzole (3 μM) induced reversible blockade of the

  15. Purification and characterization of bovine adrenal cytochrome b561 expressed in insect and yeast cell systems.

    PubMed

    Liu, Wen; Kamensky, Yury; Kakkar, Reva; Foley, Erin; Kulmacz, Richard J; Palmer, Graham

    2005-04-01

    Bovine adrenal chromaffin granule cytochrome (cyt) b561 is a transmembrane hemoprotein that plays a key role in transporting reducing equivalents from ascorbate to dopamine-beta-hydroxylase for catecholamine synthesis. We have developed procedures for expression and purification of functional bovine adrenal cyt b561 in insect and yeast cell systems. The bovine cyt b561 coding sequence, with or without a hexahistidine-tag sequence at the C-terminus, was cloned into the pVL1392 transfer vector under the control of the polyhedrin promoter to generate recombinant baculovirus for protein expression in Sf9 insect cells (approximately 0.5 mg detergent-solubilized cyt b561/L culture). For the yeast system, the cyt b561 cDNA was modified with a hexahistidine-tag sequence at the C-terminus, and inserted into the pPICZB vector under the control of the alcohol oxidase promoter. The recombinant plasmid was transformed into Pichia pastoris GS115 competent cells to give methanol-inducible cyt b561 expression (approximately 0.7 mg detergent-solubilized cyt b561/L culture). Recombinant His-tagged cyt b561 expressed in Sf9 or Pichia cells was readily solubilized from membrane fractions with dodecyl maltoside and purified to electrophoretic homogeneity by one-step chromatography on Ni-NTA affinity resin. The purified recombinant cytochrome from both systems had a heme to protein ratio close to two and was fully functional, as judged by comparison with the spectroscopic and kinetic parameters of the endogenous cytochrome from chromaffin granules. A novel procedure for isolation of chromaffin granule membranes was developed to utilize frozen adrenal glands instead of fresh tissue.

  16. Evidence for a dihydropyridine-sensitive and conotoxin-insensitive release of noradrenaline and uptake of calcium in adrenal chromaffin cells.

    PubMed Central

    Owen, P. J.; Marriott, D. B.; Boarder, M. R.

    1989-01-01

    1. It has been suggested that neuronal voltage-sensitive calcium channels (VSCC) may be divided into dihydropyridine (DHP)-sensitive (L) and DHP-insensitive (N and T), and that both the L and the N type channels are attenuated by the peptide blocker omega-conotoxin. Here the effects of omega-conotoxin on release of noradrenaline and uptake of calcium in bovine adrenal chromaffin cells were investigated. 2. Release of noradrenaline in response to 25 mM K+, 65 mM K+, 10 nM bradykinin or 10 microM prostaglandin E1 was not affected by omega-conotoxin in the range 10 nM-1 microM. 3. 45Ca2+ uptake stimulated by high K+ and prostaglandin was attenuated by 1 microM nitrendipine and enhanced by 1 microM Bay K 8644; these calcium fluxes were not modified by 20 nM omega-conotoxin. 4. With superfused rat brain striatal slices in the same medium as the above cell studies, release of dopamine in response to 25 mM K+ was attenuated by 20 nM omega-conotoxin. 5. These results show that in these neurone-like cells, release may be effected by calcium influx through DHP-sensitive but omega-conotoxin-insensitive VSCC, a result inconsistent with the suggestion that omega-conotoxin blocks both L-type and N-type neuronal calcium channels. PMID:2470457

  17. Nature of rate-limiting steps in a compartmentalized enzyme system. Quantitation of dopamine transport and hydroxylation rates in resealed chromaffin granule ghosts

    SciTech Connect

    Ahn, N.G.; Klinman, J.P.

    1989-07-25

    Using isolated chromaffin granule ghosts from bovine adrenal medullae, we have studied the kinetics of dopamine beta-monooxygenase (D beta M) activity as it is linked to dopamine transport. Measurements of the initial rates of transport and of transport-linked norepinephrine formation suggested that enzyme activity may be partially rate-limiting in the coupled carrier/enzyme system. This was confirmed by (i) measurements of initial rates of norepinephrine formation using deuterated substrate, which gave isotope effects greater than 2.0, and (ii) kinetic measurements using ghosts pulsed with varying concentrations of labeled dopamine, which indicated substantial substrate accumulation in the vesicle interior as a function of time. Initial rates of product formation, when combined with approximations of internal substrate concentrations, allowed estimates of Kcat and Km for intravesicular D beta M. Activation by external reductant was apparent in both initial rate parameters and the measurements of transients. Under conditions of optimal D beta M activity, the enzyme rate parameters (kcat = 0.31 nmol/s.mg and Km = 2 mM) indicated partial rate limitation compared to dopamine transport (kcat = 0.38 nmol/s.mg and Km = 32 microM). Compartmental analysis of the time curves, performed using numerical nonlinear least squares methods, gave least squares estimates of rate constants for a simple carrier mechanism and kcat values for D beta M which were consistent with estimates from initial rates.

  18. Functional chromaffin cell plasticity in response to stress: focus on nicotinic, gap junction, and voltage-gated Ca2+ channels

    PubMed Central

    Guérineau, Nathalie C.; Desarménien, Michel G.; Carabelli, Valentina; Carbone, Emilio

    2012-01-01

    An increase in circulating catecholamines constitutes one of the mechanisms whereby human body responds to stress. In response to chronic stressful situations, the adrenal medullary tissue exhibits crucial morphological and functional changes that are consistent with an improvement of chromaffin cell stimulus-secretion coupling efficiency. Stimulus-secretion coupling encompasses multiple intracellular (chromaffin cell excitability, Ca2+ signaling, exocytosis, endocytosis) and intercellular pathways (splanchnic nerve-mediated synaptic transmission, paracrine and endocrine communication, gap junctional coupling), each of them being potentially subjected to functional remodeling upon stress. This review focuses on three chromaffin cell incontrovertible actors, the cholinergic nicotinic receptors and the voltage-dependent T-type Ca2+ channels that are directly involved in Ca2+-dependent events controlling catecholamine secretion and electrical activity, and the gap junctional communication involved in the modulation of catecholamine secretion. We show here that these three actors react differently to various stressors, sometimes independently, sometimes in concert or in opposition. PMID:22252244

  19. Differences in CART expression and cell cycle behavior discriminate sympathetic neuroblast from chromaffin cell lineages in mouse sympathoadrenal cells.

    PubMed

    Chan, Wing Hei; Gonsalvez, David G; Young, Heather M; Southard-Smith, E Michelle; Cane, Kylie N; Anderson, Colin R

    2016-02-01

    Adrenal medullary chromaffin cells and peripheral sympathetic neurons originate from a common sympathoadrenal (SA) progenitor cell. The timing and phenotypic changes that mark this lineage diversification are not fully understood. The present study investigated the expression patterns of phenotypic markers, and cell cycle dynamics, in the adrenal medulla and the neighboring suprarenal ganglion of embryonic mice. The noradrenergic marker, tyrosine hydroxylase (TH), was detected in both presumptive adrenal medulla and sympathetic ganglion cells, but with significantly stronger immunostaining in the former. There was intense cocaine and amphetamine-regulated transcript (CART) peptide immunostaining in most neuroblasts, whereas very few adrenal chromaffin cells showed detectable CART immunostaining. This phenotypic segregation appeared as early as E12.5, before anatomical segregation of the two cell types. Cell cycle dynamics were also examined. Initially, 88% of Sox10 positive (+) neural crest progenitors were proliferating at E10.5. Many SA progenitor cells withdrew from the cell cycle at E11.5 as they started to express TH. Whereas 70% of neuroblasts (TH+/CART+ cells) were back in the cell cycle at E12.5, only around 20% of chromaffin (CART negative) cells were in the cell cycle at E12.5 and subsequent days. Thus, chromaffin cell and neuroblast lineages showed differences in proliferative behavior from their earliest appearance. We conclude that the intensity of TH immunostaining and the expression of CART permit early discrimination of chromaffin cells and sympathetic neuroblasts, and that developing chromaffin cells exhibit significantly lower proliferative activity relative to sympathetic neuroblasts.

  20. The autonomic nervous system and chromaffin tissue: neuroendocrine regulation of catecholamine secretion in non-mammalian vertebrates.

    PubMed

    Perry, Steve F; Capaldo, Anna

    2011-11-16

    If severe enough, periods of acute stress in animals may be associated with the release of catecholamine hormones (noradrenaline and adrenaline) into the circulation; a response termed the acute humoral adrenergic stress response. The release of catecholamines from the sites of storage, the chromaffin cells, is under neuroendocrine control, the complexity of which appears to increase through phylogeny. In the agnathans, the earliest branching vertebrates, the chromaffin cells which are localized predominantly within the heart, lack neuronal innervation and thus catecholamine secretion in these animals is initiated solely by humoral mechanisms. In the more advanced teleost fish, the chromaffin cells are largely confined to the walls of the posterior cardinal vein at the level of the head kidney where they are intermingled with the steroidogenic interrenal cells. Catecholamine secretion from teleost chromaffin cells is regulated by a host of cholinergic and non-cholinergic pathways that ensure sufficient redundancy and flexibility in the secretion process to permit synchronized responses to a myriad of stressors. The complexity of catecholamine secretion control mechanisms continues through the amphibians, reptiles and birds although neural (cholinergic) regulation may become increasingly important in birds. Discrete adrenal glands are present in the non-mammalian tetrapods but unlike in mammals, there is no clear division of a steroidogenic cortex and a chromaffin cell enriched medulla. However, in all groups, there is an obvious intermingling of chromaffin and steroiodogenic cells. The association of the two cell types may be particularly important in the amphibians and birds because like in mammals, the enzyme catalysing the methylation of noradrenaline to adrenaline, PNMT, is under the control of the steroid cortisol.

  1. GABAB receptors modulate catecholamine secretion in chromaffin cells by a mechanism involving cyclic AMP formation.

    PubMed

    Oset-Gasque, M J; Parramón, M; González, M P

    1993-12-01

    1. The function of gamma-aminobutyric acidB (GABAB) receptors in modulation of catecholamine secretion by chromaffin cells and the possible mechanism involved in this action have been examined. 2. The GABAB agonists (-)-baclofen and 3-aminopropylphosphinic acid (3-APPA) were found to induce a dose-dependent increase of basal catecholamine secretion. The EC50s were 151 +/- 35 microM and 225 +/- 58 microM for baclofen and 3-APPA, respectively. This stimulatory effect was specific since it could be blocked by 0.5 mM of the specific GABAB antagonist CGP-35348. 3. In contrast, preincubation of chromaffin cells with the GABAB agonists was found to inhibit, in a dose-dependent manner, the catecholamine secretion evoked by 10 microM nicotine and 200 microM muscimol. 4. The effects of GABAB agonists on both basal and evoked catecholamine secretion were found to be accompanied by parallel changes in intracellular calcium concentration ([Ca2+]i). GABAB agonists produced a dose-dependent increase in [Ca2+]i which was partially blocked by CGP 35348, but they produced a strong inhibition of the [Ca2+]i increase induced by nicotine and muscimol. 5. The GABAB agonists also produced a dose-dependent increase in intracellular cyclic AMP levels, there being a direct correlation between both increase in catecholamine secretion and in intracellular cyclic AMP levels. 6. The pretreatment of chromaffin cells with pertussis toxin doubled the catecholamine secretion and increased by four times the intracellular cyclic AMP levels evoked by GABAB agonists. 7. The possible involvement of adenylate cyclase in the mechanism of GABAA receptor modulation of catecholamine secretion is discussed.

  2. Membrane toxicity of abnormal prion protein in adrenal chromaffin cells of scrapie infected sheep.

    PubMed

    McGovern, Gillian; Jeffrey, Martin

    2013-01-01

    Transmissible spongiform encephalopathies (TSEs) or prion diseases are associated with accumulations of disease specific PrP (PrP(d)) in the central nervous system (CNS) and often the lymphoreticular system (LRS). Accumulations have additionally been recorded in other tissues including the peripheral nervous system and adrenal gland. Here we investigate the effect of sheep scrapie on the morphology and the accumulation of PrP(d) in the adrenal medulla of scrapie affected sheep using light and electron microscopy. Using immunogold electron microscopy, non-fibrillar forms of PrP(d) were shown to accumulate mainly in association with chromaffin cells, occasional nerve endings and macrophages. PrP(d) accumulation was associated with distinctive membrane changes of chromaffin cells including increased electron density, abnormal linearity and invaginations. Internalisation of PrP(d) from the chromaffin cell plasma membrane occurred in association with granule recycling following hormone exocytosis. PrP(d) accumulation and internalisation from membranes is similarly associated with perturbations of membrane structure and trafficking in CNS neurons and tingible body macrophages of the LRS. These data suggest that a major toxic effect of PrP(d) is at the level of plasma membranes. However, the precise nature of PrP(d)-membrane toxicity is tissue and cell specific suggesting that the normal protein may act as a multi-functional scaffolding molecule. We further suggest that the co-localisation of PrP(d) with exocytic granules of the hormone trafficking system may provide an additional source of infectivity in blood.

  3. Cathepsin L colocalizes with chromogranin a in chromaffin vesicles to generate active peptides.

    PubMed

    Biswas, Nilima; Rodriguez-Flores, Juan L; Courel, Maite; Gayen, Jiaur R; Vaingankar, Sucheta M; Mahata, Manjula; Torpey, Justin W; Taupenot, Laurent; O'Connor, Daniel T; Mahata, Sushil K

    2009-08-01

    Chromogranin A (CgA), the major soluble protein in chromaffin granules, is proteolytically processed to generate biologically active peptides including the catecholamine release inhibitory peptide catestatin. Here we sought to determine whether cysteine protease cathepsin L (CTSL), a novel enzyme for proteolytic processing of neuropeptides, acts like the well-established serine proteases [prohormone convertase (PC)1/3 or PC2] to generate catestatin by proteolytic processing of CgA. We found that endogenous CTSL colocalizes with CgA in the secretory vesicles of primary rat chromaffin cells. Transfection of PC12 cells with an expression plasmid encoding CTSL directed expression of CTSL toward secretory vesicles. Deconvolution fluorescence microscopy suggested greater colocalization of CTSL with CgA than the lysosomal marker LGP110. The overexpression of CTSL in PC12 cells caused cleavage of full-length CgA. CTSL also cleaved CgA in vitro, in time- and dose-dependent fashion, and specificity of the process was documented through E64 (thiol reagent) inhibition. Mass spectrometry on CTSL-digested recombinant CgA identified a catestatin-region peptide, corresponding to CgA(360-373). The pool of peptides generated from the CTSL cleavage of CgA inhibited nicotine-induced catecholamine secretion from PC12 cells. CTSL processing in the catestatin region was diminished by naturally occurring catestatin variants, especially Pro370Leu and Gly364Ser. Among the CTSL-generated peptides, a subset matched those found in the catestatin region in vivo. These findings indicate that CgA can be a substrate for the cysteine protease CTSL both in vitro and in cella, and their colocalization within chromaffin granules in cella suggests the likelihood of an enzyme/substrate relationship in vivo.

  4. GABAB receptors modulate catecholamine secretion in chromaffin cells by a mechanism involving cyclic AMP formation.

    PubMed Central

    Oset-Gasque, M. J.; Parramón, M.; González, M. P.

    1993-01-01

    1. The function of gamma-aminobutyric acidB (GABAB) receptors in modulation of catecholamine secretion by chromaffin cells and the possible mechanism involved in this action have been examined. 2. The GABAB agonists (-)-baclofen and 3-aminopropylphosphinic acid (3-APPA) were found to induce a dose-dependent increase of basal catecholamine secretion. The EC50s were 151 +/- 35 microM and 225 +/- 58 microM for baclofen and 3-APPA, respectively. This stimulatory effect was specific since it could be blocked by 0.5 mM of the specific GABAB antagonist CGP-35348. 3. In contrast, preincubation of chromaffin cells with the GABAB agonists was found to inhibit, in a dose-dependent manner, the catecholamine secretion evoked by 10 microM nicotine and 200 microM muscimol. 4. The effects of GABAB agonists on both basal and evoked catecholamine secretion were found to be accompanied by parallel changes in intracellular calcium concentration ([Ca2+]i). GABAB agonists produced a dose-dependent increase in [Ca2+]i which was partially blocked by CGP 35348, but they produced a strong inhibition of the [Ca2+]i increase induced by nicotine and muscimol. 5. The GABAB agonists also produced a dose-dependent increase in intracellular cyclic AMP levels, there being a direct correlation between both increase in catecholamine secretion and in intracellular cyclic AMP levels. 6. The pretreatment of chromaffin cells with pertussis toxin doubled the catecholamine secretion and increased by four times the intracellular cyclic AMP levels evoked by GABAB agonists. 7. The possible involvement of adenylate cyclase in the mechanism of GABAA receptor modulation of catecholamine secretion is discussed. PMID:8306105

  5. Dynamin and Myosin Regulate Differential Exocytosis from Mouse Adrenal Chromaffin Cells

    PubMed Central

    Chan, Shyue-An; Doreian, Bryan; Smith, Corey

    2011-01-01

    Neuroendocrine chromaffin cells of the adrenal medulla represent a primary output for the sympathetic nervous system. Chromaffin cells release catecholamine as well as vaso- and neuro-active peptide transmitters into the circulation through exocytic fusion of large dense-core secretory granules. Under basal sympathetic activity, chromaffin cells selectively release modest levels of catecholamines, helping to set the “rest and digest” status of energy storage. Under stress activation, elevated sympathetic firing leads to increased catecholamine as well as peptide transmitter release to set the “fight or flight” status of energy expenditure. While the mechanism for catecholamine release has been widely investigated, relatively little is known of how peptide transmitter release is regulated to occur selectively under elevated stimulation. Recent studies have shown selective catecholamine release under basal stimulation is accomplished through a transient, restricted exocytic fusion pore between granule and plasma membrane, releasing a soluble fraction of the small, diffusible molecules. Elevated cell firing leads to the active dilation of the fusion pore, leading to the release of both catecholamine and the less diffusible peptide transmitters. Here we propose a molecular mechanism regulating the activity-dependent dilation of the fusion pore. We review the immediate literature and provide new data to formulate a working mechanistic hypothesis whereby calcium-mediated dephosphorylation of dynamin I at Ser-774 leads to the recruitment of the molecular motor myosin II to actively dilate the fusion pore to facilitate release of peptide transmitters. Thus, activity-dependent dephosphorylation of dynamin is hypothesized to represent a key molecular step in the sympatho-adrenal stress response. PMID:21061163

  6. Cell adhesion molecules in adrenal medulla grafts: enhancement of chromaffin cell L1/Ng-CAM expression and reorganization of extracellular matrix following transplantation.

    PubMed

    Poltorak, M; Freed, W J

    1990-10-01

    Intracerebral adrenal medulla grafts have been used in human patients as an experimental treatment for Parkinson's disease, based on studies in animal models of this disorder. However, alterations in chromaffin cell properties after transplantation and the factors controlling graft survival are poorly understood. Since cell adhesion molecules (CAMs) are involved in regeneration and development of neural tissue in vivo and in vitro, the present study was undertaken to determine the expression of CAMs in adrenal medulla isografts. Fragments of rat adrenal medulla were implanted into the right lateral ventricle. The majority of grafts survived quite well, for up to 2 months (the longest studied period). The implanted chromaffin cells did not develop extensive processes. The cells retained tyrosine hydroxylase (TH) and dopamine beta-hydroxylase (DBH) immunoreactivity, while phenylethanolamine N-methyltransferase (PNMT) expression was decreased. Surviving transplanted chromaffin cells showed enhancement and spreading of surface L1/Ng-CAM expression as compared to normal chromaffin cells in adrenal medulla. The implanted chromaffin cells demonstrated only partial conversion to neuronal phenotypes. These chromaffin cells did not develop extensive processes, but showed an enhancement of L1/Ng-CAM expression. Surviving chromaffin cells were accompanied by reorganization of their closely associated extracellular matrix (ECM). As compared to normal in situ adrenal medulla, graft ECM demonstrated a substantial increase of L1/Ng-CAM and laminin immunoreactivities and a distinct decrease in J1/tenascin expression. Some adrenal medulla grafts degenerated, particularly when misplaced within the host brain parenchyma. In these cases the grafts showed fragmentation of ECM and gradual disappearance of CAMs. These results suggest that surviving adrenal medulla grafts exhibit increased synthesis of certain CAMs by chromaffin cells, which may be involved in interactions between

  7. Effects of Cultured Adrenal Chromaffin Cell Implants on Hindlimb Reflexes of the 6-OHDA Lesioned Rat

    PubMed Central

    Pulford, Bruce E.; Mihajlov, Andrea R.; Nornes, Howard O.; Whalen, L. Ray

    1994-01-01

    The effects of implantation of cultured adrenal medullary cells on the recovery of neurotransmitter specific reflex activity were studied in the rat spinal cord using electrophysiological testing methods. Cell suspensions of cultured neonatal adrenal medullary chromaffin (AM) cells (which produce catecholamines), or Schwann (Sc) cells (controls) were implanted into the lumbar region of the spinal cord 2 weeks after catecholamine (CA) denervation by intracisternal injection of 6-hydroxydopamine (6-OHDA). All cells were taken from 7 day neonates and cultured for 10 days in the presence of nerve growth factor (NGF). Three months after implantation, the extent of implant-associated recovery of reflex activity was determined by measuring electromyogram (EMG) activity and force associated with the long latency component of the hindlimb withdrawal reflex (which is CA modulated). After the electrophysiological testing, rats were anesthetized, and the spinal cords were rapidly removed and frozen. Spinal cords were sectioned longitudinally, and implanted cells were visualized using glyoxylic acid techniques. Labelled sections were examined to determine cell survival. Results indicate that 1) chromaffin cells survive for 3 months in the segments of the cord into which they have been implanted and 2) rats implanted with AM cells have significantly more forceful withdrawal reflexes than those that received Sc cells or received no implant after lesioning. PMID:7703294

  8. Modulation of intracellular Ca2+ levels in chromaffin cells by nanoelectropulses.

    PubMed

    Craviso, Gale L; Choe, Sophie; Chatterjee, Indira; Vernier, P Thomas

    2012-10-01

    Exposing chromaffin cells to a single 5 ns, 5 MV/m pulse causes Ca(2+) influx and a rapid, transient rise in intracellular calcium concentration ([Ca(2+)](i)). A comparison of responses at room temperature versus 37°C revealed no effect of temperature on the magnitude of the increase in [Ca(2+)](i). The Ca(2+) transient, however, was shortened in duration almost twofold at 37°C, indicating that the rate of recovery was temperature-sensitive. Temperature also affected the interval required for a second pulse to elicit another maximal rise in [Ca(2+)](i), which was shorter at the higher temperature. In addition, a second pulse applied 5s after the first pulse was sufficient to cause cells at room temperature to become refractory to subsequent stimulation. At 37°C, cells became refractory after 5 pulses regardless of whether pulse delivery was at low (1 and 10 Hz) or high (1 kHz) rates. When refractory, cells showed no signs of swelling or uptake of the impermeant dye YO-PRO-1. These results demonstrate that temperature plays a role in determining how chromaffin cells respond to and become refractory to nanoelectropulses. They also indicate that despite the ultra-short duration of the pulses, pronounced effects on cell excitability result from the application of only very few pulses.

  9. [Participation of synaptotagmin in release of catecholamines in rat adrenal chromaffin cells].

    PubMed

    Pochyniuk, O V; Zaïka, O L; Sadovyĭ, O V; Iavors'ka, O M; Kostiuk, P H; Luk'ianets, O O

    2010-01-01

    Exocytosis is known to provide such a vital processes as the release of neurotransmitters in synaptic transmission or release of hormones during secretion. The main mechanism of exocytotic process occurs through the specialized protein complex called the SNARE-complex. Due to its activity the fusion of vesicular and plasma membrane occurs and fusion pore is formed through which a content of vesicles is released outside. It is believed that just synaptotagmins which are Ca2+ dependent proteins, responsible for initiation of the process of Ca(2+)-dependent exocytosis. Synaptotagmins are located at the membrane of the vesicles and can bind two or three Ca2+ ions. In our research, we studied the role of one of the most common isoform of synaptotagmines--synaptotagmin-1. For this we used an injection of antibodies arised to synaptotagmin-1 (anti-STg-1) into isolated rat adrenal chromaffin cells to depress the function of this protein. Catecholamine secretion was measured by amperometric method. Our results showed that an exclusion of synaptotagmin-1 function in tested cells resulted in significant suppression of secretion. These data allow us to conclude that synaptotagmin-1 is a key protein which is needed for Ca(2+)-dependent exocytosis in chromaffin cells.

  10. Topography of a vacuolar-type H+-translocating ATPase: chromaffin-granule membrane ATPase I.

    PubMed Central

    Apps, D K; Percy, J M; Perez-Castineira, J R

    1989-01-01

    Proteins exposed on the cytoplasmic face of isolated chromaffin granules were labelled by lactoperoxidase-catalysed radioiodination and by non-enzymic biotinylation. Granule membranes were then prepared, and the H+-translocating ATPase isolated by fractionation with Triton X-114. The labelling of individual ATPase subunits was assessed by polyacrylamide-gel electrophoresis, followed by autoradiography or by blotting and decoration with 125I-labelled streptavidin. Subunits of 72, 57 and kDa were strongly labelled, and could be removed from the membrane at pH 11: they are therefore extrinsic proteins. The 120 kDa subunit was also labelled, but it was not solubilized at pH 11. Photolabelling with a hydrophobic probe indicated that this subunit penetrates the bilayer, and enzymic degradation studies showed the presence of N-linked oligosaccharides; this subunit therefore spans the chromaffin-granule membrane. Labelling of the 17 kDa subunit occurred predominantly on the extracytoplasmic (matrix) face of the granule membrane. These results are consistent with this V-type ATPase having a structure that is generally similar to that of mitochondrial (F-type) ATPases, although the attachment of the 120 kDa subunit may be asymmetrical. Images Fig. 1. Fig. 2. Fig. 5. PMID:2532503

  11. Identification of a Munc13-sensitive step in chromaffin cell large dense-core vesicle exocytosis

    PubMed Central

    Man, Kwun Nok M; Imig, Cordelia; Walter, Alexander M; Pinheiro, Paulo S; Stevens, David R; Rettig, Jens; Sørensen, Jakob B; Cooper, Benjamin H; Brose, Nils; Wojcik, Sonja M

    2015-01-01

    It is currently unknown whether the molecular steps of large dense-core vesicle (LDCV) docking and priming are identical to the corresponding reactions in synaptic vesicle (SV) exocytosis. Munc13s are essential for SV docking and priming, and we systematically analyzed their role in LDCV exocytosis using chromaffin cells lacking individual isoforms. We show that particularly Munc13-2 plays a fundamental role in LDCV exocytosis, but in contrast to synapses lacking Munc13s, the corresponding chromaffin cells do not exhibit a vesicle docking defect. We further demonstrate that ubMunc13-2 and Munc13-1 confer Ca2+-dependent LDCV priming with similar affinities, but distinct kinetics. Using a mathematical model, we identify an early LDCV priming step that is strongly dependent upon Munc13s. Our data demonstrate that the molecular steps of SV and LDCV priming are very similar while SV and LDCV docking mechanisms are distinct. DOI: http://dx.doi.org/10.7554/eLife.10635.001 PMID:26575293

  12. Ultrastructural morphology of adrenal chromaffin cells indicative of a process of piecemeal degranulation.

    PubMed

    Crivellato, Enrico; Nico, Beatrice; Perissin, Laura; Ribatti, Domenico

    2003-02-01

    Chromaffin cells of the mouse adrenal medulla were found by transmission electron microscopy (TEM) to exhibit ultrastructural changes suggestive of piecemeal degranulation (PMD), a unique model of cell secretion characterized by the slow release of granule materials without granules opening to the cell exterior. The expression of PMD was recognized in both adrenaline- and noradrenaline-containing cells. Ultrastructural changes included specific granule and cytoplasmic morphologies. In adrenaline-releasing cells the granule content was loosely packed or condensed, and surrounded by a clear halo. In noradrenaline-storing cells, the granule material appeared asymmetrically arranged and exhibited characteristic "semilunar" electron-dense domains within the granule chambers. Notably, altered granules did not fuse with each other or with the plasma membrane, and were intermingled with normal, resting granules. Large, empty cytoplasmic containers or vacuoles filled with partially dissolved matrices were frequently observed. In addition, both adrenaline- and noradrenaline-storing cells presented a rich supply of membrane-bound, smooth vesicles (50-200 nm diameter) that were either free in the cytoplasm or attached to granules. The finding of ultrastructural features characteristic of PMD in adrenal chromaffin cells suggests that such a secretory model may be an alternative secretory pathway to regulated exocytosis. Moreover, these results support the hypothesis that PMD may be a general degranulation pattern in cells involved in paracrine-endocrine secretion. Copyright 2003 Wiley-Liss, Inc.

  13. Calcium-independent K(+)-selective channel from chromaffin granule membranes.

    PubMed

    Arispe, N; Pollard, H B; Rojas, E

    1992-11-01

    Intact adrenal chromaffin granules and purified granule membrane ghosts were allowed to fuse with acidic phospholipid planar bilayer membranes in the presence of Ca2+ (1 mM). From both preparations, we were able to detect a large conductance potassium channel (ca. 160 pS in symmetrical 400 mM K+), which was highly selective for K+ over Na+ (PK/PNa = 11) as estimated from the reversal potential of the channel current. Channel activity was unaffected by charybdotoxin, a blocker of the [Ca2+]-activated K+ channel of large conductance. Furthermore, this channel proved quite different from the previously described channels from other types of secretory vesicle preparations, not only in its selectivity and conductance, but also in its insensitivity to both calcium and potential across the bilayer. We conclude that the chromaffin granule membrane contains a K(+)-selective channel with large conductance. We suggest that the role of this channel may include ion movement during granule assembly or recycling, and do not rule out events leading to exocytosis.

  14. Discrete signal transduction pathway utilization by a neuropeptide (PACAP) and a cytokine (TNF-alpha) first messenger in chromaffin cells, inferred from coupled transcriptome-promoter analysis of regulated gene cohorts.

    PubMed

    Samal, Babru; Ait-Ali, Djida; Bunn, Stephen; Mustafa, Tomris; Eiden, Lee E

    2013-07-01

    Cultured bovine adrenal chromaffin cells (BCCs) are employed to study first messenger-specific signaling by cytokines and neurotransmitters occurring in the adrenal medulla following immune-related stress responses. Here, we show that the cytokine TNF-alpha, and the neuropeptide transmitter PACAP, acting through the TNFR2 and PAC1 receptors, activate distinct signaling pathways, with correspondingly distinct transcriptomic signatures in chromaffin cells. We have carried out a comprehensive integrated transcriptome analysis of TNF-alpha and PACAP gene regulation in BCCs using two microarray platforms to maximize transcript identification. Microarray data were validated using qRT-PCR. More than 90% of the transcripts up-regulated either by TNF-alpha or PACAP were specific to a single first messenger. The final list of transcripts induced by each first messenger was subjected to multiple algorithms to identify promoter/enhancer response elements for trans-acting factors whose activation could account for gene expression by either TNF-alpha or PACAP. Distinct groups of transcription factors potentially controlling the expression of TNF-alpha or PACAP-responsive genes were found: most of the genes up-regulated by TNF-alpha contained transcription factor binding sites for members of the Rel transcription factor family, suggesting TNF-alpha-TNFR2 signaling occurs mainly through the NF-KB signaling pathway. Surprisingly, EGR1 was predicted to be the primary transcription factor controlling PACAP-modulated genes, suggesting PACAP signaling to the nucleus occurs predominantly through ERK, rather than CREB activation. Comparison of TNFR2-dependent versus TNFR1-dependent gene induction, and EGR1-mediated transcriptional activation, may provide a pharmacological avenue to the unique pathways activated by the first messengers TNF-alpha and PACAP in neuronal and endocrine cells.

  15. A 42-kD tyrosine kinase substrate linked to chromaffin cell secretion exhibits an associated MAP kinase activity and is highly related to a 42-kD mitogen-stimulated protein in fibroblasts.

    PubMed

    Ely, C M; Oddie, K M; Litz, J S; Rossomando, A J; Kanner, S B; Sturgill, T W; Parsons, S J

    1990-03-01

    The localization of the protein tyrosine kinase pp60c-src to the plasma membrane and to the membrane of secretory vesicles in neurally derived bovine chromaffin cells has suggested that tyrosine phosphorylations may be associated with the process of secretion. In the present study we have identified two cytosolic proteins of approximately 42 and 45 kD that become phosphorylated on tyrosine in response to secretagogue treatment. Phosphorylation of these proteins reached a maximum (3 min after stimulation) before maximum catecholamine release was observed (5-10 min after stimulation). Both secretion and tyrosine phosphorylation of p42 and p45 required extracellular Ca2+. Tyrosine-phosphorylated proteins of similar Mr have previously been identified in 3T3-L1 adipocytes stimulated with insulin (MAP kinase; Ray, L. B., and T. W. Sturgill. 1987. Proc. Natl. Acad. Sci. USA. 84:1502-1506) and in avian and rodent fibroblasts stimulated with a variety of mitogenic agents (Cooper, J. A., D. F. Bowen-Pope, E. Raines, R. Ross, and T. Hunter. 1982. Cell. 31:263-273; Nakamura, K. D., R. Martinez, and M. J. Weber. 1983. Mol. Cell. Biol. 3:380-390). Comparisons of the secretion-associated 42-kD protein of chromaffin cells with the 42-kD protein of Swiss 3T3 fibroblasts and 3T3-L1 adipocytes provide evidence that these three proteins are highly related. This evidence includes comigration during one-dimensional SDS-PAGE, cochromatography using ion exchange and hydrophobic matrices, similar isoelectric points, identical cyanogen-bromide peptide maps, and cochromatography of MAP kinase activity with the tyrosine-phosphorylated form of pp42. This protein(s), which appears to be activated in a variety of cell types, may serve a common function, perhaps in signal transduction involving a cascade of kinases.

  16. Identification of muscarinic receptor subtypes involved in catecholamine secretion in adrenal medullary chromaffin cells by genetic deletion

    PubMed Central

    Harada, Keita; Matsuoka, Hidetada; Miyata, Hironori; Matsui, Minoru; Inoue, Masumi

    2015-01-01

    Background and Purpose Activation of muscarinic receptors results in catecholamine secretion in adrenal chromaffin cells in many mammals, and muscarinic receptors partly mediate synaptic transmission from the splanchnic nerve, at least in guinea pigs. To elucidate the physiological functions of muscarinic receptors in chromaffin cells, it is necessary to identify the muscarinic receptor subtypes involved in excitation. Experimental Approach To identify muscarinic receptors, pharmacological tools and strains of mice where one or several muscarinic receptor subtypes were genetically deleted were used. Cellular responses to muscarinic stimulation in isolated chromaffin cells were studied with the patch clamp technique and amperometry. Key Results Muscarinic M1, M4 and M5 receptors were immunologically detected in mouse chromaffin cells, and these receptors disappeared after the appropriate gene deletion. Mouse cells secreted catecholamines in response to muscarinic agonists, angiotensin II and a decrease in external pH. Genetic deletion of M1, but not M3, M4 or M5, receptors in mice abolished secretion in response to muscarine, but not to other stimuli. The muscarine-induced secretion was suppressed by MT7, a snake peptide toxin specific for M1 receptors. Similarly, muscarine failed to induce an inward current in the presence of MT7 in mouse and rat chromaffin cells. The binding affinity of VU0255035 for the inhibition of muscarine-induced currents agreed with that for the M1 receptor. Conclusions and Implications Based upon the effects of genetic deletion of muscarinic receptors and MT7, it is concluded that the M1 receptor alone is responsible for muscarine-induced catecholamine secretion. PMID:25393049

  17. Modes of secretagogue-induced [Ca(2+)](i) responses in individual chromaffin cells of the perfused rat adrenal medulla.

    PubMed

    Warashina, A; Satoh, Y

    2001-12-01

    Chromaffin cells in the perfused rat adrenal medulla were loaded with indo-1 for confocal image analyses. Resting levels of [Ca(2+)](i) in chromaffin cells were similar and were stable with time. This is in contrast to the situation in isolated rat chromaffin cells, in which spontaneous oscillations of [Ca(2+)](i) are known to occur. When chromaffin cells were stimulated for 3-4 min by high K(+) or nicotine, [Ca(2+)](i) increased to a peak in 20-30 s and then declined rather smoothly. In contrast, chromaffin cells stimulated by muscarine or low pH (6.5) commonly exhibited irregular oscillations in [Ca(2+)](i). This provides additional evidence supporting the previous claim that muscarine and low pH evoke catecholamine secretion using partly shared mechanisms. Although muscarine and low pH were speculated to produce weaker responses in noradrenaline-secreting cells due to their selective stimulation of adrenaline secretion, no clear indications for segregation of cell types from [Ca(2+)](i) responses to these stimulants were found. The perfused adrenal medulla loaded with Indo-1 was also employed for simultaneously monitoring integrated changes in [Ca(2+)](i)(Ca responses) by conventional microfluorometry and in catecholamine secretion from a whole medulla (secretory responses). When the profiles of secretory responses were approximated by the kth power of the profiles of Ca responses, the k-values were estimated to be 2.2 and 2.3 for high-K(+)- and nicotine-elicited responses, respectively, whereas a k-value of 1.4 was obtained for both muscarine- and low-pH-elicited responses. An analysis showed that the significant difference in the k-value with these two classes of stimulants is accounted for by the stimulant-dependent patterns of [Ca(2+)](i) responses found in confocal image analysis.

  18. An electron microscopic study on nerve endings on adrenomedullary adrenaline cells in golden hamsters: position, size and changes due to pinealectomy.

    PubMed

    Yamauchi, Takao; Kachi, Takashi

    2008-09-01

    Effects of sham-pinealectomy and pinealectomy on preganglionic nerve endings on adrenomedullary adrenaline cells were investigated electron microscopically. Adult male golden hamsters from the normal, sham-pinealectomy and pinealectomy groups maintained under 24 h light-dark cycle and constant temperature were used at 28 days after surgery. From conventional electron microscopic specimens, montage photographs made of the adrenaline cell region at a magnification of x 11,000 were used for qualitative and quantitative electron microscopic analyses in 14 animals in each experimental group. The preganglionic nerve endings were localized mainly in the following three sites: the basal lamina part, the follicular lumen-junctional intercellular part, and the adrenaline cell-invaginated part. In the latter two parts, nerve endings and fibers had no envelope frequently, and in the former two parts, nerve endings sometimes showed the invagination complex. The frequency of nerve endings was highest in the follicular lumen-intercellular part, next highest in the basal lamina part and lowest in the A cell-invaginated part. The frequency of nerve endings in the basal lamina part was lower in the pinealectomy group than in the sham-pinealectomy group (P < 0.021), and those in the other two parts showed opposite changes, more evidently in the A cell-invaginated part. Nerve ending profiles in the adrenaline cell-invaginated part--which displayed a more rounded shape--increased in size in the pinealectomy group (longer diameter: P < 0.04; shorter diameter: P < 0.05). In conclusion, preganglionic nerve endings in the adrenal medulla of the golden hamster show differential morphological changes following PX depending on the intracellular part of A cells.

  19. Developmental change of T-type Ca2+ channel expression and its role in rat chromaffin cell responsiveness to acute hypoxia

    PubMed Central

    Levitsky, Konstantin L; López-Barneo, José

    2009-01-01

    Neonatal chromaffin cells of the adrenal medulla (AM) are intrinsic chemoreceptors that secrete catecholamines in response to hypoxia, thus contributing to fetal adaptation to extrauterine life. In most mammals studied, oxygen sensitivity of AM cells disappears a few days after birth, possibly due to innervation of the adrenal gland by the cholinergic fibres of the splanchnic nerve (∼postnatal day 7 in the rat). The mechanisms underlying these homeostatic changes in chromaffin cells are unknown. Low voltage-activated, T-type, Ca2+ channels regulate cell excitability and their expression is up-regulated by hypoxia. Hence, we hypothesized that these channels contribute to the developmental changes in the chemoreceptive properties of AM chromaffin cells. Using electrophysiological, immunocytochemical and molecular biology methodologies we show here that neonatal AM chromaffin cells express T-type Ca2+ channels (of α1H or Cav3.2 sub-type) and that the function of these channels is necessary for catecholamine release in response to acute hypoxia. T-type Ca2+ channel expression, as well as chromaffin cell responsiveness to hypoxia, decrease with postnatal maturation. Adult chromaffin cell sensitivity to hypoxia reappears after AM denervation in parallel with the recruitment of T-type Ca2+ channels. These observations indicate that T-type Ca2+ channels are essential for the acute response of chromaffin cells to hypoxia and help explain the disappearance of O2 sensitivity in adult AM chromaffin cells. Our results may also be relevant for understanding the pathogenesis of disorders associated with chronic hypoxia or maternal nicotine consumption. PMID:19273573

  20. Developmental change of T-type Ca2+ channel expression and its role in rat chromaffin cell responsiveness to acute hypoxia.

    PubMed

    Levitsky, Konstantin L; López-Barneo, José

    2009-05-01

    Neonatal chromaffin cells of the adrenal medulla (AM) are intrinsic chemoreceptors that secrete catecholamines in response to hypoxia, thus contributing to fetal adaptation to extrauterine life. In most mammals studied, oxygen sensitivity of AM cells disappears a few days after birth, possibly due to innervation of the adrenal gland by the cholinergic fibres of the splanchnic nerve (approximately postnatal day 7 in the rat). The mechanisms underlying these homeostatic changes in chromaffin cells are unknown. Low voltage-activated, T-type, Ca(2+) channels regulate cell excitability and their expression is up-regulated by hypoxia. Hence, we hypothesized that these channels contribute to the developmental changes in the chemoreceptive properties of AM chromaffin cells. Using electrophysiological, immunocytochemical and molecular biology methodologies we show here that neonatal AM chromaffin cells express T-type Ca(2+) channels (of alpha1H or Ca(v)3.2 sub-type) and that the function of these channels is necessary for catecholamine release in response to acute hypoxia. T-type Ca(2+) channel expression, as well as chromaffin cell responsiveness to hypoxia, decrease with postnatal maturation. Adult chromaffin cell sensitivity to hypoxia reappears after AM denervation in parallel with the recruitment of T-type Ca(2+) channels. These observations indicate that T-type Ca(2+) channels are essential for the acute response of chromaffin cells to hypoxia and help explain the disappearance of O(2) sensitivity in adult AM chromaffin cells. Our results may also be relevant for understanding the pathogenesis of disorders associated with chronic hypoxia or maternal nicotine consumption.

  1. Human adrenal chromaffin cell calcium channels: drastic current facilitation in cell clusters, but not in isolated cells.

    PubMed

    Gandía, L; Mayorgas, I; Michelena, P; Cuchillo, I; de Pascual, R; Abad, F; Novalbos, J M; Larrañaga, E; García, A G

    1998-10-01

    Human adrenal medullary chromaffin cells were prepared and cultured from a cystic tumoral adrenal gland whose medullary tissue was unaffected. Adrenaline-containing and noradrenaline-containing cells were identified using a confocal fluorescence microscope and antibodies against dopamine beta-hydroxylase (DBH) and phenylethanolamine N-methyltransferase (PNMT). Current/voltage (I/V) curves performed with the voltage-clamped cells bathed in 10 mM Ba2+ (holding potential, Vh=-80 mV) revealed the presence of only high-threshold voltage-dependent Ca2+ channels; T-type Ca2+ channels were not seen. By using supramaximal concentrations of selective Ca2+ channel blockers, the whole-cell IBa could be fractionated into various subcomponents. Thus, IBa had a 25% fraction sensitive to 1 microM nifedipine (L-type channels), 21% sensitive to 1 microM omega-conotoxin GVIA (N-type channels), and 60% sensitive to 2 microM omega-agatoxin IVA (P/Q-type channels). The activation of IBa was considerably slowed down, and the peak current was inhibited upon superfusion with 10 microM ATP. The slow activation and peak current blockade were reversed by strong depolarizing pre-pulses to +100 mV (facilitation). A drastic facilitation of IBa was also observed in voltage-clamped human chromaffin cell surrounded by other unclamped cells; in contrast, in voltage-clamped cells not immersed in a cell cluster, facilitation was scarce. So, facilitation of Ca2+ channels in a voltage-clamped cell seems to depend upon the exocytotic activity of neighbouring unclamped cells, which is markedly increased by Ba2+. It is concluded that human adrenal chromaffin cells mostly express P/Q-types of voltage-dependent Ca2+ channels (60%). L-Type channels and N-type channels are also expressed, but to a considerably minor extent (around 20% each). This dominance of P/Q-type channels in human chromaffin cells clearly contrasts with the relative proportion of each channel type expressed by chromaffin cells of five

  2. Functional organization of chromaffin cells and cholinergic synaptic transmission in rat adrenal medulla.

    PubMed

    Kajiwara, R; Sand, O; Kidokoro, Y; Barish, M E; Iijima, T

    1997-10-01

    Optical recordings of membrane depolarization and whole-cell patch-clamp recordings of membrane potentials and currents were obtained from chromaffin cells in slices of rat adrenal medulla. The stimulation of splanchnic nerve fibers caused a discontinuous spread of electrical activity across the slice. Cells in clusters with diameters of about 80 microns were excited simultaneously, suggesting that the adrenal medulla is organized into descrete cell complexes with common innervation. The electrical properties of chromaffin cells in situ were in agreement with previous reports on cultured cells. A fraction of the recorded cells displayed excitatory postsynaptic currents (EPSCs) of 0.2-1 nA upon the stimulation of presynaptic nerve fibers. The EPSC was blocked by hexamethonium, suggesting that nicotinic ACh receptors were involved. The decay phase of the EPSC was well fit by the sum of two exponentials with time constants of 6.3 and 57.3 ms. The relative amplitude of the fast component was 84.1%. These two exponentials may reflect activation of both fast and slow time-constant ACh receptor channels by presynaptic release of ACh. There were multiple peaks in the EPSC amplitude histograms in low-[Ca2+] saline, the first peak was at 37 pA. To resolve the quantal size, miniature EPSCs were recorded in a tetrodotoxin-containing high-[K+] solution. The miniature EPSC amplitude histograms were also multimodal with the first peak at 25 pA, which probably represents the quantal size of the synapse. The second and third peaks were at the integer multiples of the first one.

  3. Insulin-like growth factors act synergistically with basic fibroblast growth factor and nerve growth factor to promote chromaffin cell proliferation.

    PubMed Central

    Frödin, M; Gammeltoft, S

    1994-01-01

    We have investigated the effects of insulin-like growth factors (IGFs), basic fibroblast growth factor (bFGF), and nerve growth factor (NGF) on DNA synthesis in cultured chromaffin cells from fetal, neonatal, and adult rats by using 5-bromo-2'-deoxyuridine (BrdUrd) pulse labeling for 24 or 48 h and immunocytochemical staining of cell nuclei. After 6 days in culture in the absence of growth factors, nuclear BrdUrd incorporation was detected in 30% of fetal chromaffin cells, 1.5% of neonatal cells, and 0.1% of adult cells. Addition of 10 nM IGF-I or IGF-II increased the fraction of BrdUrd-labeled nuclei to 50% of fetal, 20% of neonatal, and 2% of adult chromaffin cells. The ED50 value of IGF-I- and IGF-II-stimulated BrdUrd labeling in neonatal chromaffin cells was 0.3 nM and 0.8 nM, respectively. In neonatal and adult chromaffin cells, addition of 1 nM bFGF or 2 nM NGF stimulated nuclear BrdUrd incorporation to approximately the same level as 10 nM IGF-I or IGF-II. However, the response to bFGF or NGF in combination with either IGF-I or IGF-II was more than additive, indicating that the combined effect of the IGFs and bFGF or NGF is synergistic. The degree of synergism was 2- to 4-fold in neonatal chromaffin cells and 10- to 20-fold in adult chromaffin cells compared with the effect of each growth factor alone. In contrast, the action of bFGF and NGF added together in the absence of IGFs was not synergistic or additive. IGF-II acted also as a survival factor on neonatal chromaffin cells and the cell survival was further improved when bFGF or NGF was added together with IGF-II. In conclusion, we propose that IGF-I and IGF-II act in synergy with bFGF and NGF to stimulate proliferation and survival of chromaffin cells during neonatal growth and adult maintenance of the adrenal medulla. Our findings may have implications for improving the survival of chromaffin cell implants in diseased human brain. PMID:8127879

  4. [The assessment of clinical usefulness of 131I-MIBG scintigraphy for localization of tumors of sympathetic and adrenomedullary origin--a report of multicenter phase III clinical trials].

