188Re-SSS lipiodol: radiolabelling and biodistribution following injection into the hepatic artery of rats bearing hepatoma.

PubMed

Garin, Etienne; Denizot, Benoit; Noiret, Nicolas; Lepareur, Nicolas; Roux, Jerome; Moreau, Myriam; Herry, Jean-Yves; Bourguet, Patrick; Benoit, Jean-Pierre; Lejeune, Jean-Jacques

2004-10-01

Although intra-arterial radiation therapy with 131I-lipiodol is a useful therapeutic approach to the treatment of hepatocellular carcinoma, various disadvantages limit its use. To describe the development of a method for the labelling of lipiodol with 188Re-SSS (188Re (S2CPh)(S3CPh)2 complex) and to investigate its biodistribution after injection into the hepatic artery of rats with hepatoma. 188Re-SSS lipiodol was obtained after dissolving a chelating agent, previously labelled with 188Re, in cold lipiodol. The radiochemical purity (RCP) of labelling was checked immediately. The 188Re-SSS lipiodol was injected into the hepatic artery of nine rats with a Novikoff hepatoma. They were sacrificed 1, 24 and 48 h after injection, and used for ex vivo counting. Labelling of 188Re-SSS lipiodol was achieved with a yield of 97.3+/-2.1%. The immediate RCP was 94.1+/-1.7%. Ex vivo counting confirmed a predominantly hepatic uptake, with a good tumoral retention of 188Re-SSS lipiodol, a weak pulmonary uptake and a very faint digestive uptake. The 'tumour/non-tumoral liver' ratio was high at 1, 24 and 48 h after injection (2.9+/-1.5, 4.1+/-/4.1 and 4.1+/-0.7, respectively). Using the method described here, 188Re-SSS lipiodol can be obtained with a very high yield and a satisfactory RCP. The biodistribution in rats with hepatoma indicates a good tumoral retention of 188Re-SSS lipiodol associated with a predominant hepatic uptake, a weak pulmonary uptake and a very faint digestive uptake. This product should be considered for intra-arterial radiation therapy in human hepatoma.

The spleen can influence the metastasis of AH130 hepatoma cells in rats.

PubMed

Toyonaga, M; Hiraoka, T; Tanaka, H; Miyauchi, Y

1993-06-01

The effect of pathophysiological conditions due to disturbance of the spleen is still unclear. We studied the effects of splenectomy in normal and methylcellulose-induced hypersplenic rats on the development of pulmonary metastases created by intravenous injection of ascites containing AH130 hepatoma cells from male Hos-Donryu rats. Growth of metastatic lesions in the lung was not affected by splenectomy in normal rats, but was increased by splenectomy in hypersplenic rats. Overall, there were fewer pulmonary metastases in rats with hypersplenism, but after splenectomy rats with hypersplenism had a significantly greater number of metastases than did normal rats. The metastases rate correlated somewhat with changes in the blood coagulation and T lymphocyte profile. There is a relationship between the spleen and formation of metastases in cancer. Formation of metastases in the lung was affected most by splenectomy in hypersplenism. To elucidate the mechanism by which metastases are formed in the lung under these pathologic conditions, further studies on the exact role of the spleen are required.

Perinatal choline deficiency produces abnormal sensory inhibition in Sprague-Dawley rats

PubMed Central

Stevens, Karen E.; Adams, Catherine E.; Mellott, Tiffany J.; Robbins, Emily; Kisley, Michael A.

2008-01-01

Adequate choline levels in rodents during gestation have been shown to be critical to several functions, including certain learning and memory functions, when tested at adulthood. Choline is a selective agonist for the α7 nicotinic receptor which appears in development before acetylcholine is present. Normal sensory inhibition is dependent, in part, upon sufficient numbers of this receptor in the hippocampus. The present study assessed sensory inhibition in Sprague-Dawley rats gestated on normal (1.1 g/kg), deficient (0 g/kg) or supplemented (5 g/kg) choline in the maternal diet during the critical period for cholinergic cell development (E12-18). Rats gestated on deficient choline showed abnormal sensory inhibition when tested at adulthood, while rats gestated on normal or supplemented choline showed normal sensory inhibition. Assessment of hippocampal α-bungarotoxin to visualize nicotinic α7 receptors revealed no difference between the gestational choline levels. These data suggest that attention to maternal choline levels for human pregnancy may be important to the normal functioning of the offspring. PMID:18778692

Perinatal choline deficiency produces abnormal sensory inhibition in Sprague-Dawley rats.

PubMed

Stevens, Karen E; Adams, Catherine E; Mellott, Tiffany J; Robbins, Emily; Kisley, Michael A

2008-10-27

Adequate choline levels in rodents during gestation have been shown to be critical to several functions, including certain learning and memory functions, when tested at adulthood. Choline is a selective agonist for the alpha7 nicotinic receptor which appears in development before acetylcholine is present. Normal sensory inhibition is dependent, in part, upon sufficient numbers of this receptor in the hippocampus. The present study assessed sensory inhibition in Sprague-Dawley rats gestated on normal (1.1 g/kg), deficient (0 g/kg) or supplemented (5 g/kg) choline in the maternal diet during the critical period for cholinergic cell development (E12-18). Rats gestated on deficient choline showed abnormal sensory inhibition when tested at adulthood, while rats gestated on normal or supplemented choline showed normal sensory inhibition. Assessment of hippocampal alpha-bungarotoxin to visualize nicotinic alpha7 receptors revealed no difference between the gestational choline levels. These data suggest that attention to maternal choline levels for human pregnancy may be important to the normal functioning of the offspring.

Functional ET(A)-ET(B) Receptor Cross-talk in Basilar Artery In Situ From ET(B) Receptor Deficient Rats.

PubMed

Yoon, SeongHun; Gariepy, Cheryl E; Yanagisawa, Masashi; Zuccarello, Mario; Rapoport, Robert M

2016-03-01

The role of endothelin (ET)(A)-ET(B) receptor cross-talk in limiting the ET(A) receptor antagonist inhibition of ET-1 constriction is revealed by the partial or complete dependency of the ET(A) receptor antagonist inhibition on functional removal of the ET(B) receptor. Although functional removal of the ET(B) receptor is generally accomplished with ET(B) receptor antagonist, a novel approach using rats containing a naturally occurring deletion mutation in the ET(B) receptor [rescued "spotting lethal" (sl) rats; ET(B)(sl/sl)] demonstrated increased ET(A) receptor antagonist inhibition of ET-1 constriction in vena cava. We investigated whether this deletion mutation was also sufficient to remove the ET(B) receptor dependency of the ET(A) receptor antagonist inhibition of ET-1 constriction in the basilar artery. Consistent with previous reports, ET-1 plasma levels were elevated in ET(B)(sl/sl) as compared with ET(B)(+/+) rats. ET(B) receptor antagonist failed to relax the ET-1 constricted basilar artery from ET(B)(+/+) and ET(B)(sl/sl) rats. Relaxation to combined ET(A) and ET(B) receptor antagonist was greater than relaxation to ET(A) receptor antagonist in the basilar artery from ET(B)(+/+) and, unexpectedly, ET(B)(sl/sl) rats. These findings confirm the presence of ET(A)-ET(B) receptor cross-talk in the basilar artery. We speculate that mutant ET(B) receptor expression produced by alternative splicing may be sufficient to allow cross-talk.

Peroxisome proliferators induce apoptosis in hepatoma cells.

PubMed

Canuto, R A; Muzio, G; Bonelli, G; Maggiora, M; Autelli, R; Barbiero, G; Costelli, P; Brossa, O; Baccino, F M

1998-01-01

In the AH-130 hepatoma, a poorly differentiated tumor, maintained by weekly transplantations in rats, a low percentage of cells spontaneously underwent apoptosis, mainly during the transition from logarithmic- to stationary-growth phase. It was possible to induce massive apoptosis of cells by treating them with clofibrate, a peroxisome proliferator and hypolipidemic drug. Similar results were obtained with HepG2 cells. With 1 mM clofibrate, apoptosis began to manifest itself after 1 h of treatment in vitro, and was assessed by morphological analysis, by DNA fragmentation carried out with agarose gel electrophoresis, and with flow cytometric determination of terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end-labeling. The mechanisms whereby clofibrate induces apoptosis are still unclear. Since the peroxisome proliferator-activated receptor was expressed at a very low level and was not stimulated by clofibrate in the AH-130 hepatoma cells, its involvement seems unlikely. Moreover, lipid peroxidation was not increased after clofibrate treatment. Phospholipids and cholesterol were significantly decreased. The decreased cholesterol content might suggest an inhibition of the mevalonate pathway and, therefore, of isoprenylation of proteins involved in cell proliferation.