    PubMed

    Sasaki, Y; Kubo, A; Kusakabe, K; Masaki, H; Endo, K; Yamashita, M; Nakajo, M; Kaneko, M

    1992-09-01

    A phase III clinical study of 131I-metaiodobenzylguanidine (131I-MIBG) was performed in 66 patients with tumors of sympathetic and adrenomedullary origin, including 32 patients with suspected pheochromocytoma, 25 with suspected neuroblastoma, 7 pre- or postoperative medullary carcinoma of the thyroid and each with carcinoid and suspected Sipple's syndrome. A total of 150 sites which were confirmed for presence (72 sites) or absence (78 sites) of tumors were examined on 131I-MIBG scintigrams. True positive ratio of the scintigraphy was 84.7% (61/72) and true negative ratio was 94.9% (74/78). Positive scintigraphy was obtained in 86.5% (32/37) of pheochromocytoma, 78.6% (22/28) of neuroblastoma and 100% (6/6) of medullary carcinoma of the thyroid. Accumulation of 131I-MIBG was seen in 16.8% of normal adrenal glands. Neither adverse reactions nor abnormal laboratory findings were noted in relation to 131I-MIBG injections. Our study indicates that 131I-MIBG is a safe and clinically useful radiotracers for the visualization and localization of tumors of sympathetic and adrenomedullary origin.

  5. A developmental model of neuroblastoma: differentiating stroma-poor tumors' progress along an extra-adrenal chromaffin lineage.

    PubMed

    Hoehner, J C; Gestblom, C; Hedborg, F; Sandstedt, B; Olsen, L; Påhlman, S

    1996-11-01

    The prognosis of children with neuroblastoma (NB) is dependent upon the patient's age at diagnosis, the location of the primary tumor, and histologic tumor cell differentiation. These characteristics, as well as the presumption that NB results from clonal expansion of primitive cells involved in sympathetic nervous system (SNS) development, predict that a model of tumorigenesis based upon normal fetal SNS histogenesis might indicate tumor progenitor status and define biologic and clinical behavior. Immunohistochemistry and in situ hybridization were used to examine a panel of marker gene products predicted or shown to be expressed during SNS development in the normal human fetal SNS from 8 to 24 weeks' gestational age. A similar analysis was performed in a selection of clinical NB tumors, and the results were compared. In a subset of differentiating, often extra-adrenal NB tumors in patients who frequently had a favorable outcome; advancing morphologic tumor cell differentiation spatially paralleled an advancing fetal extra-adrenal chromaffin marker gene expression phenotype (ie, increasing TrkA, TrkC, TH, IGF-2, and neuron-specific enolase expression but a lack of phenylethanolamine N-methyltransferase expression). In these tumors, expression of gene products associated with normal fetal sympathetic ganglionic differentiation (ie, Bcl-2, HNK-1, and neuropeptide Y) was lost with morphologic tumor cell differentiation. In contrast, undifferentiated tumors, the majority of which were high stage, adrenal in origin, and prognostically unfavorable, displayed marker expression characteristics mirroring that of an early fetal ganglionic lineage. Thus, we show that morphologic differentiation in stroma-poor NB tumors, long held as an important prognostic feature in tumor grading systems, often corresponds to an extra-adrenal chromaffin rather than a ganglion cell or adrenal medullary chromaffin phenotype. Understanding the biology of extra-adrenal chromaffin tissues may

  6. Fine ultrastructure of chromaffin granules in rat adrenal medulla indicative of a vesicle-mediated secretory process.

    PubMed

    Crivellato, E; Guidolin, D; Nico, B; Nussdorfer, G G; Ribatti, D

    2006-01-01

    Observation by transmission electron microscopy, coupled with morphometric analysis and estimation procedure, revealed unique ultrastructural features in 25.94% of noradrenaline (NA)-containing granules and 16.85% of adrenaline (A)-containing granules in the rat adrenal medulla. These consisted of evaginations of the granule limiting membrane to form budding structures having different morphology and extension. In 14.8% of NA granules and 12.0% of A granules, outpouches were relatively short, looked like small blebs emerging from the granule surface and generally contained electron-dense material. A proportion of 11.2% of NA granules and 4.9% of A granules revealed the most striking ultrastructural features. These secretory organelles presented thin, elongated, tail-like or stem-like appendages, which were variably filled by chromaffin substance and terminated with spherical expansions of different electron density. A cohort of vesicles of variable size (30-150 nm in diameter) and content was found either close to them or in the intergranular cytosol. Examination of adrenal medullary cells fixed by zinc iodide-osmium tetroxide (ZIO) revealed fine electron dense precipitates in chromaffin granules, budding structures as well as cytoplasmic vesicles. These data indicate that a common constituent is revealed by the ZIO histochemical reaction in chromaffin cells. As catecholic compounds are the main tissue targets of ZIO complexes, catecholamines are good candidates to be responsible for the observed ZIO reactivity. This study adds further to the hypothesis that release of secretory material from chromaffin granules may be accomplished by a vesiclular transport mechanism typical of piecemeal degranulation.

  7. Bidirectional roles of the brain 2-arachidonoyl-sn-glycerol in the centrally administered vasopressin-induced adrenomedullary outflow in rats.

    PubMed

    Shimizu, Takahiro; Yokotani, Kunihiko

    2008-03-17

    as a precursor of arachidonic acid in the centrally administered vasopressin-induced activation of the adrenomedullary outflow, and also negatively regulates the peptide-induced central response through the brain cannabinoid CB(1) receptors in rats.

  8. Novel features on the regulation by mitochondria of calcium and secretion transients in chromaffin cells challenged with acetylcholine at 37°C

    PubMed Central

    Caricati‐Neto, Afonso; Padín, Juan‐Fernando; Silva‐Junior, Edilson‐Dantas; Fernández‐Morales, José‐Carlos; de Diego, Antonio‐Miguel G.; Jurkiewicz, Aron; García, Antonio G.

    2013-01-01

    Abstract From experiments performed at room temperature, we know that the buffering of Ca2+ by mitochondria contributes to the shaping of the bulk cytosolic calcium transient ([Ca2+]c) and secretion transients of chromaffin cells stimulated with depolarizing pulses. We also know that the mitochondrial Ca2+ transporters and the release of catecholamine are faster at 37°C with respect to room temperature. Therefore, we planned this investigation to gain further insight into the contribution of mitochondrial Ca2+ buffering to the shaping of [Ca2+]c and catecholamine release transients, using some novel experimental conditions that have not been yet explored namely: (1) perifusion of bovine chromaffin cells (BCCs) with saline at 37°C and their repeated challenging with the physiological neurotransmitter acetylcholine (ACh); (2) separate blockade of mitochondrial Ca2+ uniporter (mCUP) with Ru360 or the mitochondrial Na+/Ca2+ exchanger (mNCX) with CGP37157; (3) full blockade of the mitochondrial Ca2+ cycling (mCC) by the simultaneous inhibition of the mCUP and the mNCX. Ru360 caused a pronounced delay of [Ca2+]c clearance and augmented secretion. In contrast, CGP37157 only caused a tiny delay of [Ca2+]c clearance and a mild decrease in secretion. The mCC resulting in continued Ca2+ uptake and its release back into the cytosol was interrupted by combined Ru360 + CGP37157 (Ru/CGP), the protonophore carbonyl cyanide‐p‐trifluoromethoxyphenylhydrazone, or combined oligomycin + rotenone (O/R); these three treatments caused a mild but sustained elevation of basal [Ca2+]c that, however, was not accompanied by a parallel increase in basal secretion. Nevertheless, all treatments caused a pronounced augmentation of ACh‐induced secretion, with minor changes of the ACh‐induced [Ca2+]c transients. Combined Ru/CGP did not alter the resting membrane potential in current‐clamped cells. Additionally, Ru/CGP did not increase basal [Ca2+]c near subplasmalemmal sites and caused a

  9. Development and dissipation of Ca(2+) gradients in adrenal chromaffin cells.

    PubMed Central

    Marengo, F D; Monck, J R

    2000-01-01

    We used pulsed laser imaging to measure the development and dissipation of Ca(2+) gradients evoked by the activation of voltage-sensitive Ca(2+) channels in adrenal chromaffin cells. Ca(2+) gradients appeared rapidly (<5 ms) upon membrane depolarization and dissipated over several hundred milliseconds after membrane repolarization. Dissipation occurred with an initial fast phase, as the steep gradient near the membrane collapsed, and a slower phase as the remaining shallow gradient dispersed. Inhibition of active Ca(2+) uptake by the endoplasmic reticulum (thapsigargin) and mitochondria (carbonylcyanide p-trifluoro-methoxyphenylhydrazone/oligomycin) had no effect on the size of Ca(2+) changes or the rate of gradient dissipation, suggesting that passive endogenous Ca(2+) buffers are responsible for the slow Ca(2+) redistribution. We used a radial diffusion model incorporating Ca(2+) diffusion and binding to intracellular Ca(2+) buffers to simulate Ca(2+) gradients. We included a 3D optical sectioning model, simulating the effects of out-of-focus light, to allow comparison with the measured gradients. Introduction of a high-capacity immobile Ca(2+) buffer, with a buffer capacity on the order of 1000 and appropriate affinity and kinetics, approximated the size of the Ca(2+) increases and rate of dissipation of the measured gradients. Finally, simulations without exogenous buffer suggest that the Ca(2+) signal due to Ca(2+) channel activation is restricted by the endogenous buffer to a space less than 1 microm from the cell membrane. PMID:11023887

  10. L-type calcium channels in exocytosis and endocytosis of chromaffin cells.

    PubMed

    Nanclares, Carmen; Baraibar, Andrés M; Gandía, Luis

    2017-09-02

    The coexistence of different subtypes of voltage-dependent calcium channels (VDCC) within the same chromaffin cell (CC) and the marked interspecies variability in the proportion of VDCC subtypes that are present in the plasmalemma of the CCs raises the question on their roles in controlling different physiological functions. Particularly relevant seems to be the role of VDCCs in the regulation of the exocytotic neurotransmitter release process, and its tightly coupled membrane retrieval (endocytosis) process since both are Ca(2+)-dependent processes. This review is focused on the role of Ca(2+) influx through L-type VDCC in the regulation of these two processes. It is currently accepted that the different VDCC subtypes (i.e., T, L, N, P/Q, R) contribute to exocytosis proportionally to their density of expression and gating properties. However, the pattern of stimulation defines a preferential role of the different subtypes of VDCC on exocytosis and endocytosis. Thus, L-type channels seem to control catecholamine release induced by prolonged stimuli while fast exocytosis in response to short square depolarizing pulses or action potentials is mediated by Ca(2+) entering CCs through P/Q channels. The pattern of stimulation also influences the endocytotic process, and thus, electrophysiological data suggest the sustained Ca(2+) entry through slow-inactivating L-type channels could be responsible for the activation of fast endocytosis.

  11. Temperature-Dependent Differences between Readily Releasable and Reserve Pool Vesicles in Chromaffin Cells

    PubMed Central

    Haynes, Christy L.; Siff, Lauren N.; Wightman, R. Mark

    2007-01-01

    Summary Statistical differences between amperometric traces recorded from chromaffin cells using K+ and Ba2+ secretagogues support the assertion that readily releasable pool (RRP) and reserve pool (RP) vesicles can be probed with pool-specific secretagogues. Release from the RRP was evoked by K+ while release from the RP was evoked by Ba2+. Similar temperature-dependent changes in spike area and half-width for both pools suggest that the content of RRP and RP vesicles is similar and packaged in the same way. Differences between the vesicle pools were revealed in the temperature dependence of spike frequency. While the burst spike frequency of the RRP, which is comprised of pre-docked and primed vesicles, increased 2.8% per °C, the RP spike frequency increased 12% per °C. This difference is attributed to a temperature dependent mobilization of the RP. Furthermore, the RP exhibited more foot events at room temperature than the RRP but this difference was not apparent at 37°C. This trend suggests that RP vesicle membranes have a compromised surface tension compared to RRP vesicles. Collectively, the changes of release characteristics with temperature reveal distinctions between the RRP and the RP. PMID:17467077

  12. Two distinct secretory vesicle-priming steps in adrenal chromaffin cells.

    PubMed

    Liu, Yuanyuan; Schirra, Claudia; Edelmann, Ludwig; Matti, Ulf; Rhee, JeongSeop; Hof, Detlef; Bruns, Dieter; Brose, Nils; Rieger, Heiko; Stevens, David R; Rettig, Jens

    2010-09-20

    Priming of large dense-core vesicles (LDCVs) is a Ca(2+)-dependent step by which LDCVs enter a release-ready pool, involving the formation of the soluble N-ethyl-maleimide sensitive fusion protein attachment protein (SNAP) receptor complex consisting of syntaxin, SNAP-25, and synaptobrevin. Using mice lacking both isoforms of the calcium-dependent activator protein for secretion (CAPS), we show that LDCV priming in adrenal chromaffin cells entails two distinct steps. CAPS is required for priming of the readily releasable LDCV pool and sustained secretion in the continued presence of high Ca(2+) concentrations. Either CAPS1 or CAPS2 can rescue secretion in cells lacking both CAPS isoforms. Furthermore, the deficit in the readily releasable LDCV pool resulting from CAPS deletion is reversed by a constitutively open form of syntaxin but not by Munc13-1, a priming protein that facilitates the conversion of syntaxin to the open conformation. Our data indicate that CAPS functions downstream of Munc13s but also interacts functionally with Munc13s in the LDCV-priming process.

  13. Chromaffin cells in the adrenal homolog of Aphanius fasciatus (teleost fish) express piecemeal degranulation in response to osmotic stress: a hint for a conservative evolutionary process.

    PubMed

    Crivellato, Enrico; Civinini, Annalena; Gallo, Valentina Patrizia

    2006-10-01

    The effect of severe osmotic stress on the ultrastructural morphology of chromaffin cells in the adrenal homolog of Aphanius fasciatus, a small eurhyaline teleost living in saltpans, was evaluated by electron microscopy quantitative analysis. Fishes were transferred from salt water, whose salinity was 3.7%, to dechlorinated tap water and chromaffin cells were studied at resting condition and after 2 and 48 hr from the beginning of the experiment. Ultrastructural examination revealed a series of granule and cytoplasmic changes highly specific for piecemeal degranulation (PMD), a secretory process based on vesicular transport of cargoes from within granules for extracellular release, which was previously described in chromaffin cells of the mouse, rat, and human adrenal medulla. There was indeed a significant trend toward loss of content material from chromaffin granules accompanied by enlargement of granule size. Remarkably, chromaffin granules maintained their individual close structure during the whole releasing process and eventually transformed into large empty containers. A dramatic increase in the density of small, membrane-bound, variably electron-dense vesicles free in the cytoplasm or attached to granules was recognized during the first 2 hr of stress response. These features fell to control levels after 48 hr. A similar time-course pattern was observed concerning the formation of budding projections from the surface of chromaffin granules. This study provides new insight into PMD physiology and suggests that PMD is part of an adaptive secretory response to severe osmotic stress in fishes. From an evolutionary point of view, this study lends support to the concept that PMD is a secretory mechanism highly conserved throughout vertebrate classes.

  14. Changes in P2Y2 receptor localization on adrenaline- and noradrenaline-containing chromaffin cells in the rat adrenal gland during development and aging.

    PubMed

    Afework, Mekbeb; Burnstock, Geoffrey

    2005-11-01

    Using immunohistochemistry, the occurrence and age-related changes of the P2Y2 receptor was investigated in the adrenal gland of rat at different ages, ranging from embryonic day E16 to 22 months. Immunoreactivity for the P2Y2 receptor was present in chromaffin cells and nerve fibres at all ages examined. Double labeling with the antibody against phenyl ethanolamine-N-methyltransferase, which marks adrenaline-producing chromaffin cells, revealed that only a few of the P2Y2-immunoreactive cells were adrenaline producing at embryonic day E16, the vast majority being noradrenaline-containing cells. However, immunoreactivity for adrenaline-containing cells in the P2Y2 receptor-labeled chromaffin cells increased with increasing age and at 1 week post-natal almost all chromaffin cells were positive for both P2Y2 and phenyl ethanolamine-N-methyltransferase, while noradrenaline-containing cells were minimal. At 2 weeks, there was a dramatic drop in P2Y2-immunoreactive chromaffin cells and this was maintained in adult rats, noradrenaline-containing cells dominating. In the aging rat adrenals, P2Y2 receptor-immunoreactivity was localized in subpopulations of both adrenaline and noradrenaline-producing cells. Intrinsic neurones were also visible that were positively labeled with the P2Y2 receptor antibody in the adrenals of both adult and aging rats. P2Y2-immunoreactive nerve fibres formed a plexus around the adrenal cortical cells of zona glomerulosa in the post-natal, but not in adult or aging rats. In conclusion, this study suggests that ATP, acting through P2Y2 receptors, may influence the phenotypic expression of chromaffin cells during the development and aging of the rat adrenal gland. However, during early development, when the chromaffin cells are actively dividing and during aging, when the adrenal medullary cells are known to show hyperplastic lesions, ATP acting through P2Y2 receptors may be involved in other physiological activities, such as proliferation and

  15. Inhibitory effects of caffeine on secretagogue-induced catecholamine secretion from adrenal chromaffin cells of the guinea-pig.

    PubMed Central

    Nakazato, Y.; Tani, Y.; Teraoka, H.; Sugawara, T.; Asano, T.; Ohta, T.; Ito, S.

    1994-01-01

    1. The inhibitory action of caffeine on catecholamine secretion induced by secretagogues was investigated in perfused adrenal glands and dispersed chromaffin cells of the guinea-pig. 2. Caffeine (10 mM) caused a reversible inhibition of catecholamine secretion evoked by acetylcholine (ACh, 50 microM), KCl (56 mM, high K+) and veratridine (100 microM) and that induced by muscarinic receptor activation in the absence of extracellular Ca2+ in perfused adrenal glands. 3. In dispersed chromaffin cells, caffeine caused a dose-dependent inhibition of the secretory responses to 100 microM ACh and veratridine. Forskolin (30 microM), dibutyryl cyclic AMP (1 mM) and 8-bromo cyclic AMP (1 mM) did not mimic the action of caffeine. 4. In the voltage-clamp, whole-cell recording mode (at a holding potential of -60 mV or -70 mV), ACh (100 microM) evoked an inward current, and depolarizing pulses elicited inward Na+, Ca2+ and outward K+ currents. All these responses were partially inhibited by caffeine (20 mM). 5. ACh rapidly increased the intracellular concentration of Ca2+ ([Ca2+]i) in fura-2-loaded cells in either the presence or the absence of external Ca2+, though its magnitude was decreased by about 50% in Ca(2+)-free conditions. Caffeine (20 mM) inhibited these ACh-induced increases in [Ca2+]i. 6. In permeabilized chromaffin cells, caffeine (20 mM) caused an inhibition of catecholamine secretion evoked by Ca2+ (10 microM). 7. These results suggest that caffeine inhibits evoked catecholamine secretion through mechanisms such as the blockade of voltage-dependent Na+ and Ca2+ currents and ACh receptor current, and reduction of the release of intracellularly stored Ca2+ and/or Ca(2+)-sensitivity of the secretory apparatus. PMID:8019771

  16. Distinct regulation of insulin receptor substrate-1 and -2 by 90-kDa heat-shock protein in adrenal chromaffin cells.

    PubMed

    Yoshikawa, Norie; Nemoto, Takayuki; Satoh, Shinya; Maruta, Toyoaki; Yanagita, Toshihiko; Chosa, Etsuo; Wada, Akihiko

    2010-01-01

    Multiple signaling pathways via insulin receptor substrate-1 and -2 play crucial roles in health, diseases, and therapeutics (i.e., longevity, tumorigenesis, and neuroprotection). The 90-kDa heat-shock protein (Hsp90) is an emerging target molecule of therapeutics, Hsp90 inhibitors being promising against various diseases (e.g., cancer, brain and cardiac ischemia, and neurodegenerative diseases). Much remains, however, unknown whether Hsp90 could regulate insulin receptor substrate-1 and -2 signaling pathways. In cultured bovine adrenal chromaffin cells, we observed that 24-h treatment with 1 microM geldanamycin (an inhibitor of Hsp90) decreased insulin receptor substrate-1 level, while increasing insulin receptor substrate-2 level; besides, geldanamycin lowered phosphoinositide 3-kinase, phosphoinositide-dependent kinase-1, Akt, glycogen synthase kinase-3beta, and Raf-1 levels, without changing extracellular signal-regulated kinase and its upstream kinase levels. Chronic (>or=12h) treatment with 0.1-10 microM Hsp90 inhibitor (geldanamycin, 17-allylamino-17-demethoxy-geldanamycin, herbimycin A, and radicicol) decreased insulin receptor substrate-1 level by approximately 66%, while increasing insulin receptor substrate-2 level by approximately 160%. These effects of geldanamycin (IC(50) 155 nM, EC(50) 177 nM) and 17-allylamino-17-demethoxy-geldanamycin (IC(50) 310 nM, EC(50) 260 nM) were time- and concentration-dependent. Geldanamycin-induced decrease of insulin receptor substrate-1 was attenuated by lactacystin, beta-lactone or MG132 (proteasome inhibitor), but not by calpastatin (calpain inhibitor) or leupeptin (lysosome inhibitor); geldanamycin did not affect heteroprotein complex formation between insulin receptor substrate-1 or -2 and Hsp90. Geldanamycin-induced increase of insulin receptor substrate-2 was prevented by cycloheximide or actinomycin D. Geldanamycin lowered insulin receptor substrate-1 mRNA level by approximately 39%, while raising insulin

  17. Tight mitochondrial control of calcium and exocytotic signals in chromaffin cells at embryonic life.

    PubMed

    Vestring, Stefan; Fernández-Morales, José C; Méndez-López, Iago; C Musial, Diego; G de Diego, Antonio-Miguel; Padín, J Fernando; G García, Antonio

    2015-12-01

    Calcium buffering by mitochondria plays a relevant physiological function in the regulation of Ca(2+) and exocytotic signals in mature chromaffin cells (CCs) from various adult mammals. Whether a similar or different role of mitochondrial Ca(2+) buffering is present in immature CCs at early life has not been explored. Here we present a comparative study in rat embryonic CCs and rat mother CCs, of various physiological parameters that are known to be affected by mitochondrial Ca(2+) buffering during cell activation. We found that the clearance of cytosolic Ca(2+) transients ([Ca(2+)]c) elicited by high K(+) was 7-fold faster in embryo CCs compared to mother CCs. This strongly suggests that at embryonic life, the mitochondria play a more significant role in the clearance of [Ca(2+)]c loads compared to adult life. Consistent with this view are the following results concerning the transient suppression of mitochondrial Ca(2+) buffering by protonophore FCCP, in embryonic CCs compared to mother CCs: (i) faster and greater inactivation of inward calcium currents, (ii) higher K(+)-elicited [Ca(2+)]c transients with 25-fold faster clearance, (iii) higher increase of basal catecholamine release and (iv) higher potentiation of K(+)-evoked secretion. These pronounced differences could be explained by two additional features (embryo versus mother CCs): (a) slower recovery of mitochondrial resting membrane potential after the application of a transient FCCP pulse and (b) greater relative density of the mitochondria in the cytosol. This tighter control by the mitochondria of Ca(2+) and exocytotic signals may be relevant to secure a healthy catecholamine secretory response at early life.

  18. A reassessment of the modulatory role of cyclic AMP in catecholamine secretion by chromaffin cells.

    PubMed Central

    Parramón, M; González, M P; Oset-Gasque, M J

    1995-01-01

    1. The role of adenosine 3':5'-cyclic monophosphate (cyclic AMP) in the regulation of catecholamine (CA) secretion in chromaffin cells remains equivocal from previous studies. 2. In the present study the effect of this cyclic nucleotide on basal CA secretion, as well as on intracellular calcium and membrane potential has been examined. 3. Forskolin and the permeable cyclic AMP analogue, 8-(4-chlorphenylthio)-adenosine-3'-5' monophosphate cyclic (pClpcAMP), increased basal CA secretion in a dose-dependent manner. The EC50s were 0.43 +/- 0.10 microM for forskolin and 39 +/- 9 microM for pClpcAMP. Other agonists with adenylate cyclase activity such as stimulants of adenosine receptors, beta-adrenoceptors, GABAB receptors and intestinal vasoactive peptide (VIP), also increased basal CA secretion in a highly significant manner. However, when they were added together with forskolin, CA secretion was not affected although an additive increase in cyclic AMP levels was produced. 4. Statistical analysis of the correlation between cyclic AMP levels and CA secretion evoked by these cyclic AMP increasing compounds showed that a significant direct correlation between both parameters existed only when low levels of cyclic AMP were produced by secretagogue stimulation. When the increase in intracellular cyclic AMP concentrations exceeded approximately 8 times the basal cyclic AMP levels the correlation was not significant. These results indicate a dual dose-dependent effect of cyclic AMP on basal CA secretion.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7881750

  19. Maternal perinatal undernutrition alters postnatal development of chromaffin cells in the male rat adrenal medulla.

    PubMed

    Molendi-Coste, Olivier; Laborie, Christine; Scarpa, Maria Cristina; Montel, Valérie; Vieau, Didier; Breton, Christophe

    2009-01-01

    Numerous data suggest that the development of the sympathoadrenal system is highly sensitive to the perinatal environment. We previously reported that maternal perinatal food restriction by 50% (FR50) altered chromaffin cell (CC) organization and activity in offspring at weaning. This study investigated the effects of FR50 on the postnatal time course of CC functional and structural adaptations. FR50 pups exhibited smaller and more abundant scattered clusters of noradrenergic CCs as early as postnatal day 7 (P7), indicating that morphological changes took place earlier during development. At birth, the adrenaline release was defective in FR50 pups, suggesting that maternal FR50 impaired the non-neurogenic control of catecholamine release. At P4, the catecholamine release in response to insulin-induced hypoglycaemia was also absent in FR50 pups. This was associated with the reduction of adrenal catecholamine contents, indicating that the failure to synthesize catecholamine might lead to impaired secretion. We hypothesized that maternal FR50 accelerated the functional connections between CCs and splanchnic nerve endings, leading to the premature loss of the non-neurogenic response. Acetylcholine-containing synaptic endings seemed more precociously functional in FR50 pups, as suggested by increased levels of acetylcholine esterase activity at P14. At P7, insulin-induced hypoglycaemia caused preferential adrenaline release associated with increased catecholamine contents in both groups. However, the response was accentuated in FR50 pups. At P14, the insulin challenge increased plasma levels of adrenaline in control rats, whereas it markedly enhanced the circulating level of both catecholamines in FR50 pups. We demonstrated that maternal FR50 leads to developmentally impaired noradrenergic CC aggregation and advanced splanchnic neurotransmission maturation associated with altered medulla activity in response to metabolic stress. This might contribute to the long

  20. Single particle tracking of internalized metallic nanoparticles reveals heterogeneous directed motion after clathrin dependent endocytosis in mouse chromaffin cells.

    PubMed

    Gabriel, Manuela; Moya, Jose; Gallo, Luciana; Marengo, Fernando; Estrada, Laura

    2017-09-13

    Most accepted single particle tracking methods are able to obtain high-resolution trajectories for relatively short periods of time. In this work we apply a straightforward combination of single-particle tracking microscopy and metallic nanoparticles internalization on mouse chromaffin cells to unveil the intracellular trafficking mechanism of metallic-nanoparticle-loaded vesicle (MNP-V) complexes after clathrin dependent endocytosis. We found that directed transport is the major route of MNP-Vs intracellular trafficking after stimulation (92.6% of the trajectories measured). We then studied the MNP-V speed at each point along the trajectory, and found that the application of a second depolarization stimulus during the tracking provokes an increase in the percentage of low-speed trajectory points in parallel with a decrease in the number of high-speed trajectory points. This result suggests that stimulation may facilitate the compartmentalization of internalized MNPs in a more restricted location such as was already demonstrated in neuronal and neuroendocrine cells (Bronfman et al 2003). Although further experiments will be required to address the mechanisms underlying this transport dynamics, our studies provide quantitative evidence of the heterogeneous behavior of vesicles mobility after endocytosis in chromaffin cells highlighting the potential of MNPs as alternative labels in optical microscopy to provide new insights into the vesicles dynamics in a wide variety of cellular environments. © 2017 IOP Publishing Ltd.

  1. Surface-modified CMOS IC electrochemical sensor array targeting single chromaffin cells for highly parallel amperometry measurements.

    PubMed

    Huang, Meng; Delacruz, Joannalyn B; Ruelas, John C; Rathore, Shailendra S; Lindau, Manfred

    2017-09-09

    Amperometry is a powerful method to record quantal release events from chromaffin cells and is widely used to assess how specific drugs modify quantal size, kinetics of release, and early fusion pore properties. Surface-modified CMOS-based electrochemical sensor arrays allow simultaneous recordings from multiple cells. A reliable, low-cost technique is presented here for efficient targeting of single cells specifically to the electrode sites. An SU-8 microwell structure is patterned on the chip surface to provide insulation for the circuitry as well as cell trapping at the electrode sites. A shifted electrode design is also incorporated to increase the flexibility of the dimension and shape of the microwells. The sensitivity of the electrodes is validated by a dopamine injection experiment. Microwells with dimensions slightly larger than the cells to be trapped ensure excellent single-cell targeting efficiency, increasing the reliability and efficiency for on-chip single-cell amperometry measurements. The surface-modified device was validated with parallel recordings of live chromaffin cells trapped in the microwells. Rapid amperometric spikes with no diffusional broadening were observed, indicating that the trapped and recorded cells were in very close contact with the electrodes. The live cell recording confirms in a single experiment that spike parameters vary significantly from cell to cell but the large number of cells recorded simultaneously provides the statistical significance.

  2. Modulation of muscarinic and micotinic cholinergic receptor mediated catecholamine secretion in guinea pig chromaffin cells by phorbol esters

    SciTech Connect

    Figueiredo, J.C.; Fisher, S.K.; Horowitz, M.I.

    1986-05-01

    Isolated guinea pig chromaffin cells possess both nicotinic (nAChR) and muscarinic (mAChR) cholinergic receptors that are positively coupled to catecholamine (CA) release. Sixty to 70% of CA release is mediated by nAChRs and 30-40% by mAChRs. In the absence of added calcium, nAChR mediated CA release was reduced by 65% whereas the muscarinic response was unaffected. The addition of 100nM 12-0-tetradecanoylphorbol-13-acetate (TPA), an activator of protein kinase C (PKC), also resulted in an increased CA release. Temporally and quantitatively, this response resembled that of mAChR activation. Addition of optimal concentrations of nicotine (50..mu..M) and TPA (100nM) induced a synergistic increase in CA release. Addition of muscarine (1mM) and TPA resulted in an additive response despite a 40-60% inhibition of mAChR mediated inositol phosphate release by TPA. Thus, in guinea pig chromaffin cells, it appears that PKC activation alone is a sufficient stimulus for CA release and that activation of both nicotinic and muscarinic receptors may further increase this enzyme's activity.

  3. Non-Faradaic Electrochemical Detection of Exocytosis from Mast and Chromaffin Cells Using Floating-Gate MOS Transistors

    PubMed Central

    Jayant, Krishna; Singhai, Amit; Cao, Yingqiu; Phelps, Joshua B.; Lindau, Manfred; Holowka, David A.; Baird, Barbara A.; Kan, Edwin C.

    2015-01-01

    We present non-faradaic electrochemical recordings of exocytosis from populations of mast and chromaffin cells using chemoreceptive neuron MOS (CνMOS) transistors. In comparison to previous cell-FET-biosensors, the CνMOS features control (CG), sensing (SG) and floating gates (FG), allows the quiescent point to be independently controlled, is CMOS compatible and physically isolates the transistor channel from the electrolyte for stable long-term recordings. We measured exocytosis from RBL-2H3 mast cells sensitized by IgE (bound to high-affinity surface receptors FcεRI) and stimulated using the antigen DNP-BSA. Quasi-static I-V measurements reflected a slow shift in surface potential () which was dependent on extracellular calcium ([Ca]o) and buffer strength, which suggests sensitivity to protons released during exocytosis. Fluorescent imaging of dextran-labeled vesicle release showed evidence of a similar time course, while un-sensitized cells showed no response to stimulation. Transient recordings revealed fluctuations with a rapid rise and slow decay. Chromaffin cells stimulated with high KCl showed both slow shifts and extracellular action potentials exhibiting biphasic and inverted capacitive waveforms, indicative of varying ion-channel distributions across the cell-transistor junction. Our approach presents a facile method to simultaneously monitor exocytosis and ion channel activity with high temporal sensitivity without the need for redox chemistry. PMID:26686301

  4. Lower density of L-type and higher density of P/Q-type of calcium channels in chromaffin cells of hypertensive, compared with normotensive rats.

    PubMed

    de Pascual, Ricardo; Miranda-Ferreira, Regiane; Galvão, Kleber M; Lameu, Claudina; Ulrich, Henning; Smaili, Soraya S; Jurkiewicz, Aron; García, Antonio G; Gandía, Luis

    2013-04-15

    Enhanced activity of the sympatho-adrenal axis and augmented circulating catecholamines has been implicated in the development of hypertension. Release of catecholamine from stimulated adrenal medulla chromaffin cells has been shown to be higher and longer in spontaneously hypertensive rats (SHRs), compared with normotensive Wistar rats (NWRs). Whether differences in the functional expression of voltage-dependent calcium channels (VDCCs) of the L-, N-, or P/Q subtypes may contribute to such distinct secretory behaviour, is unknown. We therefore approached here this study in voltage-clamped NWR and SHR chromaffin cells, using 10mM Ba(2+) as charge carrier (IBa) and selective blockers of each channel type. We found that compared with NWR cells, SHR chromaffin cells exhibited the following differences: (1) 30% diminution of the IBa fraction carried by L channels; (2) a doubling of the IBa fraction carried by P/Q channels; (3) more visible current modulation by ATP that could be linked to a 10-fold higher mRNA levels for purinergic receptors of the P2Y2 subtype; and (3) a higher contribution of PQ channels to the transients of the cytosolic calcium concentrations ([Ca(2+)]c) generated by K(+), compared with L channels. These results may contribute to the better understanding of the greater calcium signalling and exocytotic responses of SHR compared with NWR chromaffin cells, found in three previous reports from our laboratories. Copyright © 2013 Elsevier B.V. All rights reserved.

  5. Identification of a plasma membrane-associated guanine nucleotide exchange factor for ARF6 in chromaffin cells. Possible role in the regulated exocytotic pathway.

    PubMed

    Caumont, A S; Vitale, N; Gensse, M; Galas, M C; Casanova, J E; Bader, M F

    2000-05-26

    ADP-ribosylation factors (ARFs) constitute a family of structurally related proteins that forms a subset of the Ras superfamily of regulatory GTP-binding proteins. Like other GTPases, activation of ARFs is facilitated by specific guanine nucleotide exchange factors (GEFs). In chromaffin cells, ARF6 is associated with the membrane of secretory granules. Stimulation of intact cells or direct elevation of cytosolic calcium in permeabilized cells triggers the rapid translocation of ARF6 to the plasma membrane and the concomitant activation of phospholipase D (PLD) in the plasma membrane. Both calcium-evoked PLD activation and catecholamine secretion in permeabilized cells are strongly inhibited by a synthetic peptide corresponding to the N-terminal domain of ARF6, suggesting that the ARF6-dependent PLD activation near the exocytotic sites represents a key event in the exocytotic reaction in chromaffin cells. In the present study, we demonstrate the occurrence of a brefeldin A-insensitive ARF6-GEF activity in the plasma membrane and in the cytosol of chromaffin cells. Furthermore, reverse transcriptase-polymerase chain reaction and immunoreplica analysis indicate that ARNO, a member of the brefeldin A-insensitive ARF-GEF family, is expressed and predominantly localized in the cytosol and in the plasma membrane of chromaffin cells. Using permeabilized chromaffin cells, we found that the introduction of anti-ARNO antibodies into the cytosol inhibits, in a dose-dependent manner, both PLD activation and catecholamine secretion in calcium-stimulated cells. Furthermore, co-expression in PC12 cells of a catalytically inactive ARNO mutant with human growth hormone as a marker of secretory granules in transfected cells resulted in a 50% inhibition of growth hormone secretion evoked by depolarization with high K(+). The possibility that the plasma membrane-associated ARNO participates in the exocytotic pathway by activating ARF6 and downstream PLD is discussed.

  6. Uptake of the neurotoxin, 4-methylphenylpyridinium, into chromaffin granules and synaptic vesicles: a proton gradient drives its uptake through monoamine transporter.

    PubMed

    Moriyama, Y; Amakatsu, K; Futai, M

    1993-09-01

    Energy dependence for uptake of 4-methyphenylpyridinium (MPP+), a neurotoxin causing Parkinsonism-like symptoms, by adrenal chromaffin granule membrane vesicles and brain synaptic vesicles was studied. The compound was actively taken up by the chromaffin vesicles dependent on hydrolysis of ATP with a Km value of 22 microM and maximum velocity of 2.9 nmol/min/mg protein. The uptake was sensitive to reserpine (1 microM) and bafilomycin (50 nM) (inhibitors of the vesicular monoamine transporter and vacuolar-type H(+)-ATPase, respectively) and substrates for monoamine transporters, but insensitive to imipramine (an inhibitor of the monoamine transporter present in the plasma membrane). The uptake was greatly reduced upon dissipation of the proton gradient by ammonium ion or nigericin with KCl, but stimulated 1.6-fold by valinomycin plus K+. Dissipation of the proton gradient also induced rapid efflux of MPP+ from the vesicles. The MPP+ (monoamine) transporter was solubilized from chromaffin vesicles and reconstituted into liposomes with purified bacterial F0F1-ATPase. MPP+ was taken up by the liposomes coupled with ATP hydrolysis by F0F1, and the uptake was sensitive to reserpine, dissipation of the proton gradient, and azide. Brain synaptic vesicles also accumulated MPP+, showing similar kinetics, inhibitor sensitivities, and energy coupling to those of chromaffin vesicles. Furthermore, MPP+ inhibited the uptake of dopamine without affecting the uptake of glutamate or gamma-aminobutyrate. These results indicated that MPP+ was taken up through the reserpine-sensitive monoamine transporter into chromaffin vesicles and synaptic vesicles and that the energy for accumulation of MPP+ was supplied as a proton gradient (acidic inside) established by H(+)-ATPase.

  7. Separation between cytosolic calcium and secretion in chromaffin cells superfused with calcium ramps.

    PubMed Central

    Michelena, P; García-Pérez, L E; Artalejo, A R; García, A G

    1993-01-01

    This paper describes experiments in which cytosolic Ca2+ concentrations ([Ca2+]i) and catecholamine release were measured in two populations of chromaffin cells stimulated with a solution enriched in K+ (100 mM). Once depolarized, external Ca2+ or Ba2+ ions were offered to cells either as a single 2.5 mM step or as a ramp that linearly increased the concentration from 0 to 2.5 mM over a 10-min period. A clear separation between the changes of the [Ca2+]i and the time course of secretion was observed. Specifically, secretion and [Ca2+]i rose in parallel when a Ca2+ step was used to reach a peak in a few seconds; however, while secretion declined to the basal level, [Ca2+]i remained elevated at a plateau of 400 nM. With a Ca2+ ramp, only a transient small peak of secretion was observed, yet the [Ca2+]i remained elevated throughout the 10-min stimulation period. The separation between secretion and [Ca2+]i was observed even when voltage-dependent Ca2+ channels were expected to remain open (mild depolarization in the presence of 1 microM Bay K 8644). By using Ba2+ steps or ramps, sustained noninactivating secretory responses were obtained. The results suggest that the rate and extent of secretion are not a simple function of the [Ca2+]i at a given time; they are compatible with the following conclusions: (i) A steep extracellular-to-cytosolic Ca2+ gradient is required to produce a sharp increase in the [Ca2+]i at exocytotic sites capable of evoking a fast but transient secretory response. (ii) As a result of Cai(2+)-dependent inactivation of Ca2+ channels, those high [Ca2+]i are possible only at early times after cell depolarization. (iii) The Cai(2+)-dependent supply of storage granules to the secretory machinery cooperates with the supply of Ca2+ through Ca2+ channels to regulate the rate and extent of secretion. PMID:8475070

  8. Calcium Channel Subtypes and Exocytosis in Chromaffin Cells at Early Life.

    PubMed

    Padín, Juan Fernando; Fernández-Morales, José-Carlos; de Diego, Antonio M G; García, Antonio G

    2015-01-01

    Here we review the contribution of the various subtypes of voltage-activated calcium channels (VACCs) to the regulation of catecholamine release from chromaffin cells (CCs) at early life. Patch-clamp recording of inward currents through VACCs has revealed the expression of high-threshold VACCs (high-VACCs) of the L, N, and PQ subtypes in rat embryo CCs and ovine embryo CCs. Low-threshold VACC (low-VACC) currents (T-type) have also been recorded in rat embryo CCs and rat neonatal slices of adrenal medullae. Near full blockade by nifedipine and nimodipine of the K(+)-elicited secretion as well as the hypoxia induced secretion (HIS) supports the dominant role of L-VACC subtypes to the regulation of exocytosis at early life. Partial blockade by ω-conotoxin GVIA and ω-agatoxin IVA suggests a transient participation of N and PQ high-VACCs to the regulation of the HIS response at early stages of CC exposure to hypoxia. T-type low-VACC current did not elicit exocytosis triggered by electrical depolarising pulses applied to rat embryo CCs in one study, but largely contributed to the HIS response in neonatal rat adrenal slices in another. In spite of scarce available data, the sequence of events driving the HIS response in CCs at early life could be established as follows: (i) hypoxia blocks one or more K(+) channels; (ii) as a consequence, mild membrane depolarisation occurs; (iii) T-type low-VACCs open at membrane potentials more hyperpolarised than those required to recruit the high-VACCs; (iv) firing of action potentials then occurs; (v) fast-inactivating N and PQ high-VACCs transiently open and low-inactivating L high-VACCs remain open along the hypoxia stimulus; (vi) increase of cytosolic Ca(2+) takes place; and (vii) the exocytotic release of catecholamine occurs in two phases, an explosive initial phase, driven by Ca(2+) entry through L, N and PQ channels, followed by a more sustained catecholamine release at a slower rate driven by L-type channels.

  9. Bovine coronavirus associated syndromes.

    PubMed

    Boileau, Mélanie J; Kapil, Sanjay

    2010-03-01

    Bovine coronaviruses, like other animal coronaviruses, have a predilection for intestinal and respiratory tracts. The viruses responsible for enteric and respiratory symptoms are closely related antigenically and genetically. Only 4 bovine coronavirus isolates have been completely sequenced and thus, the information about the genetics of the virus is still limited. This article reviews the clinical syndromes associated with bovine coronavirus, including pneumonia in calves and adult cattle, calf diarrhea, and winter dysentery; diagnostic methods; prevention using vaccination; and treatment, with adjunctive immunotherapy.

  10. Therapeutic concentrations of varenicline in the presence of nicotine increase action potential firing in human adrenal chromaffin cells.

    PubMed

    Hone, Arik J; Michael McIntosh, J; Rueda-Ruzafa, Lola; Passas, Juan; de Castro-Guerín, Cristina; Blázquez, Jesús; González-Enguita, Carmen; Albillos, Almudena

    2017-01-01

    Varenicline is a nicotinic acetylcholine receptor (nAChR) agonist used to treat nicotine addiction, but a live debate persists concerning its mechanism of action in reducing nicotine consumption. Although initially reported as α4β2 selective, varenicline was subsequently shown to activate other nAChR subtypes implicated in nicotine addiction including α3β4. However, it remains unclear whether activation of α3β4 nAChRs by therapeutically relevant concentrations of varenicline is sufficient to affect the behavior of cells that express this subtype. We used patch-clamp electrophysiology to assess the effects of varenicline on native α3β4* nAChRs (asterisk denotes the possible presence of other subunits) expressed in human adrenal chromaffin cells and compared its effects to those of nicotine. Varenicline and nicotine activated α3β4* nAChRs with EC50 values of 1.8 (1.2-2.7) μM and 19.4 (11.1-33.9) μM, respectively. Stimulation of adrenal chromaffin cells with 10 ms pulses of 300 μM acetylcholine (ACh) in current-clamp mode evoked sodium channel-dependent action potentials (APs). Under these conditions, perfusion of 50 or 100 nM varenicline showed very little effect on AP firing compared to control conditions (ACh stimulation alone), but at higher concentrations (250 nM) varenicline increased the number of APs fired up to 436 ± 150%. These results demonstrate that therapeutic concentrations of varenicline are unlikely to alter AP firing in chromaffin cells. In contrast, nicotine showed no effect on AP firing at any of the concentrations tested (50, 100, 250, and 500 nM). However, perfusion of 50 nM nicotine simultaneously with 100 nM varenicline increased AP firing by 290 ± 104% indicating that exposure to varenicline and nicotine concurrently may alter cellular behavior such as excitability and neurotransmitter release. © 2016 International Society for Neurochemistry.

  11. 78 FR 73993 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-12-10

    ... Health Inspection Service 9 CFR Parts 92, 93, 94, 95, 96, and 98 RIN 0579-AC68 Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products Corrections In rule document 2013-28228 appearing on...

  12. 77 FR 20319 - Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-04

    ...; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service 9 CFR Part 93 RIN 0579-AC68 Bovine Spongiform Encephalopathy; Importation of Bovines and Bovine Products Correction In proposed rule document...

  13. Unlocking the bovine genome

    USDA-ARS?s Scientific Manuscript database

    The draft genome sequence of cattle (Bos taurus) has now been analyzed by the Bovine Genome Sequencing and Analysis Consortium and the Bovine HapMap Consortium, which together represent an extensive collaboration involving more than 300 scientists from 25 different countries. ...

  14. The effect of CdSe-ZnS quantum dots on calcium currents and catecholamine secretion in mouse chromaffin cells.

    PubMed

    Gosso, Sara; Gavello, Daniela; Giachello, Carlo N G; Franchino, Claudio; Carbone, Emilio; Carabelli, Valentina

    2011-12-01

    Semiconductor nanocrystal quantum dots (QDs) possess an enormous potential of applications in nanomedicine, drug delivery and bioimaging which derives from their unique photoemission and photostability characteristics. In spite of this, however, their interactions with biological systems and impact on human health are still largely unknown. Here we used neurosecretory mouse chromaffin cells of the adrenal gland for testing the effects of CdSe-ZnS core-shell quantum dots (5-36 nM) on Ca(2+) channels functionality and Ca(2+)-dependent neurosecretion. Prolonged exposure (24 h) to commonly used concentrations of CdSe-ZnS QDs (≥16 nM) showed that the semiconductor nanocrystal is effectively internalized into the cells without affecting cell integrity (no changes of membrane resistance and cell capacitance). QDs reduced the size of Ca(2+) currents by ∼28% in a voltage-independent manner without affecting channel gating. Correspondingly, depolarization-evoked exocytosis, measured at +10 mV, where Ca(2+) currents are maximal, was reduced by 29%. CdSe-ZnS QDs reduced the size of the readily releasable pool (RRP) of secretory vesicles by 32%, the frequency of release by 33% and the overall quantity of released catecholamines by 61%, as measured by carbon fibers amperometry. In addition, the Ca(2+)-dependence of exocytosis was reduced, whereas the catecholamine content of single granules, as well as the kinetics of release, remained unaltered. These data suggest that exposure to CdSe-ZnS QDs impairs Ca(2+) influx and severely interferes with the functionality of the exocytotic machinery, compromising the overall catecholamine supply from chromaffin cells.

  15. Adrenal Chromaffin Cells Exposed to 5-ns Pulses Require Higher Electric Fields to Porate Intracellular Membranes than the Plasma Membrane: An Experimental and Modeling Study.

    PubMed

    Zaklit, Josette; Craviso, Gale L; Leblanc, Normand; Yang, Lisha; Vernier, P Thomas; Chatterjee, Indira

    2017-08-24

    Nanosecond-duration electric pulses (NEPs) can permeabilize the endoplasmic reticulum (ER), causing release of Ca(2+) into the cytoplasm. This study used experimentation coupled with numerical modeling to understand the lack of Ca(2+) mobilization from Ca(2+)-storing organelles in catecholamine-secreting adrenal chromaffin cells exposed to 5-ns pulses. Fluorescence imaging determined a threshold electric (E) field of 8 MV/m for mobilizing intracellular Ca(2+) whereas whole-cell recordings of membrane conductance determined a threshold E-field of 3 MV/m for causing plasma membrane permeabilization. In contrast, a 2D numerical model of a chromaffin cell, which was constructed with internal structures representing a nucleus, mitochondrion, ER, and secretory granule, predicted that exposing the cell to the same 5-ns pulse electroporated the plasma and ER membranes at the same E-field amplitude, 3-4 MV/m. Agreement of the numerical simulations with the experimental results was obtained only when the ER interior conductivity was 30-fold lower than that of the cytoplasm and the ER membrane permittivity was twice that of the plasma membrane. A more realistic intracellular geometry for chromaffin cells in which structures representing multiple secretory granules and an ER showed slight differences in the thresholds necessary to porate the membranes of the secretory granules. We conclude that more sophisticated cell models together with knowledge of accurate dielectric properties are needed to understand the effects of NEPs on intracellular membranes in chromaffin cells, information that will be important for elucidating how NEPs porate organelle membranes in other cell types having a similarly complex cytoplasmic ultrastructure.

  16. The effect of in vivo hydrocortisone administration on the labelling index and size of chromaffin tissue in the postnatal and adult mouse.

    PubMed Central

    Monkhouse, W S

    1986-01-01

    Hydrocortisone administration in vivo to neonatal mice for seven days led to a significant increase in both the size and the labelling index of extra-adrenal chromaffin tissue (as represented by the para-aortic body) of 8 days old mice. In untreated animals at this age, the para-aortic body was in most cases too small to obtain a valid labelling index. In the para-aortic bodies of 14 days old, 21 days old and adult mice, the extra-adrenal chromaffin tissue was too dispersed to obtain values for either volumetric analysis or labelling indices, and hydrocortisone was without significant effect in promoting a hyperplastic response. In the postnatal adrenal medulla at all ages studied, hydrocortisone had no effect on the medullary size or on the labelling indices of either adrenaline- or noradrenaline-storing cells, although it led to a marked diminution of adrenocortical volume. The relative proportion of adrenaline-storing cells increased between the values for 8 days old animals and those for adults; this was unaffected by hydrocortisone. The cortico-medullary ratio remained unchanged from the eighth postnatal day onwards. The results are discussed and related to those of other workers. It is suggested that factors as yet unknown might modulate the response to corticosteroids of developing intra- and extra-adrenal chromaffin tissue. Images Fig. 1 Fig. 2 PMID:3693040

  17. Amelioration of sensory attention and sensorimotor deficits by chromaffin cell grafts to the cerebral cortex of nucleus basalis magnocellularis lesioned rats.

    PubMed

    Welner, S A; Koty, Z C

    1993-12-31

    Rats that have received lesions to the nucleus basalis magnocellularis display with a variety of behavioral deficits; among these are decreases in performance of maze tests as well as deficiencies on measures of general health, sensory attention and sensorimotor abilities. We have previously shown that grafts of chromaffin cells placed in the cerebral cortex of nucleus basalis magnocellularis lesioned rats can ameliorate the lesion-induced deficits in performance of a task involving spatial memory. In the present study, we find that lesion-induced deficits in the sensory attention measure of exploration of the environment (head scanning) as well as the sensorimotor behavior involving a rat righting itself when placed nose down on an inclined grid are evident at 8 weeks post-lesion in lesioned-alone rats; these deficits are significantly ameliorated by chromaffin cell grafts in the cerebral cortex placed two weeks following the lesion procedure. These findings may have relevance to the use of chromaffin cells for grafting in neurodegenerative disorders in which sensorimotor or attention deficit components are involved.

  18. Hypoxaemia-induced catecholamine secretion from adrenal chromaffin cells inhibits glucose-stimulated hyperinsulinaemia in fetal sheep

    PubMed Central

    Yates, Dustin T; Macko, Antoni R; Chen, Xiaochuan; Green, Alice S; Kelly, Amy C; Anderson, Miranda J; Fowden, Abigail L; Limesand, Sean W

    2012-01-01

    Hypoxaemia elicits adrenergic suppression of fetal glucose-stimulated hyperinsulinaemia. We postulate that this effect is mediated by catecholamines, exclusively, from fetal adrenal chromaffin cells. To investigate this hypothesis, square-wave hyperglycaemic clamp studies were performed under normoxaemic (26 ± 0.9 mmHg) and hypoxaemic (14 ± 0.3 mmHg) steady-state conditions in near-term fetal sheep that had undergone either surgical sham or bilateral adrenal demedullation (AD), values mentioned are ± SEM. Under normoxaemic conditions plasma noradrenaline concentrations were lower in AD fetuses than in sham-operated fetuses (457 ± 122 versus 1073 ± 103 pg ml−1, P < 0.05). Plasma insulin concentrations were not different at euglycaemia between shams (0.46 ± 0.07 ng ml−1) and AD fetuses (0.44 ± 0.04 ng ml−1) and increased (P < 0.05) with hyperglycaemia in both groups although to a lesser extent in AD fetuses (0.94 ± 0.19 ng ml−1) compared to shams (1.31 ± 0.15 ng ml−1; P < 0.05). Hypoxaemia increased plasma adrenaline (26-fold) and noradrenaline (5-fold) in shams but elicited no change in AD fetuses. Under hypoxaemic conditions, euglycaemic plasma insulin concentrations were reduced (P < 0.05) in both sham and AD fetuses to 0.30 ± 0.05 ng ml−1 and 0.27 ± 0.01 ng ml−1 respectively, and the insulin response to hyperglycaemia was abolished in shams but not affected in AD fetuses (0.33 ± 0.06 versus 0.73 ± 0.02 ng ml−1, P < 0.05). Hypoxaemia also induced hyperlactacaemia and hypocarbia to a greater extent in shams than in AD fetuses, indicating that catecholamines potentiate reductions in oxidative metabolism independently of insulin. These findings demonstrate that the fetal adrenal chromaffin cells are the source for acute hypoxaemia-induced elevations in fetal plasma catecholamines and suppression of glucose-stimulated hyperinsulinaemia, but other factors reduce plasma insulin at euglycaemia. PMID:22907052

  19. Cav1.3 Channels as Key Regulators of Neuron-Like Firings and Catecholamine Release in Chromaffin Cells

    PubMed Central

    Vandael, David H.F.; Marcantoni, Andrea; Carbone, Emilio

    2015-01-01

    Neuronal and neuroendocrine L-type calcium channels (Cav1.2, Cav1.3) open readily at relatively low membrane potentials and allow Ca2+ to enter the cells near resting potentials. In this way, Cav1.2 and Cav1.3 shape the action potential waveform, contribute to gene expression, synaptic plasticity, neuronal differentiation, hormone secretion and pacemaker activity. In the chromaffin cells (CCs) of the adrenal medulla, Cav1.3 is highly expressed and is shown to support most of the pacemaking current that sustains action potential (AP) firings and part of the catecholamine secretion. Cav1.3 forms Ca2+-nanodomains with the fast inactivating BK channels and drives the resting SK currents. These latter set the inter-spike interval duration between consecutive spikes during spontaneous firing and the rate of spike adaptation during sustained depolarizations. Cav1.3 plays also a primary role in the switch from “tonic” to “burst” firing that occurs in mouse CCs when either the availability of voltage-gated Na channels (Nav) is reduced or the β2 subunit featuring the fast inactivating BK channels is deleted. Here, we discuss the functional role of these “neuron-like” firing modes in CCs and how Cav1.3 contributes to them. The open issue is to understand how these novel firing patterns are adapted to regulate the quantity of circulating catecholamines during resting condition or in response to acute and chronic stress. PMID:25966692

  20. Ageing changes the cellular basis of the "fight-or-flight" response in human adrenal chromaffin cells.

    PubMed

    Elhamdani, Abdeladim; Palfrey, Clive H; Artalejo, Cristina R

    2002-01-01

    Stress-induced increases in plasma epinephrine in man have been reported to decrease with age. To investigate the possible cellular basis for this decline we determined the characteristics of calcium currents and their relationship to catecholamine secretion in isolated human adrenal chromaffin (AC) cells. Cells derived from young individuals displayed prominent prepulse facilitation of L-type Ca channels but this property was absent in cells from older subjects. Robust quantal secretion in young cells as determined by amperometry was strongly coupled to the activation of these channels with an average delay of only approximately 3 msec. N- and P-type Ca channels also contributed to secretion but were more weakly coupled to catecholamine release sites. Cells from older subjects secreted much less efficiently and showed only weak coupling between Ca channels and secretion. These studies suggest that the magnitude and timing of adrenal secretion changes with age and that the facilitation Ca channel is key to rapid activation of the fight-or-flight response in young individuals.

  1. Faster kinetics of quantal catecholamine release in mouse chromaffin cells stimulated with acetylcholine, compared with other secretagogues.

    PubMed

    Calvo-Gallardo, Enrique; López-Gil, Ángela; Méndez-López, Iago; Martínez-Ramírez, Carmen; Padín, Juan Fernando; García, Antonio G

    2016-12-01

    Adrenal chromaffin cells (CCs) have been used extensively in studies aimed at revealing the intricacies of the Ca(2+) -dependent early and late steps of regulated exocytosis. They have also served as invaluable models to study the kinetics of single-vesicle exocytotic events to infer the characteristics of opening and closing of the exocytotic fusion pore. We have here tested the hypothesis that stimulation at room temperature of CCs from mice C57BL/6 with physiological acetylcholine (ACh) and with other secretagogues (dimethylphenylpiperazinium, high K(+) , muscarine, histamine, caffeine), alone or in combination, could trigger amperometric spike events with different kinetics. We found that mean secretory spike events in CCs stimulated with ACh had a fast rise rate of 25 pA/ms and a rapid decay time of 6.2 ms, with a small quantal size (0.31 pC). Surprisingly, these parameters considerably differed from those found in CCs stimulated with all other secretagogues that triggered secretory responses with spike events having smaller rise rates, longer decay times and higher quantal sizes. ACh spikes were unaltered by atropine but mitochondrial protonophore carbonyl cyanide-4-(trifluoromethoxy)phenylhydrazone markedly slowed down the rate rise and decay time, and augmented the quantal size of mean secretory events. We conclude that the physiological neurotransmitter ACh triggers a fast and efficient exocytotic response that cannot be mimicked by other secretagogues; such response is regulated by the mitochondrial circulation of calcium ions.

  2. Serotonin (5-hydroxytryptamine, 5-HT) immunoreactive endocrine and neural elements in the chromaffin enteropancreatic system of amphibians and reptiles.

    PubMed

    Trandaburu, Tiberiu; Trandaburu, Ioana

    2007-01-01

    The diffuse chromaffin enteropancreatic system of nine species of amphibians (newts, frogs) and reptiles (turtles, lizards, snakes) was investigated immunohistochemically for the presence and topographic distribution of serotonin (5-hydroxytryptamine, 5-HT). The study revealed various numbers of serotonin-producing cells in the pancreas and intestinal epithelium and also immunolabelled nerve profiles in the villi of all species studied. In addition, two different morphological populations of serotonin cells ("open" and "closed") were localized in the functional segments of the intestines in the representative species of all the taxa investigated. Semi-quantitative evaluation of the immunolabelled pancreatic and enteric cells revealed significantly different mean numbers of labelled cells in different amphibian and reptilian taxa, and also between the various successive gut segments of each taxon. The ratio between "open" and "closed" varieties of serotonin cells recorded along the intestines followed a decreasing trend, progressive in lizards and snakes and more abrupt in newts, frogs and turtles. The above findings may help resolve several key stages of the phylogenetic evolution of poikilothermic vertebrates.

  3. Protein Crystal Bovine Insulin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The comparison of protein crystal, Bovine Insulin space-grown (left) and earth-grown (right). Facilitates the incorporation of glucose into cells. In diabetics, there is either a decrease in or complete lack of insulin, thereby leading to several harmful complications. Principal Investigator is Larry DeLucas.

  4. Protein Crystal Bovine Insulin

    NASA Technical Reports Server (NTRS)

    1991-01-01

    The comparison of protein crystal, Bovine Insulin space-grown (left) and earth-grown (right). Facilitates the incorporation of glucose into cells. In diabetics, there is either a decrease in or complete lack of insulin, thereby leading to several harmful complications. Principal Investigator is Larry DeLucas.

  5. Bovine Spongiform Encephalopathy

    USDA-ARS?s Scientific Manuscript database

    Bovine spongiform encephalopathy (BSE) is caused by a novel contagion, known to as a prion. Prions are proteins capable of converting a normal cellular protein into a prion, thereby propagating an infection. BSE is the first known prion zoonotic. As such it has attracted broad scientific and, to a r...

  6. Bovine Spongiform Encephalopathy

    USDA-ARS?s Scientific Manuscript database

    Bovine spongiform encephalopathy (BSE), also referred to as “mad cow disease” is a chronic, non-febrile, neuro-degenerative disease affecting the central nervous system. The transmissible spongiform encephalopathies (TSEs) of domestic animals, of which BSE is a member includes scrapie of sheep...

  7. Bovine milk exosome proteome

    USDA-ARS?s Scientific Manuscript database

    Exosomes are 40-100 nm membrane vesicles of endocytic origin and are found in blood, urine, amniotic fluid, bronchoalveolar lavage (BAL) fluid, as well as human and bovine milk. Exosomes are extracellular organelles important in intracellular communication/signaling, immune function, and biomarkers ...

  8. Genotyping bovine coronaviruses.

    USDA-ARS?s Scientific Manuscript database

    Bovine coronaviruses (BoCV) are enveloped, single-stranded, positive-sense RNA viruses of the Coronaviridae family. Infection is associated with enteritis and pneumonia in calves and Winter Dysentery in adult cattle. Strains, isolated more than 50 years ago, are used in vaccines and as laboratory ...

  9. Characterization of a metalloprotease from ovine chromaffin granules which cleaves a proenkephalin fragment (BAM12P) at a single arginine residue.

    PubMed Central

    Tezapsidis, N; Parish, D C

    1994-01-01

    A metalloprotease has been identified in ovine chromaffin granules which cleaves the proenkephalin fragment BAM12P to produce adrenorphin-Gly. This cleavage occurs at a single arginine residue and is an intermediate step in the production of the opiate adrenorphin in vivo. The identity of the product was confirmed by reverse-phase and ion-exchange chromatography. The adrenorphin-Gly-generating enzyme (AGE) was determined by chromatofocusing to have a pI value of 5.2 and bound strongly to a metal-chelate affinity column. After purification by gel-filtration and ion-exchange chromatography AGE was free of contaminating activities, as cleavage of radiolabelled BAM12P generated a single product as judged by reverse-phase and ion-exchange chromatography. The enzyme has a molecular mass of approx. 45 kDa and a pH optimum of 8.6 in Mops, Taps and Hepes buffers, but was inhibited by phosphate buffers. It was inhibited by micromolar concentrations of copper and zinc ions, but not by millimolar concentrations of calcium or manganese ions. The addition of BAM22P, dynorphin 1-13 or dynorphin 1-8 to the incubation mixture inhibited the cleavage of radiolabelled BAM12P. The cleavage was also inhibited by the presence of catecholamines at concentrations similar to those found within the chromaffin granule. This may explain the known effect of reserpine on chromaffin cells of reducing catecholamine levels and simultaneously increasing adrenorphin levels. It may also indicate a function for AGE and adrenorphin as reporters of intragranular conditions. Images Figure 1 PMID:8043007

  10. Depressed excitability and ion currents linked to slow exocytotic fusion pore in chromaffin cells of the SOD1(G93A) mouse model of amyotrophic lateral sclerosis.

    PubMed

    Calvo-Gallardo, Enrique; de Pascual, Ricardo; Fernández-Morales, José-Carlos; Arranz-Tagarro, Juan-Alberto; Maroto, Marcos; Nanclares, Carmen; Gandía, Luis; de Diego, Antonio M G; Padín, Juan-Fernando; García, Antonio G

    2015-01-01

    Altered synaptic transmission with excess glutamate release has been implicated in the loss of motoneurons occurring in amyotrophic lateral sclerosis (ALS). Hyperexcitability or hypoexcitability of motoneurons from mice carrying the ALS mutation SOD1(G93A) (mSOD1) has also been reported. Here we have investigated the excitability, the ion currents, and the kinetics of the exocytotic fusion pore in chromaffin cells from postnatal day 90 to postnatal day 130 mSOD1 mice, when motor deficits are already established. With respect to wild-type (WT), mSOD1 chromaffin cells had a decrease in the following parameters: 95% in spontaneous action potentials, 70% in nicotinic current for acetylcholine (ACh), 35% in Na(+) current, 40% in Ca(2+)-dependent K(+) current, and 53% in voltage-dependent K(+) current. Ca(2+) current was increased by 37%, but the ACh-evoked elevation of cytosolic Ca(2+) was unchanged. Single exocytotic spike events triggered by ACh had the following differences (mSOD1 vs. WT): 36% lower rise rate, 60% higher decay time, 51% higher half-width, 13% lower amplitude, and 61% higher quantal size. The expression of the α3-subtype of nicotinic receptors and proteins of the exocytotic machinery was unchanged in the brain and adrenal medulla of mSOD1, with respect to WT mice. A slower fusion pore opening, expansion, and closure are likely linked to the pronounced reduction in cell excitability and in the ion currents driving action potentials in mSOD1, compared with WT chromaffin cells.

  11. Down-regulation of cell surface insulin receptor and insulin receptor substrate-1 phosphorylation by inhibitor of 90-kDa heat-shock protein family: endoplasmic reticulum retention of monomeric insulin receptor precursor with calnexin in adrenal chromaffin cells.

    PubMed

    Saitoh, Tomokazu; Yanagita, Toshihiko; Shiraishi, Seiji; Yokoo, Hiroki; Kobayashi, Hideyuki; Minami, Shin-Ichi; Onitsuka, Toshio; Wada, Akihiko

    2002-10-01

    Treatment (>/=6 h) of cultured bovine adrenal chromaffin cells with geldanamycin (GA) or herbimycin A (HA), an inhibitor of the 90-kDa heat-shock protein (Hsp90) family, decreased cell surface (125)I-insulin binding. The effect of GA was concentration (EC(50) = 84 nM)- and time (t(1/2) = 8.5 h)-dependent; GA (1 microM for 24 h) lowered the B(max) value of (125)I-insulin binding by 80%, without changing the K(d) value. Western blot analysis showed that GA (>/=3 h) lowered insulin receptor (IR) level by 83% (t(1/2) = 7.4 h; EC(50) = 74 nM), while raising IR precursor level by 100% (t(1/2) = 7.9 h; EC(50) = 300 nM). Pulse-label followed by reducing and nonreducing sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that monomeric IR precursor (~190 kDa) developed into the homodimeric IR precursor (approximately 380 kDa) and the mature alpha(2)beta(2) IR (~410 kDa) in nontreated cells, but not in GA-treated cells; in GA-treated cells, the homodimerization-incompetent form of monomeric IR precursor was degraded via endoplasmic reticulum (ER)-associated protein degradation. Immunoprecipitation followed by immunoblot analysis showed that IR precursor was associated with calnexin (CNX) to a greater extent in GA-treated cells, compared with nontreated cells. GA had no effect on IR mRNA levels and internalization rate of cell surface IRs. In GA-treated cells, insulin-induced tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) was attenuated by 77%, with no change in IRS-1 level. Thus, inhibition of the Hsp90 family by GA or HA interrupts homodimerization of monomeric IR precursor in the ER and increases retention of monomeric IR precursor with CNX; this event retards cell surface expression of IR and attenuates insulin-induced activation of IRS-1.

  12. Distinguishing splanchnic nerve and chromaffin cell stimulation in mouse adrenal slices with fast-scan cyclic voltammetry

    PubMed Central

    Walsh, Paul L.; Petrovic, Jelena

    2011-01-01

    Electrical stimulation is an indispensible tool in studying electrically excitable tissues in neurobiology and neuroendocrinology. In this work, the consequences of high-intensity electrical stimulation on the release of catecholamines from adrenal gland slices were examined with fast-scan cyclic voltammetry at carbon fiber microelectrodes. A biphasic signal, consisting of a fast and slow phase, was observed when electrical stimulations typically used in tissue slices (10 Hz, 350 μA biphasic, 2.0 ms/phase pulse width) were applied to bipolar tungsten-stimulating electrodes. This signal was found to be stimulation dependent, and the slow phase of the signal was abolished when smaller (≤250 μA) and shorter (1 ms/phase) stimulations were used. The slow phase of the biphasic signal was found to be tetrodotoxin and hexamethonium independent, while the fast phase was greatly reduced using these pharmacological agents. Two different types of calcium responses were observed, where the fast phase was abolished by perfusion with a low-calcium buffer while both the fast and slow phases could be modulated when Ca2+ was completely excluded from the solution using EGTA. Perfusion with nifedipine resulted in the reduction of the slow catecholamine release to 29% of the original signal, while the fast phase was only decreased to 74% of predrug values. From these results, it was determined that high-intensity stimulations of the adrenal medulla result in depolarizing not only the splanchnic nerves, but also the chromaffin cells themselves resulting in a biphasic catecholamine release. PMID:21048165

  13. Neuronal precursors within the adult rat subventricular zone differentiate into dopaminergic neurons after substantia nigra lesion and chromaffin cell transplant.

    PubMed

    Arias-Carrión, Oscar; Hernández-López, Salvador; Ibañez-Sandoval, Osvaldo; Bargas, José; Hernández-Cruz, Arturo; Drucker-Colín, René

    2006-11-15

    Neurogenesis in the adult mammalian brain continues in the subventricular zone (SVZ). Neuronal precursors from the SVZ migrate along the rostral migratory stream to replace olfactory bulb interneurons. After the destruction of the nigro-striatal pathway (SN-lesion), some SVZ precursors begin to express tyrosine hydroxylase (TH) and neuronal markers (NeuN). Grafting of chromaffin cells (CCs) into the denervated striatum increases the number of TH+ cells (SVZ TH+ cells; Arias-Carrión et al., 2004). This study examines the functional properties of these newly differentiating TH+ cells. Under whole-cell patch-clamp, most SVZ cells recorded from lesioned and grafted animals (either TH+ or TH-) were non-excitable. Nevertheless, a small percentage of SVZ TH+ cells had the electrophysiologic phenotype of mature dopaminergic neurons and showed spontaneous postsynaptic potentials. Dopamine (DA) release was measured in SVZ and striatum from both control and SN-lesioned rats. As expected, 12 weeks after SN lesion, DA release decreased drastically. Nevertheless, 8 weeks after CCs graft, release from the SVZ of SN-lesioned rats recovered, and even surpassed that from control SVZ, suggesting that newly formed SVZ TH+ cells release DA. This study shows for the first time that in response to SN-lesions and CC grafts neural precursors within the SVZ change their developmental program, by not only expressing TH, but more importantly by acquiring excitable properties of mature dopaminergic neurons. Additionally, the release of DA in a Ca(2+)-dependent manner and the attraction of synaptic afferents from neighboring neuronal networks gives further significance to the overall findings, whose potential importance is discussed.

  14. A confocal study on the visualization of chromaffin cell secretory vesicles with fluorescent targeted probes and acidic dyes.

    PubMed

    Moreno, Alfredo; SantoDomingo, Jaime; Fonteriz, Rosalba I; Lobatón, Carmen D; Montero, Mayte; Alvarez, Javier

    2010-12-01

    Secretory vesicles have low pH and have been classically identified as those labelled by a series of acidic fluorescent dyes such as acridine orange or neutral red, which accumulate into the vesicles according to the pH gradient. More recently, several fusion proteins containing enhanced green fluorescent protein (EGFP) and targeted to the secretory vesicles have been engineered. Both targeted fluorescent proteins and acidic dyes have been used, separately or combined, to monitor the dynamics of secretory vesicle movements and their fusion with the plasma membrane. We have now investigated in detail the degree of colocalization of both types of probes using several fusion proteins targeted to the vesicles (synaptobrevin2-EGFP, Cromogranin A-EGFP and neuropeptide Y-EGFP) and several acidic dyes (acridine orange, neutral red and lysotracker red) in chromaffin cells, PC12 cells and GH(3) cells. We find that all the acidic dyes labelled the same population of vesicles. However, that population was largely different from the one labelled by the targeted proteins, with very little colocalization among them, in all the cell types studied. Our data show that the vesicles containing the proteins more characteristic of the secretory vesicles are not labelled by the acidic dyes, and vice versa. Peptide glycyl-L-phenylalanine 2-naphthylamide (GPN) produced a rapid and selective disruption of the vesicles labelled by acidic dyes, suggesting that they could be mainly lysosomes. Therefore, these labelling techniques distinguish two clearly different sets of acidic vesicles in neuroendocrine cells. This finding should be taken into account whenever vesicle dynamics is studied using these techniques.

  15. Butanol Isomers Exert Distinct Effects on Voltage-Gated Calcium Channel Currents and Thus Catecholamine Secretion in Adrenal Chromaffin Cells

    PubMed Central

    Brindley, Rebecca L.; Jewell, Mark L.; Currie, Kevin P. M.

    2014-01-01

    Butanol (C4H10OH) has been used both to dissect the molecular targets of alcohols/general anesthetics and to implicate phospholipase D (PLD) signaling in a variety of cellular functions including neurotransmitter and hormone exocytosis. Like other primary alcohols, 1-butanol is a substrate for PLD and thereby disrupts formation of the intracellular signaling lipid phosphatidic acid. Because secondary and tertiary butanols do not undergo this transphosphatidylation, they have been used as controls for 1-butanol to implicate PLD signaling. Recently, selective pharmacological inhibitors of PLD have been developed and, in some cases, fail to block cellular functions previously ascribed to PLD using primary alcohols. For example, exocytosis of insulin and degranulation of mast cells are blocked by primary alcohols, but not by the PLD inhibitor FIPI. In this study we show that 1-butanol reduces catecholamine secretion from adrenal chromaffin cells to a much greater extent than tert-butanol, and that the PLD inhibitor VU0155056 has no effect. Using fluorescent imaging we show the effect of these drugs on depolarization-evoked calcium entry parallel those on secretion. Patch-clamp electrophysiology confirmed the peak amplitude of voltage-gated calcium channel currents (ICa) is inhibited by 1-butanol, with little or no block by secondary or tert-butanol. Detailed comparison shows for the first time that the different butanol isomers exert distinct, and sometimes opposing, effects on the voltage-dependence and gating kinetics of ICa. We discuss these data with regard to PLD signaling in cellular physiology and the molecular targets of general anesthetics. PMID:25275439

  16. Effect of inositol 1,4,5-trisphosphate receptor stimulation on mitochondrial [Ca2+] and secretion in chromaffin cells.

    PubMed Central

    Montero, Mayte; Alonso, Maria Teresa; Albillos, Almudena; Cuchillo-Ibáñez, Inmaculada; Olivares, Román; Villalobos, Carlos; Alvarez, Javier

    2002-01-01

    Ca(2+) uptake by mitochondria is a potentially important buffering system able to control cytosolic [Ca(2+)]. In chromaffin cells, we have shown previously that stimulation of either Ca(2+) entry or Ca(2+) release via ryanodine receptors triggers large increases in mitochondrial [Ca(2+)] ([Ca(2+)](M)) approaching the millimolar range, whose blockade dramatically enhances catecholamine secretion [Montero, Alonso, Carnicero, Cuchillo-Ibañez, Albillos, Garcia, Carcia-Sancho and Alvarez (2000) Nat. Cell Biol. 2, 57-61]. In the present study, we have studied the effect of stimulation of inositol 1,4,5-trisphosphate (InsP(3)) receptors using histamine. We find that histamine produces a heterogeneous increase in [Ca(2+)](M), reaching peak levels at approx. 1 microM in 70% of the mitochondrial space to several hundred micromolar in 2-3% of mitochondria. Intermediate levels were found in the rest of the mitochondrial space. Single-cell imaging experiments with aequorin showed that the heterogeneity had both an intercellular and a subcellular origin. Those mitochondria responding to histamine with increases in [Ca(2+)](M) much greater than 1 microM (30%) were the same as those that also responded with large increases in [Ca(2+)](M) following stimulation with either high-K(+) medium or caffeine. Blocking mitochondrial Ca(2+) uptake with protonophores or mitochondrial inhibitors also enhanced catecholamine secretion induced by histamine. These results suggest that some InsP(3) receptors tightly co-localize with ryanodine receptors and voltage-dependent Ca(2+) channels in defined subplasmalemmal functional units designed to control secretion induced by different stimuli. PMID:11931633

  17. Heritable bovine fetal abnormalities.

    PubMed

    Whitlock, B K; Kaiser, L; Maxwell, H S

    2008-08-01

    The etiologies for congenital bovine fetal anomalies can be divided into heritable, toxic, nutritional, and infectious categories. Although uncommon in most herds, inherited congenital anomalies are probably present in all breeds of cattle and propagated as a result of specific trait selection that inadvertently results in propagation of the defect. In some herds, the occurrence of inherited anomalies has become frequent, and economically important. Anomalous traits can affect animals in a range of ways, some being lethal or requiring euthanasia on humane grounds, others altering structure, function, or performance of affected animals. Veterinary practitioners should be aware of the potential for inherited defects, and be prepared to investigate and report animals exhibiting abnormal characteristics. This review will discuss the morphologic characteristics, mode of inheritance, breeding lines affected, and the availability of genetic testing for selected heritable bovine fetal abnormalities.

  18. Selenium in bovine spermatozoa.

    PubMed

    Niemi, S M; Kuzan, F B; Senger, P L

    1981-05-01

    This study investigated the association of selenium with ejaculated bovine spermatozoa. Over 75% of the radioactive spermatozoa. Over 75% of the radioactive selenium-75 was released after 30 min of incubation in 2 X 10(-3) dithiothreitol. Of the selenium-75 released by dithiothreitol, 85% was associated with spermatozoal protein. Protein containing selenium-75 was found predominantly in a single band after polyacrylamide gel electrophoresis. Molecular weight was approximately 21,500 daltons.

  19. Sustained Exocytosis after Action Potential-Like Stimulation at Low Frequencies in Mouse Chromaffin Cells Depends on a Dynamin-Dependent Fast Endocytotic Process

    PubMed Central

    Moya-Díaz, José; Álvarez, Yanina D.; Montenegro, Mauricio; Bayonés, Lucas; Belingheri, Ana V.; González-Jamett, Arlek M.; Cárdenas, Ana M.; Marengo, Fernando D.

    2016-01-01

    Under basal conditions the action potential firing rate of adrenal chromaffin cells is lower than 0.5 Hz. The maintenance of the secretory response at such frequencies requires a continuous replenishment of releasable vesicles. However, the mechanism that allows such vesicle replenishment remains unclear. Here, using membrane capacitance measurements on mouse chromaffin cells, we studied the mechanism of replenishment of a group of vesicles released by a single action potential-like stimulus (APls). The exocytosis triggered by APls (ETAP) represents a fraction (40%) of the immediately releasable pool, a group of vesicles highly coupled to voltage dependent calcium channels. ETAP was replenished with a time constant of 0.73 ± 0.11 s, fast enough to maintain synchronous exocytosis at 0.2–0.5 Hz stimulation. Regarding the mechanism involved in rapid ETAP replenishment, we found that it depends on the ready releasable pool; indeed depletion of this vesicle pool significantly delays ETAP replenishment. On the other hand, ETAP replenishment also correlates with a dynamin-dependent fast endocytosis process (τ = 0.53 ± 0.01 s). In this regard, disruption of dynamin function markedly inhibits the fast endocytosis and delays ETAP replenishment, but also significantly decreases the synchronous exocytosis during repetitive APls stimulation at low frequencies (0.2 and 0.5 Hz). Considering these findings, we propose a model in where both the transfer of vesicles from ready releasable pool and fast endocytosis allow rapid ETAP replenishment during low stimulation frequencies. PMID:27507935

  20. Diagnostic imaging in bovine orthopedics.

    PubMed

    Kofler, Johann; Geissbühler, Urs; Steiner, Adrian

    2014-03-01

    Although a radiographic unit is not standard equipment for bovine practitioners in hospital or field situations, ultrasound machines with 7.5-MHz linear transducers have been used in bovine reproduction for many years, and are eminently suitable for evaluation of orthopedic disorders. The goal of this article is to encourage veterinarians to use radiology and ultrasonography for the evaluation of bovine orthopedic disorders. These diagnostic imaging techniques improve the likelihood of a definitive diagnosis in every bovine patient but especially in highly valuable cattle, whose owners demand increasingly more diagnostic and surgical interventions that require high-level specialized techniques.

  1. Sympathoneural and Adrenomedullary Responses to Mental Stress

    PubMed Central

    Carter, Jason R.; Goldstein, David S.

    2017-01-01

    This concept-based review provides historical perspectives and updates about sympathetic noradrenergic and sympathetic adrenergic responses to mental stress. The topic of this review has incited perennial debate, because of disagreements over definitions, controversial inferences, and limited availability of relevant measurement tools. The discussion begins appropriately with Cannon's "homeostasis" and his pioneering work in the area. This is followed by mental stress as a scientific idea and the relatively new notions of allostasis and allostatic load. Experimental models of mental stress in rodents and humans are discussed, with particular attention to ethical constraints in humans. Sections follow on sympathoneural to mental stress, reactivity of catecholamine systems, clinical pathophysiologic states, and the cardiovascular reactivity hypothesis. Future advancement of the field will require integrative approaches and coordinated efforts between physiologists and psychologists on this interdisciplinary topic. PMID:25589266

  2. α-Conotoxins Identify the α3β4* Subtype as the Predominant Nicotinic Acetylcholine Receptor Expressed in Human Adrenal Chromaffin Cells.

    PubMed

    Hone, Arik J; McIntosh, J Michael; Azam, Layla; Lindstrom, Jon; Lucero, Linda; Whiteaker, Paul; Passas, Juan; Blázquez, Jesús; Albillos, Almudena

    2015-11-01

    Ligands that selectively inhibit human α3β2 and α6β2 nicotinic acetylcholine receptor (nAChRs) and not the closely related α3β4 and α6β4 subtypes are lacking. Current α-conotoxins (α-Ctxs) that discriminate among these nAChR subtypes in rat fail to discriminate among the human receptor homologs. In this study, we describe the development of α-Ctx LvIA(N9R,V10A) that is 3000-fold more potent on oocyte-expressed human α3β2 than α3β4 and 165-fold more potent on human α6/α3β2β3 than α6/α3β4 nAChRs. This analog was used in conjuction with three other α-Ctx analogs and patch-clamp electrophysiology to characterize the nAChR subtypes expressed by human adrenal chromaffin cells. LvIA(N9R,V10A) showed little effect on the acetylcholine-evoked currents in these cells at concentrations expected to inhibit nAChRs with β2 ligand-binding sites. In contrast, the β4-selective α-Ctx BuIA(T5A,P6O) inhibited >98% of the acetylcholine-evoked current, indicating that most of the heteromeric receptors contained β4 ligand-binding sites. Additional studies using the α6-selective α-Ctx PeIA(A7V,S9H,V10A,N11R,E14A) indicated that the predominant heteromeric nAChR expressed by human adrenal chromaffin cells is the α3β4* subtype (asterisk indicates the possible presence of additional subunits). This conclusion was supported by polymerase chain reaction experiments of human adrenal medulla gland and of cultured human adrenal chromaffin cells that demonstrated prominent expression of RNAs for α3, α5, α7, β2, and β4 subunits and a low abundance of RNAs for α2, α4, α6, and α10 subunits.

  3. α-Conotoxins Identify the α3β4* Subtype as the Predominant Nicotinic Acetylcholine Receptor Expressed in Human Adrenal Chromaffin Cells

    PubMed Central

    Hone, Arik J.; McIntosh, J. Michael; Azam, Layla; Lindstrom, Jon; Lucero, Linda; Whiteaker, Paul; Passas, Juan; Blázquez, Jesús

    2015-01-01

    Ligands that selectively inhibit human α3β2 and α6β2 nicotinic acetylcholine receptor (nAChRs) and not the closely related α3β4 and α6β4 subtypes are lacking. Current α-conotoxins (α-Ctxs) that discriminate among these nAChR subtypes in rat fail to discriminate among the human receptor homologs. In this study, we describe the development of α-Ctx LvIA(N9R,V10A) that is 3000-fold more potent on oocyte-expressed human α3β2 than α3β4 and 165-fold more potent on human α6/α3β2β3 than α6/α3β4 nAChRs. This analog was used in conjuction with three other α-Ctx analogs and patch-clamp electrophysiology to characterize the nAChR subtypes expressed by human adrenal chromaffin cells. LvIA(N9R,V10A) showed little effect on the acetylcholine-evoked currents in these cells at concentrations expected to inhibit nAChRs with β2 ligand-binding sites. In contrast, the β4-selective α-Ctx BuIA(T5A,P6O) inhibited >98% of the acetylcholine-evoked current, indicating that most of the heteromeric receptors contained β4 ligand-binding sites. Additional studies using the α6-selective α-Ctx PeIA(A7V,S9H,V10A,N11R,E14A) indicated that the predominant heteromeric nAChR expressed by human adrenal chromaffin cells is the α3β4* subtype (asterisk indicates the possible presence of additional subunits). This conclusion was supported by polymerase chain reaction experiments of human adrenal medulla gland and of cultured human adrenal chromaffin cells that demonstrated prominent expression of RNAs for α3, α5, α7, β2, and β4 subunits and a low abundance of RNAs for α2, α4, α6, and α10 subunits. PMID:26330550

  4. A Post-Docking Role of Synaptotagmin 1-C2B Domain Bottom Residues R398/399 in Mouse Chromaffin Cells.

    PubMed

    Kedar, Girish H; Munch, Anders S; van Weering, Jan R T; Malsam, Jörg; Scheutzow, Andrea; de Wit, Heidi; Houy, Sébastien; Tawfik, Bassam; Söllner, Thomas H; Sørensen, Jakob B; Verhage, Matthijs

    2015-10-21

    Synaptotagmin-1 (Syt1) is the principal Ca(2+) sensor for vesicle fusion and is also essential for vesicle docking in chromaffin cells. Docking depends on interactions of the Syt1-C2B domain with the t-SNARE SNAP25/Syntaxin1 complex and/or plasma membrane phospholipids. Here, we investigated the role of the positively charged "bottom" region of the C2B domain, proposed to help crosslink membranes, in vesicle docking and secretion in mouse chromaffin cells and in cell-free assays. We expressed a double mutation shown previously to interfere with lipid mixing between proteoliposomes and with synaptic transmission, Syt1-R398/399Q (RQ), in syt1 null mutant cells. Ultrastructural morphometry revealed that Syt1-RQ fully restored the docking defect observed previously in syt1 null mutant cells, similar to wild type Syt1 (Syt1-wt). Small unilamellar lipid vesicles (SUVs) that contained the v-SNARE Synaptobrevin2 and Syt1-R398/399Q also docked to t-SNARE-containing giant vesicles (GUVs), similar to Syt1-wt. However, unlike Syt1-wt, Syt1-RQ-induced docking was strictly PI(4,5)P2-dependent. Unlike docking, neither synchronized secretion in chromaffin cells nor Ca(2+)-triggered SUV-GUV fusion was restored by the Syt1 mutants. Finally, overexpressing the RQ-mutant in wild type cells produced no effect on either docking or secretion. We conclude that the positively charged bottom region in the C2B domain--and, by inference, Syt1-mediated membrane crosslinking--is required for triggering fusion, but not for docking. Secretory vesicles dock by multiple, PI(4,5)P2-dependent and PI(4,5)P2-independent mechanisms. The R398/399 mutations selectively disrupt the latter and hereby help to discriminate protein regions involved in different aspects of Syt1 function in docking and fusion. This study provides new insights in how the two opposite sides of the C2B domain of Synaptotagmin-1 participate in secretory vesicle fusion, and in more upstream steps, especially vesicle docking. We show

  5. Enhancement of insulin-induced PI3K/Akt/GSK-3beta and ERK signaling by neuronal nicotinic receptor/PKC-alpha/ERK pathway: up-regulation of IRS-1/-2 mRNA and protein in adrenal chromaffin cells.

    PubMed

    Sugano, Takashi; Yanagita, Toshihiko; Yokoo, Hiroki; Satoh, Shinya; Kobayashi, Hideyuki; Wada, Akihiko

    2006-07-01

    In cultured bovine adrenal chromaffin cells treated with nicotine (10 microm for 24 h), phosphorylation of Akt, glycogen synthase kinase-3beta (GSK-3beta) and extracellular signal-regulated kinase (ERK)1/2 induced by insulin (100 nm for 10 min) was enhanced by approximately 62%, without altering levels of these protein kinases. Nicotine produced time (> 12 h)- and concentration (EC(50) 3.6 and 13 microm)-dependent increases in insulin receptor substrate (IRS)-1 and IRS-2 levels by approximately 125 and 105%, without altering cell surface density of insulin receptors. In these cells, insulin-induced tyrosine phosphorylation of IRS-1/IRS-2 and recruitment of phosphoinositide 3-kinase (PI3K) to IRS-1/IRS-2 were augmented by approximately 63%. The increase in IRS-1/IRS-2 levels induced by nicotine was prevented by nicotinic acetylcholine receptor (nAChR) antagonists, the Ca(2+) chelator 1,2-bis(2-aminophenoxy)-ethane-N,N,N',N'-tetra-acetic acid tetrakis-acetoxymethyl ester, cycloheximide or actinomycin D. Nicotine increased IRS-1 and IRS-2 mRNA levels by approximately 57 and approximately 50%, and this was prevented by conventional protein kinase C (cPKC) inhibitor Gö6976, or ERK kinase inhibitors PD98059 and U0126. Nicotine phosphorylated cPKC-alpha, thereby increasing phosphorylation of ERK1/ERK2, as demonstrated by using Gö6976, PD98059 or U0126. Selective activation of cPKC-alpha by thymeleatoxin mimicked these effects of nicotine. Thus, stimulation of nAChRs up-regulated expression of IRS-1/IRS-2 via Ca(2+)-dependent sequential activation of cPKC-alpha and ERK, and enhanced insulin-induced PI3K/Akt/GSK-3beta and ERK signaling pathways.

  6. Endothelin-1-induced down-regulation of NaV1.7 expression in adrenal chromaffin cells: attenuation of catecholamine secretion and tau dephosphorylation.

    PubMed

    Nemoto, Takayuki; Yanagita, Toshihiko; Maruta, Toyoaki; Sugita, Chihiro; Satoh, Shinya; Kanai, Tasuku; Wada, Akihiko; Murakami, Manabu

    2013-04-02

    Endothelin-1 and voltage-dependent sodium channels are involved in control and suppression of neuropathological factors, which contribute to sculpting the neuronal network. We previously demonstrated that veratridine-induced NaV1.7 sodium channel activation caused intracellular calcium elevation, catecholamine secretion and tau dephosphorylation in adrenal chromaffin cells. The aim of this study was to examine whether endothelin-1 could modulate NaV1.7. Our results indicated that endothelin-1 decreased the protein level of NaV1.7 and the veratridine-induced increase in intracellular calcium. In addition, it also abolished the veratridine-induced dephosphorylation of tau and the phosphorylation of glycogen synthase kinase-3β and extracellular signal-regulated kinase. These findings suggest that the endothelin-1-induced down-regulation of NaV1.7 diminishes NaV1.7-related catecholamine secretion and dephosphorylation of tau.

  7. Microelectrode Arrays of Diamond-Insulated Graphitic Channels for Real-Time Detection of Exocytotic Events from Cultured Chromaffin Cells and Slices of Adrenal Glands.

    PubMed

    Picollo, Federico; Battiato, Alfio; Bernardi, Ettore; Marcantoni, Andrea; Pasquarelli, Alberto; Carbone, Emilio; Olivero, Paolo; Carabelli, Valentina

    2016-08-02

    A microstructured graphitic 4 × 4 multielectrode array was embedded in a single-crystal diamond substrate (4 × 4 μG-SCD MEA) for real-time monitoring of exocytotic events from cultured chromaffin cells and adrenal slices. The current approach relies on the development of a parallel ion beam lithographic technique, which assures the time-effective fabrication of extended arrays with reproducible electrode dimensions. The reported device is suitable for performing amperometric and voltammetric recordings with high sensitivity and temporal resolution, by simultaneously acquiring data from 16 rectangularly shaped microelectrodes (20 × 3.5 μm(2)) separated by 200 μm gaps. Taking advantage of the array geometry we addressed the following specific issues: (i) detect both the spontaneous and KCl-evoked secretion simultaneously from several chromaffin cells directly cultured on the device surface, (ii) resolve the waveform of different subsets of exocytotic events, and (iii) monitoring quantal secretory events from thin slices of the adrenal gland. The frequency of spontaneous release was low (0.12 and 0.3 Hz, respectively, for adrenal slices and cultured cells) and increased up to 0.9 Hz after stimulation with 30 mM KCl in cultured cells. The spike amplitude as well as rise and decay time were comparable with those measured by carbon fiber microelectrodes and allowed to identify three different subsets of secretory events associated with "full fusion" events, "kiss-and-run" and "kiss-and-stay" exocytosis, confirming that the device has adequate sensitivity and time resolution for real-time recordings. The device offers the significant advantage of shortening the time to collect data by allowing simultaneous recordings from cell populations either in primary cell cultures or in intact tissues.

  8. Muscarinic and opioid receptor modulation of release of (Met/sup 5/-enkephalin immunoreactive material and catecholamines from the bovine adrenal gland

    SciTech Connect

    Barron, B.A.

    1985-01-01

    Retrogradely perfused bovine adrenal glands were stimulated by acetylcholine (ACh) and 1,1-dimethyl-4-phenyl-piperazinium (DMPP), with or without: hexamethonium (C-6), atropine, imipramine, methacholine, pilocarpine, etorphine, or diprenorphine. Stimulation by either ACh DMPP resulted in an increased release of both (Met/sup 5/)-enkephalin immunoreactive material (ME-IRM) and catecholamines as measured by radioimmunoassay and high performance liquid chromatography with electrochemical detection, respectively. ACh (5 x 10/sup -5/ M) and DMPP (5 x 10/sup -5/ M) stimulated the release of norepinephrine greater than the release of epinephrine. The action of these agents was antagonized by C-6(5 x 10/sup -4/ M). Atropine (5 x 10/sup -7/ M) antagonized the action of ACh to stimulate norepinephrine and MI-IRM release while having no effect on DMPP-stimulated release. Imipramine (5 x 10/sup -6/ M) had no effect on either ACh or DMPP-stimulated release. Methacholine (4 x 10/sup -5/ M) potentiated the DMPP (1 x 10/sup -5/ M) stimulation of ME-IRM and catecholamine release; pilocarpine (4 x 10/sup -5/ M) significantly potentiated only the DMPP-stimulated release of norepinephrine. Pilocarpine (5 x 10/sup -5/ M) and muscarine (5 x 10/sup -5/ M) had no effect on the secretion of MI-IRM and catecholamines from the bovine adrenal gland. Etorphine (5 x 10/sup -7/ M) significantly decreased the ACh and DMPP stimulation ME-IRM and catecholamine release. The activity of a muscarinic cholinergic receptor in the bovine adrenal medulla in stimulus-secretion coupling has been controversial. The binding of /sup 3/H-quinuclidinyl benzilate to chromaffin granule membranes was investigated to further characterize muscarinic receptors in the bovine adrenal gland.