Insulin-like growth factor-I stimulates H{sub 4}II rat hepatoma cell proliferation: Dominant role of PI-3'K/Akt signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alexia, Catherine; Fourmatgeat, Pascal; Delautier, Daniele

2006-04-15

Although hepatocytes are the primary source of endocrine IGF-I and -II in mammals, their autocrine/paracrine role in the dysregulation of proliferation and apoptosis during hepatocarcinogenesis and in hepatocarcinomas (HCC) remains to be elucidated. Indeed, IGF-II and type-I IGF receptors are overexpressed in HCC cells, and IGF-I is synthesized in adjacent non-tumoral liver tissue. In the present study, we have investigated the effects of type-I IGF receptor signaling on H{sub 4}II rat hepatoma cell proliferation, as estimated by {sup 3}H-thymidine incorporation into DNA. IGF-I stimulated the rate of DNA synthesis of serum-deprived H{sub 4}II cells, stimulation being maximal 3 h aftermore » the onset of IGF-I treatment and remaining elevated until at least 6 h. The IGF-I-induced increase in DNA replication was abolished by LY294002 and only partially inhibited by PD98059, suggesting that phosphoinositol-3' kinase (PI-3'K) and to a lesser extent MEK/Erk signaling were involved. Furthermore, the 3- to 19-fold activation of the Erks in the presence of LY294002 suggested a down-regulation of the MEK/Erk cascade by PI-3'K signaling. Finally, the effect of IGF-I on DNA replication was almost completely abolished in clones of H{sub 4}II cells expressing a dominant-negative form of Akt but was unaltered by rapamycin treatment of wild-type H{sub 4}II cells. Altogether, these data support the notion that the stimulation of H{sub 4}II rat hepatoma cell proliferation by IGF-I is especially dependent on Akt activation but independent on the Akt/mTOR signal0009i.« less

Adenosine receptors as markers of brain iron deficiency: Implications for Restless Legs Syndrome.

PubMed

Quiroz, César; Gulyani, Seema; Ruiqian, Wan; Bonaventura, Jordi; Cutler, Roy; Pearson, Virginia; Allen, Richard P; Earley, Christopher J; Mattson, Mark P; Ferré, Sergi

2016-12-01

Deficits of sensorimotor integration with periodic limb movements during sleep (PLMS) and hyperarousal and sleep disturbances in Restless Legs Syndrome (RLS) constitute two pathophysiologically distinct but interrelated clinical phenomena, which seem to depend mostly on alterations in dopaminergic and glutamatergic neurotransmission, respectively. Brain iron deficiency is considered as a main pathogenetic mechanism in RLS. Rodents with brain iron deficiency represent a valuable pathophysiological model of RLS, although they do not display motor disturbances. Nevertheless, they develop the main neurochemical dopaminergic changes found in RLS, such as decrease in striatal dopamine D 2 receptor density. On the other hand, brain iron deficient mice exhibit the characteristic pattern of hyperarousal in RLS, providing a tool to find the link between brain iron deficiency and sleep disturbances in RLS. The present study provides evidence for a role of the endogenous sleep-promoting factor adenosine. Three different experimental preparations, long-term (22 weeks) severe or moderate iron-deficient (ID) diets (3- or 7-ppm iron diet) in mice and short-term (3 weeks) severe ID diet (3-ppm iron diet) in rats, demonstrated a significant downregulation (Western blotting in mouse and radioligand binding saturation experiments in rat brain tissue) of adenosine A 1 receptors (A1R) in the cortex and striatum, concomitant to striatal D2R downregulation. On the other hand, the previously reported upregulation of adenosine A 2A receptors (A2AR) was only observed with severe ID in both mice and rats. The results suggest a key role for A1R downregulation in the PLMS and hyperarousal in RLS. Published by Elsevier Ltd.

Effect of intermittent hypoxia on arcuate nucleus in the leptin-deficient rat.

PubMed

Ciriello, John; Moreau, Jason M; McCoy, Aaron; Jones, Douglas L

2016-07-28

Intermittent hypoxia (IH) is a major pathophysiological consequence of obstructive sleep apnea. Recently, it has been shown that IH results in changes in body energy balance, leptin secretion and concomitant alterations in arcuate nucleus (ARC). In this study, the role of leptin on these changes was investigated in leptin-deficient rats exposed to IH or normoxic control conditions. Body weights, consumatory and locomotor behaviours, and protein signaling in ARC were assessed immediately after IH exposure. Compared to normoxia, IH altered body weight, food intake, locomotor pattern, and the plasma concentration of leptin and angiotensin II in the wild-type rat. However, these changes were not observed in the leptin-deficient rat. Within ARC of wild-type animals, IH increased phosphorylated signal transducer and activator of transcription 3 and pro-opiomelanocortin protein expression, but not in the leptin-deficient rat. The long-form leptin receptor protein expression was not altered following IH in either rat strain. These data suggest that leptin is involved in mediating the alterations to body energy balance and ARC activity following IH. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Formation of functional asialoglycoprotein receptor after transfection with cDNAs encoding the receptor proteins.

PubMed Central

McPhaul, M; Berg, P

1986-01-01

The rat asialoglycoprotein receptor (ASGP-R) has been expressed in cultured rat hepatoma cells (HTC cells) after transfection with cloned cDNAs. Fluorescence-activated cell sorting of transfected cells was used to identify the functional cDNA clones and to isolate cells expressing the ASGP-R. Simultaneous or sequential transfections with two cloned cDNAs that encode related but distinctive polypeptide chains were needed to obtain ASGP-R activity; transfection with either cDNA alone failed to produce detectable ASGP-R. The affinity of transduced ASGP-R for asialo orosomucoid is less than that of the native rat ASGP-R, and the number of surface receptors in clones expressing ASGP-R is about one-fifth that found on rat hepatocytes. Images PMID:3466162

Effect of vertical sleeve gastrectomy in melanocortin receptor 4-deficient rats.

PubMed

Mul, Joram D; Begg, Denovan P; Alsters, Suzanne I M; van Haaften, Gijs; Duran, Karen J; D'Alessio, David A; le Roux, Carel W; Woods, Stephen C; Sandoval, Darleen A; Blakemore, Alexandra I F; Cuppen, Edwin; van Haelst, Mieke M; Seeley, Randy J

2012-07-01

Bariatric surgery is currently the most effective treatment for obesity. Vertical sleeve gastrectomy (VSG), a commonly applied bariatric procedure, involves surgically incising most of the volume of the stomach. In humans, partial loss of melanocortin receptor-4 (MC4R) activity is the most common monogenic correlate of obesity regardless of lifestyle. At present it is unclear whether genetic alteration of MC4R signaling modulates the beneficial effects of VSG. Following VSG, we analyzed body weight, food intake, glucose sensitivity, and macronutrient preference of wild-type and MC4R-deficient (Mc4r(+/-) and Mc4r(-/-)) rats compared with sham-operated controls. VSG reduced body weight and fat mass and improved glucose metabolism and also shifted preference toward carbohydrates and away from fat. All of this occurred independently of MC4R activity. In addition, MC4R was resequenced in 46 human subjects who underwent VSG. We observed common genetic variations in the coding sequence of MC4R in five subjects. However, none of those variations appeared to affect the outcome of VSG. Taken together, these data suggest that the beneficial effect of VSG on body weight and glucose metabolism is not mediated by alterations in MC4R activity.

Effect of vertical sleeve gastrectomy in melanocortin receptor 4-deficient rats

PubMed Central

Mul, Joram D.; Begg, Denovan P.; Alsters, Suzanne I. M.; van Haaften, Gijs; Duran, Karen J.; D'Alessio, David A.; le Roux, Carel W.; Woods, Stephen C.; Sandoval, Darleen A.; Blakemore, Alexandra I. F.; Cuppen, Edwin; van Haelst, Mieke M.

2012-01-01

Bariatric surgery is currently the most effective treatment for obesity. Vertical sleeve gastrectomy (VSG), a commonly applied bariatric procedure, involves surgically incising most of the volume of the stomach. In humans, partial loss of melanocortin receptor-4 (MC4R) activity is the most common monogenic correlate of obesity regardless of lifestyle. At present it is unclear whether genetic alteration of MC4R signaling modulates the beneficial effects of VSG. Following VSG, we analyzed body weight, food intake, glucose sensitivity, and macronutrient preference of wild-type and MC4R-deficient (Mc4r+/− and Mc4r−/−) rats compared with sham-operated controls. VSG reduced body weight and fat mass and improved glucose metabolism and also shifted preference toward carbohydrates and away from fat. All of this occurred independently of MC4R activity. In addition, MC4R was resequenced in 46 human subjects who underwent VSG. We observed common genetic variations in the coding sequence of MC4R in five subjects. However, none of those variations appeared to affect the outcome of VSG. Taken together, these data suggest that the beneficial effect of VSG on body weight and glucose metabolism is not mediated by alterations in MC4R activity. PMID:22535749

Carbohydrate metabolism in erythrocytes of copper deficient rats.

PubMed

Brooks, S P J; Cockell, K A; Dawson, B A; Ratnayake, W M N; Lampi, B J; Belonje, B; Black, D B; Plouffe, L J

2003-11-01

Dietary copper deficiency is known to adversely affect the circulatory system of fructose-fed rats. Part of the problem may lie in the effect of copper deficiency on intermediary metabolism. To test this, weanling male Long-Evans rats were fed for 4 or 8 weeks on sucrose-based diets containing low or adequate copper content. Copper deficient rats had significantly lower plasma and tissue copper as well as lower plasma copper, zinc-superoxide dismutase activity. Copper deficient rats also had a significantly higher heart:body weight ratio when compared to pair-fed controls. Direct measurement of glycolysis and pentose phosphate pathway flux in erythrocytes using (13)C NMR showed no differences in carbon flux from glucose or fructose to pyruvate but a significantly higher flux through the lactate dehydrogenase locus in copper deficient rats (approximately 1.3 times, average of glucose and glucose + fructose measurements). Copper-deficient animals had significantly higher erythrocyte concentrations of glucose, fructose, glyceraldehyde 3-phosphate and NAD(+). Liver metabolite levels were also affected by copper deficiency being elevated in glycogen and fructose 1-phosphate content. The results show small changes in carbohydrate metabolism of copper deficient rats.

Developmental vitamin D deficiency alters MK-801-induced behaviours in adult offspring.

PubMed

Kesby, James P; O'Loan, Jonathan C; Alexander, Suzanne; Deng, Chao; Huang, Xu-Feng; McGrath, John J; Eyles, Darryl W; Burne, Thomas H J

2012-04-01

Developmental vitamin D (DVD) deficiency is a candidate risk factor for developing schizophrenia in humans. In rodents DVD deficiency induces subtle changes in the way the brain develops. This early developmental insult leads to select behavioural changes in the adult, such as an enhanced response to amphetamine-induced locomotion in female DVD-deficient rats but not in male DVD-deficient rats and an enhanced locomotor response to the N-methyl-D: -aspartate (NMDA) receptor antagonist, MK-801, in male DVD-deficient rats. However, the response to MK-801-induced locomotion in female DVD-deficient rats is unknown. Therefore, the aim of the current study was to further examine this behavioural finding in male and female rats and assess NMDA receptor density. DVD-deficient Sprague Dawley rats were assessed for locomotion, ataxia, acoustic startle response (ASR) and prepulse inhibition (PPI) of the ASR to multiple doses of MK-801. The NMDA receptor density in relevant brain regions was assessed in a drug-naive cohort. DVD deficiency increased locomotion in response to MK-801 in both sexes. DVD-deficient rats also showed an enhanced ASR compared with control rats, but PPI was normal. Moreover, DVD deficiency decreased NMDA receptor density in the caudate putamen of both sexes. These results suggest that a transient prenatal vitamin D deficiency has a long-lasting effect on NMDA-mediated signalling in the rodent brain and may be a plausible candidate risk factor for schizophrenia and other neuropsychiatric disorders.

Effects of hypoxia-inducible factor-1α silencing on the proliferation of CBRH-7919 hepatoma cells

PubMed Central

Xu, Lin-Feng; Ni, Jia-Yan; Sun, Hong-Liang; Chen, Yao-Ting; Wu, Yu-Dan

2013-01-01

AIM: To study the effects of hypoxia-inducible factor-1α (HIF-1α) silencing on the proliferation of hypoxic CBRH-7919 rat hepatoma cells. METHODS: The CBRH-7919 rat hepatoma cell line was used in this study and the hypoxic model was constructed using CoCl2. The HIF-1α-specific RNAi sequences were designed according to the gene coding sequence of rat HIF-1α obtained from GeneBank. The secondary structure of the HIF-1α gene sequence was analyzed using RNA draw software. The small interfering RNA (siRNA) transfection mixture was produced by mixing the siRNA and Lipofectamine2000TM, and transfected into the hypoxic hepatoma cells. Real time reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting assay were used to detect the expression levels of mRNA and protein. HIF-1α and vascular endothelial growth factor (VEGF) mRNA was determined using real time RT-PCR; the protein expression levels of AKT, p-AKT, p21 and cyclinD1 were determined using Western blotting. The proliferation of hepatoma cells was observed using the methyl thiazolyl tetrazolium (MTT) assay and the bromodeoxyuridine (BrdU) incorporation cell proliferation assay. RESULTS: Under induced hypoxia, the viability of the hepatoma cells reached a minimum at 800 μmol/L CoCl2; the viability of the cells was relatively high at CoCl2 concentrations between 100 μmol/L and 200 μmol/L. Under hypoxia, the mRNA and protein expression levels of HIF-1α and VEGF were significantly higher than that of hepatoma cells that were cultured in normaxia. HIF-1α-specific RNAi sequences were successfully transfected into hepatoma cells. The transfection of specific siRNAs significantly inhibited the mRNA and protein expression levels of HIF-1α and VEGF, along with the protein expression levels of p-AKT and cyclinD1; the protein expression of p21 was significantly increased, and there was no significant difference in the expression of AKT. The MTT assay showed that the amount of hepatoma cells in S

Development of Occlusive Neointimal Lesions in Distal Pulmonary Arteries of Endothelin B Receptor–Deficient Rats: A New Model of Severe Pulmonary Arterial Hypertension

PubMed Central

Ivy, D. Dunbar; McMurtry, Ivan F.; Colvin, Kelley; Imamura, Masatoshi; Oka, Masahiko; Lee, Dong-Seok; Gebb, Sarah; Jones, Peter Lloyd

2007-01-01

Background Human pulmonary arterial hypertension (PAH) is characterized by proliferation of vascular smooth muscle and, in its more severe form, by the development of occlusive neointimal lesions. However, few animal models of pulmonary neointimal proliferation exist, thereby limiting a complete understanding of the pathobiology of PAH. Recent studies of the endothelin (ET) system demonstrate that deficiency of the ETB receptor predisposes adult rats to acute and chronic hypoxic PAH, yet these animals fail to develop neointimal lesions. Herein, we determined and thereafter showed that exposure of ETB receptor–deficient rats to the endothelial toxin monocrotaline (MCT) leads to the development of neointimal lesions that share hallmarks of human PAH. Methods and Results The pulmonary hemodynamic and morphometric effects of 60 mg/kg MCT in control (MCT+/+) and ETB receptor–deficient (MCTsl/sl) rats at 6 weeks of age were assessed. MCTsl/sl rats developed more severe PAH, characterized by elevated pulmonary artery pressure, diminished cardiac output, and right ventricular hypertrophy. In MCTsl/sl rats, morphometric evaluation revealed the presence of neointimal lesions within small distal pulmonary arteries, increased medial wall thickness, and decreased arterial-to-alveolar ratio. In keeping with this, barium angiography revealed diminished distal pulmonary vasculature of MCTsl/sl rat lungs. Cells within neointimal lesions expressed smooth muscle and endothelial cell markers. Moreover, cells within neointimal lesions exhibited increased levels of proliferation and were located in a tissue microenvironment enriched with vascular endothelial growth factor, tenascin-C, and activated matrix metalloproteinase-9, factors already implicated in human PAH. Finally, assessment of steady state mRNA showed that whereas expression of ETB receptors was decreased in MCTsl/sl rat lungs, ETA receptor expression increased. Conclusions Deficiency of the ETB receptor markedly

Hepatic Arterial Infusion of Low-Density Lipoprotein Docosahexaenoic Acid Nanoparticles Selectively Disrupts Redox Balance in Hepatoma cells and Reduces Growth of Orthotopic Liver Tumors in Rats

PubMed Central

Wen, Xiaodong; Reynolds, Lacy; Mulik, Rohit S.; Kim, Soo Young; Van Treuren, Tim; Nguyen, Liem H.; Zhu, Hao; Corbin, Ian R.

2015-01-01

Background & Aims Dietary intake of the natural omega-3 fatty acid docosahexaenoic acid (DHA) has been implicated in protecting patients with viral hepatitis B or C from developing hepatocellular carcinoma (HCC). Little is known about the effects of DHA on established solid tumors. Herein, we describe a low-density lipoprotein (LDL)-based nanoparticle that acts as a transporter for unesterified DHA (LDL–DHA) and demonstrates selective cytotoxicity towards HCC cells. We investigated the ability of LDL–DHA to reduce growth of orthotopic hepatomas in rats. Methods ACI rats were given intrahepatic injections of rat hepatoma cells (H4IIE); 24 tumor-bearing rats (mean tumor diameter, ~1 cm) were subject to a single hepatic artery injection of LDL nanoparticles (2 mg/kg) loaded with DHA (LDL–DHA), triolein (LDL–TO) or sham surgery controls. Tumor growth was measured by magnetic resonance imaging and other methods; tumor, liver and serum samples were collected and assessed by histochemical, immunofluorescence, biochemical and immunoblot analyses. Results Three days after administration of LDL–TO or sham surgery, the control rats had large, highly vascularized tumors that contained proliferating cells. However, rats given LDL–DHA had smaller, pale tumors that were devoid of vascular supply and greater than 80% of the tumor tissue was necrotic. Four to 6 days after injection of LDL–DHA, the tumors were 3-fold smaller than those of control rats. The liver tissue that surrounded the tumors showed no histologic or biochemical evidence of injury. Injection of LDL–DHA into the hepatic artery of rats selectively deregulated redox reactions in tumor tissues by: increasing levels of reactive oxygen species and lipid peroxidation, depleting and oxidizing glutathione and nicotinamide adenine dinucleotide phosphate, and significantly downregulating the antioxidant enzyme glutathione peroxidase-4. Remarkably, the redox balance in the surrounding liver was not disrupted

Hepatic Arterial Infusion of Low-Density Lipoprotein Docosahexaenoic Acid Nanoparticles Selectively Disrupts Redox Balance in Hepatoma Cells and Reduces Growth of Orthotopic Liver Tumors in Rats.