  9. Inhibition of rat and bovine trypsins and chymotrypsins by soybean, bovine basic pancreatic, and bovine colostrum trypsin inhibitors.

    PubMed

    Esparza, I; Brock, J H

    1978-01-01

    1. Bovine (Bos taurus) trypsin and trypsin activity in rat (Rattus norvegicus) pancreatic extract were inhibited by soybean trypsin inhibitor and by bovine basic pancreatic and colostrum inhibitors. 2. Bovine alpha-chymotrypsin was inhibited by soybean and bovine basic pancreatic inhibitors but only weakly by colostrum inhibitor. 3. Chymotrypsin activity in rat pancreatic extract was due to at least three different components against all of which the inhibitors were largely ineffective. 4. It is concluded that bovine colostrum inhibitor has a more limited inhibition spectrum than the phylogenetically related basic pancreatic inhibitor which, in turn, is less active against rat than against bovine enzymes.

  10. The innervation of the adrenal gland. IV. Innervation of the rat adrenal medulla from birth to old age. A descriptive and quantitative morphometric and biochemical study of the innervation of chromaffin cells and adrenal medullary neurons in Wistar rats.

    PubMed Central

    Tomlinson, A; Coupland, R E

    1990-01-01

    The innervation of the adrenal medulla has been investigated in normal Wistar rats from birth to old age and ultrastructural findings compared with biochemical markers of the cholinergic innervation of the adrenal gland and catecholamine storage. Morphological evidence of the immaturity of the innervation during the first postnatal week is provided and using quantitative morphometry the innervation of chromaffin cells is shown to reach a mean total of 5.4 synapses per chromaffin cell during the period 26 days to 12 weeks of age. The variation in contents of synaptic profiles is discussed in the light of recent work that demonstrates a major sensory as well as visceral efferent innervation of the gland. Adrenal medullary neurons usually occur in closely packed groups, intimately associated with Schwann cells. Axodendritic and axosomatic synapses on these neurons are described and the likely origin of axonal processes innervating the neurons discussed. In old age the density of innervation remains the same as in young adult animals even though the medulla shows evidence of hyperplasia and hypertrophy of individual chromaffin cells. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9 Fig. 10 Fig. 11 Fig. 12 Fig. 13 Fig. 14 Fig. 15 Fig. 16 Fig. 17 Fig. 18 Fig. 19 Fig. 20 Fig. 21 Fig. 22 Fig. 23 Fig. 24 Fig. 25 PMID:2384334

  11. Vaccination against bovine babesiosis.

    PubMed

    De Vos, A J; Bock, R E

    2000-01-01

    Bovine babesiosis is an important disease caused by Babesia bovis, B. bigemina, and B. divergens. Solid immunity develops after infection and this feature has been exploited with the use of live attenuated organisms as immunogens. Attributes of live vaccines include a durable immunity to heterologous challenge after one vaccination. To overcome disadvantages relating to poor quality control (risk of contamination and adverse reactions), production procedures have been modified to meet the requirements of codes of good manufacturing practice. This includes development of methods to allow production of cryopreserved vaccine and limit antigenic drift. Killed vaccines have also been used on a limited basis and consist of antigens extracted from cultured material or blood of infected calves, and given with adjuvant. The degree and duration of immunity against heterologous challenge is not well documented. Attempts are being made to develop subunit vaccines but the progress has been slow. A better understanding of the mechanisms involved in the expression of protective immunity against Babesia spp will aid in the identification of protective antigens.

  12. Pathology of bovine tuberculosis.

    PubMed

    Domingo, M; Vidal, E; Marco, A

    2014-10-01

    Bovine tuberculosis (bTB) is a chronic granulomatous caseous-necrotising inflammatory process that mainly affects the lungs and their draining lymph nodes (Ln.). The pathological changes associated with bTB infection reflect the interplay between the host defence mechanisms and the mycobacterial virulence factors and the balance between the immunologic protective responses and the damaging inflammatory processes. Inhalation is the most common infection route and causes lesions of the nasopharynx and lower respiratory tract, including its associated lymph nodes. The initial infection (primary complex) may be followed by chronic (post-primary) tuberculosis or may be generalised. Goat tuberculosis often produces liquefactive necrosis and caverns, similarly to human TB. The assessment of the severity of TB lesions is crucial for vaccine trials. Semi-quantitative gross lesion scoring systems have been developed for cattle, but imaging technology has allowed the development of more standardised, objective, and quantitative methods, such as multi-detector computed tomography (MDCT), which provides quantitative measures of lesion volume.

  13. Properties of soluble and membrane bound dopamine-beta-monooxygenase from bovine adrenal medulla cross-linked with dimethyl suberimidate.

    PubMed

    Miras-Portugal, M T; Millaruelo, A; Vara, F

    1980-12-10

    Bovine dopamine-beta-monooxygenase from chromaffin granules in its soluble and membrane-bound forms was cross-linked with the bifunctional reagent dimethyl suberimidate, and its structural and kinetic properties were studied. 1. The cross-linking reaction does not affect the activity of soluble dopamine-beta-monooxygenase; it produces a ten percent inactivation in the membrane-bound enzyme, possibly because the linkage to other membrane proteins hinders its activity. 2. The soluble dopamine-beta-monooxygenase reaction mixture was analyzed by sodium dodecyl sulfate gel electrophoresis, showing appreciable amounts of dimer and tetramer, but only small amounts of trimer. In membrane-bound dopamine-beta-monooxygenase, subjected to the same treatment, appreciable amounts of dimer and higher aggregates were found. 3. The kinetic properties of soluble dopamine-beta-monooxygenase after the crosslinking reaction are the same as those of the native enzyme, with a ping-pong kinetic mechanism and the same real Michaelis constants for tyramine and ascorbate: KmT = 0.36 mM and KmA = 0.32 mM. Membrane-bound dopamine-beta-monooxygenase does not present a ping-pong mechanism before or after cross-linking; its real Michaelis constants are slightly modified by the cross-linking reaction: KmT = 0.4 mM and KMA = 0.4 mM.

  14. Bovine trophectoderm cell lines induced from bovine fibroblasts with reprogramming factors

    USDA-ARS?s Scientific Manuscript database

    Bovine trophectoderm (TE) cells were induced [induced bovine trophectoderm-like (iBT)] from bovine fetal liver-derived fibroblasts, and other bovine fetal fibroblasts, after viral-vector transduction with either four or six reprogramming factors (RF), including POU5F1, KLF4, SOX2, C-MYC, SV40 large ...

  15. Bovine respiratory disease model based on dual infections with infection with bovine viral diarrhea virus and bovine corona virus

    USDA-ARS?s Scientific Manuscript database

    Bovine respiratory disease complex (BRDC) is the leading cause of economic loss in the U.S. cattle industry. BRDC likely results from simultaneous or sequential infections with multiple pathogens including both viruses and bacteria. Bovine viral diarrhea virus (BVDV) and bovine corona virus (BoCV...

  16. Material Properties of Inorganic Bovine Cancellous Bovine: Nukbone

    NASA Astrophysics Data System (ADS)

    Piña, Cristina; Palma, Benito; Munguía, Nadia

    2006-09-01

    In this work, inorganic cancellous bovine bone implants prepared in the Instituto de Investigaciones en Materiales — UNAM were characterized. Elementary chemical analysis was made, toxic elements concentration were measured and the content of organic matter also. These implants fulfill all the requirements of the ASTM standards, and therefore it is possible their use in medical applications.

  17. Separate [3H]-nitrendipine binding sites in mitochondria and plasma membranes of bovine adrenal medulla.

    PubMed Central

    Ballesta, J. J.; Garcia, A. G.; Gutierrez, L. M.; Hidalgo, M. J.; Palmero, M.; Reig, J. A.; Viniegra, S.

    1990-01-01

    1. Two binding sites for the 1,4-dihydropyridine (DHP) derivative [3H]-nitrendipine have been found in the bovine adrenal medulla. The high-affinity site (Kd = 0.48 nM and Bmax = 128 fmol mg-1 protein) was specifically located in purified plasma membranes. The low-affinity site (Kd = 252 nM and Bmax = 169 pmol mg-1 protein) was located only in mitochondria. Chromaffin granule membranes lacked specific binding sites for [3H]-nitrendipine. 2. Kinetic analysis of the rates of association and dissociation of [3H]-nitrendipine, saturation isotherms and displacement experiments with unlabelled nitrendipine and PN200-110 revealed single, homogeneous populations of high- and low-affinity sites in plasma and mitochondrial membranes, respectively. 3. The high affinity site was sensitive to Ca2+ deprivation and heating; it was practically unaffected by changes in ionic strength of the medium and its optimal pH was slightly alkaline. This site exhibited a strong DHP stereoselectivity; diltiazem increased and verapamil decreased the affinity of [3H]-nitrendipine. 4. In contrast, binding of [3H]-nitrendipine to the low affinity site was more heat resistant and less affected by Ca2+ removal. Its optimal pH was slightly acid and the increase in ionic strength enhanced the number of available sites. The site had no DHP stereoselectivity. Verapamil decreased the dissociation constant of [3H]-nitrendipine acting in a non-competitive manner; diltiazem did not affect equilibrium binding parameters of [3H]-nitrendipine. 5. These results suggest that both biding sites reflect different receptor entities. The high-affinity binding site corresponds to the dihydropyridine receptor associated with the L-type calcium channel. The function of the mitochondrial, low-affinity binding site is, at present, unknown. PMID:1704272

  18. Role of hypoxia and HIF2α in development of the sympathoadrenal cell lineage and chromaffin cell tumours with distinct catecholamine phenotypic features

    PubMed Central

    Richter, Susan; Qin, Nan; Pacak, Karel; Eisenhofer, Graeme

    2013-01-01

    Hypoxia has wide-ranging impact in normal physiology and disease processes. This stimulus evokes changes in gene expression mediated by transcription factors termed hypoxia-inducible factors (HIFs) that affect numerous processes: angiogenesis, cell survival, cellular metabolism, stem cell self- renewal and multipotency, migration, invasiveness and metastatic progression in tumour cells. Over the past decade increasing numbers of reports have emerged documenting differential roles of HIF1α and HIF2α in these processes. In cells of the sympathoadrenal lineage both HIFs differentially mediate influences of hypoxia on catecholamine synthesis and secretion, but HIF2α signalling has particularly prominent functions in regulating developmental processes of growth and differentiation. This article discusses the role of HIF2α and HIF1α in the context of the development, phenotypic features and functions of chromaffin cells. Moreover, current knowledge about tumour formation in cells of the sympathoadrenal lineage, leading to catecholamine producing pheochromocytomas and paragangliomas, is analysed in the light of the HIF2α signalling network. PMID:24054150

  19. The Immediately Releasable Pool of Mouse Chromaffin Cell Vesicles Is Coupled to P/Q-Type Calcium Channels via the Synaptic Protein Interaction Site

    PubMed Central

    Álvarez, Yanina D.; Belingheri, Ana Verónica; Perez Bay, Andrés E.; Javis, Scott E.; Tedford, H. William; Zamponi, Gerald; Marengo, Fernando D.

    2013-01-01

    It is generally accepted that the immediately releasable pool is a group of readily releasable vesicles that are closely associated with voltage dependent Ca2+ channels. We have previously shown that exocytosis of this pool is specifically coupled to P/Q Ca2+ current. Accordingly, in the present work we found that the Ca2+ current flowing through P/Q-type Ca2+ channels is 8 times more effective at inducing exocytosis in response to short stimuli than the current carried by L-type channels. To investigate the mechanism that underlies the coupling between the immediately releasable pool and P/Q-type channels we transiently expressed in mouse chromaffin cells peptides corresponding to the synaptic protein interaction site of Cav2.2 to competitively uncouple P/Q-type channels from the secretory vesicle release complex. This treatment reduced the efficiency of Ca2+ current to induce exocytosis to similar values as direct inhibition of P/Q-type channels via ω-agatoxin-IVA. In addition, the same treatment markedly reduced immediately releasable pool exocytosis, but did not affect the exocytosis provoked by sustained electric or high K+ stimulation. Together, our results indicate that the synaptic protein interaction site is a crucial factor for the establishment of the functional coupling between immediately releasable pool vesicles and P/Q-type Ca2+ channels. PMID:23382986

  20. Electrophysiological properties and augmented catecholamine release from chromaffin cells of WKY and SHR rats contributing to the hypertension development elicited by chronic EtOH consumption.

    PubMed

    Bomfim, Guilherme Henrique Souza; Méndez-López, Iago; Fernández-Morales, José Carlos; Padín, Juan Fernando; Jurkiewicz, Aron; Jurkiewicz, Neide Hyppolito; García, Antonio García

    2017-05-15

    It is known that chronic ethanol (EtOH) consumption leads to hypertension development and has been associated with deleterious effects on the cardiovascular system. Whether this condition alters calcium (Ca(2+)) signaling and exocytosis in adrenal chromaffin cells (CCs) as the case is for genetic hypertension, is unknown. We explored this question in four randomized experimental groups, male Wistar Kyoto (WKY/EtOH) and Spontaneously Hypertensive (SHR/EtOH) rats were subjected to the intake of increasing EtOH concentrations (5-20%, for 30 days) and their respective controls (WKY/Control and SHR/Control) received water. WKY/EtOH developed hypertension and cardiac hypertrophy; blood aldehyde dehydrogenase (ALDH) and H2O2 were also augmented. In comparison with WKY/Control, CCs from WKY/EtOH had the following features: (i) depolarization and higher frequency of spontaneous action potentials; (ii) decreased Ca(2+) currents with slower inactivation; (iii) decreased K(+) currents; (iv) augmented K(+)-elicited cytosolic Ca(2+) transients ([Ca(2+)]c); (v) enhanced K(+)-elicited catecholamine release. These cardiovascular, blood and CCs changes were qualitatively similar to those undergone by SHR/Control and SHR/EtOH. The results suggest that the hypertension elicited by chronic EtOH has pathogenic features common to genetic hypertension namely, augmented [Ca(2+)]c transients and catecholamine release from their CCs. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Rapid structural change in synaptosomal-associated protein 25 (SNAP25) precedes the fusion of single vesicles with the plasma membrane in live chromaffin cells.

    PubMed

    Zhao, Ying; Fang, Qinghua; Herbst, Adam Drew; Berberian, Khajak N; Almers, Wolfhard; Lindau, Manfred

    2013-08-27

    The SNARE complex consists of the three proteins synaptobrevin-2, syntaxin, and synaptosomal-associated protein 25 (SNAP25) and is thought to execute a large conformational change as it drives membrane fusion and exocytosis. The relation between changes in the SNARE complex and fusion pore opening is, however, still unknown. We report here a direct measurement relating a change in the SNARE complex to vesicle fusion on the millisecond time scale. In individual chromaffin cells, we tracked conformational changes in SNAP25 by total internal reflection fluorescence resonance energy transfer (FRET) microscopy while exocytotic catecholamine release from single vesicles was simultaneously recorded using a microfabricated electrochemical detector array. A local rapid and transient FRET change occurred precisely where individual vesicles released catecholamine. To overcome the low time resolution of the imaging frames needed to collect sufficient signal intensity, a method named event correlation microscopy was developed, which revealed that the FRET change was abrupt and preceded the opening of an exocytotic fusion pore by ∼90 ms. The FRET change correlated temporally with the opening of the fusion pore and not with its dilation.

  2. Parallel Recording of Neurotransmitters Release from Chromaffin Cells Using a 10 × 10 CMOS IC Potentiostat Array with On-Chip Working Electrodes

    PubMed Central

    Kim, Brian Namghi; Herbst, Adam D.; Kim, Sung June; Minch, Bradley A.; Lindau, Manfred

    2012-01-01

    Neurotransmitter release is modulated by many drugs and molecular manipulations. We present an active CMOS-based electrochemical biosensor array with high throughput capability (100 electrodes) for on-chip amperometric measurement of neurotransmitter release. The high-throughput of the biosensor array will accelerate the data collection needed to determine statistical significance of changes produced under varying conditions, from several weeks to a few hours. The biosensor is designed and fabricated using a combination of CMOS integrated circuit (IC) technology and a photolithography process to incorporate platinum working electrodes on-chip. We demonstrate the operation of an electrode array with integrated high-gain potentiostats and output time-division multiplexing with minimum dead time for readout. The on-chip working electrodes are patterned by conformal deposition of Pt and lift-off photolithography. The conformal deposition method protects the underlying electronic circuits from contact with the electrolyte that covers the electrode array during measurement. The biosensor was validated by simultaneous measurement of amperometric currents from 100 electrodes in response to dopamine injection, which revealed the time course of dopamine diffusion along the surface of the biosensor array. The biosensor simultaneously recorded neurotransmitter release successfully from multiple individual living chromaffin cells. The biosensor was capable of resolving small and fast amperometric spikes reporting release from individual vesicle secretions. We anticipate that this device will accelerate the characterization of the modulation of neurotransmitter secretion from neuronal and endocrine cells by pharmacological and molecular manipulations of the cells. PMID:23084756

  3. Catecholamine exocytosis during low frequency stimulation in mouse adrenal chromaffin cells is primarily asynchronous and controlled by the novel mechanism of Ca2+ syntilla suppression

    PubMed Central

    Lefkowitz, Jason J; DeCrescenzo, Valerie; Duan, Kailai; Bellve, Karl D; Fogarty, Kevin E; Walsh, John V; ZhuGe, Ronghua

    2014-01-01

    Adrenal chromaffin cells (ACCs), stimulated by the splanchnic nerve, generate action potentials (APs) at a frequency near 0.5 Hz in the resting physiological state, at times described as ‘rest and digest’. How such low frequency stimulation in turn elicits sufficient catecholamine exocytosis to set basal sympathetic tone is not readily explained by the classical mechanism of stimulus–secretion coupling, where exocytosis is synchronized to AP-induced Ca2+ influx. By using simulated action potentials (sAPs) at 0.5 Hz in isolated patch-clamped mouse ACCs, we show here that less than 10% of all catecholaminergic exocytosis, measured by carbon fibre amperometry, is synchronized to an AP. The asynchronous phase, the dominant phase, of exocytosis does not require Ca2+ influx. Furthermore, increased asynchronous exocytosis is accompanied by an AP-dependent decrease in frequency of Ca2+ syntillas (i.e. transient, focal Ca2+ release from internal stores) and is ryanodine sensitive. We propose a mechanism of disinhibition, wherein APs suppress Ca2+ syntillas, which themselves inhibit exocytosis as they do in the case of spontaneous catecholaminergic exocytosis. PMID:25128575

  4. Knockout of the BK β2 subunit abolishes inactivation of BK currents in mouse adrenal chromaffin cells and results in slow-wave burst activity

    PubMed Central

    Martinez-Espinosa, Pedro L.; Yang, Chengtao; Gonzalez-Perez, Vivian; Xia, Xiao-Ming

    2014-01-01

    Rat and mouse adrenal medullary chromaffin cells (CCs) express an inactivating BK current. This inactivation is thought to arise from the assembly of up to four β2 auxiliary subunits (encoded by the kcnmb2 gene) with a tetramer of pore-forming Slo1 α subunits. Although the physiological consequences of inactivation remain unclear, differences in depolarization-evoked firing among CCs have been proposed to arise from the ability of β2 subunits to shift the range of BK channel activation. To investigate the role of BK channels containing β2 subunits, we generated mice in which the gene encoding β2 was deleted (β2 knockout [KO]). Comparison of proteins from wild-type (WT) and β2 KO mice allowed unambiguous demonstration of the presence of β2 subunit in various tissues and its coassembly with the Slo1 α subunit. We compared current properties and cell firing properties of WT and β2 KO CCs in slices and found that β2 KO abolished inactivation, slowed action potential (AP) repolarization, and, during constant current injection, decreased AP firing. These results support the idea that the β2-mediated shift of the BK channel activation range affects repetitive firing and AP properties. Unexpectedly, CCs from β2 KO mice show an increased tendency toward spontaneous burst firing, suggesting that the particular properties of BK channels in the absence of β2 subunits may predispose to burst firing. PMID:25267913

  5. Grafts of extra-adrenal chromaffin cells as aggregates show better survival rate and regenerative effects on parkinsonian rats than dispersed cell grafts.

    PubMed

    Galan-Rodriguez, B; del-Marco, A; Flores, J A; Ramiro-Fuentes, S; Gonzalez-Aparicio, R; Tunez, I; Tasset, I; Fernandez-Espejo, E

    2008-03-01

    The objective was to discern the neuroregenerative effect of grafts of extra-adrenal cells of the Zuckerkandl's paraganglion (ZP) in the nigrostriatal circuit, by using the retrograde model of parkinsonism in rats. The antiparkinsonian efficacy of two types of grafting procedures was studied (cell aggregates vs. dispersed cells), and GDNF and TGFbeta(1) (dopaminotrophic factors) as well as dopamine presence in extra-adrenal tissue was analyzed. Extra-adrenal chromaffin cells are noradrenergics, tissue dopamine is low, and they express both GDNF and TGFbeta(1). Grafts of cell aggregates, not of dispersed cells, exerted a trophic regeneration of the host striatum, leading to amelioration of motor deficits. Sprouting of spared dopaminergic fibers within the striatum, reduction of dopamine axon degeneration, and/or enhanced phenotypic expression of TH would explain striatal regeneration. Grafted cells as aggregates showed a better survival rate than dispersed cells, and they express higher levels of GDNF. Higher survivability and GDNF content together with the neurorestorative and dopaminotrophic action of both GDNF and TGFbeta(1) could account for striatal recovery and functional amelioration after grafting ZP cell aggregates. Finally, nigral degeneration and partial degeneration of ventral tegmental area were not precluded after transplantation, indicating that the trophic effect of grafts was local within the host striatum.

  6. Knockout of the BK β2 subunit abolishes inactivation of BK currents in mouse adrenal chromaffin cells and results in slow-wave burst activity.

    PubMed

    Martinez-Espinosa, Pedro L; Yang, Chengtao; Gonzalez-Perez, Vivian; Xia, Xiao-Ming; Lingle, Christopher J

    2014-10-01

    Rat and mouse adrenal medullary chromaffin cells (CCs) express an inactivating BK current. This inactivation is thought to arise from the assembly of up to four β2 auxiliary subunits (encoded by the kcnmb2 gene) with a tetramer of pore-forming Slo1 α subunits. Although the physiological consequences of inactivation remain unclear, differences in depolarization-evoked firing among CCs have been proposed to arise from the ability of β2 subunits to shift the range of BK channel activation. To investigate the role of BK channels containing β2 subunits, we generated mice in which the gene encoding β2 was deleted (β2 knockout [KO]). Comparison of proteins from wild-type (WT) and β2 KO mice allowed unambiguous demonstration of the presence of β2 subunit in various tissues and its coassembly with the Slo1 α subunit. We compared current properties and cell firing properties of WT and β2 KO CCs in slices and found that β2 KO abolished inactivation, slowed action potential (AP) repolarization, and, during constant current injection, decreased AP firing. These results support the idea that the β2-mediated shift of the BK channel activation range affects repetitive firing and AP properties. Unexpectedly, CCs from β2 KO mice show an increased tendency toward spontaneous burst firing, suggesting that the particular properties of BK channels in the absence of β2 subunits may predispose to burst firing.

  7. Dissociation of inositol polyphosphates from the C2B domain of synaptotagmin facilitates spontaneous release of catecholamines in adrenal chromaffin cells. A suggestive evidence of a fusion clamp by synaptotagmin.

    PubMed

    Sasakawa, Nobuyuki; Ohara-Imaizumi, Mica; Fukuda, Mitsunori; Kabayama, Hiroyuki; Mikoshiba, Katsuhiko; Kumakura, Konosuke

    2011-06-01

    Synaptotagmins (Syts) serve as a Ca²+ sensor in the release of neurotransmitters and hormones. Inositol polyphosphates (InsPPs) such as Inositol 1,3,4,5,6-pentakisphosphate (InsP₅) and inositol hexakisphosphate (InsP₆) bind to Ca²+-binding C2B domain of Syt I and II, and inhibit transmitter release. We have shown that the inhibition by InsPPs is reversed by Ca²+ in adrenal chromaffin cells, while a rapid accumulation of endogenous InsP₅ and InsP₆ upon depolarizing stimuli have been reported in these and some other cells. Such a rapid accumulation of InsPPs, if not all, might reflect their dissociation from C2B domain of Syt. To elucidate the functional relevance, we studied the effects of antibodies against C2A and C2B domains (anti-C2A Ab, anti-C2B Ab) on the accumulation of InsPPs induced by Ca²+ in digitonin-permeabilized adrenal chromaffin cells. Anti-C2B Ab by itself caused an accumulation of InsPPs in the permeabilizing medium, and increased spontaneous release of catecholamines (CA). Anti-C2A Ab abolished Ca²+-induced increase of InsPPs in cytosolic component, and inhibited Ca²+-evoked release of CA with little effect on the spontaneous release. Microinjection of InsP₆ but not inositol hexakissulfate into intact chromaffin cells inhibited both spontaneous and nicotine-evoked exocytotic events. These results suggest that endogenous InsPPs bound to the C2B domain clamp spontaneous fusion of the docked or primed vesicles at resting level of intracellular Ca²+, and binding of Ca²+ to the C2A or/and C2B domain facilitate fusion dissociating InsPPs from Syt in adrenal chromaffin cells. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'. Copyright © 2011 Elsevier Ltd. All rights reserved.

  8. Chronic hypoxia up-regulates α1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells

    PubMed Central

    Carabelli, V; Marcantoni, A; Comunanza, V; de Luca, A; Díaz, J; Borges, R; Carbone, E

    2007-01-01

    α1H T-type channels recruited by β1-adrenergic stimulation in rat chromaffin cells (RCCs) are coupled to fast exocytosis with the same Ca2+ dependence of high-threshold Ca2+ channels. Here we show that RCCs exposed to chronic hypoxia (CH) for 12–18 h in 3% O2 express comparable densities of functional T-type channels that depolarize the resting cells and contribute to low-voltage exocytosis. Following chronic hypoxia, most RCCs exhibited T-type Ca2+ channels already available at −50 mV with the same gating, pharmacological and molecular features as the α1H isoform. Chronic hypoxia had no effects on cell size and high-threshold Ca2+ current density and was mimicked by overnight incubation with the iron-chelating agent desferrioxamine (DFX), suggesting the involvement of hypoxia-inducible factors (HIFs). T-type channel recruitment occurred independently of PKA activation and the presence of extracellular Ca2+. Hypoxia-recruited T-type channels were partially open at rest (T-type ‘window-current’) and contributed to raising the resting potential to more positive values. Their block by 50 μm Ni2+ caused a 5–8 mV hyperpolarization. The secretory response associated with T-type channels could be detected following mild cell depolarizations, either by capacitance increases induced by step depolarizations or by amperometric current spikes induced by increased [KCl]. In the latter case, exocytotic bursts could be evoked even with 2–4 mm KCl and spike frequency was drastically reduced by 50 μm Ni2+. Chronic hypoxia did not alter the shape of spikes, suggesting that hypoxia-recruited T-type channels increase the number of secreted vesicles at low voltages, without altering the mechanism of catecholamine release and the quantal content of released molecules. PMID:17690152

  9. Low-threshold exocytosis induced by cAMP-recruited CaV3.2 (alpha1H) channels in rat chromaffin cells.

    PubMed

    Giancippoli, A; Novara, M; de Luca, A; Baldelli, P; Marcantoni, A; Carbone, E; Carabelli, V

    2006-03-01

    We have studied the functional role of CaV3 channels in triggering fast exocytosis in rat chromaffin cells (RCCs). CaV3 T-type channels were selectively recruited by chronic exposures to cAMP (3 days) via an exchange protein directly activated by cAMP (Epac)-mediated pathway. Here we show that cAMP-treated cells had increased secretory responses, which could be evoked even at very low depolarizations (-50, -40 mV). Potentiation of exocytosis in cAMP-treated cells did not occur in the presence of 50 microM Ni2+, which selectively blocks T-type currents in RCCs. This suggests that the "low-threshold exocytosis" induced by cAMP is due to increased Ca2+ influx through cAMP-recruited T-type channels, rather than to an enhanced secretion downstream of Ca2+ entry, as previously reported for short-term cAMP treatments (20 min). Newly recruited T-type channels increase the fast secretory response at low voltages without altering the size of the immediately releasable pool. They also preserve the Ca2+ dependence of exocytosis, the initial speed of vesicle depletion, and the mean quantal size of single secretory events. All this indicates that cAMP-recruited CaV3 channels enhance the secretory activity of RCCs at low voltages by coupling to the secretory apparatus with a Ca2+ efficacy similar to that of already existing high-threshold Ca2+ channels. Finally, using RT-PCRs we found that the fast inactivating low-threshold Ca2+ current component recruited by cAMP is selectively associated to the alpha1H (CaV3.2) channel isoform.

  10. Low-Threshold Exocytosis Induced by cAMP-Recruited CaV3.2 (α1H) Channels in Rat Chromaffin Cells

    PubMed Central

    Giancippoli, A.; Novara, M.; de Luca, A.; Baldelli, P.; Marcantoni, A.; Carbone, E.; Carabelli, V.

    2006-01-01

    We have studied the functional role of CaV3 channels in triggering fast exocytosis in rat chromaffin cells (RCCs). CaV3 T-type channels were selectively recruited by chronic exposures to cAMP (3 days) via an exchange protein directly activated by cAMP (Epac)-mediated pathway. Here we show that cAMP-treated cells had increased secretory responses, which could be evoked even at very low depolarizations (−50, −40 mV). Potentiation of exocytosis in cAMP-treated cells did not occur in the presence of 50 μM Ni2+, which selectively blocks T-type currents in RCCs. This suggests that the “low-threshold exocytosis” induced by cAMP is due to increased Ca2+ influx through cAMP-recruited T-type channels, rather than to an enhanced secretion downstream of Ca2+ entry, as previously reported for short-term cAMP treatments (20 min). Newly recruited T-type channels increase the fast secretory response at low voltages without altering the size of the immediately releasable pool. They also preserve the Ca2+ dependence of exocytosis, the initial speed of vesicle depletion, and the mean quantal size of single secretory events. All this indicates that cAMP-recruited CaV3 channels enhance the secretory activity of RCCs at low voltages by coupling to the secretory apparatus with a Ca2+ efficacy similar to that of already existing high-threshold Ca2+ channels. Finally, using RT-PCRs we found that the fast inactivating low-threshold Ca2+ current component recruited by cAMP is selectively associated to the α1H (CaV3.2) channel isoform. PMID:16361341

  11. Chronic hypoxia up-regulates alpha1H T-type channels and low-threshold catecholamine secretion in rat chromaffin cells.

    PubMed

    Carabelli, V; Marcantoni, A; Comunanza, V; de Luca, A; Díaz, J; Borges, R; Carbone, E

    2007-10-01

    alpha(1H) T-type channels recruited by beta(1)-adrenergic stimulation in rat chromaffin cells (RCCs) are coupled to fast exocytosis with the same Ca(2+) dependence of high-threshold Ca(2+) channels. Here we show that RCCs exposed to chronic hypoxia (CH) for 12-18 h in 3% O(2) express comparable densities of functional T-type channels that depolarize the resting cells and contribute to low-voltage exocytosis. Following chronic hypoxia, most RCCs exhibited T-type Ca(2+) channels already available at -50 mV with the same gating, pharmacological and molecular features as the alpha(1H) isoform. Chronic hypoxia had no effects on cell size and high-threshold Ca(2+) current density and was mimicked by overnight incubation with the iron-chelating agent desferrioxamine (DFX), suggesting the involvement of hypoxia-inducible factors (HIFs). T-type channel recruitment occurred independently of PKA activation and the presence of extracellular Ca(2+). Hypoxia-recruited T-type channels were partially open at rest (T-type 'window-current') and contributed to raising the resting potential to more positive values. Their block by 50 microm Ni(2+) caused a 5-8 mV hyperpolarization. The secretory response associated with T-type channels could be detected following mild cell depolarizations, either by capacitance increases induced by step depolarizations or by amperometric current spikes induced by increased [KCl]. In the latter case, exocytotic bursts could be evoked even with 2-4 mm KCl and spike frequency was drastically reduced by 50 microm Ni(2+). Chronic hypoxia did not alter the shape of spikes, suggesting that hypoxia-recruited T-type channels increase the number of secreted vesicles at low voltages, without altering the mechanism of catecholamine release and the quantal content of released molecules.

  12. Reduced availability of voltage-gated sodium channels by depolarization or blockade by tetrodotoxin boosts burst firing and catecholamine release in mouse chromaffin cells

    PubMed Central

    Vandael, David H F; Ottaviani, Matteo M; Legros, Christian; Lefort, Claudie; Guérineau, Nathalie C; Allio, Arianna; Carabelli, Valentina; Carbone, Emilio

    2015-01-01

    Action potential (AP) firing in mouse chromaffin cells (MCCs) is mainly sustained by Cav1.3 L-type channels that drive BK and SK currents and regulate the pacemaking cycle. As secretory units, CCs optimally recruit Ca2+ channels when stimulated, a process potentially dependent on the modulation of the AP waveform. Our previous work has shown that a critical determinant of AP shape is voltage-gated sodium channel (Nav) channel availability. Here, we studied the contribution of Nav channels to firing patterns and AP shapes at rest (−50 mV) and upon stimulation (−40 mV). Using quantitative RT-PCR and immunoblotting, we show that MCCs mainly express tetrodotoxin (TTX)-sensitive, fast-inactivating Nav1.3 and Nav1.7 channels that carry little or no Na+ current during slow ramp depolarizations. Time constants and the percentage of recovery from fast inactivation and slow entry into closed-state inactivation are similar to that of brain Nav1.3 and Nav1.7 channels. The fraction of available Nav channels is reduced by half after 10 mV depolarization from −50 to −40 mV. This leads to low amplitude spikes and a reduction in repolarizing K+ currents inverting the net current from outward to inward during the after-hyperpolarization. When Nav channel availability is reduced by up to 20% of total, either by TTX block or steady depolarization, a switch from tonic to burst firing is observed. The spontaneous occurrence of high frequency bursts is rare under control conditions (14% of cells) but leads to major Ca2+-entry and increased catecholamine release. Thus, Nav1.3/Nav1.7 channel availability sets the AP shape, burst-firing initiation and regulates catecholamine secretion in MCCs. Nav channel inactivation becomes important during periods of high activity, mimicking stress responses. PMID:25620605

  13. A model for the initiation and progression of non-chromaffin paragangliomas: An autosomal dominant disorder with genetic heterogeneity and genomic imprinting

    SciTech Connect

    Mariman, E.C.M.; Beersum, S.E.C. van; Ropers, H.H.

    1994-09-01

    Non-chromaffin paragangliomas are autosomal dominantly inherited tumors of the head and neck region (frequency: 1:30,000). Genomic imprinting influences the expression of the disorder. Tumor development is restricted to offspring of male disease gene carriers. By linkage analysis and haplotyping of a single family, in which the pattern of inheritance is consistent with genomic imprinting, we have mapped the gene to a 5 cM region of chromosome 11q13.1 between D11S956 and PYGM. A maximum lod score of 7.62 at {theta}=0.0 was obtained for D11S480. This interval does not overlap with the segment 11q22.3-q23.3, to which a locus for glomus tumors has been assigned in other families. Moreover, the 5cM interval was excluded as the location of the disease gene in a second family showing the imprinting phenomenon, whereas an indication for linkage was obtained (Z=+2.65) with markers from the distal locus. These observations argue for the presence of two distinct imprinted genes for paragangliomas on 11q. Clinical findings suggest that at least one, but probably both genes code for tumor suppressor required for tumor initiation. According to this model, imprinting would account for the silencing of the two maternal copies, whereas a paternal copy would be inactive due to an inherited mutation. Tumors would then result from somatic inactivation of the other paternal gene copy in individual cells. In tumors, relaxation of imprinting seems to be a frequent feature. Here, it would necessitate subsequent inactivation of maternal gene copies to allow tumor progression. Indeed, selective loss of maternal alleles in paragangliomas has been observed with markers from 11 q. Definite proof for this model should come from the isolation and expression studies of the involved genes.

  14. Secretory vesicle aminopeptidase B related to neuropeptide processing: molecular identification and subcellular localization to enkephalin- and NPY-containing chromaffin granules.

    PubMed

    Hwang, Shin-Rong; O'Neill, Audrey; Bark, Steven; Foulon, Thierry; Hook, Vivian

    2007-03-01

    Biosynthesis of peptide hormones and neurotransmittters involves proteolysis of proprotein precursors by secretory vesicle cathepsin L. Cathepsin L generates peptide intermediates with basic residues at their NH(2)-termini, indicating that Arg/Lys aminopeptidase is needed to generate the smaller biologically active peptide. Therefore, this study identified the Arg/Lys aminopeptidase that is present in secretory vesicles of adrenal medulla and neuroendocrine tissues, achieved by molecular cloning and localization in 'model' neuropeptide-containing secretory vesicles (bovine). Molecular cloning of the bovine aminopeptidase B (AP-B) cDNA defined its primary sequence that allowed selection of antisera for immunolocalization studies. AP-B was present in secretory vesicles that contain cathepsin L with the neuropeptides enkephalin and neuropeptide Y. The AP-B in several neuroendocrine tissues was detected by western blots. Recombinant bovine AP-B showed preference for Arg-methylcoumarinamide substrate. AP-B was inhibited by arphamenine, an inhibitor of aminopeptidases. Bovine AP-B showed similar activities for Arg-(Met)enkephalin (ME) and Lys-ME neuropeptide substrates to generate ME, while rat AP-B preferred Arg-ME. Furthermore, AP-B possesses an acidic pH optimum of 5.5-6.5 that is similar to the internal pH of secretory vesicles. The significant finding of the secretory vesicle localization of AP-B with neuropeptides and cathepsin L suggests a role for this exopeptidase in the biosynthesis of neuropeptides.

  15. Bovine polymorphonuclear leukocyte killing of Tritrichomonas foetus.

    PubMed

    Aydintug, M K; Widders, P R; Leid, R W

    1993-07-01

    The role of bovine antibody and complement in bovine neutrophil-mediated killing of Tritrichomonas foetus was investigated. No neutrophil-mediated trichomonacidal activity was detected when Hanks' balanced salt solution, a widely utilized and weakly buffered medium, was used. This lack of neutrophil activity was evident even in the presence of specific bovine antibody and bovine complement. Moreover, the pH of the weakly buffered Hanks' balanced salt solution was observed to fall from pH 7.0 to 5.8 in 4 h at 37 degrees C in the presence of T. foetus. The pH of 5.8 inhibited the bactericidal activity of bovine neutrophils for Staphylococcus epidermidis by 53.2% and may have contributed to the lack of neutrophil-mediated trichomonacidal activity in the weakly buffered salt solution. However, T. foetus was susceptible to bovine neutrophil-mediated destruction when a HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanesulfonic acid)-buffered Hanks' balanced salt solution was used (21.8% killing by neutrophils alone). Neither specific bovine immune serum nor purified immune bovine immunoglobulin G2 alone enhanced bovine neutrophil-mediated killing. When complement-sensitized trichomonads were incubated with bovine neutrophils, killing of T. foetus was observed, a result which represented the additive effects of each treatment. Significant (P < 0.05) killing of trichomonads was observed when antibody- and complement-opsonized trichomonads were exposed to bovine neutrophils (> 70% parasite destruction), an effect which reflected the additive nature of each treatment.

  16. Association of Bovine Viral Diarrhea Virus with Multiple Viral Infections in Bovine Respiratory Disease Outbreaks

    PubMed Central

    Richer, Lisette; Marois, Paul; Lamontagne, Lucie

    1988-01-01

    We investigated eleven outbreaks of naturally occurring bovine respiratory diseases in calves and adult animals in the St-Hyacinthe area of Quebec. Specific antibodies to bovine herpesvirus-1, bovine viral diarrhea virus, respiratory syncytial virus, parainfluenza type 3 virus, reovirus type 3, and serotypes 1 to 7 of bovine adenovirus were found in paired sera from diseased animals. Several bovine viruses with respiratory tropism were involved concomitantly in herds during an outbreak of bovine respiratory disease. In addition, concomitant fourfold rises of antibody titers were frequently observed to two or more viral agents in seroconverted calves (61%) or adult animals (38%). Bovine viral diarrhea virus was found to be the most frequent viral agent associated with multiple viral infection in calves only (92%). PMID:17423116

  17. A circannual rhythm in bovine pineal serotonin.

    PubMed

    Philo, R; Reiter, R J

    1980-06-15

    Bovine pineal serotonin (5-HT) was analyzed at the time of the solstices and equinoxes from December, 1975 until June, 1978. The highest values of 5-HT were detected at the winter solstices and lowest values at the summer solstices of each year examined. The peaks in bovine pineal 5-HT correspond with a lessened fertility in cattle reported during the winter months.

  18. Models of bovine babesiosis including juvenile cattle.

    PubMed

    Saad-Roy, C M; Shuai, Zhisheng; van den Driessche, P

    2015-03-01

    Bovine Babesiosis in cattle is caused by the transmission of protozoa of Babesia spp. by ticks as vectors. Juvenile cattle (<9 months of age) have resistance to Bovine Babesiosis, rarely show symptoms, and acquire immunity upon recovery. Susceptibility to the disease varies between breeds of cattle. Models of the dynamics of Bovine Babesiosis transmitted by the cattle tick that include these factors are formulated as systems of ordinary differential equations. Basic reproduction numbers are calculated, and it is proved that if these numbers are below the threshold value of one, then Bovine Babesiosis dies out. However, above the threshold number of one, the disease may approach an endemic state. In this case, control measures are suggested by determining target reproduction numbers. The percentage of a particular population (for example, the adult bovine population) needed to be controlled to eradicate the disease is evaluated numerically using Columbia data from the literature.

  19. Phosphatase is responsible for run down, and probably G protein- mediated inhibition of inwardly rectifying K+ currents in guinea pig chromaffin cells

    PubMed Central

    1995-01-01

    The mechanism of G protein-mediated inhibition of an inwardly rectifying K+ current (IIR) in adrenal chromaffin cells was investigated using the whole-cell version of the patch clamp technique. In case of recording with use of ATP-containing patch solution, the IIR was well maintained; otherwise, it ran down within 15 min. This run down was not prevented by replacement with adenylyl-imidodiphosphate, a nonhydrolysable analogue of ATP, but was markedly reduced by the addition to the ATP-free solution of 1 microM calyculin A, a specific inhibitor of serine/threonine phosphatase 1 (PP1) and 2A (PP2A). The addition of alkaline phosphatase to the ATP-containing solution facilitated run down of the current, and application of 100 microM H-7, a general kinase inhibitor, reversibly suppressed IIR. These results taken together suggest that inwardly rectifying K+ channels are under the influence of kinase and phosphatase without external signals. Infusion of nonhydrolysable analogues of GTP, guanosine-5'-O-(3- thiophosphate) (GTP gamma S) or guanylyl-imidodiphosphate, through the pipette produced little inward current at -55 mV, but completely inhibited IIR within approximately 5 or 6 min in all cells tested in the presence of 12 microM Mg2+ inside the cell. In contrast, infusion of aluminum fluoride (AlF) complex, another GTP binding (G) protein activator, consistently produced large inward currents, but did not alter IIR noticeably for 15 min in 17% of the cells tested. In the other cells, the inhibition of IIR developed slowly after long latent periods. This inhibitory potency of AlF was not enhanced by an increase in Mg2+ concentrations. Subtraction of the current-voltage relationship before from that noted during the generation of inward current by AlF complex revealed that the inward current diminished progressively with hyperpolarizations, as is the case with a nonselective cation current (INS) induced by a muscarinic agonist. Thus, AlF complex seems to be potent with

  20. Bovine papillomavirus isolation by ultracentrifugation.

    PubMed

    Araldi, R P; Giovanni, D N S; Melo, T C; Diniz, N; Mazzuchelli-de-Souza, J; Sant'Ana, T A; Carvalho, R F; Beçak, W; Stocco, R C

    2014-11-01

    The bovine papillomavirus (BPV) is the etiological agent of bovine papillomatosis, which causes significant economic losses to livestock, characterized by the presence of papillomas that regress spontaneously or persist and progress to malignancy. Currently, there are 13 types of BPVs described in the literature as well as 32 putative new types. This study aimed to isolate viral particles of BPV from skin papillomas, using a novel viral isolation method. The virus types were previously identified with new primers designed. 77 cutaneous papilloma samples of 27 animals, Simmental breed, were surgically removed. The DNA was extracted and subjected to PCR using Delta-Epsilon and Xi primers. The bands were purified and sequenced. The sequences were analyzed using software and compared to the GenBank database, by BLAST tool. The viral typing showed a prevalence of BPV-2 in 81.81% of samples. It was also detected the presence of the putative new virus type BR/UEL2 in one sample. Virus isolation was performed by ultracentrifugation in a single density of cesium chloride. The method of virus isolation is less laborious than those previously described, allowing the isolation of complete virus particles of BPV-2.

  1. Bovine somatic cell nuclear transfer.

    PubMed

    Ross, Pablo J; Cibelli, Jose B

    2010-01-01

    Somatic cell nuclear transfer (SCNT) is a technique by which the nucleus of a differentiated cell is introduced into an oocyte from which its genetic material has been removed by a process called enucleation. In mammals, the reconstructed embryo is artificially induced to initiate embryonic development (activation). The oocyte turns the somatic cell nucleus into an embryonic nucleus. This process is called nuclear reprogramming and involves an important change of cell fate, by which the somatic cell nucleus becomes capable of generating all the cell types required for the formation of a new individual, including extraembryonic tissues. Therefore, after transfer of a cloned embryo to a surrogate mother, an offspring genetically identical to the animal from which the somatic cells where isolated, is born. Cloning by nuclear transfer has potential applications in agriculture and biomedicine, but is limited by low efficiency. Cattle were the second mammalian species to be cloned after Dolly the sheep, and it is probably the most widely used species for SCNT experiments. This is, in part due to the high availability of bovine oocytes and the relatively higher efficiency levels usually obtained in cattle. Given the wide utilization of this species for cloning, several alternatives to this basic protocol can be found in the literature. Here we describe a basic protocol for bovine SCNT currently being used in our laboratory, which is amenable for the use of the nuclear transplantation technique for research or commercial purposes.

  2. Adipogenesis of bovine perimuscular preadipocytes

    SciTech Connect

    Taniguchi, Masaaki; Le Luo Guan; Zhang Bing; Dodson, Michael V.; Okine, Erasmus; Moore, Stephen S.

    2008-02-01

    In this study, non-transformed progeny adipofibroblasts, derived from mature adipocyte dedifferentiation, was used as a novel in vitro model to study adipogenic gene expression in cattle. Adipofibroblasts from dedifferentiated mature perimuscular fat (PMF) tissue were cultured with differentiation stimulants until the cells exhibited morphological differentiation. Treated cells were harvested from day 2 to 16 for RNA extraction, whereas control cells were cultured without addition of stimulants. Results from time course gene expression assays by quantitative real-time PCR revealed that peroxisome proliferator-activated receptor gamma (PPAR-{gamma}), sterol regulatory element binding protein 1 (SREBP-1) and their six down-stream genes were co-expressed at day 2 post-differentiation induction. When compared to other adipogenesis culture systems, the adipogenic gene expression of bovine PMF adipofibroblasts culture was different, especially to the rodent model. Collectively, these results demonstrated PPAR-{gamma} and SREBP-1 cooperatively play a key role to regulate the re-differentiation of bovine adipofibroblasts, during early conversion stages in vitro.

  3. [Toxinology of bovine paraplegic syndrome].

    PubMed

    Sevcik, C; Brito, J C; D'Suze, G; Mijares, A J; Domínguez, M G

    1993-01-01

    A clinical entity named "Bovine Paraplegic Syndrome" ("Síndrome Parapléjico de los Bovinos") has spread alarmingly, in the cattle growing areas of the central and eastern plains of Venezuela. Approximately four million cattle are bread in the area were the disease occurs. The mortality index due to the disease ranges 5 to 25% of the animals at risk, mostly cows, pregnant or lactating. The principal characteristic of the bovine paraplegic syndrome is decubitus, ventral or sternal, in animals that make vane efforts to stand when stimulated. The diagnosis is established ruling out, clinically and with laboratory findings, that the animals are suffering known diseases with similar symptoms such as paralytic rabies, botulism and blood parasites such Trypanosoma sp., Babesia sp., and Anaplasma sp.. Death occurs always, usually after few days, and to this date there is no known treatment able to save the sick cows. In this work, we describe results that suggest the presence of a toxin in the cattle suffering and prone to suffer the syndrome; it is a natural toxin produced by ruminal bacteria. In squid giant axons under voltage clamp conditions, this toxin is very specific to block sodium current during nerve electrical activity.

  4. Effect of maternal antibody upon vaccination with infectious bovine rhinotracheitis and bovine virus diarrhea vaccines.

    PubMed Central

    Menanteau-Horta, A M; Ames, T R; Johnson, D W; Meiske, J C

    1985-01-01

    This report presents the normal rate of decay of maternal antibody and the influence of maternal antibody on responses to a single vaccination with modified-live bovine virus diarrhea and infectious bovine rhinotracheitis virus vaccines at 196 days of age and on response to vaccinations with the same vaccines given twice at 84 and 196 days of age. Passive immunity decreased to near zero over the first six months of life for both bovine virus diarrhea and infectious bovine rhinotracheitis controls. All calves seroconverted to bovine virus diarrhea vaccine at 84 days of age, even though high levels (greater than 1:32) of maternal antibodies were present. These calves did not seroconvert to infectious bovine rhinotracheitis vaccine at 84 days of age when high levels (less than 1:16) of maternal antibodies were present. Calves responded well to bovine virus diarrhea and infectious bovine rhinotracheitis vaccines given only once at 196 days of age after passive immunity disappeared. Calves which were revaccinated with infectious bovine rhinotracheitis seroconverted showing a more rapid response than the single vaccinates. Those revaccinated with bovine virus diarrhea showed an immediate response of small magnitude. PMID:2985214

  5. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Catalase (bovine liver). 184.1034 Section 184.1034... Listing of Specific Substances Affirmed as GRAS § 184.1034 Catalase (bovine liver). (a) Catalase (bovine liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It...

  6. 21 CFR 184.1034 - Catalase (bovine liver).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Catalase (bovine liver). 184.1034 Section 184.1034... Listing of Specific Substances Affirmed as GRAS § 184.1034 Catalase (bovine liver). (a) Catalase (bovine liver) (CAS Reg. No. 81457-95-6) is an enzyme preparation obtained from extracts of bovine liver. It...

  7. Saturated hydrocarbons in bovine liver

    PubMed Central

    Nagy, Bartholomew; Modzeleski, Vincent E.; Scott, Ward M.

    1969-01-01

    A homologous series of n-alkanes (C14–C33) and two isoprenoid hydrocarbons, 2,6,10,14-tetramethylhexadecane (phytane) and 2,6,10,14-tetramethylpentadecane (pristane) have been identified in bovine liver. Another branched but non-isoprenoid alkane and three isomers of molecular formula C20H40 were partially identified. Phytane and the C18–C22 and C29–C33 n-alkanes were found to be the major components in liver, suggesting that at least the main hydrocarbon components were derived from various plants in the diet. The hydrocarbons were separated and identified by a series of steps involving solvent extraction, saponification, elution chromatography on alumina and silica gel columns, molecular sieving and by infrared and ultraviolet spectroscopy, followed by combined capillary gas chromatography–mass spectrometry. PMID:5820649

  8. Bovine mastitis: frontiers in immunogenetics.

    PubMed

    Thompson-Crispi, Kathleen; Atalla, Heba; Miglior, Filippo; Mallard, Bonnie A

    2014-01-01

    Mastitis is one of the most prevalent and costly diseases in the dairy industry with losses attributable to reduced milk production, discarded milk, early culling, veterinary services, and labor costs. Typically, mastitis is an inflammation of the mammary gland most often, but not limited to, bacterial infection, and is characterized by the movement of leukocytes and serum proteins from the blood to the site of infection. It contributes to compromised milk quality and the potential spread of antimicrobial resistance if antibiotic treatment is not astutely applied. Despite the implementation of management practises and genetic selection approaches, bovine mastitis control continues to be inadequate. However, some novel genetic strategies have recently been demonstrated to reduce mastitis incidence by taking advantage of a cow's natural ability to make appropriate immune responses against invading pathogens. Specifically, dairy cattle with enhanced and balanced immune responses have a lower occurrence of disease, including mastitis, and they can be identified and selected for using the high immune response (HIR) technology. Enhanced immune responsiveness is also associated with improved response to vaccination, increased milk, and colostrum quality. Since immunity is an important fitness trait, beneficial associations with longevity and reproduction are also often noted. This review highlights the genetic regulation of the bovine immune system and its vital contributions to disease resistance. Genetic selection approaches currently used in the dairy industry to reduce the incidence of disease are reviewed, including the HIR technology, genomics to improve disease resistance or immune response, as well as the Immunity(+)™ sire line. Improving the overall immune responsiveness of cattle is expected to provide superior disease resistance, increasing animal welfare and food quality while maintaining favorable production levels to feed a growing population.

  9. Bovine Mastitis: Frontiers in Immunogenetics

    PubMed Central

    Thompson-Crispi, Kathleen; Atalla, Heba; Miglior, Filippo; Mallard, Bonnie A.

    2014-01-01

    Mastitis is one of the most prevalent and costly diseases in the dairy industry with losses attributable to reduced milk production, discarded milk, early culling, veterinary services, and labor costs. Typically, mastitis is an inflammation of the mammary gland most often, but not limited to, bacterial infection, and is characterized by the movement of leukocytes and serum proteins from the blood to the site of infection. It contributes to compromised milk quality and the potential spread of antimicrobial resistance if antibiotic treatment is not astutely applied. Despite the implementation of management practises and genetic selection approaches, bovine mastitis control continues to be inadequate. However, some novel genetic strategies have recently been demonstrated to reduce mastitis incidence by taking advantage of a cow’s natural ability to make appropriate immune responses against invading pathogens. Specifically, dairy cattle with enhanced and balanced immune responses have a lower occurrence of disease, including mastitis, and they can be identified and selected for using the high immune response (HIR) technology. Enhanced immune responsiveness is also associated with improved response to vaccination, increased milk, and colostrum quality. Since immunity is an important fitness trait, beneficial associations with longevity and reproduction are also often noted. This review highlights the genetic regulation of the bovine immune system and its vital contributions to disease resistance. Genetic selection approaches currently used in the dairy industry to reduce the incidence of disease are reviewed, including the HIR technology, genomics to improve disease resistance or immune response, as well as the Immunity+™ sire line. Improving the overall immune responsiveness of cattle is expected to provide superior disease resistance, increasing animal welfare and food quality while maintaining favorable production levels to feed a growing population. PMID

  10. Growth and metabolism of murine and bovine embryos in bovine uterine flushing-supplemented culture media.

    PubMed Central

    Rondeau, M; Guay, P; Goff, A K; Cooke, G M

    1996-01-01

    The aim of this study was to compare the development and metabolic activity of cultured murine and bovine embryos in 2 standard media (HAM F-10 and RPMI) in the presence or absence of bovine uterine flushings. Murine morulae (n = 653) and day 7 bovine embryos (n = 273) were cultured for 18 h or 36 h in either HAM F-10 or RPMI in the presence or absence of bovine uterine flushings. After culture, the development, quality, and metabolic activity (glucose utilization or methionine uptake and incorporation) of embryos was assessed. It was found that HAM F-10 (without uterine flushings) was a more suitable medium than RPMI for optimal development and metabolism of murine and bovine embryos. Poor quality and development, as well as decreased metabolism, were evident after culture of murine embryos in RPMI; in contrast, this medium had no adverse effects on bovine embryos in culture. Supplementation of HAM F-10 with bovine uterine flushings improved the growth of murine embryos and the protein synthesis (as measured by an increased methionine incorporation) for both murine and bovine embryos. However, supplementation with bovine uterine flushings could not overcome deficiencies of an inappropriate medium (RPMI) for murine embryos. Supplementation of a well-defined culture medium with uterine flushings increased metabolism of embryos in culture, and thus might help to increase pregnancy rates after transfer of such embryos to recipient cows. PMID:8825988

  11. Double patch clamp reveals that transient fusion (kiss-and-run) is a major mechanism of secretion in calf adrenal chromaffin cells: high calcium shifts the mechanism from kiss-and-run to complete fusion.

    PubMed

    Elhamdani, Abdeladim; Azizi, Fouad; Artalejo, Cristina R

    2006-03-15

    Transient fusion ("kiss-and-run") is accepted as a mode of transmitter release both in central neurons and neuroendocrine cells, but the prevalence of this mechanism compared with full fusion is still in doubt. Using a novel double patch-clamp method (whole cell/cell attached), permitting the recording of unitary capacitance events while stimulating under a variety of conditions including action potentials, we show that transient fusion is the predominant (>90%) mode of secretion in calf adrenal chromaffin cells. Raising intracellular Ca2+ concentration ([Ca]i) from 10 to 200 microM increases the incidence of full fusion events at the expense of transient fusion. Blocking rapid endocytosis that normally terminates transient fusion events also promotes full fusion events. Thus, [Ca]i controls the transition between transient and full fusion, each of which is coupled to different modes of endocytosis.

  12. Activation of bovine neutrophils by Brucella spp.

    PubMed

    Keleher, Lauren L; Skyberg, Jerod A

    2016-09-01

    Brucellosis is a globally important zoonotic infectious disease caused by gram negative bacteria of the genus Brucella. While many species of Brucella exist, Brucella melitensis, Brucella abortus, and Brucella suis are the most common pathogens of humans and livestock. The virulence of Brucella is largely influenced by its ability to evade host factors, including phagocytic killing mechanisms, which are critical for the host response to infection. The aim of this study was to characterize the bovine neutrophil response to virulent Brucella spp. Here, we found that virulent strains of smooth B. abortus, B. melitensis, B. suis, and virulent, rough, strains of Brucella canis possess similar abilities to resist killing by resting, or IFN-γ-activated, bovine neutrophils. Bovine neutrophils responded to infection with a time-dependent oxidative burst that varied little between Brucella spp. Inhibition of TAK1, or SYK kinase blunted the oxidative burst of neutrophils in response to Brucella infection. Interestingly, Brucella spp. did not induce robust death of bovine neutrophils. These results indicate that bovine neutrophils respond similarly to virulent Brucella spp. In addition, virulent Brucella spp., including naturally rough strains of B. canis, have a conserved ability to resist killing by bovine neutrophils. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Anti-Bovine Programmed Death-1 Rat–Bovine Chimeric Antibody for Immunotherapy of Bovine Leukemia Virus Infection in Cattle

    PubMed Central

    Okagawa, Tomohiro; Konnai, Satoru; Nishimori, Asami; Maekawa, Naoya; Ikebuchi, Ryoyo; Goto, Shinya; Nakajima, Chie; Kohara, Junko; Ogasawara, Satoshi; Kato, Yukinari; Suzuki, Yasuhiko; Murata, Shiro; Ohashi, Kazuhiko

    2017-01-01

    Blockade of immunoinhibitory molecules, such as programmed death-1 (PD-1)/PD-ligand 1 (PD-L1), is a promising strategy for reinvigorating exhausted T cells and preventing disease progression in a variety of chronic infections. Application of this therapeutic strategy to cattle requires bovinized chimeric antibody targeting immunoinhibitory molecules. In this study, anti-bovine PD-1 rat–bovine chimeric monoclonal antibody 5D2 (Boch5D2) was constructed with mammalian expression systems, and its biochemical function and antiviral effect were characterized in vitro and in vivo using cattle infected with bovine leukemia virus (BLV). Purified Boch5D2 was capable of detecting bovine PD-1 molecules expressed on cell membranes in flow cytometric analysis. In particular, Biacore analysis determined that the binding affinity of Boch5D2 to bovine PD-1 protein was similar to that of the original anti-bovine PD-1 rat monoclonal antibody 5D2. Boch5D2 was also capable of blocking PD-1/PD-L1 binding at the same level as 5D2. The immunomodulatory and therapeutic effects of Boch5D2 were evaluated by in vivo administration of the antibody to a BLV-infected calf. Inoculated Boch5D2 was sustained in the serum for a longer period. Boch5D2 inoculation resulted in activation of the proliferation of BLV-specific CD4+ T cells and decrease in the proviral load of BLV in the peripheral blood. This study demonstrates that Boch5D2 retains an equivalent biochemical function to that of the original antibody 5D2 and is a candidate therapeutic agent for regulating antiviral immune response in vivo. Clinical efficacy of PD-1/PD-L1 blockade awaits further experimentation with a large number of animals. PMID:28638381

  14. Anti-Bovine Programmed Death-1 Rat-Bovine Chimeric Antibody for Immunotherapy of Bovine Leukemia Virus Infection in Cattle.

    PubMed

    Okagawa, Tomohiro; Konnai, Satoru; Nishimori, Asami; Maekawa, Naoya; Ikebuchi, Ryoyo; Goto, Shinya; Nakajima, Chie; Kohara, Junko; Ogasawara, Satoshi; Kato, Yukinari; Suzuki, Yasuhiko; Murata, Shiro; Ohashi, Kazuhiko

    2017-01-01

    Blockade of immunoinhibitory molecules, such as programmed death-1 (PD-1)/PD-ligand 1 (PD-L1), is a promising strategy for reinvigorating exhausted T cells and preventing disease progression in a variety of chronic infections. Application of this therapeutic strategy to cattle requires bovinized chimeric antibody targeting immunoinhibitory molecules. In this study, anti-bovine PD-1 rat-bovine chimeric monoclonal antibody 5D2 (Boch5D2) was constructed with mammalian expression systems, and its biochemical function and antiviral effect were characterized in vitro and in vivo using cattle infected with bovine leukemia virus (BLV). Purified Boch5D2 was capable of detecting bovine PD-1 molecules expressed on cell membranes in flow cytometric analysis. In particular, Biacore analysis determined that the binding affinity of Boch5D2 to bovine PD-1 protein was similar to that of the original anti-bovine PD-1 rat monoclonal antibody 5D2. Boch5D2 was also capable of blocking PD-1/PD-L1 binding at the same level as 5D2. The immunomodulatory and therapeutic effects of Boch5D2 were evaluated by in vivo administration of the antibody to a BLV-infected calf. Inoculated Boch5D2 was sustained in the serum for a longer period. Boch5D2 inoculation resulted in activation of the proliferation of BLV-specific CD4(+) T cells and decrease in the proviral load of BLV in the peripheral blood. This study demonstrates that Boch5D2 retains an equivalent biochemical function to that of the original antibody 5D2 and is a candidate therapeutic agent for regulating antiviral immune response in vivo. Clinical efficacy of PD-1/PD-L1 blockade awaits further experimentation with a large number of animals.

  15. Bovine viral diarrhea virus: involvement in bovine respiratory disease and diagnostic challenges

    USDA-ARS?s Scientific Manuscript database

    This paper reviews the contribution of bovine viral diarrhea viruses (BVDV) to the development of Bovine Respiratory Disease (BRD). Veterinarians and producers generally consider BRD as one of the most significant diseases affecting production in the cattle industry. BRD can affect the performance (...

  16. Antimicrobial activity of bovine NK-lysin-derived peptides on bovine respiratory pathogen Histophilus somni

    USDA-ARS?s Scientific Manuscript database

    Bovine NK-lysins, which are functionally and structurally similar to human granulysin and porcine NK-lysin, are predominantly found in the granules of cytotoxic T-lymphocytes and NK-cells. Although antimicrobial activity of bovine NK-lysin has been assessed for several bacterial pathogens, not all t...

  17. Vaccination against bovine respiratory disease.

    PubMed

    Phillip, J I

    1975-01-01

    Vaccination is but one element in a control programme for bovine respiratory disease. Its laboratory study can be divorced from the others but its field application cannot. The problems associated with the development of effective vaccines fall into two broad groups: multiplicity and ubiquity of pathogens and secondly the identification of the crucial elements in an immune response. Agricultural systems which experience annual outbreaks of respiratory disease attributable to the same pathogen in cattle of specific age have the choice of using passive or active immunity of minimal valency. In the majority of systems the cause and timing of an outbreak cannot be predicted and therefore multivalent vaccines are required. Both inactivated and modified live products are available for use against the well-known pathogens. Their relative advantages hinge on the significance attributed to the ability to stimulate the production of particular immunoglobulins at specific body sites and the persistence of the responses. The widely held view that success requires the stimulation of secretory antibodies by intranasal administration of living vaccines is not universally accepted. An assessment of their protective value is not easily made because of the difficulty of reproducing an adequate field challenge in the laboratory. The measurement of serological responses and virus shedding times following challenge are of limited value as alternatives.

  18. Bovine acidosis: implications on laminitis.

    PubMed

    Nocek, J E

    1997-05-01

    Bovine lactic acidosis syndrome is associated with large increases of lactic acid in the rumen, which result from diets that are high in ruminally available carbohydrates, or forage that is low in effective fiber, or both. The syndrome involves two separate anatomical areas, the gastrointestinal tract and body fluids, and is related to the rate and extent of lactic acid production, utilization, and absorption. Clinical manifestations range from loss of appetite to death. Lactic acid accumulates in the rumen when the bacteria that synthesize lactic acid outnumber those that utilize lactic acid. The systemic impact of acidosis may have several physiological implications, including laminitis, a diffuse aseptic inflammation of the laminae (corium). Although a nutritional basis for the disease exists, etiology includes a multitude of interactive factors, such as metabolic and digestive disorders, postpartum stress, and localized trauma, which lead to the release of vasoactive substances that trigger mechanisms that cause degenerative changes in the foot. The severity of laminitis is related to the frequency, intensity, and duration of systemic acidotic insults on the mechanisms responsible for the release of vasoactive substance. The critical link between acidosis and laminitis appears to be associated with a persistent hypoperfusion, which results in ischemia in the digit. Management of acidosis is critical in preventing laminitis. High producing dairy herds attempting to maximize energy intake are continually confronted with subclinical acidosis and laminitis. Management of feeding and husbandry practices can be implemented to reduce incidence of disease.

  19. Bovine colostrum: an emerging nutraceutical.

    PubMed

    Bagwe, Siddhi; Tharappel, Leo J P; Kaur, Ginpreet; Buttar, Harpal S

    2015-09-01

    Nutraceutical, a term combining the words "nutrition" and "pharmaceuticals", is a food or food product that provides health benefits as an adjuvant or alternative therapy, including the treatment and prevention of infectious diseases in children and adults. There is emerging evidence that bovine colostrum (BC) may be one of the promising nutraceuticals which can prevent or mitigate various diseases in newborns and adults. Immunity-related disorders are one of the leading causes of mortality in the world. BC is rich in immunity, growth and antimicrobial factors, which promote tissue growth and the maturation of digestive tract and immune function in neonatal animals and humans. The immunoglobulins and lactoferrin present in colostrum are known to build natural immunity in newborns which helps to reduce the mortality rate in this population. Also, the side-effect profile of colostrum proteins and possible lactose intolerance is relatively less in comparison with milk. In general, BC is considered safe and well tolerated. Since colostrum has several important nutritional constituents, well-designed, double-blind, placebo-controlled studies with colostrum products should be conducted to widen its therapeutic use. The objectives of this review are to create awareness about the nutraceutical properties of colostrum and to discuss the various ongoing alternative treatments of colostrum and its active ingredients as well as to address colostrum's future nutraceutical and therapeutic implications in humans.

  20. Steroidogenesis in fetal bovine gonads.

    PubMed Central

    Dominguez, M M; Liptrap, R M; Basrur, P K

    1988-01-01

    Gonadal steroidogenesis in bovine fetuses of 40 to 125 days gestation was examined using histochemical procedures and radioimmunoassay on gonadal cultures to determine the physiological correlates of gonadal morphogenesis in cattle. Gonadal morphology and the in vitro secretion patterns were distinct between the sexes by 45 days when testes secreted significantly higher levels of testosterone and androstenedione and lower levels of estrone and 17 beta-estradiol that the ovaries (p less than 0.0001). It would appear that the main steroid route in the ovaries of 45 to 70 day old fetuses is the androstenedione to estrone to 17 beta-estradiol pathway. The high estrone secretion and the decreasing levels of 17 beta-estradiol and testosterone in the ovaries of 70 to 125 day fetuses suggest an inhibition of 17 beta-hydroxysteroid dehydrogenase activity. It is postulated that this shift in steroid biosynthetic pathways may be related to the change in cellular events from mitosis to meiosis in fetal ovaries. Images Fig. 1. Fig. 2. Fig. 3. Fig. 4. Fig. 7. PMID:3196968

  1. Immunoproteomic identification of bovine pericardium xenoantigens

    PubMed Central

    Griffiths, Leigh G.; Choe, Leila H.; Reardon, Kenneth F.; Dow, Steven W.; Orton, E. Christopher

    2008-01-01

    Bovine pericardium is an important biomaterial with current application in glutaraldehyde-fixed bioprosthetic heart valves and possible future application as an unfixed biological scaffold for tissue engineering. The importance of both humoral and cell-mediated rejection responses toward fixed and unfixed xenogeneic tissues has become increasingly apparent. However, the full scope and specific identities of bovine pericardium proteins that can elicit an immune response remain largely unknown. In this study, an immunoproteomic approach was used to survey bovine pericardium proteins for their ability to elicit a humoral immune response in rabbits. A two-stage protein extraction protocol was used to separate bovine pericardium proteins into water- and lipid-soluble fractions. Two-dimensional gel electrophoresis was performed to separate the proteins from each fraction. Western blots were generated from two-dimensional gels of both bovine pericardium protein fractions. These blots were probed with serum from rabbits immunized with bovine pericardium and a secondary antibody was used to assess for IgG positivity. Western blots were compared to duplicate two-dimensional gels and proteins in matched spots were identified by tandem mass spectrometry. Thirty-one putative protein antigens were identified, eight of which are known to be antigenic from previous studies. All of the putative antigens demonstrated progressive staining intensity with increasing days of post-exposure serum. Identified antigenic proteins represented a variety of functional and structural protein types, and included both cellular and matrix proteins. The results of this study have implications for the use of bovine pericardium as a biomaterial in bioprostheses and tissue engineering applications, as well as xenotransplantation in general. PMID:18514307

  2. Serological responses in calves to vaccines against bovine respiratory syncytial, infectious bovine rhinotracheitis, bovine viral diarrhoea and parainfluenza-3 viruses.

    PubMed

    Tollis, M; Di Trani, L; Cordioli, P; Vignolo, E; Di Pasquale, I

    1996-01-01

    The Istituto Superiore di Sanità (ISS), the National Veterinary Services Laboratory in Italy, is in charge of assessing the quality, safety and efficacy of veterinary vaccines before and after licensing. To evaluate the relative potency of several vaccines against bovine respiratory syncytial virus (BRSV), infectious bovine rhinotracheitis virus (IBRV), bovine viral diarrhoea virus (BVDV) and parainfluenza-3 virus (PI3V), the serological responses in vaccinated calves were studied. Vaccination with any of the vaccines under study induced specific antibody titres against the different viral antigens. The differences of the mean antibody titres within and among the test group vaccines were statistically significant. The results confirm and support those obtained by other authors in similar studies, suggesting that serological responses in vaccinated calves can be used as a helpful means of assessing the relative potency of vaccines against viral respiratory diseases of cattle. The criteria allowing such an evaluation are discussed.

  3. Recent Progress in Cryopreservation of Bovine Oocytes

    PubMed Central

    Hochi, Shinichi

    2014-01-01

    Principle of oocyte cryoinjury is first overviewed and then research history of cryopreservation using bovine oocytes is summarized for the last two decades with a few special references to recent progresses. Various types of cryodevices have been developed to accelerate the cooling rate and applied to the oocytes from large domestic species enriched with cytoplasmic lipid droplets. Two recent approaches include the qualitative improvement of IVM oocytes prior to the vitrification and the short-term recovery culture of vitrified-warmed oocytes prior to the subsequent IVF. Supplementation of L-carnitine to IVM medium of bovine oocytes has been reported to reduce the amount of cytoplasmic lipid droplets and improve the cryotolerance of the oocytes, but it is still controversial whether the positive effect of L-carnitine is reproducible. Incidence of multiple aster formation, a possible cause for low developmental potential of vitrified-warmed bovine oocytes, was inhibited by a short-term culture of the postwarm oocytes in the presence of Rho-associated coiled-coil kinase (ROCK) inhibitor. Use of an antioxidant α-tocopherol, instead of the ROCK inhibitor, also supported the revivability of the postwarm bovine oocytes. Further improvements of the vitrification procedure, combined with pre- and postvitrification chemical treatment, would overcome the high sensitivity of bovine oocytes to cryopreservation. PMID:24738063

  4. Bovine viral diarrhea virus: biotypes and disease.

    PubMed Central

    Deregt, D; Loewen, K G

    1995-01-01

    Bovine viral diarrhea virus continues to produce significant economic losses for the cattle industry and challenges investigators with the complexity of diseases it produces and the mechanisms by which it causes disease. This paper updates and attempts to clarify information regarding the roles of noncytopathic and cytopathic bovine viral diarrhea viruses in persistent infections and mucosal disease. It also covers, in brief, what is known of the new diseases: thrombocytopenia and hemorrhagic disease, and a disease resembling mucosal disease that is apparently caused solely by noncytopathic virus. Although a good understanding of the roles of the 2 biotypes in the production of persistent infections and the precipitation of mucosal disease has been obtained, there are still unanswered questions regarding the origin of cytopathic viruses and the mechanism by which they cause pathological changes in cells. It is apparent, however, that cytopathic bovine viral diarrhea viruses arise by mutation of noncytopathic viruses, and it is known that p80 is the marker protein for cytopathic viruses. The previous distinction between mild bovine viral diarrhea and fatal mucosal disease has been eroded with the emergence of new virulent bovine viral diarrhea viruses. The new diseases pose a threat to the cattle industry and present a new challenge for investigators. Index Veterinarius (1984-1994) and Medline (1985-1994) databases and personal files updated since 1987 from BIOSIS Previews and Biosciences Information Services were used to search the literature. Images Figure 1. PMID:7648541

  5. Recent progress in cryopreservation of bovine oocytes.

    PubMed

    Hwang, In-Sul; Hochi, Shinichi

    2014-01-01

    Principle of oocyte cryoinjury is first overviewed and then research history of cryopreservation using bovine oocytes is summarized for the last two decades with a few special references to recent progresses. Various types of cryodevices have been developed to accelerate the cooling rate and applied to the oocytes from large domestic species enriched with cytoplasmic lipid droplets. Two recent approaches include the qualitative improvement of IVM oocytes prior to the vitrification and the short-term recovery culture of vitrified-warmed oocytes prior to the subsequent IVF. Supplementation of L-carnitine to IVM medium of bovine oocytes has been reported to reduce the amount of cytoplasmic lipid droplets and improve the cryotolerance of the oocytes, but it is still controversial whether the positive effect of L-carnitine is reproducible. Incidence of multiple aster formation, a possible cause for low developmental potential of vitrified-warmed bovine oocytes, was inhibited by a short-term culture of the postwarm oocytes in the presence of Rho-associated coiled-coil kinase (ROCK) inhibitor. Use of an antioxidant α-tocopherol, instead of the ROCK inhibitor, also supported the revivability of the postwarm bovine oocytes. Further improvements of the vitrification procedure, combined with pre- and postvitrification chemical treatment, would overcome the high sensitivity of bovine oocytes to cryopreservation.

  6. 65 FR 63227 - Declaration of Emergency Because of Bovine Tuberculosis

    Federal Register 2010, 2011, 2012, 2013, 2014

    2000-10-23

    ...; ] DEPARTMENT OF AGRICULTURE Office of the Secretary Declaration of Emergency Because of Bovine Tuberculosis Bovine tuberculosis (tuberculosis) is a chronic debilitating disease caused by Mycobacterium bovis. The... animal health agencies to eradicate tuberculosis from domestic livestock in the United States...

  7. Bovine Eimeria species in Austria.

    PubMed

    Koutny, H; Joachim, A; Tichy, A; Baumgartner, W

    2012-05-01

    Bovine eimeriosis is considered to be of considerable importance for the productivity and health of cattle worldwide. Despite the importance of cattle farming in Austria, little is known in this country about the abundance and distribution of bovine Eimeria spp. The objective of this study was to obtain detailed information about the occurrence of different Eimeria spp. on Austrian dairy farms. Fecal samples from individual calves (n = 868) from 296 farms all over Austria (82 districts) were collected. Additionally, each farmer was questioned about the occurrence of calf diarrhea, and about the knowledge on coccidiosis and possible control measures. On 97.97% of the investigated farms, calves excreted Eimeria oocysts, and 83.67% of the individual samples were positive. After sporulation of positive samples pooled from each farm, 11 Eimeria species were found, with E. bovis (in 65.54% of the samples and 27.74% of the farms), E.zuernii (63.85%/13.86%), E. auburnensis (56.76%/13.41%) and E. ellipsoidalis (54.05%/14.38%) being the most prevalent, followed by E. alabamensis (45.61%/11.56%), E. subspherica (35.14%/5.5.05%), E. cylindrica (33.11%/7.00%), and E. canadensis (31.08%/7.74%). E. wyomingensis, E. pellita and E. bukidnonensis were only found sporadically (3.04-4.73% of the samples and 0.16-0.59% of the farms). Mixed infections were present on all farms (2-9 Eimeria species/farm). Prevalences by state provinces were high throughout with 77.1-87.9% of the samples and 93.8-100% of the farms. Lower Austria had the highest percentage of positive farms, and Vorarlberg the lowest. Individual OPG (oocysts per gram of feces) values were generally low; 75% of the samples had an OPG of 1,000 or less. The highest detected OPG was 72,400. The mean OPG was 2,525 with above average numbers in Tirol, Carinthia, and Lower Austria. The mean OPG values were significantly positively correlated with the cattle density in the different districts. The majority of the samples were from

  8. Bovine serum albumin: survival and osmolarity effect in bovine spermatozoa stored above freezing point.

    PubMed

    Nang, C F; Osman, K; Budin, S B; Ismail, M I; Jaffar, F H F; Mohamad, S F S; Ibrahim, S F

    2012-05-01

    Liquid nitrogen preservation in remote farms is a limitation. The goal of this study was to determine optimum temperature above freezing point for bovine spermatozoa preservation using bovine serum albumin (BSA) as a supplementation. Pooled semen sample from three ejaculates was subjected to various BSA concentration (1, 4, 8 and 12 mg ml(-1)), before incubation in different above freezing point temperatures (4, 25 and 37 °C). Viability assessment was carried out against time from day 0 (fresh sample) until all spermatozoa become nonviable. Optimal condition for bovine spermatozoa storage was at 4 °C with 1 mg ml(-1) BSA for almost 7 days. BSA improved bovine spermatozoa viability declining rate to 44.28% at day 4 and 57.59% at day 7 compared to control, with 80.54% and 98.57% at day 4 and 7 respectively. Increase in BSA concentration did not improve sperm viability. Our results also confirmed that there was a strong negative correlation between media osmolarity and bovine spermatozoa survival rate with r = 0.885, P < 0.0001. Bovine serum albumin helps to improve survival rate of bovine spermatozoa stored above freezing point. © 2011 Blackwell Verlag GmbH.

  9. Parthenogenetic activation of bovine oocytes using bovine and murine phospholipase C zeta

    PubMed Central

    Ross, Pablo J; Beyhan, Zeki; Iager, Amy E; Yoon, Sook-Young; Malcuit, Christopher; Schellander, Karl; Fissore, Rafael A; Cibelli, Jose B

    2008-01-01

    Background During natural fertilization, sperm fusion with the oocyte induces long lasting intracellular calcium oscillations which in turn are responsible for oocyte activation. PLCZ1 has been identified as the factor that the sperm delivers into the egg to induce such a response. We tested the hypothesis that PLCZ1 cRNA injection can be used to activate bovine oocytes. Results Mouse and bovine PLCZ1 cRNAs were injected into matured bovine oocytes at different concentrations. Within the concentrations tested, mouse PLCZ1 injection activated bovine oocytes at a maximum rate when the pipette concentration of cRNA ranged from 0.25 to 1 μg/μL, while bovine PLCZ1 was optimal at 0.1 μg/μL. At their most effective concentrations, PLCZ1 induced parthenogenetic development at rates similar to those observed using other activation stimuli such as Ionomycin/CHX and Ionomycin/DMAP. Injection of mouse and bovine PLCZ1 cRNA induced dose-dependent sperm-like calcium oscillations whose frequency increased over time. Injection of bovine and mouse PLCZ1 cRNA also induced IP3R-1 degradation, although bovine PLCZ1 cRNA evoked greater receptor degradation than its mouse counterpart. Conclusion Injection of PLCZ1 cRNA efficiently activated bovine oocytes by inducing a sperm-like calcium oscillatory pattern. Importantly, the high rate of aneuploidy encountered in parthenogenetic embryos activated by certain chemical means was not observed in PLCZ1 activated embryos. PMID:18284699

  10. Arachidonate metabolism in bovine gallbladder muscle

    SciTech Connect

    Nakano, M.; Hidaka, T.; Ueta, T.; Ogura, R.

    1983-04-01

    Incubation of (1-/sup 14/C)arachidonic acid (AA) with homogenates of bovine gallbladder muscle generated a large amount of radioactive material having the chromatographic mobility of 6-keto-PGF1 alpha (stable product of PGI2) and smaller amounts of products that comigrated with PGF2 alpha PGE2. Formation of these products was inhibited by the cyclooxygenase inhibitor indomethacin. The major radioactive product identified by thin-layer chromatographic mobility and by gas chromatography - mass spectrometric analysis was found to be 6-keto-PGF1 alpha. The quantitative metabolic pattern of (1-/sup 14/C)PGH2 was virtually identical to that of (1-/sup 14/C)AA. Incubation of arachidonic acid with slices of bovine gallbladder muscle released labile anti-aggregatory material in the medium, which was inhibited by aspirin or 15-hydroperoxy-AA. These results indicate that bovine gallbladder muscle has a considerable enzymatic capacity to produce PGI2 from arachidonic acid.

  11. Epidemiologic survey of bovine diseases in Suriname.

    PubMed

    Corbett, W T; Guy, J; Lieuw-A-Joe, R; Hunter, L; Grindem, C; Levy, M; Cullen, J; Vaz, V

    1989-01-01

    A seroepidemiologic survey of cattle diseases was undertaken in Suriname in 1985 to help assess the livestock disease situation in that country. The six diseases covered by the survey were bovine coronavirus infection, bovine rhinotracheitis, bovine virus diarrhea, brucellosis, parainfluenza-3 infection, and respiratory syncytial virus infection. The results indicated relatively low prevalences of these diseases compared to the prevalences found in most developed countries. The reasons for this are uncertain, but the finding suggests that the cattle population in Suriname could lack extensive exposure to these diseases and so could be highly susceptible to them. In addition, the evident need for more thoroughgoing survey data points up the need to establish a continuous animal data health monitoring system in Suriname--as well as in other developing countries where there is a need to objectively assess the livestock disease picture.

  12. Eradication of Infectious Bovine Rhinotracheitis Virus (Bovine Herpesvirus 1) from a Herd of Beef Cattle

    PubMed Central

    Bradley, J. A.

    1985-01-01

    Infectious bovine rhinotracheitis virus was eradicated from a 150 cow beef herd at the Animal Diseases Research Institute, Lethbridge, Alberta. Tests used to accomplish this included standard and modified serum-virus neutralization tests and an enzymelinked immunosorbent assay. These results and those of preliminary pilot studies in the herd and in a nonvaccinated, infectious bovine rhinotracheitis-infected 450 cow beef herd suggest that eradication of infectious bovine rhinotracheitis infection can be considered as a practical control alternative to vaccination, and that young animals in purebred herds could be monitored serologically and isolated, to enhance their eligibility for entry into artificial insemination studs or for export. PMID:17422544

  13. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 6 2010-04-01 2010-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  14. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 6 2013-04-01 2013-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  15. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 6 2014-04-01 2014-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  16. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 6 2011-04-01 2011-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  17. 21 CFR 522.1125 - Hemoglobin glutamer-200 (bovine).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 6 2012-04-01 2012-04-01 false Hemoglobin glutamer-200 (bovine). 522.1125 Section... § 522.1125 Hemoglobin glutamer-200 (bovine). (a) Specifications. Each 125 milliliter bag contains 13 grams per deciliter of polymerized hemoglobin of bovine origin in modified Lactated Ringer's Solution...

  18. 76 FR 26239 - Bovine Tuberculosis and Brucellosis; Public Meetings

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-05-06

    ...; ] DEPARTMENT OF AGRICULTURE Animal and Plant Health Inspection Service Bovine Tuberculosis and Brucellosis... framework being developed for the bovine tuberculosis and brucellosis programs in the United States. The... tuberculosis (TB) and bovine brucellosis in the United States. In keeping with its commitment to partnering...

  19. 76 FR 38602 - Bovine Tuberculosis and Brucellosis; Program Framework

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... Animal and Plant Health Inspection Service Bovine Tuberculosis and Brucellosis; Program Framework AGENCY... extending the comment period on a new framework being developed for the bovine tuberculosis and brucellosis... (USDA) is currently developing proposed revisions to its programs regarding bovine tuberculosis (TB) and...

  20. Demecolcine-assisted enucleation for bovine cloning.

    PubMed

    Tani, Tetsuya; Shimada, Hiroaki; Kato, Yoko; Tsunoda, Yukio

    2006-01-01

    The present study demonstrated that demecolcine treatment for at least 30 min produces a membrane protrusion in metaphase II-stage bovine oocytes. The maternal chromosome mass is condensed within the protrusion, which makes it easy to remove the maternal chromosomes for nuclear transfer (NT). Maturation promoting factor activity, but not mitogen-activated protein kinase activity, increased up to 30% in oocytes during demecolcine treatment. One normal healthy calf was obtained after transfer of four NT blastocysts produced following demecolcine treatment. Demecolcine treatment did not increase the potential of NT oocytes to develop into blastocysts. The present study demonstrated that chemically-assisted removal of chromosomes is effective for bovine cloning.

  1. Covalent coupling of bovine growth hormone to its receptor in bovine liver membranes.

    PubMed

    Badinga, L; Collier, R J; Thatcher, W W; Quintana, S J; Bazer, F W

    1987-07-01

    The structure of bovine somatotropin receptor was examined following covalent coupling of iodinated recombinant bovine growth hormone ([125I]rbGH) to bovine liver membrane receptors using ethylene glycol bis(succinimidyl succinate). Iodinated rbGH was incorporated into a complex of estimated Mr of 140,000 under reducing conditions. Excess unlabeled rbGH, but not bovine prolactin (bPRL), inhibited completely the incorporation of [125I]rbGH into the Mr = 140,000 species. In dairy bulls, the Mr = 140,000 complex was undetectable soon after birth but became predominant at 6 months of age. No evidence was found to support presence of bPRL receptors in steer liver membranes. Assuming a 1:1 stoichiometry of hormone binding to receptor, it appears that bGH binds to a major receptor subunit of Mr = 119,000 which does not recognize bPRL.

  2. Concurrent Bovine Virus Diarrhea and Bovine Papular Stomatitis Infection in a Calf

    PubMed Central

    Bohac, J. G.; Yates, W. D. G.

    1980-01-01

    A case of concurrent infection with the viruses of bovine virus diarrhea and papular stomatitis in a calf is reported. The difficulties posed by such situations are described and the criteria used for diagnosis outlined. The two diseases are reviewed briefly and the possible mechanisms whereby bovine virus diarrhea virus is suspected of facilitating infection by other agents are discussed. ImagesFigure 1.Figure 2.Figure 3.Figure 4. PMID:7459795

  3. Abnormal fibrillin metabolism in bovine Marfan syndrome.

    PubMed Central

    Potter, K. A.; Hoffman, Y.; Sakai, L. Y.; Byers, P. H.; Besser, T. E.; Milewicz, D. M.

    1993-01-01

    Bovine Marfan syndrome is a disorder that closely resembles human Marfan syndrome in its clinical signs and pathological lesions. The similarities between the human and bovine diseases suggest that similar metabolic defects could be responsible. Although indirect immunofluorescent assays for fibrillin in skin biopsies did not distinguish affected cattle from control animals, cultures of skin fibroblasts of affected animals were distinguished from normal, unrelated control animals and normal half-siblings on the basis of fibrillin staining. After 72 to 96 hours in culture, stained with anti-fibrillin monoclonal antibody 201, hyperconfluent fibroblast cultures of affected cattle had less immunoreactive fibrillin than control cultures, and the staining pattern was granular rather than fibrillar. Under similar culture conditions, normal bovine aortic smooth muscle cells produced large amounts of immunoreactive fibrillin, but smooth muscle cells from a single affected cow showed markedly less fibrillin staining. In pulse-chase metabolic labeling experiments with [35S]cysteine, dermal fibroblasts from 6 affected calves, incorporated far less fibrillin into the extracellular matrix than control cells. These findings are similar to those reported in human Marfan syndrome, and they suggest that the bovine Marfan syndrome, like the human disorder, is caused by a mutation in fibrillin, leading to defective microfibrillar synthesis. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 PMID:8456941

  4. Molecular biology of bovine viral diarrhea virus

    USDA-ARS?s Scientific Manuscript database

    Bovine viral diarrhea viruses (BVDV) are arguably the most important viral pathogen of ruminants worldwide and can cause severe economic loss. Clinical symptoms of the disease caused by BVDV range from subclinical to severe acute hemorrhagic syndrome, with the severity of disease being strain depend...

  5. Recombinant Bovine Growth Hormone Criticism Grows.

    ERIC Educational Resources Information Center

    Gaard, Greta

    1995-01-01

    Discusses concerns related to the use of recombinant bovine growth hormone in the United States and other countries. Analyses the issue from the perspectives of animal rights, human health, world hunger, concerns of small and organic farmers, costs to the taxpayer, and environmental questions. A sidebar discusses Canadian review of the hormone.…

  6. Bovine immunodeficiency virus: facts and questions.

    PubMed

    Belloc, C; Polack, B; Schwartz-Cornil, I; Brownlie, J; Lévy, D

    1996-01-01

    Bovine immunodeficiency virus (BIV) is a lentivirus whose serologic prevalence is worldwide. Little is known about its impact on animal health status, pathogenesis and mode of transmission. Understanding BIV biology implies isolation of new viral strains and long-term studies on experimentally-infected cows and surrogate hosts such as rabbits.

  7. Control of bovine hepatic fatty acid oxidation

    SciTech Connect

    Jesse, B.W.; Emery, R.S.; Thomas, J.W.

    1986-09-01

    Fatty acid oxidation by bovine liver slices and mitochondria was examined to determine potential regulatory sites of fatty acid oxidation. Conversion of 1-(/sup 14/C)palmitate to /sup 14/CO/sub 2/ and total (/sup 14/C)acid-soluble metabolites was used to measure fatty acid oxidation. Oxidation of palmitate (1 mM) was linear in both liver slice weight and incubation time. Carnitine stimulated palmitate oxidation; 2 mM dl-carnitine produced maximal stimulation of palmitate oxidation to both CO/sup 2/ and acid-soluble metabolites. Propionate (10 mM) inhibited palmitate oxidation by bovine liver slices. Propionate (.5 to 10 mM) had no effect on palmitate oxidation by mitochondria, but malonyl Coenzyme A, the first committed intermediate of fatty acid synthesis, inhibited mitochondrial palmitate oxidation (inhibition constant = .3 ..mu..M). Liver mitochonndrial carnitine palmitoyltransferase exhibited Michaelis constants for palmitoyl Coenzyme A and l-carnitine of 11.5 ..mu..M and .59 mM, respectively. Long-chain fatty acid oxidation in bovine liver is regulated by mechanisms similar to those in rats but adapted to the unique digestive physiology of the bovine.

  8. Study of chromosomal alterations in bovine leukosis.

    PubMed

    Predescu, E; Athanasiu, P; Nastac, E; Hozoc, M

    1977-01-01

    The results of a cytogenetic study of the "CT 384" cell line obtained from bovine leukemic lymph nodes are presented. Multiple chromosomal alterations were found in the 265 metaphases examined: numeric anomalies (aneuploidy and polyploidy), morphologic aberrations (dicentric, annular, giant, filamentous chromosomes) and chromosomal lesions (arm breaks).

  9. An unusual presentation of enzootic bovine leukosis.

    PubMed Central

    Sparling, A M

    2000-01-01

    A 6-year-old, Holstein x Simmental cow diagnosed with pyelonephritis had increasing difficulty rising and became recumbent, despite treatment with antibiotics. A serological test for the bovine leukemia virus was positive; at necropsy, the left kidney and ureter and the myocardium showed lesions of lymphosarcoma, confirmed by histology. PMID:10769770

  10. A physical map of the bovine genome

    USDA-ARS?s Scientific Manuscript database

    Background Cattle are important agriculturally and relevant as a model organism. Previously described genetic and radiation hybrid (RH) maps of the bovine genome have been used to identify genomic regions and genes affecting specific traits. Application of these maps to identify influential geneti...

  11. Neurotransmitter Receptor Binding in Bovine Cerebral Microvessels

    NASA Astrophysics Data System (ADS)

    Peroutka, Stephen J.; Moskowitz, Michael A.; Reinhard, John F.; Synder, Solomon H.

    1980-05-01

    Purified preparations of microvessels from bovine cerebral cortex contain substantial levels of alpha-adrenergic, beta-adrenergic, and histamine 1 receptor binding sites but only negligible serotonin, muscarinic cholinergic, opiate, and benzodiazepine receptor binding. Norepinephrine and histamine may be endogenous regulators of the cerebral microcirculation at the observed receptors.

  12. Bovine Bacillus anthracis in Cameroon ▿ †

    PubMed Central

    Pilo, Paola; Rossano, Alexandra; Bamamga, Hamadou; Abdoulkadiri, Souley; Perreten, Vincent; Frey, Joachim

    2011-01-01

    Bovine Bacillus anthracis isolates from Cameroon were genetically characterized. They showed a strong homogeneity, and they belong, together with strains from Chad, to cluster Aβ, which appears to be predominant in western Africa. However, one strain that belongs to a newly defined clade (D) and cluster (D1) is penicillin resistant and shows certain phenotypes typical of Bacillus cereus. PMID:21705535

  13. NUTRIENTS AND EPIGENETICS IN BOVINE CELLS

    USDA-ARS?s Scientific Manuscript database

    This is a chapter for a book titled “Livestock Epigenetics” edited by Dr. Hasan Khatib and published by Wiley-Blackwell. This chapter is focused on the research development in our laboratory in the area of interaction of nutrients and genomic phonotype in bovine cells. Briefly, the Research on nutri...