PubMed

Wen, Xiaodong; Reynolds, Lacy; Mulik, Rohit S; Kim, Soo Young; Van Treuren, Tim; Nguyen, Liem H; Zhu, Hao; Corbin, Ian R

2016-02-01

Dietary intake of the natural omega-3 fatty acid docosahexaenoic acid (DHA) has been implicated in protecting patients with viral hepatitis B or C from developing hepatocellular carcinoma (HCC). Little is known about the effects of DHA on established solid tumors. Here we describe a low-density lipoprotein-based nanoparticle that acts as a transporter for unesterified DHA (LDL-DHA) and demonstrates selective cytotoxicity toward HCC cells. We investigated the ability of LDL-DHA to reduce growth of orthotopic hepatomas in rats. AxC-Irish (ACI) rats were given intrahepatic injections of rat hepatoma cells (H4IIE); 24 tumor-bearing rats (mean tumor diameter, ∼1 cm) were subject to a single hepatic artery injection of LDL nanoparticles (2 mg/kg) loaded with DHA (LDL-DHA), triolein (LDL-TO), or sham surgery controls. Tumor growth was measured by magnetic resonance imaging and other methods; tumor, liver, and serum samples were collected and assessed by histochemical, immunofluorescence, biochemical, and immunoblot analyses. Three days after administration of LDL-TO or sham surgery, the control rats had large, highly vascularized tumors that contained proliferating cells. However, rats given LDL-DHA had smaller, pale tumors that were devoid of vascular supply and >80% of the tumor tissue was necrotic. Four to 6 days after injection of LDL-DHA, the tumors were 3-fold smaller than those of control rats. The liver tissue that surrounded the tumors showed no histologic or biochemical evidence of injury. Injection of LDL-DHA into the hepatic artery of rats selectively deregulated redox reactions in tumor tissues by increasing levels of reactive oxygen species and lipid peroxidation, depleting and oxidizing glutathione and nicotinamide adenine dinucleotide phosphate, and significantly down-regulating the antioxidant enzyme glutathione peroxidase-4. Remarkably, the redox balance in the surrounding liver was not disrupted. LDL-DHA nanoparticle selectively kills hepatoma cells

Preliminary Characterization of a Leptin Receptor Knockout Rat Created by CRISPR/Cas9 System.

PubMed

Bao, Dan; Ma, Yuanwu; Zhang, Xu; Guan, Feifei; Chen, Wei; Gao, Kai; Qin, Chuan; Zhang, Lianfeng

2015-11-05

Leptin receptor, which is encoded by the diabetes (db) gene and is highly expressed in the choroid plexus, regulatesenergy homeostasis, the balance between food intake and energy expenditure, fertility and bone mass. Here, using CRISPR/Cas9 technology, we created the leptin receptor knockout rat. Homozygous leptin receptor null rats are characterized by obesity, hyperphagia, hyperglycemia, glucose intolerance, hyperinsulinemia and dyslipidemia. Due to long-term poor glycemic control, the leptin receptor knockout rats also develop some diabetic complications such as pancreatic, hepatic and renal lesions. In addition, the leptin receptor knockout rats show a significant decrease in bone volume and bone mineral density of the femur compared with their wild-type littermates. Our model has rescued some deficiency of the existing rodent models, such as the transient hyperglycemia of db/db mice in the C57BL/6J genetic background and the delayed onset of glucose intolerance in the Zucker rats, and it is proven to be a useful animal model for biomedical and pharmacological research on obesity and diabetes.

Perinatal thiamine deficiency-induced spontaneous abortion and pup-killing responses in rat dams.

PubMed

Bâ, Abdoulaye

2013-03-01

may modulate cAMP/Ca2+ -dependent estradiol-triggered responses which in turn control dopamine synthesis. Consequently, thiamine deficiency induced perinatally triggers pup-killing responses in pregnancy-terminated rats by the following toxic effects: (i) disturbances of estrogen production and/or release affecting dopamine synthesis; (ii) alterations of dopamine inhibition on central oxytocinergic system-related maternal aggressiveness. Likewise, our results indicate also that perinatal thiamine deficiency alone induces spontaneous abortion, reduces litter size, and lowers birth weight, which together suggest changing in the fetoplacental estrogen receptor alpha/progesterone receptor A ratio during gestation, via autocrine/paracrine regulation disturbances. Those hypotheses should be confirmed by further investigations.

Increased PRPP synthetase activity in cultured rat hepatoma cells containing mutations in the hypoxanthine-guanine phosphoribosyltransferase gene.

PubMed

Graf, L H; McRoberts, J A; Harrison, T M; Martin, D W

1976-07-01

Nine independently derived clones of mutagenized rat hepatoma cells selected for resistance to 6-mercaptopurine (6-MP) or 6-thioguanine (6-ThioG) have been isolated. Each has severely reduced catalytic activity of hypoxanthine-guanine phosphoribosyltransferase (HPRT) and seven of them possess significantly increased activities of phosphoribosylpyrophosphate (PRPP) synthetase. The degrees of elevations of PRPP synthetase activities do not correlate with the degrees of deficiencies of HPRT activities. The cells from one of these clones, 1020/12, posses 40% of the normal HPRT catalytic activity and overproduce purines. We have extensively examined the cells from this clone. Immunotration studies of 1020/12 cells indicate that there is a mutation in the structural gene for HPRT. Although they possess increased specific catalytic activities of the enzyme. PRPP synthetase, the catalytic parameters, heat stability, and isoelectric pH of PRPP synthetase from 1020/12 cells are indistinguishable from those of the enzyme from wild-type cells. The cause of purine overproduction by 1020/12 cells appears to be the elevated PRPP synthetase activity, rather than a PRPP "sparing" effect stemming from reduced HPRT activity. Support for this idea is provided by the observation that the complete loss of HPRT activity in a clone derived from 1020/12 cells does not further enhance the levels of PRPP synthetase or purine overproduction. We propose that the elevated levels of PRPP synthetase activity in these HPRT deficient cells result from a mutational event in the structural gene for HPRT, and that this causes the disruption of a previously undescribed regulatory function of this gene on the expression of the PRPP synthetase gene.

Perinatal n-3 fatty acid deficiency selectively reduces myo-inositol levels in the adult rat PFC: an in vivo (1)H-MRS study.

PubMed

McNamara, Robert K; Able, Jessica; Jandacek, Ronald; Rider, Therese; Tso, Patrick; Lindquist, Diana M

2009-03-01

To investigate the effects of omega-3 fatty acid deficiency on phosphatidylinositol signaling in brain, myo-inositol (mI) concentrations were determined in the prefrontal cortex (PFC) of omega-3 fatty acid deficient rats by in vivo proton magnetic resonance spectroscopy ((1)H-MRS). To generate graded deficits in PFC docosahexaenoic acid (22:6n-3) (DHA) composition, perinatal and postweaning alpha-linolenic acid (18:3n-3) (ALA) deficiency models were used. Adult male rats were scanned in a 7T Bruker Biospec system and a (1)H-MRS spectrum acquired from the bilateral medial PFC. Rats were then challenged with SKF83959, a selective agonist at phosphoinositide (PI)-coupled dopamine D(1) receptors. Postmortem PFC fatty acid composition was determined by gas chromatography. Relative to controls, PFC DHA composition was significantly reduced in adult postweaning (-27%) and perinatal (-65%) ALA-deficiency groups. Basal PFC mI concentrations were significantly reduced in the perinatal deficiency group (-21%, P = 0.001), but not in the postweaning deficiency group (-1%, P = 0.86). Among all rats, DHA composition was positively correlated with mI concentrations and the mI/creatine (Cr) ratio. SKF83959 challenge significantly increased mI concentrations only in the perinatal deficiency group (+16%, P = 0.02). These data demonstrate that perinatal deficits in cortical DHA accrual significantly and selectively reduce mI concentrations and augment receptor-generated mI synthesis.

Inflammation protects copper deficient rats from carbon tetrachloride toxicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yang, F.L.; Joseph, E.; DiSilvestro, R.A.

1991-03-11

Copper deficient rats show low resistance to CCl{sub 4}, possibly due to low liver Cu-Zn superoxide dismutase (SOD) activities. If Cu-Zn SOD is involved, deficiency effects should be aggravated by inflammation which further lowers Cu-Zn SOD activities in deficient rats. On the contrary, inflammation from 0.1 ml turpentine (im, lef) protected these rats from CCl{sub 4} damage assessed by serum activities of 2 liver enzymes. CCl{sub 4} was given ip at 200 {mu}l/kg, 48 h after turpentine, 24 h before sacrifice. Rats were fed low copper for 40 days before CCl{sub 4} challenge. Inflammation also protected rats fed adequate coppermore » from injury, though injury in noninflamed rats was less than with noninflamed deficients. Protection could result from the large increase observed in liver metallothionein, an induction not restricted by copper deficiency. Alternatively, inflammation may block P-450 activation of CCl{sub 4}. Both explanations are currently under investigation, as is the role, if any, of Cu-Zn SOD in resisting CCl{sub 4} injury.« less

Alterations in the lipid metabolism of rat aorta: effects of vitamin a deficiency.

PubMed

Gatica, Laura V; Vega, Verónica A; Zirulnik, Fanny; Oliveros, Liliana B; Gimenez, María S

2006-01-01

Antioxidants are known to reduce cardiovascular disease by reducing the concentration of free radicals in the vessel wall and by preventing the oxidative modification of low-density lipoproteins. The prooxidative effect of a vitamin-A-deficient diet on the aorta has previously been demonstrated by us. In this study, the lipid metabolism in the aorta of rats fed on a vitamin-A-deficient diet was evaluated. Vitamin A deficiency induced a hypolipidemic effect (lower serum triglyceride and cholesterol levels) and a decreased serum paraoxonase 1/arylesterase activity. The concentrations of triglycerides, total cholesterol, free and esterified cholesterol, and phospholipids were increased in the aorta of vitamin-A-deficient rats. The phospholipid compositions showed an increase in phosphatidylcholine (PC), phosphatidylinositol plus phosphatidylserine and phosphatidylethanolamine, a decrease in sphingomyelin, and no change in phosphatidylglycerol. In the aorta, the increase in triglycerides was associated with an increased fatty acid synthesis and mRNA expression of diacylglycerol acyltransferase 1. The increased PC content was attributed to an increased synthesis, as measured by [methyl-(14)C]choline incorporation into PC and high CTP:phosphocholine cytidylyltransferase-alpha mRNA expression. The cholesterol synthesis, evaluated by [1-(14)C]acetate incorporated into cholesterol and mRNA expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase, did not change. The lipoprotein lipase and lectin-like oxidized low-density lipoprotein receptor 1 mRNA expression levels increased in the aorta of vitamin-A-deficient animals. The incorporation of vitamin A into the diet of vitamin-A-deficient rats reverted all the changes observed. These results indicate that a vitamin-A-deficient diet,in addition to having a prooxidative effect, alters the aorta lipid metabolism.