  14. Recombinant Bovine Growth Hormone Criticism Grows.

    ERIC Educational Resources Information Center

    Gaard, Greta

    1995-01-01

    Discusses concerns related to the use of recombinant bovine growth hormone in the United States and other countries. Analyses the issue from the perspectives of animal rights, human health, world hunger, concerns of small and organic farmers, costs to the taxpayer, and environmental questions. A sidebar discusses Canadian review of the hormone.…

  15. Thrombocytopenia in lambs fed with bovine colostrum.

    PubMed

    Schreuder, B E

    1993-03-01

    Artificially reared lambs, fed with bovine colostrum, died within 48 hours after birth, showing thrombocytopenia and extensive haemorrhages on autopsy. The mechanism behind was not fully understood, but experimental immunization of young cattle against sheep red blood cells, carried out five years earlier on the same farm, may have played a role.

  16. A physical map of the bovine genome

    PubMed Central

    Snelling, Warren M; Chiu, Readman; Schein, Jacqueline E; Hobbs, Matthew; Abbey, Colette A; Adelson, David L; Aerts, Jan; Bennett, Gary L; Bosdet, Ian E; Boussaha, Mekki; Brauning, Rudiger; Caetano, Alexandre R; Costa, Marcos M; Crawford, Allan M; Dalrymple, Brian P; Eggen, André; Everts-van der Wind, Annelie; Floriot, Sandrine; Gautier, Mathieu; Gill, Clare A; Green, Ronnie D; Holt, Robert; Jann, Oliver; Jones, Steven JM; Kappes, Steven M; Keele, John W; de Jong, Pieter J; Larkin, Denis M; Lewin, Harris A; McEwan, John C; McKay, Stephanie; Marra, Marco A; Mathewson, Carrie A; Matukumalli, Lakshmi K; Moore, Stephen S; Murdoch, Brenda; Nicholas, Frank W; Osoegawa, Kazutoyo; Roy, Alice; Salih, Hanni; Schibler, Laurent; Schnabel, Robert D; Silveri, Licia; Skow, Loren C; Smith, Timothy PL; Sonstegard, Tad S; Taylor, Jeremy F; Tellam, Ross; Van Tassell, Curtis P; Williams, John L; Womack, James E; Wye, Natasja H; Yang, George; Zhao, Shaying

    2007-01-01

    Background Cattle are important agriculturally and relevant as a model organism. Previously described genetic and radiation hybrid (RH) maps of the bovine genome have been used to identify genomic regions and genes affecting specific traits. Application of these maps to identify influential genetic polymorphisms will be enhanced by integration with each other and with bacterial artificial chromosome (BAC) libraries. The BAC libraries and clone maps are essential for the hybrid clone-by-clone/whole-genome shotgun sequencing approach taken by the bovine genome sequencing project. Results A bovine BAC map was constructed with HindIII restriction digest fragments of 290,797 BAC clones from animals of three different breeds. Comparative mapping of 422,522 BAC end sequences assisted with BAC map ordering and assembly. Genotypes and pedigree from two genetic maps and marker scores from three whole-genome RH panels were consolidated on a 17,254-marker composite map. Sequence similarity allowed integrating the BAC and composite maps with the bovine draft assembly (Btau3.1), establishing a comprehensive resource describing the bovine genome. Agreement between the marker and BAC maps and the draft assembly is high, although discrepancies exist. The composite and BAC maps are more similar than either is to the draft assembly. Conclusion Further refinement of the maps and greater integration into the genome assembly process may contribute to a high quality assembly. The maps provide resources to associate phenotypic variation with underlying genomic variation, and are crucial resources for understanding the biology underpinning this important ruminant species so closely associated with humans. PMID:17697342

  17. Molecular analysis of the bovine anaphylatoxin C5a receptor

    PubMed Central

    Nemali, Sailasree; Siemsen, Daniel W.; Nelson, Laura K.; Bunger, Peggy L.; Faulkner, Craig L.; Rainard, Pascal; Gauss, Katherine A.; Jutila, Mark A.; Quinn, Mark T.

    2008-01-01

    Recruitment of phagocytes to inflammatory sites involves the coordinated action of several chemoattractants, including the anaphylatoxin C5a. While the C5a receptor (C5aR) has been well characterized in humans and rodents, little is known about the bovine C5aR. Here, we report cloning of bovine C5R1, the gene encoding bovine C5aR. We also analyzed genomic sequence upstream of the C5R1 translation start site. Although the bovine C5aR amino acid sequence was well conserved among species, significant differences in conserved features were found, including major differences in the N terminus, intracellular loop 3, and transmembrane domain VII. Analysis of C5aR expression by flow cytometry and confocal microscopy demonstrated high levels of C5aR on all bovine neutrophils and a subset of bovine monocytes. C5aR was not expressed on resting or activated bovine lymphocytes, although C5aR message was present in these cells. C5aR was also expressed on a small subset of bovine mammary epithelial cells. Pharmacological analysis of bovine C5aR-mediated responses showed that bovine C5a and C5adesArg both induced dose-dependent calcium fluxes and chemotaxis in bovine neutrophils, with similar efficacy for both agonists. Treatment of bovine neutrophils with C5a or C5adesArg resulted in homologous desensitization of bovine C5aR and cross-desensitization to interleukin 8 (IL-8) and platelet-activating factor (PAF); whereas, treatment with IL-8 or PAF did not cross-desensitize the cells to C5a or C5adesArg. Overall, these studies provide important information regarding distinct structural and functional features that may contribute to the unique pharmacological properties of bovine C5aR. PMID:18480166

  18. Bovine rhinitis viruses are common in U.S. cattle with bovine respiratory disease.

    PubMed

    Hause, Ben M; Collin, Emily A; Anderson, Joe; Hesse, Richard A; Anderson, Gary

    2015-01-01

    Bovine rhinitis viruses (BRV) are established etiological agents of bovine respiratory disease complex however little research into their epidemiology and ecology has been published for several decades. In the U.S., only bovine rhinitis A virus 1 (BRAV1) has been identified while bovine rhinitis A virus 2 (BRAV2) and bovine rhinitis B virus (BRBV) were previously only identified in England and Japan, respectively. Metagenomic sequencing of a nasal swab from a bovine respiratory disease (BRD) diagnostic submission from Kansas identified contigs with approximately 90% nucleotide similarity to BRAV2 and BRBV. A combination of de novo and templated assemblies using reference genomes yielded near complete BRAV2 and BRBV genomes. The near complete genome of bovine rhinitis A virus 1 (BRAV1) was also determined from a historical isolate to enable further molecular epidemiological studies. A 5'-nuclease reverse transcription PCR assay targeting the 3D polymerase gene was designed and used to screen 204 archived BRD clinical specimens. Thirteen (6.4%) were positive. Metagenomic sequencing of six positive samples identified mixed BRAV1/BRAV2, BRAV1/BRBV and BRAV2/BRBV infections for five samples. One sample showed infection only with BRAV1. Seroprevalence studies using a cell culture adapted BRBV found immunofluorescence assay-reactive antibodies were common in the herds analyzed. Altogether, these results demonstrate that BRV infections are common in cattle with respiratory disease and that BRAV1, BRAV2 and BRBV co-circulate in U.S. cattle and have high similarity to viruses isolated more than 30 years ago from diverse locations.

  19. Bovine trophectoderm cells induced from bovine fibroblasts with induced pluripotent stem cell reprogramming factors.

    PubMed

    Talbot, Neil C; Sparks, Wendy O; Phillips, Caitlin E; Ealy, Alan D; Powell, Anne M; Caperna, Thomas J; Garrett, Wesley M; Donovan, David M; Blomberg, Le Ann

    2017-06-01

    Thirteen independent induced bovine trophectroderm (iBT) cell lines were established by reprogramming bovine fetal liver-derived fibroblasts after viral-vector transduction with either six or eight factors, including POU5F1 (OCT4), KLF4, SOX2, MYC, NANOG, LIN28, SV40 large T antigen, and hTERT. Light- and electron-microscopy analysis showed that the iBT cells had epithelial cell morphology typical of bovine trophectoderm cells. Reverse-transcription-PCR assays indicated that all of the cell lines expressed interferon-tau (IFNT) at passages 1 or 2. At later passages (≥ passage 8), however, immunoblot and antiviral activity assays revealed that more than half of the iBT cell lines had stopped expressing IFNT. Messenger RNAs specific to trophectoderm differentiation and function were found in the iBT cell lines, and 2-dimensional-gel analysis for cellular proteins showed an expression pattern similar to that of trophectoderm cell lines derived from bovine blastocysts. Integration of some of the human reprogramming factors, including POU5F1, KLF4, SOX2, MYC, NANOG, and LIN28, were detected by PCR, but their transcription was mostly absent in the iBT cell lines. Gene expression assessment of endogenous bovine reprogramming factor orthologs revealed endogenous bLIN28 and bMYC transcripts in all; bSOX2 and bNANOG in none; and bKLF4 and bPOU5F1 in less than half of the iBT cell lines. These results demonstrate that bovine trophectoderm can be induced via reprogramming factor expression from bovine liver-derived fibroblasts, although other fibroblast populations-e.g., derived from fetal thigh tissue-may produce similar results, albeit at lower frequencies. © 2017 Wiley Periodicals, Inc.

  20. Ontogeny of the Bovine Immune Response 1

    PubMed Central

    Schultz, R. D.; Dunne, H. W.; Heist, C. E.

    1973-01-01

    The ontogenesis of the bovine immune response was studied in three embryos (<40 days) and 106 fetuses of various ages. In the absence of overt antigenic stimulation, fetuses had lymphoid development of the thymus at 42 days of gestation, the spleen was structurally present at 55 days, and certain peripheral lymph nodes were present at 60 days. Mesenteric lymph nodes were structurally present by 100 days of gestation, and lymphoid tissue of the gastrointestinal tract, particularly the lower ileum, was observed in histologic sections of a 175-day fetus with a bacterial infection. Pyroninophilic cells, plasma cells, and germinal centers were present in lymph node sections of antigenically stimulated fetuses. Lymphoid tissue developed more rapidly in fetuses with bacteria, viral antigens, or apparent maternal red-blood-cell antigens than in the normal fetus. Thymic and splenic indices reached maximal values in the 205- to 220-day fetal age group. Immunoglobulin M (IgM)-containing cells were first observed, by immunofluorescence, in a single fetus at 59 days of gestation. Immunoglobulin G (IgG)-containing cells were observed at 145 days of gestation in one fetus with a bacterial and viral infection. IgM-containing cells were observed in 36 fetuses and IgM and IgG cells were present in seven fetuses. Spleen, lymph nodes, thymus, bone marrow, and liver of one fetus from a dam with lymphosarcoma had immunoglobulin-containing cells. Hemal lymph nodes, blood (buffy coat), Peyer patches, and heart and lung sections from fetuses with immunoglobulin-containing cells in spleen or lymph node did not have immunoglobulin-containing cells. Antigens of the virus of bovine virus diarrhea-mucosal disease (BVD) were detected in one fetus, and antigens of infectious bovine rhinotracheitis (IBR) virus were detected in three fetuses; however, viruses were not isolated in primary bovine embryonic kidney cells. Two of the three fetuses with IBR virus antigens had neutralizing serum antibody

  1. Radiodensity and hardness of enamel and dentin of human and bovine teeth, varying bovine teeth age.

    PubMed

    Fonseca, R B; Haiter-Neto, F; Carlo, H L; Soares, C J; Sinhoreti, M A C; Puppin-Rontani, R M; Correr-Sobrinho, L

    2008-11-01

    Studies have evaluated dental hard tissues characteristics from animal species in order to be used as a substitute for human teeth. The aim of this study was to evaluate the radiodensity and hardness of human and bovine enamel and dentin, varying bovine teeth age. Five specimens (1mm thick) were obtained from animals aged 20 (B20), 30 (B30), 38 (B38) and 48 (B48)months and from 20 to 30-years-old human third molars (H). The radiographic images were taken with a phosphor plaque digital system (Digora Optime). The radiodensity was obtained and Knoop hardness (KHN) was recorded (100g for 15s--5 indentations per specimen). Data were analyzed by one-way ANOVA following Tukey's HSD test and Dunnet's two-sided t-test. Radiodensity was similar within enamel groups, but bovine dentin presented higher radiodensity than human one regardless of age groups. Enamel-KHN showed differences between B20-B30 and B38-B48-H, and dentin-KHN was similar within all groups. Enamel was always more radiodense than dentin and also presented higher KHN (p=0.001). The use of bovine enamel or dentin should take into consideration the teeth age, but as a general rule it should be recommended to select older bovine teeth due to better chances to find greater similarity with human teeth.

  2. A solid phase adsorption method for preparation of bovine serum albumin-bovine hemoglobin conjugate.

    PubMed

    Hu, Tao; Su, Zhiguo

    2003-02-13

    A solid phase adsorption method was proposed to prepare well-defined bovine serum albumin-bovine hemoglobin (Hb) conjugate. After adsorption by the solid phase, Q Sepharose Fast Flow media, bovine serum albumin (BSA) molecules were allowed to react with glutaraldehyde. The spacing out of BSA molecules on the solid phase was assumed to limit polymerization of BSA molecules, except some molecules bound closely on the solid phase resulting in minor dimer formation. Following the elution procedure, the activated monomeric BSA was separated from the dimers by gel filtration chromatography on Superdex 200 and then reacted with bovine Hb at 4 degrees C and pH 9.5. The 1:1 (BSA:Hb) conjugate was obtained with the yield of 64%. The P(50) values of the conjugates, prepared under anaerobic and aerobic conditions, were 19.1 and 14.2 mmHg, respectively. The dependence of the P(50) on chloride ions for the conjugate was slightly diminished, presumably due to covalent attachment of BSA to bovine Hb.

  3. Dental fluorosis in bovine temporary teeth

    SciTech Connect

    Suttie, J.W.; Clay, A.B.; Shearer, T.R.

    1985-02-01

    Deciduous incisors from calves born to dams fed an average of 40 mg of fluoride/kg of forage ration (40 ppm) were compared with incisors from calves born to dams fed a normal dairy ration. Skeletal fluoride concentration in the calves born to fluoride-fed dams was increased 5 to 8 fold, but enamel mottling and hypoplasia, typical of permanent bovine incisor dental fluorosis were not seen by gross, histologic, or radiologic examination. Decreases in the amount of enamel on the tooth or hardness of the enamel were not observed. These data do not support recent reports of widespread dental fluorosis of deciduous bovine teeth as a clinical sign of fluoride toxicity.

  4. Flow of bovine collagen in rectangular slit

    NASA Astrophysics Data System (ADS)

    Skočilas, Jan; Žitný, Rudolf; Štancl, Jaromír; Solnař, Stanislav; Landfeld, Aleš; Houška, Milan

    2017-05-01

    This contribution deals with the investigation of the bovine collagen flow in the rectangular slit. The slightly compressible collagen liquid (9.5% mass fraction of native bovine collagen in water) was extruded by capillary rheometer of given geometry. A piston pushed the collagen sample from a container to the rectangular capillary. The extrusion rheometer is equipped by pressure sensors mounted at wall of capillary and manually adjusted hydraulic drive enables continuous variation of the piston velocity. The pressure profiles are measured in five places along the capillary simultaneously with increasing shear rate within the range from 1500 to 5000 s-1. It is possible to identify non-elastic shear flow characteristic and the compressibility of collagen matter.

  5. Molecular detection of bovine kobuviruses in Italy.

    PubMed

    Di Martino, Barbara; Di Profio, Federica; Di Felice, Elisabetta; Ceci, Chiara; Pistilli, Maria Gabriella; Marsilio, Fulvio

    2012-12-01

    Faecal samples obtained from either asymptomatic or diarrhoeic calves in Italy were screened for bovine kobuviruses (BKVs) using specific primers. BKV RNA was detected in 4.9 % of the samples, with higher positivity rates in diarrhoeic calves (5.3 %) than in asymptomatic animals (4.8 %), although the difference was not statistically significant. Upon sequence analysis, all of the Italian viruses formed a tight group along with BKV-like sequences previously detected in Thailand and Japan.

  6. Bovine tuberculosis and the endangered Iberian lynx.

    PubMed

    Briones, V; de Juan, L; Sánchez, C; Vela, A I; Galka, M; Montero; Goyache, J; Aranaz, A; Domìnguez, L

    2000-01-01

    We report the first case of bovine tuberculosis in a free-living Iberian lynx (Lynx pardina), an extremely endangered feline, from Doñana National Park in Spain. The isolate (Mycobacterium bovis) correlates by molecular characterization with other isolates from wild ungulates in the park, strongly suggesting an epidemiologic link. Mycobacterium bovis infects many animal species, with wild and free-ranging domestic ungulates being the main reservoirs in nature (1).

  7. Thermal inactivation of bovine immunodeficiency virus.

    PubMed Central

    Moore, E C; Keil, D; Coats, K S

    1996-01-01

    Cell-associated bovine immunodeficiency virus (BIV) and cell-free BIV were subjected to increasing temperatures, including pasteurization conditions. To determine the effect of heat treatment on BIV viability, reverse transcriptase activity and infectivity of the heat-treated virus were assessed. BIV was inactivated by heating to 47 degrees C for 30 min and by low- and high-temperature pasteurization conditions. PMID:8900024

  8. Bovine tuberculosis and the endangered Iberian lynx.

    PubMed Central

    Briones, V.; de Juan, L.; Sánchez, C.; Vela, A. I.; Galka, M.; Montero; Goyache, J.; Aranaz, A.; Domìnguez, L.

    2000-01-01

    We report the first case of bovine tuberculosis in a free-living Iberian lynx (Lynx pardina), an extremely endangered feline, from Doñana National Park in Spain. The isolate (Mycobacterium bovis) correlates by molecular characterization with other isolates from wild ungulates in the park, strongly suggesting an epidemiologic link. Mycobacterium bovis infects many animal species, with wild and free-ranging domestic ungulates being the main reservoirs in nature (1). PMID:10756155

  9. Is bovine milk a health hazard?

    PubMed

    Oski, F A

    1985-01-01

    Whole bovine milk should not be fed to infants during the first year of life because of its association with occult gastrointestinal bleeding, iron deficiency anemia, and cow's milk allergy. The consumption of whole milk after the first year of life should be discouraged because of its potential role in a variety of disorders including atherosclerosis, recurrent abdominal pain of childhood, cataracts, milk-borne infections, and juvenile delinquency.

  10. [Bovine viral diarrhea control in Russian Federation].

    PubMed

    Guliukin, M I; Iurov, K P; Glotov, A G; Donchenko, N A

    2013-01-01

    Bovine viral diarrhea (BVD) is one of the greatest challenges for breeding and commercial livestock. It is characterized by lesions of the respiratory and gastrointestinal tract, abortion, infertility, immune deficiency, and persistence of the pathogen. In this work, a set of measures for the rehabilitation and prevention of BVD in cattle is described. It includes the data of the literature, guidance documents for the diagnosis and control of BVD adopted by OIE, EU countries, USA, as well as the results of this research.

  11. Production of cattle immunotolerant to bovine viral diarrhea virus.

    PubMed Central

    McClurkin, A W; Littledike, E T; Cutlip, R C; Frank, G H; Coria, M F; Bolin, S R

    1984-01-01

    Inoculation of bovine virus diarrhea virus into 58 to 125 day old fetuses of bovine virus diarrhea virus seropositive pregnant cows, or inoculation of bovine virus diarrhea virus into seronegative cows 42 to 114 days pregnant, may produce clinically normal calves which are persistently infected with the specific isolate of bovine virus diarrhea virus yet seronegative to the homologous and heterologous isolates. Reinoculation of these persistently infected cattle with their homologous isolate produced no neutralizing antibody response to bovine virus diarrhea virus. These persistently infected cattle were immunocompetent as they developed neutralizing serotiters to infectious bovine rhinotracheitis, parainfluenza-3 viruses and agglutinating serotiters to Pasteurella hemolytica . Images Fig. 1. Fig. 2. Fig. 3. PMID:6326980

  12. Elimination kinetic of recombinant somatotropin in bovine.

    PubMed

    Le Breton, Marie-Hélène; Rochereau-Roulet, Sandrine; Pinel, Gaud; Cesbron, Nora; Le Bizec, Bruno

    2009-04-01

    Bovine somatotropin (bST), also called growth hormone is a protein hormone produced by the pituitary gland and responsible directly or indirectly for various effects on growth, development and reproductive functions. Its recombinant bovine somatotropin form (rbST) is used in dairy cattle to enhance milk production. Even if the effects of treatment with rbST have been largely studied, until now analytical methods able to detect rbST were limited to immunoassays, which suffer from the impossibility to distinguish between the endogenous and the recombinant form. In this study, a sample preparation procedure based on different precipitation steps, extraction on solid phase and enzymatic digestion was used to purify rbST from serum. The detection was performed by liquid chromatography coupled to tandem mass spectrometry in positive electrospray ionization mode (LC-ESI(+)-MS/MS) allowing the unambiguous identification and quantification of rbST in serum. Samples collected from a cow treated with recombinant bovine somatotropin were analysed and for the first time, the elimination kinetic specific to recombinant somatotropin has been characterized in serum. Detection of rbST was possible from 4h 30min to 4 days after administration and concentration was found up to 10ngmL(-1) during the kinetic.

  13. Computed Tomography of the Normal Bovine Tarsus.

    PubMed

    Hagag, U; Tawfiek, M; Brehm, W; Gerlach, K

    2016-12-01

    The objective of this study was to provide a detailed multiplanar computed tomographic (CT) anatomic reference for the bovine tarsus. The tarsal regions from twelve healthy adult cow cadavers were scanned in both soft and bone windows via a 16-slice multidetector CT scanner. Tarsi were frozen at -20(o) C and sectioned to 10-mm-thick slices in transverse, dorsal and sagittal planes respecting the imaging protocol. The frozen sections were cleaned and then photographed. Anatomic structures were identified, labelled and compared with the corresponding CT images. The sagittal plane was indispensable for evaluation of bone contours, the dorsal plane was valuable in examination of the collateral ligaments, and both were beneficial for assessment of the tarsal joint articulations. CT images allowed excellent delineation between the cortex and medulla of bones, and the trabecular structure was clearly depicted. The tarsal soft tissues showed variable shades of grey, and the synovial fluid was the lowest attenuated structure. This study provided full assessment of the clinically relevant anatomic structures of the bovine tarsal joint. This technique may be of value when results from other diagnostic imaging techniques are indecisive. Images presented in this study should serve as a basic CT reference and assist in the interpretation of various bovine tarsal pathology.

  14. Bovine growth hormone: human food safety evaluation.

    PubMed

    Juskevich, J C; Guyer, C G

    1990-08-24

    Scientists in the Food and Drug Administration (FDA), after reviewing the scientific literature and evaluating studies conducted by pharmaceutical companies, have concluded that the use of recombinant bovine growth hormone (rbGH) in dairy cattle presents no increased health risk to consumers. Bovine GH is not biologically active in humans, and oral toxicity studies have demonstrated that rbGH is not orally active in rats, a species responsive to parenterally administered bGH. Recombinant bGH treatment produces an increase in the concentration of insulin-like growth factor-I (IGF-I) in cow's milk. However, oral toxicity studies have shown that bovine IGF-I lacks oral activity in rats. Additionally, the concentration of IGF-I in milk of rbGH-treated cows is within the normal physiological range found in human breast milk, and IGF-I is denatured under conditions used to process cow's milk for infant formula. On the basis of estimates of the amount of protein absorbed intact in humans and the concentration of IGF-I in cow's milk during rbGH treatment, biologically significant levels of intact IGF-I would not be absorbed.

  15. PHYSICOCHEMICAL CHARACTERIZATION OF LYOPHILIZED BOVINE BONE GRAFTS

    PubMed Central

    Galia, Carlos Roberto; Lourenço, André Luis; Rosito, Ricardo; Souza Macedo, Carlos Alberto; Camargo, Lourdes Maria Araujo Quaresma

    2015-01-01

    To evaluate the physicochemical characteristics of lyophilized bovine grafts manufactured on a semi-industrial scale (Orthogen; Baumer S/A*) in accordance with a protocol previously developed by the authors. Methods: The lyophilized bovine bone grafts were characterized by means of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffractometry (XRD), thermogravimetric (TG) analysis, differential exploratory scanning calorimetry (DSC) and Fourier-transform infrared (FT-IR) spectroscopy. Results: Ca was the main component (60%) found in the samples, followed by P (28%) and O (5%). The mean (sd) pore size was 316 μm (146.7), ranging from 91.2 to 497.8 μm, and 333.5 μm (304.8), ranging from 87.2 to 963.9 μm, at 50x and 150x magnification, respectively. The hydroxyapatite peaks were at 26°C and 32°C, and mass losses were observed between 250°C and 640°C, corresponding to organic material and water. Two temperature transitions (45.67°C and 91.89°C) showed denaturation of type 1 collagen and dehydration of hydroxyapatite. Conclusion: The physicochemical assessment of lyophilized bovine bone grafts in accordance with the protocol developed at semi-industrial scale confirmed that this product presents excellent biocompatibility, with characteristics similar to natural bone. PMID:27027036

  16. Evidence for Parachlamydia in bovine abortion.

    PubMed

    Ruhl, Silke; Casson, Nicola; Kaiser, Carmen; Thoma, Ruedi; Pospischil, Andreas; Greub, Gilbert; Borel, Nicole

    2009-03-16

    Bovine abortion of unknown infectious aetiology still remains a major economic problem. In this study, we focused on a new possible abortigenic agent called Parachlamydia acanthamoebae. Retrospective samples (n=235) taken from late-term abortions in cattle were investigated by real-time diagnostic PCR for Chlamydiaceae and Parachlamydia spp., respectively. Histological sections of cases positive by real-time PCR for any Chlamydia-related agent were further examined by immunohistochemistry using specific antibodies. Chlamydophila abortus was detected only in three cases (1.3%) by real-time PCR and ArrayTube Microarray playing a less important role in bovine abortion compared to the situation in small ruminants in Switzerland. By real-time PCR as many as 43 of 235 (18.3%) cases turned out to be positive for Parachlamydia. The presence of Parachlamydia within placental lesions was confirmed in 35 cases (81.4%) by immunohistochemistry. The main histopathological feature in parachlamydial abortion was purulent to necrotizing placentitis (25/43). Parachlamydia should be considered as a new abortigenic agent in Swiss cattle. Since Parachlamydia may be involved in lower respiratory tract infections in humans, bovine abortion material should be handled with care given the possible zoonotic risk.

  17. Oxytocin binding sites in bovine mammary tissue

    SciTech Connect

    Zhao, Xin.

    1989-01-01

    Oxytocin binding sites were identified and characterized in bovine mammary tissue. ({sup 3}H)-oxytocin binding reached equilibrium by 50 min at 20{degree}C and by 8 hr at 4{degree}C. The half-time of displacement at 20{degree}C was approximately 1 hr. Thyrotropin releasing hormone, adrenocorticotropin, angiotensin I, angiotensin II, pentagastrin, bradykinin, xenopsin and L-valyl-histidyl-L-leucyl-L-threonyl-L-prolyl-L-valyl-L-glutamyl-L-lysine were not competitive. In the presence of 10 nM LiCl, addition of oxytocin to dispersed bovine mammary cells, in which phosphatidylinositol was pre-labelled, caused a time and dose-dependent increase in radioactive inositiol monophosphate incorporation. The possibility that there are distinct vasopressin receptors in bovine mammary tissue was investigated. ({sup 3}H)-vasopressin binding reached equilibrium by 40 min at 20{degree}. The half-time of displacement at 20{degree}C was approximately 1 hr. The ability of the peptides to inhibit ({sup 3}H)-vasopressin binding was: (Thr{sup 4},Gly{sup 7})-oxytocin > Arg{sup 8}-vasopressin > (lys{sup 8})-vasopressin > (Deamino{sup 1},D-arg{sup 8})-vasopressin > oxytocin > d (CH{sub 2}){sub 5}Tyr(Me)AVP.

  18. Cloning and expression of bovine glucose transporter GLUT12.

    PubMed

    Miller, Peter J; Finucane, Kiera A; Hughes, Megan; Zhao, Feng-Qi

    2005-11-01

    GLUT12 is a new member of facilitative glucose transporters. It was originally cloned from a human breast cancer cell line and its expression has been detected in rat mammary gland. Glucose transport across the plasma membrane of mammary epithelial cells is a rate-limiting factor in milk production. To examine GLUT12's expression and facilitate the study of GLUT12's potential role in supporting milk synthesis in lactating bovine mammary gland, we cloned bovine GLUT12 and examined its distribution of mRNA expression in bovine tissues. The full-length mRNA of bGLUT12 is 2,423 base pairs long and is predicted to encode a protein of 621 amino acids with a molecular weight of approximately 67 kDa. The deduced amino acid sequence of bovine GLUT12 is 87% and 82% identical to the sequences of human and mouse GLUT12. The sequence of bGLUT12 contains several characteristically conserved sugar transporter family signatures. Analysis of current bovine genomic data indicates that bovine GLUT12 gene consists of five exons. The major in vitro transcription and translation product of bovine GLUT12 cDNA migrated at an apparent molecular weight of 41 kDa. In the presence of canine microsomal membranes, the translation product increased to 43 kDa, suggesting glycosylation. GLUT12 mRNA was found in all bovine tissues examined, but most abundant in bovine spleen and skeletal muscle, at intermediate levels in bovine kidney, testes, and mammary gland, and at lower levels in bovine liver, lung and intestine. Immunofluorescence staining showed that, in the presence of insulin, bGLUT12 is mainly distributed in the cytoplasm of the transiently transfected MAC-T bovine mammary epithelial cells.

  19. Bovine viral diarrhea virus in New World camelids.

    PubMed

    Belknap, E B; Collins, J K; Larsen, R S; Conrad, K P

    2000-11-01

    A virus known to cause multiple problems in cattle, bovine viral diarrhea virus, was isolated from 3 different cases in New World camelids. Virus isolation, immunoperoxidase staining, and fluorescent antibody staining were used to detect the virus. The herds involved were screened for antibody titers to bovine viral diarrhea and virus isolation from the buffy coat. Bovine viral diarrhea virus should be considered as a cause of death in young and old New World camelids.

  20. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis

    PubMed Central

    Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M. E.; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

    2015-01-01

    Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis. PMID:26713450

  1. Lactic Acid Bacteria Isolated from Bovine Mammary Microbiota: Potential Allies against Bovine Mastitis.

    PubMed

    Bouchard, Damien S; Seridan, Bianca; Saraoui, Taous; Rault, Lucie; Germon, Pierre; Gonzalez-Moreno, Candelaria; Nader-Macias, Fatima M E; Baud, Damien; François, Patrice; Chuat, Victoria; Chain, Florian; Langella, Philippe; Nicoli, Jacques; Le Loir, Yves; Even, Sergine

    2015-01-01

    Bovine mastitis is a costly disease in dairy cattle worldwide. As of yet, the control of bovine mastitis is mostly based on prevention by thorough hygienic procedures during milking. Additional strategies include vaccination and utilization of antibiotics. Despite these measures, mastitis is not fully under control, thus prompting the need for alternative strategies. The goal of this study was to isolate autochthonous lactic acid bacteria (LAB) from bovine mammary microbiota that exhibit beneficial properties that could be used for mastitis prevention and/or treatment. Sampling of the teat canal led to the isolation of 165 isolates, among which a selection of ten non-redundant LAB strains belonging to the genera Lactobacillus and Lactococcus were further characterized with regard to several properties: surface properties (hydrophobicity, autoaggregation); inhibition potential of three main mastitis pathogens, Staphylococcus aureus, Escherichia coli and Streptococcus uberis; colonization capacities of bovine mammary epithelial cells (bMEC); and immunomodulation properties. Three strains, Lactobacillus brevis 1595 and 1597 and Lactobacillus plantarum 1610, showed high colonization capacities and a medium surface hydrophobicity. These strains are good candidates to compete with pathogens for mammary gland colonization. Moreover, nine strains exhibited anti-inflammatory properties, as illustrated by the lower IL-8 secretion by E. coli-stimulated bMEC in the presence of these LAB. Full genome sequencing of five candidate strains allowed to check for undesirable genetic elements such as antibiotic resistance genes and to identify potential bacterial determinants involved in the beneficial properties. This large screening of beneficial properties while checking for undesirable genetic markers allowed the selection of promising candidate LAB strains from bovine mammary microbiota for the prevention and/or treatment of bovine mastitis.

  2. Microstructure and hardness of bovine enamel in roselle extract solution

    NASA Astrophysics Data System (ADS)

    Dame, M. T.; Noerdin, A.; Indrani, D. J.

    2017-08-01

    The aim of this study was to analyze the effect of roselle extract solution on the microstructure and hardness of bovine enamel. Ten bovine teeth and a 5% concentration of roselle extract solution were prepared. Immersions of each bovine tooth in roselle extract solution were conducted up to 60 minutes. The bovine enamel surface was characterized in hardness and microscopy. It was apparent that the initial hardness was 328 KHN, and after immersion in 15 and 60 min, the values decrease to 57.4 KHN and 11 KHN, respectively. Scanning electron microscopy (SEM) revealed changes in enamel rods after immersion in the roselle extract solution.

  3. The evolution of bovine viral diarrhea: a review.

    PubMed

    Goens, S Denise

    2002-12-01

    The economic importance of bovine viral diarrhea is increasing with the emergence of seemingly more virulent viruses, as evidenced by outbreaks of hemorrhagic syndrome and severe acute bovine viral diarrhea beginning in the 1980s and 1990s. It appears that evolutionary changes in bovine viral diarrhea virus were responsible for these outbreaks. The genetic properties of the classical bovine viral diarrhea virus that contribute to the basis of current diagnostic tests, vaccines, and our understanding of pathogenic mechanisms are now being reevaluated because of these "new" virus strains. This shift in virulence has confounded both nomenclature and the significance of current bovine viral diarrhea virus categorization. The purpose of this review is to summarize our current understanding of bovine viral diarrhea virus with a chronological review of prevailing scientific tenets and practices as described in clinical and scientific North American veterinary journals and textbooks. The first part of this review describes how we have arrived at our current understanding of the viruses, the diseases, and their nomenclature. The second part of the review deals with current concepts in virology and how these concepts may both explain and predict bovine viral diarrhea virus pathogenesis. By reviewing how knowledge of bovine viral diarrhea has evolved and the theories of how the virus itself is able to evolve, the interpretation of diagnostic tests are more effectively utilized in the control and treatment of bovine viral diarrhea virus associated disease.

  4. In vitro protective effect of bacteria-derived bovine alpha interferon I1 against selected bovine viruses.

    PubMed

    Gillespie, J H; Robson, D S; Scott, F W; Schiff, E I

    1985-12-01

    We used bacteria-derived bovine alpha-interferon I1 (Bo IFN-alpha I1) to study its antiviral effect in a bovine turbinate cell line on bovine diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza 3 virus, and pseudorabies virus. We based our study upon replicate tests for each strain by using a block titration system with various concentrations of Bo IFN-alpha I1 against various concentrations of virus. The data were compiled in two-axis tables (replicate X concentration) and were statistically analyzed by the Spearman-Kärber method. An increase in the concentration of Bo IFN-alpha I1 enhanced its protective effect against every test virus strain. Bo IFN-alpha I1 had a marked in vitro effect on the bovine diarrhea viral strains. It demonstrated less protection against the pseudorabies and parainfluenza 3 viruses. Its effectiveness against the two infectious bovine rhinotracheitis viral strains was lesser and of a low order.

  5. Effects of resin or charcoal treatment on fetal bovine serum and bovine calf serum.

    PubMed

    Cao, Zhimin; West, Clint; Norton-Wenzel, Carol S; Rej, Robert; Davis, Faith B; Davis, Paul J; Rej, Robert

    2009-01-01

    Charcoal- or resin-stripping of fetal bovine serum (FBS) or bovine calf serum (BCS) intended for supplementation of cell culture media is widely practiced to remove a variety of endogenous compounds, including steroid, peptide, and thyroid hormones. The possibility that stripping removes other biologically relevant factors from serum may not be appreciated. In this report, standardized clinical laboratory testing methods were used to assess the effects of resin- and charcoal-stripping on content in FBS and BCS of more than 25 analytes in the sera. In addition to hormones, the serum constituents affected by stripping are certain vitamins, electrolytes, enzyme activities, and metabolites.

  6. Diagnosis and Control of Viral Diseases of Reproductive Importance: Infectious Bovine Rhinotracheitis and Bovine Viral Diarrhea.

    PubMed

    Newcomer, Benjamin W; Givens, Daniel

    2016-07-01

    Both bovine viral diarrhea virus and bovine herpesvirus 1 can have significant negative reproductive impacts on cattle health. Vaccination is the primary control method for the viral pathogens in US cattle herds. Polyvalent, modified-live vaccines are recommended to provide optimal protection against various viral field strains. Of particular importance to bovine viral diarrhea control is the limitation of contact of pregnant cattle with potential viral reservoirs during the critical first 125 days of gestation.

  7. Endothelial Cells from Bovine Adrenal Medulla Develop Capillary-Like Growth Patterns in Culture

    NASA Astrophysics Data System (ADS)

    Banerjee, Dipak K.; Ornberg, Richard L.; Youdim, Moussa B. H.; Heldman, Eli; Pollard, Harvey B.

    1985-07-01

    The endocrine barrier between chromaffin cells and the blood stream in the adrenal medulla is made of capillary endothelial cells. We have now succeeded in isolating endothelial cells from adrenal medullary tissue, which are probably derived from this barrier. These cells grow on plastic surfaces in the absence of special growth factors or collagen overlays and differentiate into organized structures quite similar to true capillaries. The cells contain factor VIII:R, a marker for endothelial cells, and form intercellular junctions characteristic of capillary endothelial cells. They also synthesize and secrete basal lamina structures and engage in transcytosis, a characteristic ultrastructural and functional combination of exocytosis and endocytosis across the thin endothelial cell processes. These endothelial cells can take up and deaminate catecholamines by A-type monoamine oxidase, an enzyme functionally distinct from the B-type monoamine oxidase found in chromaffin cells. These data indicate that the chromaffin cell and its endothelial cell neighbor may constitute the functional unit of catecholamine metabolism in the adrenal medulla.

  8. Perspectives on the History of Bovine TB and the Role of Tuberculin in Bovine TB Eradication

    PubMed Central

    Good, Margaret; Duignan, Anthony

    2011-01-01

    Tuberculosis remains a significant disease of animals and humans worldwide. Bovine tuberculosis is caused by Mycobacteria with an extremely wide host range and serious, although currently probably underdiagnosed, zoonotic potential. Where bovine tuberculosis controls are effective, human zoonotic TB, due to Mycobacterium bovis or M. caprae, is uncommon and clinical cases are infrequent in cattle. Therefore, the control and ultimate eradication of bovine tuberculosis is desirable. Tuberculin tests are the primary screening tool used in bovine eradication. The choice of tuberculin test is dependent on the environment in which it is to be used. Tuberculin potency is critical to test performance, and the accurate determination of potency is therefore particularly important. The design of a control or eradication programme should take into consideration the fundamental scientific knowledge, the epidemiological profile of disease, the experience of other eradication programmes, and the presence, in the same ecosystem, of maintenance hosts, in which infection is self-sustaining and which are capable of transmitting infection. A control or eradication programme will necessarily require modification as it progresses and must be under constant review to identify the optimal desirable goals, the efficacy of policy, and constraints to progress. PMID:21547209

  9. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    USDA-ARS?s Scientific Manuscript database

    Long-term (i.e., 14 days) cultured IFN-gamma ELISPOT assays measure central memory T cell (Tcm) responses in both humans and cattle. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT responses correlate with protection. In other species, Tcm’s pose low activation threshold and a...

  10. Bovine central memory T cells are highly proliferative in response to bovine tuberculosis infection

    USDA-ARS?s Scientific Manuscript database

    Long-term (i.e., 14 days) cultured IFN-gamma responses of peripheral blood mononuclear cells are used as a correlate of T cell central memory (Tcm) responses in both humans and cattle. With bovine tuberculosis, vaccine-elicited long-term IFN-gamma ELISPOT assays are a correlate of protection. Recent...

  11. Characterization studies on mycoplasmas isolated from bovine mastitis and the bovine respiratory tract.

    PubMed

    Dellinger, J D; Jasper, D E; Ilić, M

    1977-07-01

    Mycoplasmas isolated from bovine mastitis in California were classified into five distinct species. These included Mycoplasma bovis, M. bovigenitalium, M. alkalescens, M. canadenfe, and an unidentified strain, ST-6. Strains frequently recovered from the nose of young calves proved to be M. arginini, M. bovirhinis was recovered from the respiratory tract but was not a common finding.

  12. Description and analysis of the Bovine Gene Atlas - An extensive compendium of bovine transcript profiles

    USDA-ARS?s Scientific Manuscript database

    The Bovine Gene Atlas (BGA) is a compendium of over 7.2 million unique 20-base transcript tags profiled from 81 tissues acquired from the cow “L1 Dominette 01449” (L1D), her male fetus, her 255-day-old heifer calf, and her father. The BGA tags were generated on a next-generation massively parallel ...

  13. Isolation of bovine herpesvirus-1 from vesicular lesions of the bovine udder.

    PubMed

    Guy, J S; Potgieter, L N; McCracken, M; Martin, W

    1984-04-01

    Bovine herpesvirus-1 was isolated from vesicular lesions on the udder and mammary papillae (teats) of a Charolais cow. Lesions on the animal consisted of papules and vesicles up to 10 mm in diameter. The virus was identified by fluorescent antibody and serum-neutralization tests.

  14. Discovery of a Bovine Enterovirus in Alpaca

    PubMed Central

    McClenahan, Shasta D.; Scherba, Gail; Borst, Luke; Fredrickson, Richard L.; Krause, Philip R.; Uhlenhaut, Christine

    2013-01-01

    A cytopathic virus was isolated using Madin-Darby bovine kidney (MDBK) cells from lung tissue of alpaca that died of a severe respiratory infection. To identify the virus, the infected cell culture supernatant was enriched for virus particles and a generic, PCR-based method was used to amplify potential viral sequences. Genomic sequence data of the alpaca isolate was obtained and compared with sequences of known viruses. The new alpaca virus sequence was most similar to recently designated Enterovirus species F, previously bovine enterovirus (BEVs), viruses that are globally prevalent in cattle, although they appear not to cause significant disease. Because bovine enteroviruses have not been previously reported in U.S. alpaca, we suspect that this type of infection is fairly rare, and in this case appeared not to spread beyond the original outbreak. The capsid sequence of the detected virus had greatest homology to Enterovirus F type 1 (indicating that the virus should be considered a member of serotype 1), but the virus had greater homology in 2A protease sequence to type 3, suggesting that it may have been a recombinant. Identifying pathogens that infect a new host species for the first time can be challenging. As the disease in a new host species may be quite different from that in the original or natural host, the pathogen may not be suspected based on the clinical presentation, delaying diagnosis. Although this virus replicated in MDBK cells, existing standard culture and molecular methods could not identify it. In this case, a highly sensitive generic PCR-based pathogen-detection method was used to identify this pathogen. PMID:23950875

  15. Bovine and equine peritubular and intertubular dentin.

    PubMed

    Stock, S R; Deymier-Black, A C; Veis, A; Telser, A; Lux, E; Cai, Z

    2014-09-01

    Dentin contains 1-2μm diameter tubules extending from the pulp cavity to near the junction with enamel. Peritubular dentin (PTD) borders the tubule lumens and is surrounded by intertubular dentin (ITD). Differences in PTD and ITD composition and microstructure remain poorly understood. Here, a (∼200nm)(2), 10.1keV synchrotron X-ray beam maps X-ray fluorescence and X-ray diffraction simultaneously around tubules in 15-30μm thick bovine and equine specimens. Increased Ca fluorescence surrounding tubule lumens confirms that PTD is present, and the relative intensities in PTD and ITD correspond to carbonated apatite (cAp) volume fraction of ∼0.8 in PTD vs. 0.65 assumed for ITD. In the PTD near the lumen edges, Zn intensity is strongly peaked, corresponding to a Zn content of ∼0.9mgg(-1) for an assumed concentration of ∼0.4mgg(-1) for ITD. In the equine specimen, the Zn K-edge position indicates that Zn(2+) is present, similar to bovine dentin (Deymier-Black et al., 2013), and the above edge structure is consistent with spectra from macromolecules related to biomineralization. Transmission X-ray diffraction shows only cAp, and the 00.2 diffraction peak (Miller-Bravais indices) width is constant from ITD to the lumen edge. The cAp 00.2 average preferred orientation is axisymmetric (about the tubule axis) in both bovine and equine dentin, and the axisymmetric preferred orientation continues from ITD through the PTD to the tubule lumen. These data indicate that cAp structure does not vary from PTD to ITD.

  16. Elastic modulus varies along the bovine femur.

    PubMed

    Nobakhti, Sabah; Katsamenis, Orestis L; Zaarour, Nizar; Limbert, Georges; Thurner, Philipp J

    2017-07-01

    Bone is a heterogeneous material and its mechanical properties vary within the body. Variations in the mechanical response of different bone samples taken from the body cannot be fully explained by only looking at local compositional information at the tissue level. Due to different states of the stress within bones, one might expect that mechanical properties change over the length of a bone; this has not been a matter of systematic research in previous studies. In this study, the distribution of the tissue elastic modulus along the bovine femur is investigated using three-point bending tests. Two bovine femora were split to seven and eight blocks from proximal to distal metaphysis, respectively and twenty beam shaped bone samples were extracted and tested from each block. Based on our findings, the longitudinal elastic modulus follows a gradient pattern along the bovine femur as it increases along the bone from the proximal metaphysis to mid-diaphysis and then decreases toward the distal metaphysis again. Considering long bones to be subjected to bending loads, this mechanism alters the bone structure to support load in the regions where it is needed; similar as outlined by Wolff's law. In another part of this study, microfocus X-ray computed tomography (μCT) was found unable to predict the same trend of changes for the elastic modulus via image-based or density-based elastic moduli calculations. This is insofar important as conventional finite element models of bone are often directly shaped from μCT data. Based on our findings, it seems that current computed tomography based finite element models generated in this manner may not adequately capture the local variation of material behavior of bone tissue, but this may be improved by considering the changes of the elastic modulus along the femur. Copyright © 2017. Published by Elsevier Ltd.

  17. Discovery of a bovine enterovirus in alpaca.

    PubMed

    McClenahan, Shasta D; Scherba, Gail; Borst, Luke; Fredrickson, Richard L; Krause, Philip R; Uhlenhaut, Christine

    2013-01-01

    A cytopathic virus was isolated using Madin-Darby bovine kidney (MDBK) cells from lung tissue of alpaca that died of a severe respiratory infection. To identify the virus, the infected cell culture supernatant was enriched for virus particles and a generic, PCR-based method was used to amplify potential viral sequences. Genomic sequence data of the alpaca isolate was obtained and compared with sequences of known viruses. The new alpaca virus sequence was most similar to recently designated Enterovirus species F, previously bovine enterovirus (BEVs), viruses that are globally prevalent in cattle, although they appear not to cause significant disease. Because bovine enteroviruses have not been previously reported in U.S. alpaca, we suspect that this type of infection is fairly rare, and in this case appeared not to spread beyond the original outbreak. The capsid sequence of the detected virus had greatest homology to Enterovirus F type 1 (indicating that the virus should be considered a member of serotype 1), but the virus had greater homology in 2A protease sequence to type 3, suggesting that it may have been a recombinant. Identifying pathogens that infect a new host species for the first time can be challenging. As the disease in a new host species may be quite different from that in the original or natural host, the pathogen may not be suspected based on the clinical presentation, delaying diagnosis. Although this virus replicated in MDBK cells, existing standard culture and molecular methods could not identify it. In this case, a highly sensitive generic PCR-based pathogen-detection method was used to identify this pathogen.