Enhanced antitumor efficacy on hepatoma-bearing rats with adriamycin-loaded nanoparticles administered into hepatic artery.

PubMed

Chen, Jiang-Hao; Ling, Rui; Yao, Qing; Wang, Ling; Ma, Zhong; Li, Yu; Wang, Zhe; Xu, Hu

2004-07-01

To investigate the antitumor activity of adriamycin (ADR) encapsulated in nanoparticles (NADR) and injected into the hepatic artery of hepatoma-bearing rats. NADR was prepared by the interfacial polymerization method. Walker-256 carcinosarcomas were surgically implanted into the left liver lobes of 60 male Wistar rats, which were divided into 4 groups at random (15 rats per group). On the 7th day after implantation, normal saline (NS), free ADR (FADR), NADR, or ADR mixed with unloaded nanoparticles (ADR+NP) was respectively injected via the hepatic artery (i.a.) of rats in different groups. The dose of ADR in each formulation was 2.0 mg/kg body weight and the concentration was 1.0 mg/mL. Survival time, tumor enlargement ratio, and tumor necrosis degree were compared between each group. Compared with the rats that received NS i.a., the rats that received FADR or ADR+NP acquired apparent inhibition on tumor growth, as well as prolonged their life span. Further significant anticancer efficacy was observed in rats that received i.a. administration of NADR. Statistics indicated that NADR brought on a more significant tumor inhibition and more extensive tumor necrosis, as compared to FADR or ADR+NP. The mean tumor enlargement ratio on the 7th day after NADR i.a. was 1.106. The mean tumor-bearing survival time was 39.50 days. Prolonged life span ratio was 109.22% as compared with rats that accepted NS. Therapeutic effect of ADR on liver malignancy can be significantly enhanced by its nanopaticle formulation and administration via hepatic artery.

Prevention of anemia alleviates heart hypertrophy in copper deficient rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lure, M.D.; Fields, M.; Lewis, C.G.

1991-03-11

The present investigation was designed to examine the role of anemia in the cardiomegaly and myocardial pathology of copper deficiency. Weanling rats were fed a copper deficient diet containing either starch (ST) or fructose (FRU) for five weeks. Six rats consuming the FRU diet were intraperitoneally injected once a week with 1.0 ml/100g bw of packed red blood cells (RBC) obtained from copper deficient rats fed ST. FRU rats injected with RBC did not develop anemia. Additionally, none of the injected rats exhibited heart hypertrophy or gross pathology and all survived. In contrast, non-injected FRU rats were anemic, exhibited severemore » signs of copper deficiency which include heart hypertrophy with gross pathology, and 44% died. Maintaining the hematocrit with RBC injections resulted in normal heart histology and prevented the mortality associated with the fructose x copper interaction. The finding suggest that the anemia associated with copper deficiency contributes to heart pathology.« less

Essential fatty acid deficiency delays the onset of puberty in the female rat.

PubMed

Smith, S S; Neuringer, M; Ojeda, S R

1989-09-01

This study assessed the effect of a dietary deficiency in the essential fatty acids (EFA) linoleic and linolenic acids on the onset of female puberty. EFA deficiency was produced in female rats by means of a semipurified diet and was biochemically documented by analyzing serum and erythrocyte fatty acid levels of more than 30 fatty acids, including all members of the n-6 and n-3 series. Levels of linoleic acid (18:2 n-6) and all n-6 derivatives, particularly arachidonic acid, were strikingly reduced. A less pronounced but clear-cut decrease in n-3 fatty acids, including docosahexaenoic acid (22:6 n-3) was also found. The times of puberty and first ovulation, as assessed by the ages at vaginal opening and first diestrus, were significantly delayed in EFA-deficient rats. The mechanisms underlying this delay appear to reside at both hypothalamic and ovarian sites. Simulation of preovulatory plasma estradiol (E2) levels via implantation of E2-containing Silastic capsules evoked a LH surge 30 h later in control juvenile rats, but not in EFA-deficient animals, indicating a delay in the development of the hypothalamic component of E2-positive feedback in the latter group. This delay appears to be due at least in part to reduced prostaglandin E2 (PGE2) synthesis, as the ability of the neurotransmitter norepinephrine to induce PGE2 release from median eminence nerve terminals was markedly reduced in EFA-deficient rats compared with that in controls. The decrease in hypothalamic PGE2 release was related to the EFA deficiency and not to reduced PG synthase activity, as determined by HPLC analysis of PG synthase products derived from exogenous [14C]arachidonic acid. Basal and hCG-stimulated PGE2 synthesis was also compromised in ovaries from EFA-deficient rats. Depressed gonadal function resulting from the EFA deficiency was further evidenced by a reduced gonadotropin receptor content, a blunted E2 response to hCG in vitro, and an increase in mean serum FSH levels. These

Phencyclidine-induced social withdrawal results from deficient stimulation of cannabinoid CB₁ receptors: implications for schizophrenia.

PubMed

Seillier, Alexandre; Martinez, Alex A; Giuffrida, Andrea

2013-08-01

The neuronal mechanisms underlying social withdrawal, one of the core negative symptoms of schizophrenia, are not well understood. Recent studies suggest an involvement of the endocannabinoid system in the pathophysiology of schizophrenia and, in particular, of negative symptoms. We used biochemical, pharmacological, and behavioral approaches to investigate the role played by the endocannabinoid system in social withdrawal induced by sub-chronic administration of phencyclidine (PCP). Pharmacological enhancement of endocannabinoid levels via systemic administration of URB597, an inhibitor of endocannabinoid degradation, reversed social withdrawal in PCP-treated rats via stimulation of CB1 receptors, but reduced social interaction in control animals through activation of a cannabinoid/vanilloid-sensitive receptor. In addition, the potent CB agonist CP55,940 reversed PCP-induced social withdrawal in a CB₁-dependent manner, whereas pharmacological blockade of CB₁ receptors by either AM251 or SR141716 reduced the time spent in social interaction in control animals. PCP-induced social withdrawal was accompanied by a decrease of anandamide (AEA) levels in the amygdala and prefrontal cortex, and these deficits were reversed by URB597. As CB₁ receptors are predominantly expressed on GABAergic interneurons containing the anxiogenic peptide cholecystokinin (CCK), we also examined whether the PCP-induced social withdrawal resulted from deficient CB₁-mediated modulation of CCK transmission. The selective CCK2 antagonist LY225910 blocked both PCP- and AM251-induced social withdrawal, but not URB597 effect in control rats. Taken together, these findings indicate that AEA-mediated activation of CB₁ receptors is crucial for social interaction, and that PCP-induced social withdrawal results from deficient endocannabinoid transmission.

Adiposity profile in the dwarf rat: an unusually lean model of profound growth hormone deficiency.

PubMed

Davies, Jeffrey S; Gevers, Evelien F; Stevenson, Amy E; Coschigano, Karen T; El-Kasti, Muna M; Bull, Melanie J; Elford, Carole; Evans, Bronwen A J; Kopchick, John J; Wells, Timothy

2007-05-01

This study describes the previously uncharacterized ontogeny and regulation of truncal adipose reserves in the profoundly GH-deficient dwarf (dw/dw) rat. We show that, despite normal proportionate food intake, dw/dw rats develop abdominal leanness and hypoleptinemia (circulating leptin halved in dw/dw males, P < 0.05) during puberty. This contrasts with the hyperleptinemia seen in moderately GH-deficient Tgr rats (circulating leptin doubled at 6 wk of age, P < 0.05) and in GH receptor-binding protein (GHR/BP)-null mice (circulating leptin doubled; P < 0.05). This lean/hypoleptinemic phenotype was not completely normalized by GH treatment, but dw/dw rats developed abdominal obesity in response to neonatal MSG treatment or maintenance on a high-fat diet. Unlike Tgr rats, dw/dw rats did not become obese with age; plasma leptin levels and fat pad weights became similar to those in wild-type rats. In contrast with truncal leanness, tibial marrow adiposity was normal in male and doubled in female dwarves (P < 0.01), this increase being attributable to increased adipocyte number (P < 0.01). Neonatal MSG treatment and high-fat feeding elevated marrow adiposity in dw/dw rats by inducing adipocyte enlargement (P < 0.05). These results demonstrate that, despite lipolytic influence of GH, severe GH deficiency in dw/dw rats is accompanied by a paradoxical leanness. This lean/hypoleptinemic phenotype is not solely attributable to reduced GH signaling and does not appear to result from a reduction in nutrient intake or the ability of dw/dw adipocytes to accumulate lipid. Disruption of preadipocyte differentiation or adipocyte proliferation in the dw/dw rat may lead to the development of this unusually lean/hypoleptinemic phenotype.