  18. Prevalence, transmission and impact of bovine leukosis in Michigan dairies

    USDA-ARS?s Scientific Manuscript database

    Bovine leukosis, caused by infection with the retrovirus bovine leukemia virus (BLV), has been characterized as a contagious, but practically benign disease of the immune system. National Animal Health Monitoring Surveys in 1996 and 2007 indicate complacency has resulted in high prevalence of infect...

  19. Bovine viral diarrhea virus modulation of monocyte derived macrophages

    USDA-ARS?s Scientific Manuscript database

    Bovine viral diarrhea virus (BVDV) is a single stranded, positive sense RNA virus and is the causative agent of bovine viral diarrhea (BVD). Disease can range from persistently infected (PI) animals displaying no clinical symptoms of disease to an acute, severe disease. Presently, limited studies ha...

  20. 79 FR 43923 - Approved Tests for Bovine Tuberculosis in Cervids

    Federal Register 2010, 2011, 2012, 2013, 2014

    2014-07-29

    ... Animal and Plant Health Inspection Service 9 CFR Part 77 Approved Tests for Bovine Tuberculosis in... comments. SUMMARY: We are amending the regulations regarding official tuberculosis tests for captive cervids to remove the CervidTB Stat- Pak as an official bovine tuberculosis test for the following...

  1. 9 CFR 113.309 - Bovine Parainfluenza3 Vaccine.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Live Virus Vaccines § 113.309 Bovine Parainfluenza3 Vaccine. Bovine Parainfluenza3 Vaccine shall be produced from virus-bearing cell culture fluids. Only Master Seed Virus which has been established as pure, safe...

  2. 9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Virus. 113.216 Section 113.216 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.216 Bovine Rhinotracheitis Vaccine, Killed Virus. Infectious Bovine...

  3. 9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Virus. 113.216 Section 113.216 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.216 Bovine Rhinotracheitis Vaccine, Killed Virus. Infectious Bovine...

  4. 9 CFR 113.216 - Bovine Rhinotracheitis Vaccine, Killed Virus.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Virus. 113.216 Section 113.216 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE VIRUSES, SERUMS, TOXINS, AND ANALOGOUS PRODUCTS; ORGANISMS AND VECTORS STANDARD REQUIREMENTS Killed Virus Vaccines § 113.216 Bovine Rhinotracheitis Vaccine, Killed Virus. Infectious Bovine...

  5. Identification of highly active flocculant proteins in bovine blood

    USDA-ARS?s Scientific Manuscript database

    Bovine blood is an excellent flocculating agent, faster acting and as effective on a mass basis as polyacrylamide, the most widely utilized polymeric flocculant. To determine the molecular basis of flocculation activity, whole bovine blood (BB) and BB plasma were fractionated by size exclusion chro...

  6. Detection of lipomannan in cattle infected with bovine tuberculosis

    USDA-ARS?s Scientific Manuscript database

    Early and rapid detection of bovine tuberculosis (bTB) is critical to controlling the spread of this disease in cattle and other animals. In this study, we demonstrate the development of an immunoassay for the direct detection of the bovine bTB biomarker, lipomannan (LM) in serum using a waveguide-...

  7. Colostrum proinflammatory cytokines as biomarkers of bovine immune response to bovine tuberculosis (bTB).

    PubMed

    Sánchez-Soto, Eduardo; Ponce-Ramos, Rosa; Hernández-Gutiérrez, Rodolfo; Gutiérrez-Ortega, Abel; Álvarez, Angel H; Martínez-Velázquez, Moisés; Absalón, Angel E; Ortiz-Lazareno, Pablo; Limón-Flores, Alberto; Estrada-Chávez, Ciro; Herrera-Rodríguez, Sara E

    2017-02-01

    Bovine colostrum contains compounds, which provide passive immune protection from mother to newborn calves. Little is known about cytokine levels and their role in bovine colostrum. Moreover, the capacity of bovine colostrum cells to mount specific immune responses after natural exposure to bovine tuberculosis (bTB) antigens in dairy herds has not been studied, thus far. The purpose of this study was to identify biomarkers for bTB infection measurable in bovine colostrum. The present study reveals that isolated-immune colostrum cells can mount a specific immune response against bTB antigens, by measuring the novo IFN-γ release in cell culture. We found that IFN-γ levels in the responders (Bov(+)) to bTB antigen were higher than in non-responders (Bov(-)). On the other hand, proinflammatory cytokines contained in colostrum's whey were tested in Tuberculin Skin Test (TST) reactor (TST(+)) and non-reactor (TST(-)) animals to assess their potential role as biomarker. We observed that IFN-γ levels were lower or undetectable, as opposed to IL4 levels were measurable, the TNF-α level was higher in TST(-) than TST(+), while IL-6 levels showed the opposite reaction and with no statistical significance. Moreover, IL-1α mRNA expression levels were higher in colostrum mononuclear cells (CMC) in Bov(+) cattle. Collectively, these data suggest that the differential expression of pro and anti-inflammatory cytokines could have relevant value to diagnose bTB in cattle. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Effect of charcoal:dextran stripped fetal bovine serum on in vitro development of bovine embryos.

    PubMed

    Mesalam, Ayman; Kong, Rami; Khan, Imran; Chowdhury, Mmr; Choi, Byung-Hyun; Kim, Sung Woo; Cho, Kyu-Woan; Jin, Jong-In; Kong, Il-Keun

    2017-09-16

    This study investigated the ability of charcoal:dextran stripped fetal bovine serum (CDS FBS) and heat-inactivated fetal bovine serum (HI FBS) to support in vitro development of bovine embryos. The developmental ability and quality of bovine embryos were determined by assessing their cell number, lipid content, mitochondrial activity, gene expression, and cryo-tolerance. The percentage of embryos that formed a blastocyst was significantly (P<0.05) higher in medium containing CDS FBS than in medium containing HI FBS (42.84±0.78% vs. 36.85±0.89%, respectively). Furthermore, the beneficial effects of CDS FBS on embryos were associated with significantly (P<0.05) increased mitochondrial activity, as identified by MitoTracker Green, as well as a reduced intracellular lipid content, as identified by Nile red staining, which increased their cryo-tolerance. Quantitative reverse transcription PCR showed that the mRNA levels of acyl-CoA synthetase long-chain family member 3, acyl-coenzyme A dehydrogenase long-chain, hydroxymethylglutaryl-CoA reductase, and insulin-like growth factor 2 receptor were significantly (P<0.05) increased upon culture with CDS FBS. Moreover, the mRNA levels of sirtuin 1, superoxide dismutase 2, and the anti-apoptotic gene B-cell lymphoma 2 in frozen-thawed blastocysts were significantly (P<0.05) higher in the CDS FBS-supplemented group than in the HI FBS-supplemented group, whereas that of the pro-apoptotic gene BCL2-associated X protein was significantly lower. Taken together, these data suggest that supplementation of medium with CDS FBS improves the in vitro developmental competence and cryo-tolerance of bovine embryos. Copyright © 2017 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  9. Bovine aortic arch with supravalvular aortic stenosis.

    PubMed

    Idhrees, Mohammed; Cherian, Vijay Thomas; Menon, Sabarinath; Mathew, Thomas; Dharan, Baiju S; Jayakumar, K

    2016-09-01

    A 5-year-old boy was diagnosed to have supravalvular aortic stenosis (SVAS). On evaluation of CT angiogram, there was associated bovine aortic arch (BAA). Association of BAA with SVAS has not been previously reported in literature, and to best of our knowledge, this is the first case report of SVAS with BAA. Recent studies show BAA as a marker for aortopathy. SVAS is also an arteriopathy. In light of this, SVAS can also possibly be a manifestation of aortopathy associated with BAA.

  10. Dynamic Rheooptical Behavior of Isolated Bovine Cornea

    PubMed Central

    Kaplan, Donald; Bettelheim, Frederick A.

    1972-01-01

    The dynamic Young's modulus E′ and loss modulus E″ were obtained for isolated bovine cornea using a direct-reading dynamic viscoelastometer. Within the temperature range (0-60°C) and frequency range (3.5-110 Hz) studied, both moduli were temperature and frequency independent. The dynamic birefringence of the cornea was measured in a special apparatus designed for this purpose in conjunction with the dynamic viscoelastometer. The stress-optical and strain-optical coefficients as well as the corresponding phase angles were evaluated as a function of temperature and frequency. The strain- and stress-optical coefficients were both temperature and frequency dependent. PMID:4655663

  11. A bovine aortic arch in humans

    PubMed Central

    Arnáiz-García, María Elena; González-Santos, Jose María; López-Rodriguez, Javier; Dalmau-Sorli, María José; Bueno-Codoñer, María; Arévalo-Abascal, Adolfo; Fdez García-Hierro, Jose Ma; Arnáiz-García, Ana María; Arnáiz, Javier

    2014-01-01

    We describe a curious congenital variation of human aortic arch (AA) branching pattern termed the “bovine aortic arch”. Rather than arising directly from the AA as a separate branch as occurs in the most common AA branching pattern, the left common carotid artery moves to the right and merges from the brachiocephalic trunk. It is the normal AA branching pattern presented in a number of animals (canines, felines or Macaque monkeys) but it has nothing to do with anatomy of AA in ruminant animals, including cattle and buffalo. That is why it is one of the most widely misnomers used in medical literature whose origin is nowadays unknown. PMID:24973853

  12. A bovine aortic arch in humans.

    PubMed

    Arnáiz-García, María Elena; González-Santos, Jose María; López-Rodriguez, Javier; Dalmau-Sorli, María José; Bueno-Codoñer, María; Arévalo-Abascal, Adolfo; Fdez García-Hierro, Jose Ma; Arnáiz-García, Ana María; Arnáiz, Javier

    2014-01-01

    We describe a curious congenital variation of human aortic arch (AA) branching pattern termed the "bovine aortic arch". Rather than arising directly from the AA as a separate branch as occurs in the most common AA branching pattern, the left common carotid artery moves to the right and merges from the brachiocephalic trunk. It is the normal AA branching pattern presented in a number of animals (canines, felines or Macaque monkeys) but it has nothing to do with anatomy of AA in ruminant animals, including cattle and buffalo. That is why it is one of the most widely misnomers used in medical literature whose origin is nowadays unknown.

  13. Bovine achondrogenesis: evidence for defective chondrocyte differentiation.

    PubMed

    Horton, W A; Jayo, M J; Leipold, H W; Machado, M A; Campbell, D; Ahmed, S

    1987-01-01

    A survey study of growth cartilage abnormalities in bovine bone dysplasias revealed that a disorder in Holstein cattle called bulldog calf closely resembles human achondrogenesis Type II. Substantial amounts of Type I collagen and other non Type II collagens were detected in the bulldog cartilage which was comprised primarily of extensive vascular canals and cells having the characteristics of hypertrophic and degenerative chondrocytes normally found in the growth plate. It is proposed that chondrocytes throughout the bulldog growth cartilage prematurely differentiate into hypertrophic cells that degenerate and predispose the cartilage to vascular invasion and the formation of cartilage canals. The presence of these canals probably accounts for most of the observed collagen abnormalities.

  14. Bovine neosporosis: clinical and practical aspects.

    PubMed

    Almería, S; López-Gatius, F

    2013-10-01

    Neospora caninum is a protozoan parasite with a wide host range but with a preference for cattle and dogs. Since the description of N. caninum as a new genus and species in 1988, bovine neosporosis has become a disease of international concern as it is among the main causes of abortion in cattle. At present there is no effective treatment or vaccine. This review focuses on the epidemiology of the disease and on prospects for its control in cattle. Finally, based on the implications of clinical findings reported to date, a set of recommendations is provided for veterinarians and cattle farmers.

  15. Ultrasonography of bovine urinary tract disorders.

    PubMed

    Floeck, Martina

    2009-11-01

    Ultrasonography is a helpful diagnostic tool in cattle with urinary tract disorders. It can be used to diagnose pyelonephritis, urolithiasis, hydronephrosis, renal cysts, renal tumors, amyloidosis, cystitis, bladder paralysis, bladder rupture, bladder neoplasms, and, occasionally, nephrosis, glomerulonephritis, and embolic nephritis. This article describes the anatomy, scanning technique, indications, limitations, normal and pathologic sonographic appearance of the bovine urinary tract. References from horses and humans are included, especially when the sonographic findings in these species may complement the understanding of similar diseases reported in cattle.

  16. Bovine viral diarrhea virus: global status.

    PubMed

    Ridpath, Julia F

    2010-03-01

    Despite the success of regional bovine viral diarrhea viruses (BVDV) eradication programs, infections remain a source of economic loss for producers. The wide variation among BVDV results in differences in genotype, biotype, virulence, and types of infections. BVDV infect a range of domestic and wild ruminants. Clinical presentation varies depending on strain of virus, species of host, immune status of host, reproductive status of host, age of host, and concurrent infections. Recent advances in BVDV research and diagnostics have led to the development of regional eradication/control programs, the most efficacious of which focus on biosecurity, surveillance, and control.

  17. Comparative analysis of human and bovine teeth: radiographic density.

    PubMed

    Tanaka, Jefferson Luis Oshiro; Medici Filho, Edmundo; Salgado, José Antônio Pereira; Salgado, Miguel Angel Castillo; Moraes, Luiz Cesar de; Moraes, Mari Eli Leonelli de; Castilho, Julio Cezar de Melo

    2008-01-01

    Since bovine teeth have been used as substitutes for human teeth in in vitro dental studies, the aim of this study was to compare the radiographic density of bovine teeth with that of human teeth to evaluate their usability for radiographic studies. Thirty bovine and twenty human teeth were cut transversally in 1 millimeter-thick slices. The slices were X-rayed using a digital radiographic system and an intraoral X-ray machine at 65 kVp and 7 mA. The exposure time (0.08 s) and the target-sensor distance (40 cm) were standardized for all the radiographs. The radiographic densities of the enamel, coronal dentin and radicular dentin of each slice were obtained separately using the 'histogram' tool of Adobe Photoshop 7.0 software. The mean radiographic densities of the enamel, coronal dentin and radicular dentin were calculated by the arithmetic mean of the slices of each tooth. One-way ANOVA demonstrated statistically significant differences for the densities of bovine and human enamel (p < 0.05) and for bovine and human coronal dentin (p < 0.05). No statistically significant differences were found for the bovine and human radicular dentin (p > 0.05). Based on the results, the authors concluded that: a) the radiographic density of bovine enamel is significantly higher than that of human enamel; b) the radiodensity of bovine coronal dentin is statistically lower than the radiodensity of human coronal dentin; bovine radicular dentin is also less radiodense than human radicular dentin, although this difference was not statistically significant; c) bovine teeth should be used with care in radiographic in vitro studies.

  18. Markers on Bovine Chromosome 20 Associated with Carcass Quality and Composition Traits and Incidence of Contracting Infectious Bovine Keratoconjunctivitis

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to evaluate single nucleotide polymorphisms (SNP) on bovine chromosome 20 to fine map a previously identified QTL associated with the incidence of infectious bovine keratoconjunctivitis (IBK). Crossbred steers (GPE7; n = 539) derived from sires of 7 Bos taurus breeds...

  19. Markers on bovine chromosome 20 associated with carcass quality and composition traits and incidence of contracting infectious bovine keratoconjunctivitis

    USDA-ARS?s Scientific Manuscript database

    The objective of this study was to use single nucleotide polymorphisms (SNP) on bovine chromosome 20 to fine map a previously identified QTL associated with the incidence of infectious bovine keratoconjunctivitis (IBK). Crossbred steers (GPE7; n = 539) derived from sires of 7 Bos Taurus breeds and h...

  20. Nonlinear viscoelastic characterization of bovine trabecular bone.

    PubMed

    Manda, Krishnagoud; Wallace, Robert J; Xie, Shuqiao; Levrero-Florencio, Francesc; Pankaj, Pankaj

    2017-02-01

    The time-independent elastic properties of trabecular bone have been extensively investigated, and several stiffness-density relations have been proposed. Although it is recognized that trabecular bone exhibits time-dependent mechanical behaviour, a property of viscoelastic materials, the characterization of this behaviour has received limited attention. The objective of the present study was to investigate the time-dependent behaviour of bovine trabecular bone through a series of compressive creep-recovery experiments and to identify its nonlinear constitutive viscoelastic material parameters. Uniaxial compressive creep and recovery experiments at multiple loads were performed on cylindrical bovine trabecular bone samples ([Formula: see text]). Creep response was found to be significant and always comprised of recoverable and irrecoverable strains, even at low stress/strain levels. This response was also found to vary nonlinearly with applied stress. A systematic methodology was developed to separate recoverable (nonlinear viscoelastic) and irrecoverable (permanent) strains from the total experimental strain response. We found that Schapery's nonlinear viscoelastic constitutive model describes the viscoelastic response of the trabecular bone, and parameters associated with this model were estimated from the multiple load creep-recovery (MLCR) experiments. Nonlinear viscoelastic recovery compliance was found to have a decreasing and then increasing trend with increasing stress level, indicating possible stiffening and softening behaviour of trabecular bone due to creep. The obtained parameters from MLCR tests, expressed as second-order polynomial functions of stress, showed a similar trend for all the samples, and also demonstrate stiffening-softening behaviour with increasing stress.

  1. Identification of Prototheca zopfii from Bovine Mastitis

    PubMed Central

    Zaini, F; Kanani, A; Falahati, M; Fateh, R; Salimi-Asl, M; Saemi, N; Farahyar, Sh; Kheirabad, A Kargar; Nazeri, M

    2012-01-01

    Background: The aim of this study was identification of the epidemiology of Prototheca zopfii species from the milk samples of dairy cattle in Isfahan, central Iran. Methods: Milk samples were obtained from 230 dairy cattle, 130 with and 100 without mastitis, in Isfahan. The samples were cultured in Prototheca Isolation Medium (PIM) and Sabouraud’s dextrose agar. All P. zopfii isolates were identified by morphological and biochemical methods. Then, as a confirmatory test they were examined by genotype-specific PCR. Results: Four P. zopfii strains (3.07%) were isolated from the 130 samples of dairy cattle with clinical mastitis and there was no isolation from totally 100 samples of healthy bovines without mastitis. Specific PCR product (about 946 bp) was detected in four isolates. Conclusion: It seems that P. zopfii genotype II plays a key role in affecting bovine mastitis that confirmed other previous studies. Our study was the first, which identified the Prototheca species by traditional and molecular methods in Iran and Middle East as well. PMID:23113230

  2. Tensile strength of bovine trabecular bone.

    PubMed

    Kaplan, S J; Hayes, W C; Stone, J L; Beaupré, G S

    1985-01-01

    Data on the tensile and compressive properties of trabecular bone are needed to define input parameters and failure criteria for modeling total joint replacements. To help resolve differences in reports comparing tensile and compressive properties of trabecular bone, we have developed new methods, based on porous foam technology, for tensile testing of fresh/frozen trabecular bone specimens. Using bovine trabecular bone from an isotropic region from the proximal humerus as a model material, we measured ultimate strengths in tension and compression for two groups of 24 specimens each. The average ultimate strength in tension was 7.6 +/- 2.2 (95% C.I.) MPa and in compression was 12.4 +/- 3.2 MPa. This difference was statistically significant (p = 0.013) and was not related to density differences between the test groups (p = 0.28). Strength was related by a power-law function of the local apparent density, but, even accounting for density influences, isotropic bovine trabecular bone exhibits significantly lower strengths in tension than in compression.

  3. Ultrasonographic anatomy of the bovine eye.

    PubMed

    Potter, Timothy J; Hallowell, Gayle D; Bowen, I Mark

    2008-01-01

    The purposes of the study were to describe the ultrasonographic appearance and measurements of the normal bovine eye, to compare the measurements to those reported previously for cadaveric eyes and to describe differences between ocular dimensions of Holstein Friesian and Jersey cattle. Sixty transpalpebral ocular ultrasonographic examinations were performed on 30 adult Holstein Friesian cows, and 16 examinations were performed on 8 adult Jersey cows. Transpalpebral ultrasonographic images were obtained with a 10 MHz linear transducer in both horizontal and vertical imaging planes. The ultrasonographic appearance of structures within the bovine eye is similar to that in other species, although the ciliary artery was frequently identified, appearing as a 0.33 +/- 0.04 cm diameter hypoechoic area. The axial length of the globe was significantly greater in Holstein Friesian cattle (3.46 +/- 0.09 cm) compared with Jersey cattle (3.27 +/- 0.19 cm; P = 0.001), although the vitreous depth was smaller in Holstein Friesian cattle (1.46 +/- 0.09 cm) (P = 0.0009). The anterioposterior depth of the lens was significantly greater in Jersey cattle (1.92 +/- 0.11 cm) and the cornea was thinner in Jersey cattle (0.17 +/- 0.02 cm). The appearance and ocular distances for live animals were similar to those reported previously for cadaveric specimens. The knowledge of normal ocular dimensions facilitates the use of ultrasonography in the evaluation of ocular disease in cattle.

  4. Looseness in bovine leather: microstructural characterization.

    PubMed

    Wells, Hannah C; Holmes, Geoff; Haverkamp, Richard G

    2016-06-01

    A substantial proportion of bovine leather production may be of poor quality, with the leather suffering from a characteristic known as looseness. This defect results in a poor visual appearance and greatly reduced value. The structural mechanism of looseness is not well understood. Samples of loose and tight bovine leather are characterized using small-angle X-ray scattering, ultrasonic imaging, and electron microscopy. The density of fibre packing and orientation of the fibrils are analysed. Tensile strength is also measured. Loose leather is characterized by more highly aligned collagen fibrils. This results in a weaker connection between the layers. There is a looser packing of the fibres in loose leather than in tight leather, with more gaps between fibre bundles, particularly in a region in the lower grain. This region is visible with in situ ultrasonic imaging. Loose leather has a higher tensile strength than tight leather. While a high degree of collagen fibril alignment is normally associated with strong leather, it has been shown that too much alignment results in loose leather. Understanding the physical basis of looseness is the first step in identifying looseness in hides and learning how to prevent looseness from developing during leather manufacture. © 2015 Society of Chemical Industry. © 2015 Society of Chemical Industry.

  5. Toxicology of a bovine paraplegic syndrome.

    PubMed

    Sevcik, C; Brito, J C; D'Suze, G; Domínguez-Bello, M G; Lovera, M; Mijares, A J; Bónoli, S

    1993-12-01

    A clinical entity named 'bovine paraplegic syndrome' ('síndrome parapléjico de los bovinos') has spread alarmingly in the cattle-growing areas of the central and eastern plains of Venezuela. It is estimated that four million cattle are bred in the area where the disease occurs. The mortality ranges from 5 to 25% of the animals at risk, mostly pregnant or lactating cows. The principal characteristic of the bovine paraplegic syndrome is ventral or sternal decubitus, in animals that make vain efforts to stand when stimulated. The diagnosis is established when all other possible causes (e.g. paralytic rabies, botulism and blood parasites such as Anaplasma marginal, Babesia bovis, B. bigemina, and Trypanosoma vivax) have been ruled out clinically and by laboratory tests. Death always occurs, usually after a few days, and there is no known treatment. In this work, we describe results that show the presence of a toxin in the cattle suffering from, or liable to suffer from the syndrome. The toxin is produced by ruminal bacteria. In squid giant axons under voltage clamp conditions, the toxin blocks the sodium current. We detected the toxin analytically by absorbance measurements at 340 nm after reacting with picrylsulfonic acid. We obtained a good separation of the toxin with isocratic high pressure liquid chromatography, using 40% methanol in water on phenylborasil columns.

  6. Bovine Mastitis Associated with Prototheca blaschkeae▿

    PubMed Central

    Marques, Sara; Silva, Eliane; Kraft, Christine; Carvalheira, Júlio; Videira, Arnaldo; Huss, Volker A. R.; Thompson, Gertrude

    2008-01-01

    Bovine mastitis is an important and complex disease responsible for economic losses in the dairy industry. Biotype II strains of the green alga Prototheca zopfii can be involved, most often resulting in chronic mastitis of difficult treatment associated with reduced milk production. This type of infection is rare, but the number of reported cases is increasing worldwide. In order to determine the kind of species involved in mastitis by Prototheca in northwest Portugal, 41 Prototheca isolates were genetically characterized. The algae are part of Prototheca isolates that were collected during a 6-year period, isolated from the milk of 41 dairy cows in a total of 22 herds with a history of increasing somatic cell counts, mild clinical signs of udder infection, and unsuccessful response to the usual therapy. PCR amplification of the 18S ribosomal DNA (rDNA), amplified rDNA restriction analysis, and phylogenetic analyses of the 18S rDNA sequences were performed. Thirty-seven isolates were identified as P. zopfii var. hydrocarbonea and four as Prototheca blaschkeae. These data suggest a high incidence of P. zopfii var. hydrocarbonea mastitis in the region and demonstrate for the first time the involvement of P. blaschkeae with bovine mammary gland infections. PMID:18434557

  7. Copy number variation in the bovine genome

    PubMed Central

    2010-01-01

    Background Copy number variations (CNVs), which represent a significant source of genetic diversity in mammals, have been shown to be associated with phenotypes of clinical relevance and to be causative of disease. Notwithstanding, little is known about the extent to which CNV contributes to genetic variation in cattle. Results We designed and used a set of NimbleGen CGH arrays that tile across the assayable portion of the cattle genome with approximately 6.3 million probes, at a median probe spacing of 301 bp. This study reports the highest resolution map of copy number variation in the cattle genome, with 304 CNV regions (CNVRs) being identified among the genomes of 20 bovine samples from 4 dairy and beef breeds. The CNVRs identified covered 0.68% (22 Mb) of the genome, and ranged in size from 1.7 to 2,031 kb (median size 16.7 kb). About 20% of the CNVs co-localized with segmental duplications, while 30% encompass genes, of which the majority is involved in environmental response. About 10% of the human orthologous of these genes are associated with human disease susceptibility and, hence, may have important phenotypic consequences. Conclusions Together, this analysis provides a useful resource for assessment of the impact of CNVs regarding variation in bovine health and production traits. PMID:20459598

  8. Expression of a 50 kDa putative receptor for bovine viral diarrhea virus in bovine fetal tissues.

    PubMed Central

    Zheng, L; Zhang, S; Xue, W; Kapil, S; Minocha, H C

    1998-01-01

    The expression of a 50 kDa bovine viral diarrhea virus putative receptor in different bovine fetal tissues from 3-month old fetuses was studied. The receptor expression was examined by immunocytochemical staining and by immunoblotting using antiidiotypic probe (anti-D89). Intense specific staining in enterocytes of the small and large intestines, cortical tubular epithelial cells of kidneys, respiratory epithelial cells of the trachea and esophageal mucosal epithelial cells was observed, demonstrating the strong expression of bovine viral diarrhea virus receptor in the tissues. Weak staining was found in cerebellum, thymus, spleen, liver, cerebrum, and lung tissues; however, heart tissues were negative. Immunoblotting results correlated with the immunoperoxidase staining assays. Thus, the expression levels of the receptor are variable in different tissues. This pattern of expression may provide clues to the pathogenic potential of bovine viral diarrhea virus in the bovine fetus. Images Figure 1. Figure 2. PMID:9553718

  9. 81 FR 12832 - Brucellosis and Bovine Tuberculosis; Update of General Provisions

    Federal Register 2010, 2011, 2012, 2013, 2014

    2016-03-11

    ...-AD65 Brucellosis and Bovine Tuberculosis; Update of General Provisions AGENCY: Animal and Plant Health... tuberculosis and those governing brucellosis and revise the bovine tuberculosis- and brucellosis-related import... bovine tuberculosis and those governing brucellosis, as well as to revise the bovine tuberculosis-...

  10. Polyamine degradation in foetal and adult bovine serum.

    PubMed Central

    Gahl, W A; Pitot, H C

    1982-01-01

    1. Using protein-separative chromatographic procedures and assays specific for putrescine oxidase and spermidine oxidase, adult bovine serum was found to contain a single polyamine-degrading enzyme with substrate preferences for spermidine and spermine. Apparent Km values for these substrates were approx. 40 microM. The apparent Km for putrescine was 2 mM. With spermidine as substrate, the Ki values for aminoguanidine (AM) and methylglyoxal bis(guanylhydrazone) (MGBG) were 70 microM and 20 microM respectively. 2. Bovine serum spermidine oxidase degraded spermine to spermidine to putrescine and N8-acetylspermidine to N-acetylputrescine. Acrolein was produced in all these reactions and recovered in quantities equivalent to H2O2 recovery. 3. Spermidine oxidase activity was present in foetal bovine serum, but increased markedly after birth to levels in adult serum that were almost 100 times the activity in foetal bovine serum. 4. Putrescine oxidase, shown to be a separate enzyme from bovine serum spermidine oxidase, was present in foetal bovine serum but absent from bovine serum after birth. This enzyme displayed an apparent Km for putrescine of 2.6 microM. The enzyme was inhibited by AM and MGBG with Ki values of 20 nM. Putrescine, cadaverine and 1,3-diaminopropane proved excellent substrates for the enzyme compared with spermidine and spermine, and N-acetylputrescine was a superior substrate to N1- or N8-acetylspermidine. PMID:7092834

  11. Developmental abnormalities in mice transgenic for bovine oncostatin M.

    PubMed Central

    Malik, N; Haugen, H S; Modrell, B; Shoyab, M; Clegg, C H

    1995-01-01

    Oncostatin M belongs to the subfamily of hematopoietin cytokines that binds a receptor complex containing gp130. To date, only the human form of oncostatin M has been identified, and its evolutionary conservation is unresolved. We have isolated a bovine gene whose open reading frame encodes a precursor protein that is 58% identical to human oncostatin M. A comparison of the bovine and human amino acid sequences predicts significant similarity, including the four-alpha-helical-bundle structure and the placement of disulfide bridges. As with the human protein, bovine oncostatin M binds specific receptors on human H2981 cells and inhibits the proliferation of human A375 tumor cells and mouse M1 leukemia cells. To identify activities regulated in vivo, we injected bovine oncostatin M fusion genes containing various tissue-specific promoters into mouse embryos. The frequencies of transgenic mice were reduced significantly, suggesting that overexpression of the bovine cytokine is detrimental to normal mouse development. In addition to deaths associated with expression in neurons and keratinized epithelia, bovine oncostatin M caused abnormalities in bone growth and spermatogenesis, stimulated fibrosis surrounding islets in the pancreas, and disrupted normal lymphoid tissue development. This work establishes the existence of a nonprimate oncostatin M gene and provides the first demonstration that this cytokine can function in a pleiotropic manner in vivo. Information regarding bovine oncostatin M may help characterize the structure and function of this cytokine in other vertebrate species. PMID:7739518

  12. [Antiviral activity of different drugs in vitro against viruses of bovine infectious rhinotracheitis and bovine diarrhea].

    PubMed

    Glotov, A G; Glotova, T I; Sergeev, A A; Belkina, T V; Sergeev, A N

    2004-01-01

    In vitro experiments studied the antiviral activity of 11 different drugs against viruses of bovine infective rhinotracheitis (BIRT) and bovine viral diarrhea (BVD). The 50% inhibiting concentrations of the test agents were determined in the monolayers of MDBK and KCT cell cultures. Only did phosprenyl show a virucidal activity against BIRT virus. All the tested drugs significantly inhibited the reproduction of BIRT virus in the sensitive MDBK cell cultures. Thus, bromuridin, acyclovir, ribavirin and methisazonum inhibited the virus by > or = 100,000 times; liposomal ribavirin, gossypolum, anandinum, polyprenolum, phosprenyl, by 1000-10,000 times; eracond and argovit, by 100 times. In experiments on BVD virus, the cultured KCT cells displayed the antiviral activity of bromuridin, phosprenil, polyprenolum, methisazonum, acyclovir, gossypolum, argovit, and ribavirin (in two variants), which caused a statistically significant (100-10,000-fold) decrease in the productive activity of this virus. Eracond and anandid proved to be ineffective.

  13. Nonspecific suppressive effect of bovine herpesvirus type 1 on bovine leukocyte functions.

    PubMed Central

    Filion, L G; McGuire, R L; Babiuk, L A

    1983-01-01

    The effect of bovine herpesvirus type 1 on the specific and nonspecific immune response of calves was examined. Animals with or without prior aerosol exposure to Pasteurella haemolytica serotype A1 were aerosol challenged with 10(8) PFU of virus. Blood and serum samples were taken before and after virus challenge for determining cell-mediated, humoral, and neutrophil responses. A significant depression of the blastogenic responses to phytohemagglutinin, P. haemolytica, and Pasteurella multocida and of neutrophil chemotactic response was observed 4 to 7 days after challenge. However, the antibacterial activity of neutrophils was not significantly affected by virus exposure. Anti-bovine herpesvirus type 1 antibody responses were detected 11 days postchallenge. A significant elevation of the anti-P. haemolytica antibody response (day 0 versus day +11) was detected in animals previously exposed to P. haemolytica. PMID:6311742

  14. Epigenetic analysis of bovine parthenogenetic embryonic fibroblasts.

    PubMed

    Kaneda, Masahiro; Takahashi, Masashi; Yamanaka, Ken-Ichi; Saito, Koji; Taniguchi, Masanori; Akagi, Satoshi; Watanabe, Shinya; Nagai, Takashi

    2017-08-19

    Although more than 100 imprinted genes have already been identified in the mouse and human genomes, little is known about genomic imprinting in cattle. For a better understanding of these genes in cattle, parthenogenetically activated bovine blastocysts were transferred to recipient cows to obtain parthenotes, and fibroblasts derived from a Day 40 (Day 0 being the day of parthenogenetic activation) parthenogenetic embryo (BpEFs) were successfully obtained. Bovine embryonic fibroblasts (BEFs) were also isolated from a normal fertilized embryo obtained from an artificially inseminated cow. The expression of imprinted genes was analyzed by RT-PCR. Paternally expressed genes (PEGs) in mouse (viz., IGF2, PEG3, ZAC1, NDN, DLK1, SGCE, and PEG10) were expressed in BEFs, but not in BpEFs, suggesting that these genes are also imprinted in cattle. However, other PEGs in mouse (viz., IMPACT, MAGEL2, SNRPN, and PEG1/MEST) were expressed in both BEFs and BpEFs. These genes may not be imprinted in BEFs. The expression of seven maternally expressed genes in mouse was also analyzed, and only CDKN1C was not expressed in BpEFs. The DNA methylation patterns of repetitive elements (Satellite I, Satellite II, alpha-satellite, and Art2) were not different between the BEFs and BpEFs; however, the differentially methylated region (DMR) of paternally methylated H19 was hypomethylated, whereas those of maternally methylated PEG3 and PEG10 were hypermethylated in BpEFs, as expected. The methylation of the SNRPN DMR was not different between the BEFs and BpEFs, in accordance with the SNRPN expression levels in both cell types. The XIST gene, which is essential for X chromosome inactivation in females, was expressed in BpEFs, whereas its DMR was half-methylated, suggesting that X chromosome inactivation is normal in these cells. Microarray analysis was also applied to identify novel PEGs that should be expressed only in BEFs but not in BpEFs. More than 300 PEG candidate genes, including IGF2

  15. Alteration in ultrastructural morphology of bovine embryos following subzonal microinjection of bovine viral diarrhea virus (BVDV).

    PubMed

    Kubovicová, E; Makarevich, A V; Pivko, J; Chrenek, P; Grafenau, P; Ríha, L'; Sirotkin, A V; Louda, F

    2008-08-01

    The aim of the present study was to evaluate the development and ultrastructure of preimplantation bovine embryos that were exposed to bovine viral diarrhea virus (BVDV) in vitro. The embryos were recovered from superovulated and fertilized Holstein-Friesian donor cows on day 6 of the estrous cycle. Compact morulae were microinjected with 20 pl of BVDV suspension (10(5.16) TCID(50)/ml viral stock diluted 1:4) under the zona pellucida (ZP), then washed in SOF medium and cultured for 24-48 h. Embryos were evaluated for developmental stages and then processed immunocytochemically for the presence of viral particles, using fluorescent anti-BVDV-FITC conjugate. Ultrastructure of cellular organelles was analysed by transmission electron microscopy (TEM).After microinjection of BVDV under the ZP, significantly more (p<0.001) embryos (83.33%) were arrested at the morula stage compared with the intact control (30.33%). Immunocytochemical analysis localized the BVDV-FITC signal inside the microinjected embryos. TEM revealed: (i) the presence of virus-like particles in the dilated endoplasmic reticulum and in cytoplasmic vacuoles of the trophoblast and embryoblast cells; (ii) the loss of microarchitecture: and (iii) abnormal disintegrated nuclei, which lacked reticular structure and the heterochromatin area. In all, the embryo nuclear structure was altered and the microarchitecture of the nucleolus had disappeared when compared with the nuclei from control embryos. Dilatation of the intercellular space and the loss of the intercellular gap junctions were often observed in bovine BVDV-exposed embryos. These findings provide evidence for the adverse effect of BVDV virus on the development of bovine embryos, which is related to irreversible changes in the ultrastructure of cell organelles.

  16. Bovine somatotropin attenuates phorbol ester-induced prostaglandin F2alpha production in bovine endometrial cells.

    PubMed

    Badinga, L; Guzeloglu, A; Thatcher, W W

    2002-03-01

    The recent observation that bovine somatotropin (bST) treatment at a timed insemination improves pregnancy rates in lactating dairy cows raises the possibility that growth hormone (GH) may modulate the endocrine and biochemical cross talk between the conceptus and maternal uterus at the time of pregnancy establishment in cattle. The objective of this study was to characterize the cellular and molecular mechanisms by which exogenous GH affects phorbol ester-induced prostaglandin F2alpha (PGF2alpha) production in cultured bovine endometrial (BEND) cells. Serum-deprived BEND cells were incubated with or without recombinant bovine GH (rbGH), insulin-like growth factor (IGF)-I, recombinant bovine interferon (rbIFN)-tau or a combination of rbGH + rbIFN-tau for 3 h and then treated with phorbol 12,13-dibutyrate (PDBu) for an additional 6 h. Exogenous PDBu increased PGF2alpha secretion and steady-state levels of COX-2 mRNA within 3 h. Priming of BEND cells with rbGH reduced PGF2alpha response to PDBu, whereas cotreatment with IGF-I amplified PDBu induction of PGF2alpha. Preincubation of cell monolayers with rbIFN-tau suppressed PGF2alpha and COX-2 mRNA responses to PDBu. Inhibitory effects of rbGH and rbIFN-tau on PDBu-induced PGF2alpha production were additive. Results provide the first direct evidence that supplemental bST may interact with conceptus-secreted IFN-tau to modulate PGF2alpha secretion at the critical time of maternal recognition of pregnancy.

  17. Native and recombinant bovine growth hormone antagonize insulin action in cultured bovine adipose tissue.

    PubMed

    Etherton, T D; Evock, C M; Kensinger, R S

    1987-08-01

    The current study was undertaken to determine if pituitary bovine GH (pbGH) and recombinant bGH (rbGH) antagonized insulin action in bovine adipose tissue after acute (2-h) and chronic (48-h) exposure and whether this was an intrinsic property of bGH. Insulin action (measured as the effect on incorporation of acetate-carbon into long-chain fatty acids) was unaffected by bGH in short term incubations regardless of whether hydrocortisone (HC) was present. After 48 h of culture, however, both pbGH and rbGH similarly antagonized the ability of insulin to maintain lipogenic capacity. This antagonism was dependent upon the presence of HC and was dose dependent, with half-maximal inhibition of insulin action occurring at about 0.5 ng/ml bGH. Bovine PRL did not mimic the effects of bGH on insulin action. These results establish that bGH antagonizes insulin action in bovine adipose tissue and that this effect is dependent upon long term exposure and the inclusion of HC in the culture medium. The fact that both rbGH and pbGH acted similarly indicates that this is an intrinsic property of bGH. The effect of bGH on insulin-dependent maintenance of lipogenic capacity may play an important role in redirecting nutrients away from adipose tissue to other tissues, such as muscle or mammary tissue. It is speculated that this metabolic effect of bGH plays an important role in the adaptive response to chronic bGH treatment, which increases milk yield of dairy cows and growth performance of beef cattle.

  18. Seroprevalence of bovine herpesvirus-1 antibodies in bovines in five districts of Uttarakhand

    PubMed Central

    Thakur, Vipul; Kumar, Mahesh; Rathish, R. L.

    2017-01-01

    Aim: This study was conducted to know the status of bovine herpesvirus-1 (BHV-1) antibodies in the bovines of the selected area of Uttarakhand. Materials and Methods: A total of 489 serum samples, 392 of cattle and 97 of buffaloes were randomly collected from the unvaccinated bovine population of five districts viz., Dehradun, Haridwar, Nainital, Pithoragarh, and Udham Singh Nagar and were tested by avidin biotin enzyme-linked immunosorbent assay for BHV-1 antibodies. Results: The overall prevalence was observed to be 29.03%. At district level, the highest prevalence was recorded in Pithoragarh district (40.00%) while it was lowest in district Udham Singh Nagar (16.00%). The prevalence of BHV-1 antibodies was found to be higher in unorganized dairy units (31.02%) compared to organized farms (26.51%) in Uttarakhand. Buffaloes were found to have greater prevalence (38.14%) than cattle (26.78%) while on sex-wise basis; it was found that more females (30.08%) were harboring antibodies to the virus than males (16.21%). Conclusion: The study revealed that the population in the area under study has been exposed to BHV-1 and hence prevention and control strategies must be implemented. PMID:28344394

  19. Bovine papillomavirus DNA in milk, blood, urine, semen, and spermatozoa of bovine papillomavirus-infected animals.

    PubMed

    Lindsey, C L; Almeida, M E; Vicari, C F; Carvalho, C; Yaguiu, A; Freitas, A C; Beçak, W; Stocco, R C

    2009-01-01

    Papillomavirus infection in bovines is associated with cutaneous papillomatosis on the hide, udders and other epithelial tissues, as well as in oral respiratory, alimentary and urinary tract mucosa. Bovine papillomavirus (BPV) is also considered the etiological agent of esophageal tumors and the malignant bladder tumors that characterize the clinical condition associated with chronic enzootic hematuria. After infective viral DNA was found in cattle blood and BPV1, 2 and 4 DNA in cattle reproductive and embryonic tissues, we looked for and found BPV DNA in blood, milk, urine, seminal fluid, and spermatozoa of BPV-infected animals. Peripheral blood lymphocyte cultures from BPV-infected animals had high rates of chromosome aberrations, including radial rearrangements that signal oncogenic potential and viral interaction with telomeric regions. The finding of BPV DNA in body fluids and tissues other than the epithelium demonstrates co-infection of other tissues or cell types by papillomavirus and shows the potential role of lymphocytes, seminal fluid and spermatozoa in BPV transmission. Our findings reinforce a peremptory need for prophylactic and therapeutic instruments to curtail this disease in bovine livestock.

  20. Comparison of diagnostic tests for diagnosis of infectious bovine rhinotracheitis in natural cases of bovine abortion.

    PubMed

    Mahajan, V; Banga, H S; Deka, D; Filia, G; Gupta, A

    2013-11-01

    Rapid and precise diagnosis plays a pivotal role in implementing suitable control measures in natural field cases of bovine abortion due to infection with bovine herpesvirus (BHV)-1. In the present study, serology, virus isolation, histopathology, immunohistochemistry (IHC) and real-time polymerase chain reaction (PCR) for amplification of the gene encoding glycoprotein B were applied for diagnosis of infectious bovine rhinotracheitis (IBR) in cases of abortion. The seroprevalence of IBR in the population studied was 26.3% as determined by indirect enzyme-linked immunosorbent assay. BHV-1 abortions occurred between 4 and 8 months of gestation with an average gestational age of 6 months. Affected placentae showed necrosis of chorionic villi and of the endothelium of small villous blood vessels with characteristic intranuclear (IN) acidophilic inclusion bodies. Similar inclusions were also seen in most of the tissues examined. BHV-1 antigen was identified immunohistochemically in necrotic foci in the liver, the endothelium of placental blood vessels, the bronchial epithelium and hepatocytes. Lesions in the brain also had IN inclusion bodies that labelled positively by IHC. Eighteen samples (nine of stomach content, two of placental cotyledons, five of pooled fetal tissue and two of vaginal discharge) out of 84 tested were positive by real-time PCR for BHV-1.

  1. Effects in calves of mixed infections with bovine viral diarrhea virus and several other bovine viruses.

    PubMed

    Castrucci, G; Ferrari, M; Traldi, V; Tartaglione, E

    1992-10-01

    The objective of this study was to verify whether a mixed infection in calves with bovine viral diarrhea virus (BVDV) and other bovine viruses, such as bovid herpesvirus-4 (BHV-4), parainfluenza-3 (PI-3) and infectious bovine rhinotracheitis (IBR) virus, would influence the pathogenesis of the BVDV infection sufficiently to result in the typical form of mucosal disease being produced. Accordingly, two experiments were undertaken. In one experiment calves were first infected with BVDV and subsequently with BHV-4 and IBR virus, respectively. The second experiment consisted in a simultaneous infection of calves with BVDV and PI-3 virus or BVDV and IBR virus. From the first experiment it seems that BVDV infection can be reactivated in calves by BHV-4 and IBR virus. Evidence of this is that BVDV, at least the cytopathic (CP) strain, was recovered from calves following superinfection. Moreover, following such superinfection the calves showed signs which could most likely be ascribed to the pathogenetic activity of BVDV. Superinfection, especially by IBR virus, created a more severe clinical response in calves that were initially infected with CP BVDV, than in those previously given the non-cytopathic (NCP) biotype of the virus. Simultaneous infection with PI-3 virus did not seem to modify to any significant extent the pathogenesis of the experimentally induced BVDV infection whereas a severe clinical response was observed in calves when simultaneous infection was made with BVDV and IBR virus.

  2. Bovine noroviruses: A missing component of calf diarrhoea diagnosis.

    PubMed

    Di Felice, Elisabetta; Mauroy, Axel; Pozzo, Fabiana Dal; Thiry, Damien; Ceci, Chiara; Di Martino, Barbara; Marsilio, Fulvio; Thiry, Etienne

    2016-01-01

    Noroviruses are RNA viruses that belong to the Genus Norovirus, Family Caliciviridae, and infect human beings and several animal species, including cattle. Bovine norovirus infections have been detected in cattle of a range of different ages throughout the world. Currently there is no suitable cell culture system for these viruses and information on their pathogenesis is limited. Molecular and serological tests have been developed, but are complicated by the high genetic and antigenic diversity of bovine noroviruses. Bovine noroviruses can be detected frequently in faecal samples of diarrhoeic calves, either alone or in association with other common enteric pathogens, suggesting a role for these viruses in the aetiology of calf enteritis.

  3. Extracellular Ionic Composition Alters Kinetics of Vesicular Release of Catecholamines and Quantal Size During Exocytosis at Adrenal Medullary Cells

    DTIC Science & Technology

    1994-07-05

    cytosolic calcium concentration in single bovine adrenal chromaffin cells form video imaging of fura - 2 , EMBO J. 8, 401-411. Pollard, H. B., Ornberg, R...Key words: chromaffin cells, catecholamine, barium induced exocytosis, fura - 2 , calcium independent exocytosis Running title: Effects of extracellular...calibration of the fluorescent calcium indicator Fura - 2 , Cell Calcium 11, 75-83. Winkler, H. (1976) The Composition of Adrenal Chromaffin Granules

  4. LukMF′ is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis

    PubMed Central

    Vrieling, Manouk; Boerhout, Eveline M.; van Wigcheren, Glenn F.; Koymans, Kirsten J.; Mols-Vorstermans, Tanja G.; de Haas, Carla J. C.; Aerts, Piet C.; Daemen, Ineke J. J. M.; van Kessel, Kok P. M.; Koets, Ad P.; Rutten, Victor P. M. G.; Nuijten, Piet J.M.; van Strijp, Jos A. G.; Benedictus, Lindert

    2016-01-01

    Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal leukocidins in the pathogenesis of bovine S. aureus disease. We show that LukAB, in contrast to the γ-hemolysins, LukED, and LukMF′, was unable to kill bovine neutrophils, and identified CXCR2 as a bovine receptor for HlgAB and LukED. Furthermore, we assessed functional leukocidin secretion by bovine mastitis isolates and observed that, although leukocidin production was strain dependent, LukMF′ was most abundantly secreted and the major toxin killing bovine neutrophils. To determine the role of LukMF′ in bovine mastitis, cattle were challenged with high (S1444) or intermediate (S1449, S1463) LukMF′-producing isolates. Only animals infected with S1444 developed severe clinical symptoms. Importantly, LukM was produced in vivo during the course of infection and levels in milk were associated with the severity of mastitis. Altogether, these findings underline the importance of LukMF′ as a virulence factor and support the development of therapeutic approaches targeting LukMF′ to control S. aureus mastitis in cattle. PMID:27886237

  5. LukMF' is the major secreted leukocidin of bovine Staphylococcus aureus and is produced in vivo during bovine mastitis.