Hepatocyte transplantation for enzyme deficiency disease in congenic rats.

PubMed

Vroemen, J P; Buurman, W A; Heirwegh, K P; van der Linden, C J; Kootstra, G

1986-08-01

Long-term effects of hepatocyte transplantation (HTX) in the treatment of enzyme deficiency disease were studied. Congenic enzyme-deficient (R/APfd-j/j) and non-enzyme-deficient (R/APfd) rats were used as recipients and donors, respectively. The R/APfd-j/j rat strain is congenitally deficient of bilirubin uridyldiphosphate (UDP)-glucuronyl transferase. R/APfd-j/j rats underwent HTX by intrasplenic injection of 10(7) isolated R/APfd hepatocytes (group 1A). Another group of R/APfd-j/j rats was treated similarly, but underwent splenectomy after 11 weeks (group 1B). Controls consisted of R/APfd-j/j rats grafted with 10(7) R/APfd-j/j hepatocytes (group 2), and R/APfd-j/j rats that underwent a sham operation (group 3). Total plasma bilirubin (TB) levels were significantly reduced in groups 1A and 1B during the experiment (both P less than 0.01). In the control groups TB reduction was not observed. Bile analyses at 30 weeks after HTX showed that in group 1A 13.7 +/- 2.7% of total biliary bilirubin was conjugated. In group 1B a significantly lower fraction was conjugated: 6.6 +/- 1.1% (P less than 0.05). Conjugated bilirubin was not found in bile of groups 2 and 3. Histology showed survival of hepatocytes in all spleens of rats of groups 1A, 1B and 2. It is concluded that congenic hepatocytes from R/APfd donors are not rejected after transplantation into the R/APfd-j/j rat, and maintain long-term function. Splenectomy does not abolish, but does reduce, the therapeutic effect significantly, indicating that part of the transplanted hepatocytes maintains function in the enzyme-deficient host liver. The congenic R/APfd-j/j and R/APfd rat strains represent a new animal model for research in metabolic deficiency disease.

Evaluating the potential of (188)Re-ECD/lipiodol as a therapeutic radiopharmaceutical by intratumoral injection for hepatoma treatment.

PubMed

Luo, Tsai-Yueh; Shih, Ying-Hsia; Chen, Chiung-Yu; Tang, I-Chung; Wu, Yu-Long; Kung, Hong-Chang; Lin, Wuu-Jyh; Lin, Xi-Zhang

2009-10-01

Intratumoral injection of a radiopharmaceutical is a potential modality to treat liver tumors. Rhenium-188 ((188)Re) was used to chelate with ethyl cysteinate dimer (ECD) in lipiodol solution to form (188)Re-ECD/lipiodol, which was then evaluated for its therapeutic potential in a rodent hepatoma model. Male Sprague-Dawley rats were implanted with N1-S1 hepatoma cells orthotopically and randomly divided into two groups. Group 1 (n = 29) and group 2 (n = 10) received (188)Re-ECD/lipiodol (30.4 +/- 21.8 MBq/0.1 mL) and 0.1 mL of normal saline by intratumoral injection, respectively. Three rats in group 1 were imaged by micro-single-photon emission computed tomography/computed tomography scan to evaluate the biodistribution pattern. All rats were monitored for change of tumor size and survival rate after 2 months. The in vitro stability test showed that (188)Re-ECD was well-retained in the lipiodol phase for 48 hours. The biodistribution image revealed that radioactivity was retained well in hepatomas 24 hours postinjection. Long-term studies demonstrated that rats treated with (188)Re-ECD/Lipiodol had smaller tumor volumes and a better survival rate, compared to the control group. At the end of observation, the survival rates in groups 1 and 2 were 62% and 20%, respectively (p < 0.05). (188)Re-ECD/lipiodol via direct intratumoral injection shows potential for treating hepatoma and warrants further clinical trials.

[Effect of Acaí (Euterpe oleracea) on biological expression characteristics of deficiency-heat and deficiency-cold rats].

PubMed

Wang, Lin-Yuan; Zhang, Jian-Jun; Wang, Chun; Zhu, Ying-Li; Wang, Zi-Chen; He, Cheng; Qu, Yan; Wang, Sha

2016-10-01

To study the effects of Acaí on biological expression characteristics in rats with deficiency-heat and deficiency-cold syndromes, SD rats were divided into blank group, deficiency-heat model group, deficiency-heat+Phellodendri Chinensis Cortex group, deficiency-heat+Acaí high dose and low dose groups, deficiency-cold model group, deficiency-cold+Cinnamomi Cortex group, deficiency-cold+Acaí high dose and low dose groups. The rats were treated with intramuscular injection of hydrocortisone (20 mg•kg⁻¹) or dexamethasone sodium phosphate (0.35 mg•kg⁻¹) for 21 days to set up deficiency-heat model and deficiency-cold models. The levels of cAMP, cGMP, T3, T4 and rT3 were detected by radioimmunoassay. The levels of TP, UA, TC, TG and ALB were detected by colorimetry. The level of cAMP, cAMP/cGMP in serum were reduced in Acaí high dose group (P<0.05, P<0.001). The levels of T3, T4 and rT3 were significantly reduced in the Acaí high dose group (P<0.01, P<0.001, P<0.05). The levels of TP, UA, TC, TG and ALB were significantly reduced in the Acaí high dose group (P<0.001, P<0.05, P<0.05, P<0.05, P<0.01). However, Acaí had no obvious effects on deficiency-cold models. Acaí showed the same effect with Phellodendri Chinensis Cortex in adjusting the levels of deficiency-heat rats; but unlike Cinnamomi Cortex, Acaí showed no obvious effects in adjusting the levels of deficiency-cold rats. Copyright© by the Chinese Pharmaceutical Association.

Noni leaf and black tea enhance bone regeneration in estrogen-deficient rats.

PubMed

Shalan, Nor Aijratul Asikin Mohd; Mustapha, Noordin M; Mohamed, Suhaila

2017-01-01

Black tea and Nonileaf are among the dietary compounds that can benefit patients with bone resorption disorders. Their bone regeneration effects and their mechanisms were studied in estrogen-deficient rats. Noni leaves (three doses) and black tea water extracts were fed to ovariectomized rats for 4 mo, and their effects (analyzed via mechanical measurements, micro-computed tomography scan, and reverse transcriptase polymerase chain reaction mRNA) were compared with Remifemin (a commercial phytoestrogen product from black cohosh). The water extracts (dose-dependently for noni leaves) increased bone regeneration biomarker (runt-related transcription factor 2, bone morphogenetic protein 2, osteoprotegerin, estrogen receptor 1 [ESR1], collagen type I alpha 1A) expressions and reduced the inflammatory biomarkers (interleukin-6, tumor necrosis factor-α, nuclear factor [NF]-κB, and receptor activator of NF-κB ligand) mRNA expressions/levels in the rats. The extracts also improved bone physical and mechanical properties. The extracts demonstrated bone regeneration through improving bone size and structure, bone mechanical properties (strength and flexibility), and bone mineralization and density. The catechin-rich extract favored bone regeneration and suppressed bone resorption. The mechanisms involved enhancing osteoblast generation and survival, inhibiting osteoclast growth and activities, suppressing inflammation, improving bone collagen synthesis and upregulating ESR1 expression to augment phytoestrogenic effects. Estrogen deficiency bone loss and all extracts studied (best effect from Morinda leaf at 300 mg/kg body weight) mitigated the loss, indicating benefits for the aged and menopausal women. Copyright © 2016 Elsevier Inc. All rights reserved.

Activation of the ATP-ubiquitin-proteasome pathway in skeletal muscle of cachectic rats bearing a hepatoma

NASA Technical Reports Server (NTRS)

Baracos, V. E.; DeVivo, C.; Hoyle, D. H.; Goldberg, A. L.

1995-01-01

Rats implanted with Yoshida ascites hepatoma (YAH) show a rapid and selective loss of muscle protein due mainly to a marked increase (63-95%) in the rate of protein degradation (compared with rates in muscles of pair-fed controls). To define which proteolytic pathways contribute to this increase, epitrochlearis muscles from YAH-bearing and control rats were incubated under conditions that modify different proteolytic systems. Overall proteolysis in either group of rats was not affected by removal of Ca2+ or by blocking the Ca(2+)-dependent proteolytic system. Inhibition of lysosomal function with methylamine reduced proteolysis (-12%) in muscles from YAH-bearing rats, but not in muscles of pair-fed rats. When ATP production was also inhibited, the remaining accelerated proteolysis in muscles of tumor-bearing rats fell to control levels. Muscles of YAH-bearing rats showed increased levels of ubiquitin-conjugated proteins and a 27-kDa proteasome subunit in Western blot analysis. Levels of mRNA encoding components of proteolytic systems were quantitated using Northern hybridization analysis. Although their total RNA content decreased 20-38%, pale muscles of YAH-bearing rats showed increased levels of ubiquitin mRNA (590-880%) and mRNA for multiple subunits of the proteasome (100-215%). Liver, kidney, heart, and brain showed no weight loss and no change in these mRNA species. Muscles of YAH-bearing rats also showed small increases (30-40%) in mRNA for cathepsins B and D, but not for calpain I or heat shock protein 70. Our findings suggest that accelerated muscle proteolysis and muscle wasting in tumor-bearing rats result primarily from activation of the ATP-dependent pathway involving ubiquitin and the proteasome.

Response of the iron-deficient erythrocyte in the rat to hyperoxia

NASA Technical Reports Server (NTRS)

Larkin, E. C.; Kimzey, S. L.; Siler, K.

1978-01-01

Normal and iron-deficient rats were exposed to 90% O2 at 760 Torr for 24 or 48 h. Erythrocyte response to hyperoxia was monitored by potassium (rubidium) influx studies, by storage stress, and by ultrastructural studies. Normal rat erythrocytes exhibited morphological changes and decrease of ouabain-sensitive potassium influx compared to unexposed controls. Both components of erythrocyte potassium influx were affected by iron deficiency. Erythrocytes from unexposed iron-deficient rats showed a 50% increase in ouabain-sensitive potassium influx compared to controls. Iron-deficient rats exposed to hyperoxia for 24 or 48 h, had erythrocytes with morphological changes. Erythrocytes of iron-deficient rats exposed for 24 h showned no influx change; those exposed for 48 h showed a decrease of ouabain-sensitive influx compared to erythrocytes of controls.

Species-specific differences in peroxisome proliferation, catalase, and SOD2 upregulation as well as toxicity in human, mouse, and rat hepatoma cells induced by the explosive and environmental pollutant 2,4,6-trinitrotoluene.

PubMed

Naumenko, Ekaterina Anatolevna; Ahlemeyer, Barbara; Baumgart-Vogt, Eveline

2017-03-01

2,4,6-Trinitrotoluene (TNT) has been widely used as an explosive substance and its toxicity is still of interest as it persisted in polluted areas. TNT is metabolized in hepatocytes which are prone to its toxicity. Since analysis of the human liver or hepatocytes is restricted due to ethical reasons, we investigated the effects of TNT on cell viability, reactive oxygen species (ROS) production, peroxisome proliferation, and antioxidative enzymes in human (HepG2), mouse (Hepa 1-6), and rat (H4IIEC3) hepatoma cell lines. Under control conditions, hepatoma cells of all three species were highly comparable exhibiting identical proliferation rates and distribution of their cell cycle phases. However, we found strong differences in TNT toxicity with the lowest IC 50 values (highest cell death rate) for rat cells, whereas human and mouse cells were three to sevenfold less sensitive. Moreover, a strong decrease in cellular dehydrogenase activity (MTT assay) and increased ROS levels were noted. TNT caused peroxisome proliferation with rat hepatoma cells being most responsive followed by those from mouse and human. Under control conditions, rat cells contained fivefold higher peroxisomal catalase and mitochondrial SOD2 activities and a twofold higher capacity to reduce MTT than human and mouse cells. TNT treatment caused an increase in catalase and SOD2 mRNA and protein levels in human and mouse, but not in rat cells. Similarly, human and mouse cells upregulated SOD2 activity, whereas rat cells failed therein. We conclude that TNT induced oxidative stress, peroxisome proliferation and mitochondrial damage which are highest in rat cells rendering them most susceptible toward TNT. © 2016 Wiley Periodicals, Inc. Environ Toxicol 32: 989-1006, 2017. © 2016 Wiley Periodicals, Inc.

Beer improves copper metabolism and increases longevity in Cu-deficient rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, R.J.; Klevay, L.M.

Moderate consumption of alcoholic beverages decreases risk of death from ischemic heart disease (IHD). Evidence suggests that Cu-deficiency is important in the etiology and pathophysiology of IHD. The effect of beer (25 ng Cu/ml) drinking on the severity of Cu-deficiency was examined in weanling, male Sprague-Dawley rats fed a low Cu diet (0.84 {mu}g Cu/g). Beer drinking increased median longevity to 204 or 299 d from 62 or 42 d respectively in rats drinking water in two experiments (15 rats/group). In experiment 3, a single dose of {sup 67}Cu (3.3 {mu}Ci as chloride) was added to 1 g of feedmore » and given to 12-h fasted rats 30 d after the start of the experiment. Whole body counting over 13 d showed apparent Cu absorption and t{sub {1/2}} (biological) were greater in Cu-deficient rats drinking beer than in similar rats drinking water. Plasma cholesterol was lower but hematocrit and liver Cu were higher in surviving rats drinking beer than in rats drinking water. Body weight was not affected by beer in any experiment. In experiment 4, a 4% aqueous ethanol solution had no effect on longevity of copper deficient rats. A non-alcohol component of beer alters Cu metabolism and mitigates the severity of nutritional Cu-deficiency in rats.« less

Iron deficiency and iron excess damage mitochondria and mitochondrial DNA in rats

PubMed Central

Walter, Patrick B.; Knutson, Mitchell D.; Paler-Martinez, Andres; Lee, Sonia; Xu, Yu; Viteri, Fernando E.; Ames, Bruce N.

2002-01-01

Approximately two billion people, mainly women and children, are iron deficient. Two studies examined the effects of iron deficiency and supplementation on rats. In study 1, mitochondrial functional parameters and mitochondrial DNA (mtDNA) damage were assayed in iron-deficient (≤5 μg/day) and iron-normal (800 μg/day) rats and in both groups after daily high-iron supplementation (8,000 μg/day) for 34 days. This dose is equivalent to the daily dose commonly given to iron-deficient humans. Iron-deficient rats had lower liver mitochondrial respiratory control ratios and increased levels of oxidants in polymorphonuclear-leukocytes, as assayed by dichlorofluorescein (P < 0.05). Rhodamine 123 fluorescence of polymorphonuclear-leukocytes also increased (P < 0.05). Lowered respiratory control ratios were found in daily high-iron-supplemented rats regardless of the previous iron status (P < 0.05). mtDNA damage was observed in both iron-deficient rats and rats receiving daily high-iron supplementation, compared with iron-normal rats (P < 0.05). Study 2 compared iron-deficient rats given high doses of iron (8,000 μg) either daily or every third day and found that rats given iron supplements every third day had less mtDNA damage on the second and third day after the last dose compared to daily high iron doses. Both inadequate and excessive iron (10 × nutritional need) cause significant mitochondrial malfunction. Although excess iron has been known to cause oxidative damage, the observation of oxidant-induced damage to mitochondria from iron deficiency has been unrecognized previously. Untreated iron deficiency, as well as excessive-iron supplementation, are deleterious and emphasize the importance of maintaining optimal iron intake. PMID:11854522

Ascorbic acid deficiency aggravates stress-induced gastric mucosal lesions in genetically scorbutic ODS rats.

PubMed

Ohta, Y; Chiba, S; Imai, Y; Kamiya, Y; Arisawa, T; Kitagawa, A

2006-12-01

We examined whether ascorbic acid (AA) deficiency aggravates water immersion restraint stress (WIRS)-induced gastric mucosal lesions in genetically scorbutic ODS rats. ODS rats received scorbutic diet with either distilled water containing AA (1 g/l) or distilled water for 2 weeks. AA-deficient rats had 12% of gastric mucosal AA content in AA-sufficient rats. AA-deficient rats showed more severe gastric mucosal lesions than AA-sufficient rats at 1, 3 or 6 h after the onset of WIRS, although AA-deficient rats had a slight decrease in gastric mucosal AA content, while AA-sufficient rats had a large decrease in that content. AA-deficient rats had more decreased gastric mucosal nonprotein SH and vitamin E contents and increased gastric mucosal lipid peroxide content than AA-sufficient rats at 1, 3 or 6 h of WIRS. These results indicate that AA deficiency aggravates WIRS-induced gastric mucosal lesions in ODS rats by enhancing oxidative damage in the gastric mucosa.

Spontaneous apoptosis in a rat hepatoma cell line and its inhibition by dexamethasone.

PubMed

Chaya, D; Fougère-Deschatrette, C; Weiss, M C

1996-01-01

Cultures of dedifferentiated rat hepatoma Rab1-5-1 cells exhibit spontaneously a high level of mortality during the exponential growth phase. We demonstrate that these cells die by apoptosis, showing chromatin condensation and internucleosomal DNA fragmentation. Cells of the original H4II cell line and of its differentiated and dedifferentiated derivatives also die by apoptosis, but only in heavily confluent cultures. We evaluated mortality with time in Rab1-5-1 cultures by establishing growth curves, including quantification of floating cells, and conclude that up to half of the cells in a culture are lost to apoptosis. The production of apoptotic cells is abolished by the presence of 10(-6) M dexamethasone and this inhibition is reversible in 48 hours. Rab1-5-1 cells that spontaneously die by apoptosis with high frequency represent a novel model to investigate factors that regulate the spontaneous frequency of death, and to study the nature and the kinetics of commitment to the apoptotic pathway.

Leptin receptor-deficient obese Zucker rats reduce their food intake in response to a systemic supply of calories from glucose.

PubMed

Gilbert, Marc; Magnan, Christophe; Turban, Sophie; André, Jocelyne; Guerre-Millo, Michèle

2003-02-01

It has been established that leptin exerts a negative control on food intake, allowing one to maintain stable caloric intake over time. The aim of the present study was to investigate whether leptin regulates food intake when a supply of calories is provided by the systemic route. Experiments were carried out in leptin receptor-deficient obese fa/fa rats and lean Fa/fa controls. In both groups, 48 h of glucose infusion reduced food intake in proportion to caloric supply, resulting in virtually no change in total caloric intake as compared to before the infusion. This hypophagic response was reproduced without adding systemic calories, but by increasing glucose and insulin concentrations specifically in the brain through carotid artery infusion. Concomitant intracerebroventricular administration of 5-(tetradecyloxy)-2-furoic acid, an acetyl CoA carboxylase inhibitor that precludes malonyl-CoA synthesis, abolished the restriction of feeding in carotid-infused lean and obese rats. These data indicate that a supply of calories via glucose infusion induces a hypophagic response independent of leptin signaling in the rat, and support the hypothesis that a rise in central malonyl-CoA, triggered by increased glucose and insulin concentrations, participates in this adaptation. This process could contribute to the limiting of hyperphagia, primarily when leptin signaling is altered, as in the obese state.