    PubMed

    Vrieling, Manouk; Boerhout, Eveline M; van Wigcheren, Glenn F; Koymans, Kirsten J; Mols-Vorstermans, Tanja G; de Haas, Carla J C; Aerts, Piet C; Daemen, Ineke J J M; van Kessel, Kok P M; Koets, Ad P; Rutten, Victor P M G; Nuijten, Piet J M; van Strijp, Jos A G; Benedictus, Lindert

    2016-11-25

    Staphylococcus aureus is a major human and animal pathogen and a common cause of mastitis in cattle. S. aureus secretes several leukocidins that target bovine neutrophils, crucial effector cells in the defence against bacterial pathogens. In this study, we investigated the role of staphylococcal leukocidins in the pathogenesis of bovine S. aureus disease. We show that LukAB, in contrast to the γ-hemolysins, LukED, and LukMF', was unable to kill bovine neutrophils, and identified CXCR2 as a bovine receptor for HlgAB and LukED. Furthermore, we assessed functional leukocidin secretion by bovine mastitis isolates and observed that, although leukocidin production was strain dependent, LukMF' was most abundantly secreted and the major toxin killing bovine neutrophils. To determine the role of LukMF' in bovine mastitis, cattle were challenged with high (S1444) or intermediate (S1449, S1463) LukMF'-producing isolates. Only animals infected with S1444 developed severe clinical symptoms. Importantly, LukM was produced in vivo during the course of infection and levels in milk were associated with the severity of mastitis. Altogether, these findings underline the importance of LukMF' as a virulence factor and support the development of therapeutic approaches targeting LukMF' to control S. aureus mastitis in cattle.

  6. Studies on bovine demodecosis in northern Nigeria.

    PubMed

    Slingenbergh, J; Mohammed, A N; Bida, S A

    1980-04-01

    Summary The study reported in the present paper discusses the clinical and histological picture of bovine demodecosis and the morphology of Demodex mites as seen in four cows suffering from generalized demodecosis. There were no clinical signs of other skin affections. Changes in both the number and the appearance of visible skin lesions were seen and related to the level of nutrition and the exposure to sunshine of the cattle. Histological sections of some skin nodules showed the presence of mite colonies in the hair follicles. Only adults were seen in the sebaceous glands. Microscopical study of the morphology of the mites revealed the presence of two types of demodicids in the skin lesions and three types from epilated eyelashes. Morphological criteria are presented to aid in identification of species and of life stages.

  7. Tear and decohesion of bovine pericardial tissue.

    PubMed

    Tobaruela, Almudena; Elices, Manuel; Bourges, Jean Yves; Rojo, Francisco Javier; Atienza, José Miguel; Guinea, Gustavo

    2016-10-01

    The aim of this study was to evaluate quantitatively the fracture-by tear and delamination-of bovine pericardium tissues which are usually employed for the manufacture of bioprosthetic valves. A large number of samples (77) were tested in root-to-apex and circumferential directions, according to a standardised tear test (ASTM D 1938). Before performing the tear test, some samples were subjected to 1000 cycles of fatigue to a maximum stress of 3MPa. Fracture toughness of tearing and delamination were computed by following a simple fracture model. The study showed significantly lower values of delamination toughness compared with tear delamination. Moreover, tear forces were different in each test direction, revealing a clear orthotropic behaviour. All these results, as well as the testing procedure, could be of value for future research in the physiological function of pericardium tissues and clinical applications. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Stroma-free hemoglobin from bovine blood.

    PubMed

    Lima, Maria Celiana P; Andrade, Cristina T

    2007-01-01

    Isolation and purification of bovine hemoglobin (HbBv) was carried out after reaction of whole blood with carbon monoxide. Washing/centrifugation steps were used to eliminate leukocytes, platelets, and plasma proteins. Hypotonic media and ultrasound radiation were used to lyse red blood cells. Lyse by ultrasound was shown to lead to solutions at the highest concentrations in HbBv, and the least concentrations in major phospholipids contaminants. Additional purification procedures were performed to remove membrane proteins and phospholipids. In the first case, proteins were denatured by thermal treatment, and filtered. To eliminate phospholipids, liquid chromatography was used with strong anion exchangers. Purity of HbBv was evaluated by normal phase high performance liquid chromatography (HPLC), electrophoresis, and size-exclusion HPLC.

  9. The core lipocalin, bovine beta-lactoglobulin.

    PubMed

    Sawyer, L; Kontopidis, G

    2000-10-18

    The lipocalin family became established shortly after the structural similarity was noted between plasma retinol binding protein and the bovine milk protein, beta-lactoglobulin. During the past 60 years, beta-lactoglobulin has been studied by essentially every biochemical technique available and so there is a huge literature upon its properties. Despite all of these studies, no specific biological function has been ascribed definitively to the protein, although several possibilities have been suggested. During the processing of milk on an industrial scale, the unpredictable nature of the process has been put down to the presence of beta-lactoglobulin and certainly the whey protein has been implicated in the initiation of aggregation that leads to the fouling of heat exchangers. This short review of the properties of the protein will concentrate mainly on studies carried out under essentially physiological conditions and will review briefly some of the possible functions for the protein that have been described.

  10. Bovine and human papillomaviruses: a comparative review.

    PubMed

    Munday, J S

    2014-11-01

    Fifty years ago, inoculation with bovine papillomavirus (BPV) was found to cause mesenchymal tumors of the skin in cattle and horses, as well as tumors of the bladder in cattle. Subsequent to these studies of BPVs, human papillomaviruses (HPVs) were found to cause cervical cancer resulting in intense research into papillomaviruses. During the past 50 years, the ways that HPVs and BPVs cause disease have been investigated, and both HPVs and BPVs have been associated with an increasingly diverse range of diseases. Herein, the biology, oncogenic mechanisms, and diseases associated with BPVs are compared with those of HPVs. As reviewed, there are currently significant differences between BPVs and HPVs. However, research 50 years ago into BPVs formed a prologue for the recognition that papillomaviruses have a significant role in human disease, and it is possible that future research may similarly reveal that BPVs are less different from HPVs than is currently recognized. © The Author(s) 2014.

  11. Tylosin susceptibility of Staphylococci from bovine mastitis.

    PubMed

    Entorf, Monika; Feßler, Andrea T; Kadlec, Kristina; Kaspar, Heike; Mankertz, Joachim; Peters, Thomas; Schwarz, Stefan

    2014-07-16

    Although the 16-membered macrolide tylosin is commonly used for the treatment of bovine mastitis, little information is currently available about the susceptibility of mastitis pathogens to tylosin. In the present study, 112 Staphylococcus aureus and 110 coagulase-negative Staphylococcus (CoNS) spp. isolates from cases of bovine mastitis were tested by broth microdilution and agar disk diffusion with 30 μg tylosin disks. Susceptibility to erythromycin was tested by broth microdilution and disk diffusion using 15 μg disks. Both test populations showed bimodal distributions of minimal inhibitory concentrations (MICs) and zone diameters with eleven S. aureus and eight CoNS isolates showing tylosin MICs of ≥ 256 μg/ml and no zones of growth inhibition around the tylosin 30 μg disks. All 19 isolates with tylosin MICs of ≥ 256 μg/ml were also resistant to erythromycin. For six additional erythromycin-resistant isolates, tylosin MICs of 1-8 μg/ml were observed. One S. aureus and two CoNS isolates showed inducible macrolide resistance. PCR analysis of the 25 erythromycin-resistant staphylococcal isolates identified the resistance genes erm(A), erm(B), erm(C), erm(T), mph(C) and msr(A) alone or in different combinations. An excellent correlation between the results of the different tylosin susceptibility tests (broth microdilution versus disk diffusion) was seen for S. aureus and CoNS isolates. Since tylosin does not induce the expression of the aforementioned erm genes, isolates with an inducible resistance phenotype may - if only tylosin is tested - be falsely classified as tylosin-susceptible. Thus, erythromycin should be tested in parallel and tylosin should only be used for the treatment of infections caused by erythromycin-susceptible staphylococci. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. Pathogenicity of molecularly cloned bovine leukemia virus.

    PubMed Central

    Rovnak, J; Boyd, A L; Casey, J W; Gonda, M A; Jensen, W A; Cockerell, G L

    1993-01-01

    To delineate the mechanisms of bovine leukemia virus (BLV) pathogenesis, four full-length BLV clones, 1, 8, 9, and 13, derived from the transformed cell line FLK-BLV and a clone construct, pBLV913, were introduced into bovine spleen cells by microinjection. Microinjected cells exhibited cytopathic effects and produced BLV p24 and gp51 antigens and infectious virus. The construct, pBLV913, was selected for infection of two sheep by inoculation of microinjected cells. After 15 months, peripheral blood mononuclear cells from these sheep served as inocula for the transfer of infection to four additional sheep. All six infected sheep seroconverted to BLV and had detectable BLV DNA in peripheral blood mononuclear cells after amplification by polymerase chain reaction. Four of the six sheep developed altered B/T-lymphocyte ratios between 33 and 53 months postinfection. One sheep died of unrelated causes, and one remained hematologically normal. Two of the affected sheep developed B lymphocytosis comparable to that observed in animals inoculated with peripheral blood mononuclear cells from BLV-infected cattle. This expanded B-lymphocyte population was characterized by elevated expression of B-cell surface markers, spontaneous blastogenesis, virus expression in vitro, and increased, polyclonally integrated provirus. One of these two sheep developed lymphocytic leukemia-lymphoma at 57 months postinfection. Leukemic cells had the same phenotype and harbored a single, monoclonally integrated provirus but produced no virus after in vitro cultivation. The range in clinical response to in vivo infection with cloned BLV suggests an important role for host immune response in the progression of virus replication and pathogenesis. Images PMID:8230433

  13. Methionine requirements for the preimplantation bovine embryo.

    PubMed

    BONILLA, Luciano; LUCHINI, Daniel; DEVILLARD, Estelle; HANSEN, Peter J

    2010-10-01

    The early embryo's nutritional environment plays an important role in establishing its developmental potential. However, little is known about the specific nutrient requirements of the embryo. The objective of the present study was to determine requirements of the in vitro produced bovine embryo for the essential amino acid methionine. In addition to serving as a precursor for polypeptides, methionine plays roles in regulation of translation, DNA methylation, and antioxidant balance. In the first experiment, embryos were cultured in potassium simplex optimized medium - bovine embryo modification 2 containing 0, 35, 50, 100, 200 or 400 µmol/l L-methionine for 8 days. There was no effect of methionine concentration on cleavage rate. The percent of oocytes that developed to blastocyst was lower for embryos without methionine at Day 7 and 8 than other groups but was similar for embryos cultured with 35-400 µmol/l. Neither total cell number, allocation of cells to trophectoderm or inner cell mass, or frequency of apoptosis was affected by methionine concentration. In the second experiment, embryos were cultured with 0, 7, 14, 21, 28 or 35 µmol/l methionine. There was no effect of methionine concentration on cleavage rate. The percent of oocytes that developed to blastocyst was lower for embryos without methionine at Day 7 and 8 but was not different between embryos cultured with 7-35 µmol/l methionine. However, the proportion of blastocysts that were expanded, hatching or hatched on Day 7 was reduced at lower concentrations of methionine (7 and 14). DNA methylation of blastocyst nuclei was unaffected by methionine concentration but intracellular glutathione content was higher for embryos cultured without methionine. In conclusion, the methionine requirement for preimplantation development is between 14 and 21 µmol/l. These concentrations are lower or similar to those found in the reproductive tract and suggest that methionine deficiency is not a common cause of

  14. Lipidome signatures in early bovine embryo development.

    PubMed

    Sudano, Mateus J; Rascado, Tatiana D S; Tata, Alessandra; Belaz, Katia R A; Santos, Vanessa G; Valente, Roniele S; Mesquita, Fernando S; Ferreira, Christina R; Araújo, João P; Eberlin, Marcos N; Landim-Alvarenga, Fernanda D C

    2016-07-15

    Mammalian preimplantation embryonic development is a complex, conserved, and well-orchestrated process involving dynamic molecular and structural changes. Understanding membrane lipid profile fluctuation during this crucial period is fundamental to address mechanisms governing embryogenesis. Therefore, the aim of the present work was to perform a comprehensive assessment of stage-specific lipid profiles during early bovine embryonic development and associate with the mRNA abundance of lipid metabolism-related genes (ACSL3, ELOVL5, and ELOVL6) and with the amount of cytoplasmic lipid droplets. Immature oocytes were recovered from slaughterhouse-derived ovaries, two-cell embryos, and eight- to 16-cell embryos, morula, and blastocysts that were in vitro produced under different environmental conditions. Lipid droplets content and mRNA transcript levels for ACSL3, ELOVL5, and ELOVL6, monitored by lipid staining and quantitative polymerase chain reaction, respectively, increased at morula followed by a decrease at blastocyst stage. Relative mRNA abundance changes of ACSL3 were closely related to cytoplasmic lipid droplet accumulation. Characteristic dynamic changes of phospholipid profiles were observed during early embryo development and related to unsaturation level, acyl chain length, and class composition. ELOVL5 and ELOVL6 mRNA levels were suggestive of overexpression of membrane phospholipids containing elongated fatty acids with 16, 18, and 20 carbons. In addition, putative biomarkers of key events of embryogenesis, embryo lipid accumulation, and elongation were identified. This study provides a comprehensive description of stage-specific lipidome signatures and proposes a mechanism to explain its potential relationship with the fluctuation of both cytoplasmic lipid droplets content and mRNA levels of lipid metabolism-related genes during early bovine embryo development.

  15. Cartilage (Bovine and Shark) (PDQ®)—Patient Version

    Cancer.gov

    Expert-reviewed information summary about the use of bovine and shark cartilage as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  16. Conservation of molecular interactions stabilizing bovine and mouse rhodopsin †

    PubMed Central

    Kawamura, Shiho; Colozo, Alejandro T.; Müller, Daniel J.; Park, Paul S.-H.

    2010-01-01

    Rhodopsin is the light receptor that initiates phototransduction in rod photoreceptor cells. The structure and function of rhodopsin is tightly linked to molecular interactions that stabilize and determine the receptor's functional state. Single-molecule force spectroscopy (SMFS) was used to localize and quantify molecular interactions that structurally stabilize bovine and mouse rhodopsin from native disc membranes of rod photoreceptor cells. The mechanical unfolding of bovine and mouse rhodopsin revealed nine major unfolding intermediates, each intermediate defining a structurally stable segment in the receptor. These stable structural segments had similar localization and occurrence in both bovine and mouse samples. For each structural segment, parameters describing their unfolding energy barrier were determined by dynamic SMFS. No major differences were observed between bovine and mouse rhodopsin thereby implying that the structures of both rhodopsins are largely stabilized by similar molecular interactions. PMID:21038881

  17. Cartilage (Bovine and Shark) (PDQ®)—Health Professional Version

    Cancer.gov

    Expert-reviewed information summary about the use of bovine and shark cartilage as a treatment for people with cancer. Note: The information in this summary is no longer being updated and is provided for reference purposes only.

  18. Current usage and future directions for the bovine pericardial patch

    PubMed Central

    Li, Xin; Guo, Yuanyuan; Ziegler, Kenneth; Model, Lynn; Eghbalieh, Sammy D. D.; Brenes, Robert; Kim, Susun; Shu, Chang; Dardik, Alan

    2010-01-01

    Bovine pericardium is widely used in surgery and is commonly used for a patch after arteriotomy during cardiovascular surgery. Bovine pericardial patches have several advantages compared to prosthetic patches, including superior biocompatability, easy handling, less suture line bleeding and possibly reduced rates of infection. These advantages of bovine pericardium have led to its common use during carotid endarterectomy. However, long-term clinical results reported after carotid endarterectomy have suggested several issues that may be related to the patch including restenosis, pseudoaneurysm formation, infection, fibrosis, calcification and thrombosis. These complications may diminish the long-term efficacy of carotid endarterectomy and suggest potential areas for improvement of surgical patches. Understanding the mechanisms by which bovine pericardium heals after patch angioplasty may lead to next generation tissue engineered patches. PMID:21276709

  19. Aspiration lung disorders in bovines: a case report and review.

    PubMed

    Shakespeare, Anthony S

    2012-11-01

    Lung aspiration disorders in bovines are invariably diagnosed as infectious aspiration pneumonias. There is a distinct differentiation between aspiration pneumonia and aspiration pneumonitis in humans that can be applied to bovines. The nature and quantity of the aspirate can result in differing pathogeneses which can require differing therapeutic approaches. Whilst blood gases were important in detecting and prognosticating lung problems, changes in barometric pressure with altitude have to be considered when interpreting partial pressures of oxygen. Anatomical differences in the lungs of bovines can explain why this species is more prone to certain pneumonic problems. Pulmonary physiotherapy is important in treating lung disorders in humans and should be considered as an adjunct therapy in bovine respiratory conditions. A case work-up was used to highlight some of the points discussed in this article.

  20. Detection and characterization of viruses as field and vaccine strains in feedlot cattle with bovine respiratory disease

    USDA-ARS?s Scientific Manuscript database

    This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected fro...

  1. No evidence for a bovine mastitis Escherichia coli pathotype.

    PubMed

    Leimbach, Andreas; Poehlein, Anja; Vollmers, John; Görlich, Dennis; Daniel, Rolf; Dobrindt, Ulrich

    2017-05-08

    Escherichia coli bovine mastitis is a disease of significant economic importance in the dairy industry. Molecular characterization of mastitis-associated E. coli (MAEC) did not result in the identification of common traits. Nevertheless, a mammary pathogenic E. coli (MPEC) pathotype has been proposed suggesting virulence traits that differentiate MAEC from commensal E. coli. The present study was designed to investigate the MPEC pathotype hypothesis by comparing the genomes of MAEC and commensal bovine E. coli. We sequenced the genomes of eight E. coli isolated from bovine mastitis cases and six fecal commensal isolates from udder-healthy cows. We analyzed the phylogenetic history of bovine E. coli genomes by supplementing this strain panel with eleven bovine-associated E. coli from public databases. The majority of the isolates originate from phylogroups A and B1, but neither MAEC nor commensal strains could be unambiguously distinguished by phylogenetic lineage. The gene content of both MAEC and commensal strains is highly diverse and dominated by their phylogenetic background. Although individual strains carry some typical E. coli virulence-associated genes, no traits important for pathogenicity could be specifically attributed to MAEC. Instead, both commensal strains and MAEC have very few gene families enriched in either pathotype. Only the aerobactin siderophore gene cluster was enriched in commensal E. coli within our strain panel. This is the first characterization of a phylogenetically diverse strain panel including several MAEC and commensal isolates. With our comparative genomics approach we could not confirm previous studies that argue for a positive selection of specific traits enabling MAEC to elicit bovine mastitis. Instead, MAEC are facultative and opportunistic pathogens recruited from the highly diverse bovine gastrointestinal microbiota. Virulence-associated genes implicated in mastitis are a by-product of commensalism with the primary function

  2. On-Farm Use of Ultrasonography for Bovine Respiratory Disease.

    PubMed

    Ollivett, Theresa L; Buczinski, Sébastien

    2016-03-01

    Thoracic ultrasonography (TUS) in young cattle has recently gained momentum as an accurate and practical tool for identifying the lung lesions associated with bovine respiratory disease. As cattle producers increasingly seek input from their veterinarians on respiratory health issues, bovine practitioners should consider adding TUS to their practice models. This article discusses the relevant literature regarding TUS in young cattle, current acceptable techniques, and practical on-farm applications.

  3. Comparative molecular analysis of ovine and bovine Streptococcus uberis isolates.

    PubMed

    Gilchrist, T L; Smith, D G E; Fitzpatrick, J L; Zadoks, R N; Fontaine, M C

    2013-02-01

    Streptococcus uberis causes clinical and subclinical mastitis in cattle and sheep, but it is unknown whether the composition of Strep. uberis populations differs between host species. To address this, we characterized a collection of bovine and ovine Strep. uberis isolates with shared geographical and temporal origins by means of an expanded multilocus sequence typing scheme. Among 14 ovine and 35 bovine isolates, 35 allelic profiles were detected. Each allelic profile was associated with a single host species and all but one were new to the multilocus sequence typing database. The median number of new alleles per isolate was higher for ovine isolates than for bovine isolates. None of the ovine isolates belonged to the global clonal complexes 5 or 143, which are commonly associated with bovine mastitis and which have a wide geographical distribution. Ovine isolates also differed from bovine isolates in carriage of plasminogen activator genes, with significantly higher prevalence of pauB in ovine isolates. Isolates that were negative for yqiL, one of the targets of multilocus sequence typing, were found among ovine and bovine isolates and were not associated with a specific sequence type or global clonal complex. One bovine isolate carried a gapC allele that was probably acquired through lateral gene transfer, most likely from Streptococcus salivarius. We conclude that ovine isolates are distinct from bovine isolates of Strep. uberis, and that recombination between isolates from different host species or bacterial species could contribute to changes in virulence gene profiles with relevance for vaccine development. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  4. Purification of lipopolysaccharide-binding protein from bovine serum.

    PubMed

    Bochsler, P N; Yang, Z; Murphy, C L; Carroll, R C

    1996-06-01

    Lipopolysaccharide-binding protein (LBP) plays a central role in presentation of bacterial-derived lipopolysaccharide (LPS; endotoxin) to leukocytes such as macrophages and neutrophils. Interaction of LBP with LPS is significant because LBP-LPS complexes promote activation of leukocytes and the immune system, which results in enhanced secretion of a spectrum of proinflammatory cytokines. An improved, simplified method was used to purify bovine LBP from serum. Methodology consisted of ion-exchange chromatography using Bio-Rex 70 resin, followed by gel-filtration chromatography (Sephacryl S-200 resin) of a selected ion-exchange fraction (0.22-0.50 M NaCl). Densitometric scans on silver-stained polyacrylamide gels of chromatographically-derived proteins indicated up to 88.7% purity of the resultant 64kD protein (bovine LBP) in the cleanest fractions. The isoelectric point of bovine LBP was determined to be 6.8. Identity of the protein was substantiated by western-blot analysis, and by N-terminus amino acid sequence analysis with favorable comparison to published sequence data from rabbit, human, and murine LBP Identity was corroborated by use of purified bovine LBP in bioassays which demonstrated enhanced tissue factor expression of LPS (1 ng ml(-1)-stimulated bovine alveolar macrophages. Tissue factor expression was inhibitable in these assays using anti-CD14 monoclonal antibodies, which is also consistent with LBP-mediated activation of cells. When bovine LBP was heated at 56 degrees C for 30 min, the biological activity was reduced by 50% in the macrophage-based bioassays. Biological activity of bovine LBP was completely destroyed by heating at 62 degrees C for 30 min, which compared favorably with data resulting from use of fetal bovine serum.

  5. Is bovine dentine an appropriate substitute in abrasion studies?

    PubMed

    Wegehaupt, Florian J; Widmer, Raffaella; Attin, Thomas

    2010-04-01

    The study aimed to compare the wear behaviour of human and bovine dentine due to toothbrushing with different relative dentin abrasivity (RDA) toothpastes. Forty human and 40 bovine dentine samples were prepared from bovine lower incisors or human premolars roots, and baseline surface profiles were recorded. The samples were distributed to four groups (each group n = 10 human and 10 bovine samples) and brushed with fluoridated experimental toothpastes with different RDAs (group A: RDA 10, B: RDA 20, C: RDA 50, and D: RDA 100). Toothbrushing was performed in an automatic brushing machine with a brushing frequency of 60 strokes per minute and a brushing force of 2.5 N. After 2, 5, 10, and 25 min of toothbrushing, new surface profiles were recorded, and the dentine wear was calculated with a customized computer programme. The dentine wear of human and bovine dentine within the four groups was compared with unpaired t tests. No statistically significant difference was recorded for the dentine wear of human and bovine samples within the different groups.

  6. Exposure of Mice to Topical Bovine Thrombin Induces Systemic Autoimmunity

    PubMed Central

    Schoenecker, Jonathan G.; Johnson, Rachel K.; Lesher, Aaron P.; Day, Jarrod D.; Love, Stephanie D.; Hoffman, Maureane R.; Ortel, Thomas L.; Parker, William; Lawson, Jeffrey H.

    2001-01-01

    Bovine thrombin is used as an aid to hemostasis in medical and surgical procedures. At least 500,000 Americans are exposed to this therapeutic annually and reports suggest that exposure is associated with the development of autoreactive antibodies. To determine whether bovine thrombin can induce pathological autoimmunity we exposed nonautoimmune-prone galactose-α1-3-galactose-deficient mice to the two bovine thrombin preparations currently approved for use in the United States. We found that, like humans exposed to bovine thrombin, mice developed an immune response against the therapeutic and the xenogeneic carbohydrate galactose-α1-3-galactose, and some mice developed autoantibodies against clotting factors. Further, unexpectedly, a single exposure to this therapeutic also induced autoimmunity with features characteristic of systemic lupus erythematosus including antibodies against nuclear antigens, native DNA, double-stranded DNA, and cardiolipin. High levels of these autoantibodies correlated with glomerulonephritis in all mice evaluated. This autoimmune syndrome was detected in mice 15 weeks after a secondary exposure to bovine thrombin and female mice were found to develop the syndrome at a significantly greater frequency than males. Thus, these studies indicate that exposure to bovine thrombin preparations can induce a pathological systemic autoimmune syndrome with lupus-like serology. PMID:11696457

  7. Potential applications for antiviral therapy and prophylaxis in bovine medicine.

    PubMed

    Newcomer, Benjamin W; Walz, Paul H; Givens, M Daniel

    2014-06-01

    Viral disease is one of the major causes of financial loss and animal suffering in today's cattle industry. Increases in global commerce and average herd size, urbanization, vertical integration within the industry and alterations in global climate patterns have allowed the spread of pathogenic viruses, or the introduction of new viral species, into regions previously free of such pathogens, creating the potential for widespread morbidity and mortality in naïve cattle populations. Despite this, no antiviral products are currently commercially licensed for use in bovine medicine, although significant progress has been made in the development of antivirals for use against bovine viral diarrhea virus (BVDV), foot and mouth disease virus (FMDV) and bovine herpesvirus (BHV). BVDV is extensively studied as a model virus for human antiviral studies. Consequently, many compounds with efficacy have been identified and a few have been successfully used to prevent infection in vivo although commercial development is still lacking. FMDV is also the subject of extensive antiviral testing due to the importance of outbreak containment for maintenance of export markets. Thirdly, BHV presents an attractive target for antiviral development due to its worldwide presence. Antiviral studies for other bovine viral pathogens are largely limited to preliminary studies. This review summarizes the current state of knowledge of antiviral compounds against several key bovine pathogens and the potential for commercial antiviral applications in the prevention and control of several selected bovine diseases.

  8. Homologous recombination in bovine pestiviruses. Phylogenetic and statistic evidence.

    PubMed

    Jones, Leandro Roberto; Weber, E Laura

    2004-12-01

    Bovine pestiviruses (Bovine Viral Diarrea Virus 1 (BVDV 1) and Bovine Viral Diarrea Virus 2 (BVDV 2)) belong to the genus Pestivirus (Flaviviridae), which is composed of positive stranded RNA viruses causing significant economic losses world-wide. We used phylogenetic and bootstrap analyses to systematically scan alignments of previously sequenced genomes in order to explore further the evolutionary mechanisms responsible for variation in the virus. Previously published data suggested that homologous crossover might be one of the mechanisms responsible for the genomic rearrangements observed in cytopathic (cp) strains of bovine pestiviruses. Nevertheless, homologous recombination involves not just homologous crossovers, but also replacement of a homologous region of the acceptor RNA. Furthermore, cytopathic strains represent dead paths in evolution, since they are isolated exclusively from the fatal cases of mucosal disease. Herein, we report evidence of homologous inter-genotype recombination in the genome of a non-cytopathic (ncp) strain of Bovine Viral Diarrea Virus 1, the type species of the genus Pestivirus. We also show that intra-genotype homologous recombination might be a common phenomenon in both species of Pestivirus. This evidence demonstrates that homologous recombination contribute to the diversification of bovine pestiviruses in nature. Implications for virus evolution, taxonomy and phylogenetics are discussed.

  9. Modulation of arachidonic acid metabolism by bovine alveolar macrophages

    SciTech Connect

    O'Sullivan, M.G.

    1989-01-01

    The purpose of this study were to identify the arachidonic acid (AA) metabolites produced by cultured bovine alveolar macrophages (AM), to investigate the effects of various stimuli on the production of those metabolites, and to study the effect of interferons and lipopolysaccharide on AA metabolism by AM. Initial studies were conducted to ascertain which AA metabolites are produced by bovine alveolar macrophages. Cultured macrophages were labeled with tritiated arachidonic acid and stimulated with calcium ionophore A23187. The radiolabeled AA metabolites released were identified using reverse-phase high-performance liquid chromatography. The production of LTB{sub 4}, TXB{sub 2}, and PGF{sub 2{alpha}} by AM stimulated with A23187 or opsonized zymosan (OPZ) was measured using radioimmunoassay. Finally, the effects of recombinant bovine interferon alpha{sub 1}-1 (IFN-{alpha}{sub 1}-1), recombinant bovine interferon gamma (IFN-{gamma}), and lipopolysaccharide (LPS) derived from Escherichia coli 0111:B4 on the AA metabolism of bovine AM were investigated. These studies indicate that appropriately stimulated bovine AM are the source of a number of AA metabolites. Furthermore, the production of these metabolites may be dramatically altered by exposure of the AM to IFNs or LPS. Such exposure could occur in vivo during gram negative bacterial pneumonias following viral infections. Because AA metabolites are intimately involved in the inflammatory process, it is possible that AM may contribute to the development of pulmonary inflammation in certain situations.

  10. Stability of Bovine viral diarrhea virus 1 nucleic acid in fetal bovine samples stored under different conditions

    USDA-ARS?s Scientific Manuscript database

    Infection of pregnant cattle with bovine viral diarrhea viruses can result in reproductive disease that includes fetal reabsorption, mummification, abortion, still births, congenital defects affecting structural, neural, reproductive and immune systems and the birth of calves persistently infected w...

  11. Bovine coronavirus antibody titers at weaning negatively correlate with incidence of bovine respiratory disease in the feed yard

    USDA-ARS?s Scientific Manuscript database

    Bovine respiratory disease complex (BRDC) is a multifactorial disease caused by complex interactions among viral and bacterial pathogens, stressful management practices and host genetic variability. Although vaccines and antibiotic treatments are readily available to prevent and treat infection caus...

  12. Antibody response against three widespread bovine viruses is not impaired in Holstein cattle carrying bovine leukocyte antigen DRB3.2 alleles associated with bovine leukemia virus resistance.

    PubMed

    Juliarena, M A; Poli, M; Ceriani, C; Sala, L; Rodríguez, E; Gutierrez, S; Dolcini, G; Odeon, A; Esteban, E N

    2009-01-01

    Due to the wide dissemination of bovine leukemia virus (BLV) infection among dairy cattle, control and eradication programs based on serological detection of infected cattle and subsequent culling face a major economic task. In Argentina, genetic selection of cattle carrying alleles of the bovine leukocyte antigen (BoLA) DRB3.2 gene associated with BLV-infection resistance, like *0902, emerges as the best additional tool toward controlling virus spread. A potential risk in expanding or segregating BoLA selected populations of cattle is that it might increase susceptibility to other common viruses. Special concern raises the strong association found between low proviral load and low antibody titer against major BLV structural proteins. This phenomenon might depend on host genetic factors influencing other viruses requiring, unlike BLV, strong and long-lasting humoral immune response to prevent infection. In this study, we demonstrate that there is no association among neutralizing antibody titers against foot and mouth disease virus, bovine viral diarrhea virus, or bovine herpesvirus type 1 and polymorphism of the BoLA DRB3.2 gene. Conversely, there is strong association between BoLA DRB3.2*0902 and low antibody titers against 2 BLV structural proteins--env gp51 and gag p24--to date, the best BLV resistance marker. There is also significant association between low antibody titers against gp51 and p24 and BoLA DRB3.2*1701 and low antibody titers against p24 and BoLA DRB3.2*1101 or 02. Our data suggest that increasing BoLA-selected BLV-resistant cattle or segregating BoLA-associated alleles to BLV susceptibility would not affect the resistance or the predisposition to bovine viral diarrhea virus, bovine herpesvirus type 1, or foot and mouth disease virus infection.

  13. Increased bovine Tim-3 and its ligand expressions during bovine leukemia virus infection.

    PubMed

    Okagawa, Tomohiro; Konnai, Satoru; Ikebuchi, Ryoyo; Suzuki, Saori; Shirai, Tatsuya; Sunden, Yuji; Onuma, Misao; Murata, Shiro; Ohashi, Kazuhiko

    2012-05-23

    The immunoinhibitory receptor T cell immunoglobulin domain and mucin domain-3 (Tim-3) and its ligand, galectin-9 (Gal-9), are involved in the immune evasion mechanisms for several pathogens causing chronic infections. However, there is no report concerning the role of Tim-3 in diseases of domestic animals. In this study, cDNA encoding for bovine Tim-3 and Gal-9 were cloned and sequenced, and their expression and role in immune reactivation were analyzed in bovine leukemia virus (BLV)-infected cattle. Predicted amino acid sequences of Tim-3 and Gal-9 shared high homologies with human and mouse homologues. Functional domains, including tyrosine kinase phosphorylation motif in the intracellular domain of Tim-3 were highly conserved among cattle and other species. Quantitative real-time PCR analysis showed that bovine Tim-3 mRNA is mainly expressed in T cells such as CD4+ and CD8+ cells, while Gal-9 mRNA is mainly expressed in monocyte and T cells. Tim-3 mRNA expression in CD4+ and CD8+ cells was upregulated during disease progression of BLV infection. Interestingly, expression levels for Tim-3 and Gal-9 correlated positively with viral load in infected cattle. Furthermore, Tim-3 expression level closely correlated with up-regulation of IL-10 in infected cattle. The expression of IFN-γ and IL-2 mRNA was upregulated when PBMC from BLV-infected cattle were cultured with Cos-7 cells expressing Tim-3 to inhibit the Tim-3/Gal-9 pathway. Moreover, combined blockade of the Tim-3/Gal-9 and PD-1/PD-L1 pathways significantly promoted IFN-γ mRNA expression compared with blockade of the PD-1/PD-L1 pathway alone. These results suggest that Tim-3 is involved in the suppression of T cell function during BLV infection.

  14. Bovine immunodeficiency virus and bovine leukemia virus and their mixed infection in Iranian Holstein cattle.

    PubMed

    Brujeni, Gholamreza Nikbakht; Poorbazargani, Taghi Taghi; Nadin-Davis, Susan; Tolooie, Mohammad; Barjesteh, Neda

    2010-10-04

    Bovine immunodeficiency virus (BIV) and bovine leukemia virus (BLV) have worldwide distributions, but their prevalences in Iran are unknown. We investigated the presence of infections in Iranian Holstein cattle and determined changes in hematological values for infected animals. Nested PCR was used on blood samples from 143 animals Holstein cattle to detect proviral BIV and BLV gag sequences. Flow cytometric analysis was performed using monoclonal antibodies (mAbs) against CD4, CD8, and CD21 bovine T lymphocyte subsets. Proviral BIV and BLV gag sequences were detected in 20.3% and 17% of the animals, respectively. BIV-BLV confection was also detected in 4.2% of the study population but this was not statistically significant. Flow cytometric analysis showed that both BIV-infected cows and non-infected ones had CD4/CD8 ratios of 2.45 and 1.43, respectively, and this difference was significant. BLV infected and non-infected animals had no significant differences in their CD4/CD8 ratio. In comparison to non-infected cattle, those with both BIV and BLV had a significant decrease in their CD4/CD8 ratios (1.5 % vs. 2.3; P = 0.01). This is the first report of BIV and BLV infections in Iran. We found no evidence that infection with one agent predisposed an animal to infection with the other. BIV infection may have a role in decreasing T CD8 counts, but this may depend on the genetics of the cattle and virus strains involved.

  15. Bovine herpesvirus 4 is tropic for bovine endometrial cells and modulates endocrine function.

    PubMed

    Donofrio, Gaetano; Herath, Shan; Sartori, Chiara; Cavirani, Sandro; Flammini, Cesidio Filippo; Sheldon, Iain Martin

    2007-07-01

    Bovine postpartum uterine disease, metritis, affects about 40% of animals and is widely considered to have a bacterial aetiology. Although the gamma-herpesvirus bovine herpesvirus 4 (BoHV-4) has been isolated from several outbreaks of metritis or abortion, the role of viruses in endometrial pathology and the mechanisms of viral infection of uterine cells are often ignored. The objectives of the present study were to explore the interaction, tropism and outcomes of BoHV-4 challenge of endometrial stromal and epithelial cells. Endometrial stromal and epithelial cells were purified and infected with a recombinant BoHV-4 carrying an enhanced green fluorescent protein (EGFP) expression cassette to monitor the establishment of infection. BoHV-4 efficiently infected both stromal and epithelial cells, causing a strong non-apoptotic cytopathic effect, associated with robust viral replication. The crucial step for the BoHV-4 endometriotropism appeared to be after viral entry as there was enhanced transactivation of the BoHV-4 immediate early 2 gene promoter following transient transfection into the endometrial cells. Infection with BoHV-4 increased cyclooxygenase 2 protein expression and prostaglandin estradiol secretion in endometrial stromal cells, but not epithelial cells. Bovine macrophages are persistently infected with BoHV-4, and co-culture with endometrial stromal cells reactivated BoHV-4 replication in the persistently infected macrophages, suggesting a symbiotic relationship between the cells and virus. In conclusion, the present study provides evidence of cellular and molecular mechanisms, supporting the concept that BoHV-4 is a pathogen associated with uterine disease.

  16. In vitro protective effect of bacteria-derived bovine alpha interferon I1 against selected bovine viruses.

    PubMed Central

    Gillespie, J H; Robson, D S; Scott, F W; Schiff, E I

    1985-01-01

    We used bacteria-derived bovine alpha-interferon I1 (Bo IFN-alpha I1) to study its antiviral effect in a bovine turbinate cell line on bovine diarrhea virus, infectious bovine rhinotracheitis virus, parainfluenza 3 virus, and pseudorabies virus. We based our study upon replicate tests for each strain by using a block titration system with various concentrations of Bo IFN-alpha I1 against various concentrations of virus. The data were compiled in two-axis tables (replicate X concentration) and were statistically analyzed by the Spearman-Kärber method. An increase in the concentration of Bo IFN-alpha I1 enhanced its protective effect against every test virus strain. Bo IFN-alpha I1 had a marked in vitro effect on the bovine diarrhea viral strains. It demonstrated less protection against the pseudorabies and parainfluenza 3 viruses. Its effectiveness against the two infectious bovine rhinotracheitis viral strains was lesser and of a low order. PMID:2999188

  17. Washing and trypsin treatment of in vitro derived bovine embryos exposed to bovine viral diarrhea virus.

    PubMed

    Trachte, E; Stringfellow, D; Riddell, K; Galik, P; Riddell, M; Wright, J

    1998-10-01

    Gametes, somatic cells and materials of animal origin in media are potential sources for introducing bovine viral diarrhea virus (BVDV) into systems for production of IVF bovine embryos. Further, the efficacy of washing and trypsin treatment for removal of BVDV from IVF embryos is questionable. Washing and trypsin treatments recommended by the International Embryo Transfer Society for in vivo-derived embryos were applied to in vitro-derived, virus-exposed, bovine embryos in this side-by-side comparison of treatments. Embryos for the study were produced in a virus-free system in which follicular oocytes were matured and fertilized in vitro and presumptive zygotes were co-cultured with bovine uterine tubal cells for 7 d. A total of 18 trials was performed, 9 using a noncytopathic BVDV and 9 using a cytopathic BVDV. In each trial, 4 equal groups of 10 or less, zona pellucida-intact embryos/ova were assembled, including 2 groups of morulae and blastocysts (M/B) and 2 groups of nonfertile or degenerated ova (NFD). Each group was prewashed and exposed to 10(4) to 10(6) TCID50/mL of either noncytopathic (SD-1) or cytopathic (NADL) BVDV for 2 h. Following in vitro viral exposure, one group of M/B and one group of NFD were washed. The other groups of M/B and NFD were trypsin-treated. Both treatments were consistent with IETS guidelines. After in vitro exposure to noncytopathic BVDV and washing, viral assays of 100% (9/9) and 78% (7/9) of the groups of M/B and NFD ova, respectively, were positive. After in vitro exposure to cytopathic BVDV and washing, viral assay of 33% (3/9) of the groups of both M/B and NFD ova were positive. After in vitro exposure to noncytopathic BVDV and trypsin treatment, viral assay of 44% (4/9) of groups of M/B and 67% (6/9) of groups of NFD ova were positive. Finally, after in vitro exposure to cytopathic BVDV and trypsin treatment, viral assay of 22% (2/9) of the groups of M/B and 44% (4/9) of the groups of NFD ova were positive. Contingency

  18. Cerebral Candidal Abscess and Bovine Viral Diarrhoea Virus Infection in an Aborted Bovine Fetus.

    PubMed

    Vilander, A C; Niles, G A; Frank, C B

    2016-01-01

    Candida species are opportunistic fungi associated with immunosuppression and are the most commonly isolated fungal pathogens from the human central nervous system. Invasive candidiasis is reported uncommonly in animals and there have only been two reports of candidal infection of the brain. This report presents a case of a cerebral candidal abscess in an aborted late-term calf co-infected with bovine viral diarrhoea virus. Candida etchellsii, a species not previously identified as pathogenic, was identified as the causative agent by polymerase chain reaction. Copyright © 2016 Elsevier Ltd. All rights reserved.

  19. Dynamic compressive response of bovine liver tissues.

    PubMed

    Pervin, Farhana; Chen, Weinong W; Weerasooriya, Tusit

    2011-01-01

    This study aims to experimentally determine the strain rate effects on the compressive stress-strain behavior of bovine liver tissues. Fresh liver tissues were used to make specimens for mechanical loading. Experiments at quasi-static strain rates were conducted at 0.01 and 0.1 s(-1). Intermediate-rate experiments were performed at 1, 10, and 100 s(-1). High strain rate (1000, 2000, and 3000 s(-1)) experiments were conducted using a Kolsky bar modified for soft material characterization. A hollow transmission bar with semi-conductor strain gages was used to sense the weak forces from the soft specimens. Quartz-crystal force transducers were used to monitor valid testing conditions on the tissue specimens. The experiment results show that the compressive stress-strain response of the liver tissue is non-linear and highly rate-sensitive, especially when the strain rate is in the Kolsky bar range. The tissue stiffens significantly with increasing strain rate. The responses from liver tissues along and perpendicular to the liver surface were consistent, indicating isotropic behavior.

  20. Spatial epidemiology of bovine tuberculosis in Mexico.

    PubMed

    Martínez, Horacio Zendejas; Suazo, Feliciano Milián; Cuador Gil, José Quintín; Bello, Gustavo Cruz; Anaya Escalera, Ana María; Márquez, Gabriel Huitrón; Casanova, Leticia García

    2007-01-01

    The purpose of this study was to use geographic information systems (GIS) and geo-statistical methods of ordinary kriging to predict the prevalence and distribution of bovine tuberculosis (TB) in Jalisco, Mexico. A random sample of 2 287 herds selected from a set of 48 766 was used for the analysis. Spatial location of herds was obtained by either a personal global positioning system (GPS), a database from the Instituto Nacional de Estadìstica Geografìa e Informàtica (INEGI) or Google Earth. Information on TB prevalence was provided by the Jalisco Commission for the Control and Eradication of Tuberculosis (COEETB). Prediction of TB was obtained using ordinary kriging in the geostatistical analyst module in ArcView8. A predicted high prevalence area of TB matching the distribution of dairy cattle was observed. This prediction was in agreement with the prevalence calculated on the total 48 766 herds. Validation was performed taking estimated values of TB prevalence at each municipality, extracted from the kriging surface and then compared with the real prevalence values using a correlation test, giving a value of 0.78, indicating that GIS and kriging are reliable tools for the estimation of TB distribution based on a random sample. This resulted in a significant savings of resources.

  1. Characterization of enterotoxigenic bovine Escherichia coli.

    PubMed Central

    Sivaswamy, G; Gyles, C L

    1976-01-01

    Among 300 isolates of bovine Escherichia coli, 56 which had been found enterotoxigenic in calf gut loops were characterized on the basis of O and K antigens, colonial morphology and resistance to seven antimicrobial drugs. The 56 isolates enterotoxigenic in the calf were compared with the nonenterotoxigenic ones. Of the 56 enterotoxigenic E. coli the majority possessed the A type of K antigen and had OK groups, O9:K(PS274) or O101:K(RVC118). Fourteen of these isolates had the K99 antigen. None of 27 isolates found enterotoxigenic in the piglet but not in the calf possessed the K99 antigen or belonged to OK groups O9:K(PS274) or O101:K(RVC118). Comparison of the patterns of resistance to seven antimicrobial drugs showed that all enterotoxigenic and nonenterotoxigenic isolates were susceptible to nitrofurantoin and sulphachlorphyridiazine and that there was no significant difference in the patterns between the two groups. The majority of enterotoxigenic isolates were mucoid, whereas most of the nonenterotoxigenic isolates were nonmucoid. PMID:793694

  2. Bovine leukocyte adhesion deficiency (BLAD): a review.

    PubMed

    Nagahata, Hajime

    2004-12-01

    Bovine leukocyte adhesion deficiency (BLAD) in Holstein cattle is an autosomal recessive congenital disease characterized by recurrent bacterial infections, delayed wound healing and stunted growth, and is also associated with persistent marked neutrophilia. The molecular basis of BLAD is a single point mutation (adenine to guanine) at position 383 of the CD18 gene, which caused an aspartic acid to glycine substitution at amino acid 128 (D128G) in the adhesion molecule CD18. Neutrophils from BLAD cattle have impaired expression of the beta2 integrin (CD11a,b,c/CD18) of the leukocyte adhesion molecule. Abnormalities in a wide spectrum of adherence dependent functions of leukocytes have been fully characterized. Cattle affected with BLAD have severe ulcers on oral mucous membranes, severe periodontitis, loss of teeth, chronic pneumonia and recurrent or chronic diarrhea. Affected cattle die at an early age due to the infectious complications. Holstein bulls, including carrier sires that had a mutant BLAD gene in heterozygote were controlled from dairy cattle for a decade. The control of BLAD in Holstein cattle by publishing the genotypes and avoiding the mating between BLAD carriers was found to be successful. This paper provides an overview of the genetic disease BLAD with reference to the disease in Holstein cattle.

  3. Bovine enteroviruses as indicators of fecal contamination.

    PubMed

    Ley, Victoria; Higgins, James; Fayer, Ronald

    2002-07-01

    Surface waters frequently have been contaminated with human en