Minimum Selenium Requirements Increase When Repleting Second-Generation Selenium-Deficient Rats but Are Not Further Altered by Vitamin E Deficiency.

PubMed

Sunde, Roger A; Thompson, Kevin M; Fritsche, Kevin L; Evenson, Jacqueline K

2017-05-01

Second-generation selenium-deficient weanling rats fed graded levels of dietary Se were used (a) to study the impact of initial Se deficiency on dietary Se requirements; (b) to determine if further decreases in selenoperoxidase expression, especially glutathione peroxidase 4 (Gpx4), affect growth or gross disease; and (c) to examine the impact of vitamin E deficiency on biochemical and molecular biomarkers of Se status. Rats were fed a vitamin E-deficient and Se-deficient crystalline amino acid diet (3 ng Se/g diet) or that diet supplemented with 100 μg/g all-rac-α-tocopheryl acetate and/or 0, 0.02, 0.05, 0.075, 0.1, or 0.2 μg Se/g diet as Na 2 SeO 3 for 28 days. Se-supplemented rats grew 6.91 g/day as compared to 2.17 and 3.87 g/day for vitamin E-deficient/Se-deficient and vitamin E-supplemented/Se-deficient groups, respectively. In Se-deficient rats, liver Se, plasma Gpx3, red blood cell Gpx1, liver Gpx1 and Gpx4 activities, and liver Gpx1 mRNA levels decreased to <1, <1, 21, 1.6, 49, and 11 %, respectively, of levels in rats fed 0.2 μg Se/g diet. For all biomarkers, ANOVA indicated significant effects of dietary Se, but no significant effects of vitamin E or vitamin E × Se interaction, showing that vitamin E deficiency, even in severely Se-deficient rat pups, does not result in compensatory changes in these biochemical and molecular biomarkers of selenoprotein expression. Se requirements determined in this study, however, were >50 % higher than in previous studies that started with Se-adequate rats, demonstrating that dietary Se requirements determined using initially Se-deficient animals can result in overestimation of Se requirements.

Vitamin A Deficiency Induces Congenital Spinal Deformities in Rats

PubMed Central

Li, Zheng; Shen, Jianxiong; Wu, William Ka Kei; Wang, Xiaojuan; Liang, Jinqian; Qiu, Guixing; Liu, Jiaming

2012-01-01

Most cases of congenital spinal deformities were sporadic and without strong evidence of heritability. The etiology of congenital spinal deformities is still elusive and assumed to be multi-factorial. The current study seeks to elucidate the effect of maternal vitamin A deficiency and the production of congenital spinal deformities in the offsping. Thirty two female rats were randomized into two groups: control group, which was fed a normal diet; vitamin A deficient group, which were given vitamin A-deficient diet from at least 2 weeks before mating till delivery. Three random neonatal rats from each group were killed the next day of parturition. Female rats were fed an AIN-93G diet sufficient in vitamin A to feed the rest of neonates for two weeks until euthanasia. Serum levels of vitamin A were assessed in the adult and filial rats. Anteroposterior (AP) spine radiographs were obtained at week 2 after delivery to evaluate the presence of the skeletal abnormalities especially of spinal deformities. Liver and vertebral body expression of retinaldehyde dehydrogenase (RALDHs) and RARs mRNA was assessed by reverse transcription-real time PCR. VAD neonates displayed many skeletal malformations in the cervical, thoracic, the pelvic and sacral and limbs regions. The incidence of congenital scoliosis was 13.79% (8/58) in the filial rats of vitamin A deficiency group and 0% in the control group. Furthermore, vitamin A deficiency negatively regulate the liver and verterbral body mRNA levels of RALDH1, RALDH2, RALDH3, RAR-α, RAR-β and RAR-γ. Vitamin A deficiency in pregnancy may induce congenital spinal deformities in the postnatal rats. The decreases of RALDHs and RARs mRNA expression induced by vitamin A deprivation suggest that vertebral birth defects may be caused by a defect in RA signaling pathway during somitogenesis. PMID:23071590

Phencyclidine-Induced Social Withdrawal Results from Deficient Stimulation of Cannabinoid CB1 Receptors: Implications for Schizophrenia

PubMed Central

Seillier, Alexandre; Martinez, Alex A; Giuffrida, Andrea

2013-01-01

The neuronal mechanisms underlying social withdrawal, one of the core negative symptoms of schizophrenia, are not well understood. Recent studies suggest an involvement of the endocannabinoid system in the pathophysiology of schizophrenia and, in particular, of negative symptoms. We used biochemical, pharmacological, and behavioral approaches to investigate the role played by the endocannabinoid system in social withdrawal induced by sub-chronic administration of phencyclidine (PCP). Pharmacological enhancement of endocannabinoid levels via systemic administration of URB597, an inhibitor of endocannabinoid degradation, reversed social withdrawal in PCP-treated rats via stimulation of CB1 receptors, but reduced social interaction in control animals through activation of a cannabinoid/vanilloid-sensitive receptor. In addition, the potent CB agonist CP55,940 reversed PCP-induced social withdrawal in a CB1-dependent manner, whereas pharmacological blockade of CB1 receptors by either AM251 or SR141716 reduced the time spent in social interaction in control animals. PCP-induced social withdrawal was accompanied by a decrease of anandamide (AEA) levels in the amygdala and prefrontal cortex, and these deficits were reversed by URB597. As CB1 receptors are predominantly expressed on GABAergic interneurons containing the anxiogenic peptide cholecystokinin (CCK), we also examined whether the PCP-induced social withdrawal resulted from deficient CB1-mediated modulation of CCK transmission. The selective CCK2 antagonist LY225910 blocked both PCP- and AM251-induced social withdrawal, but not URB597 effect in control rats. Taken together, these findings indicate that AEA-mediated activation of CB1 receptors is crucial for social interaction, and that PCP-induced social withdrawal results from deficient endocannabinoid transmission. PMID:23563893

Effects of probiotics on methionine choline deficient diet-induced steatohepatitis in rats.

PubMed

Karahan, Nermin; Işler, Mehmet; Koyu, Ahmet; Karahan, Aynur G; Başyığıt Kiliç, Gülden; Cırış, Ibrahim Metin; Sütçü, Recep; Onaran, Ibrahim; Cam, Hakan; Keskın, Muharrem

2012-04-01

Intestinal bacteria induce endogenous signals that play a pathogenic role in hepatic insulin resistance and non-alcoholic fatty liver disease. Probiotics could modulate the gut flora and could influence the gut-liver axis. We aimed to investigate the preventive effect of two probiotic mixtures on the methionine choline-deficient diet-induced non-alcoholic steatohepatitis model in rats. Two studies, short-term (2 weeks) and long-term (6 weeks), were carried out using 60 male Wistar rats. The 2-week study included six groups. Rats were fed with methionine choline-deficient diet or pair-fed control diet and were given a placebo or one of two probiotic mixtures (Pro-1 and Pro-2) by orogastric gavage. In the 6-week study, rats were allocated into four groups and were fed with methionine choline-deficient diet or pair-fed control diet and given a placebo or Pro-2. At the end of the 2- and 6-week periods, blood samples were obtained, the animals were sacrificed, and liver tissues were removed. Serum alanine aminotransferase activity was determined; histologic and immunohistochemical analysis was performed for steatosis, inflammation, protein expression of tumor necrosis factor-α, and apoptosis markers. In both studies, methionine choline-deficient diet caused an elevation of serum alanine aminotransferase activity, which was slightly reduced by Pro-1 and Pro-2. In the 2- and 6-week studies, feeding with methionine choline-deficient diet resulted in steatosis and inflammation, but not fibrosis, in all rats. In the 2-week study, in rats fed with methionine choline-deficient diet and given Pro-1, steatosis and inflammation were present in 2 of 6 rats. In rats fed with methionine choline-deficient diet and given Pro-2, steatosis was detected in 3 of 6 rats, while inflammation was present in 2 of 6 rats. In the 6-week study, in rats fed with methionine choline-deficient diet and given Pro-2, steatosis and inflammation were present in 3 of 6 rat livers. In both the 2- and 6

Effects of a Tripeptide Iron on Iron-Deficiency Anemia in Rats.

PubMed

Xiao, Chen; Lei, Xingen; Wang, Qingyu; Du, Zhongyao; Jiang, Lu; Chen, Silu; Zhang, Mingjie; Zhang, Hao; Ren, Fazheng

2016-02-01

This study aims to investigate the effects of a tripeptide iron (REE-Fe) on iron-deficiency anemia rats. Sprague-Dawley rats were randomly divided into seven groups: a normal control group, an iron-deficiency control group, and iron-deficiency groups treated with ferrous sulfate (FeSO4), ferrous glycinate (Fe-Gly), or REE-Fe at low-, medium-, or high-dose groups. The rats in the iron-deficiency groups were fed on an iron-deficient diet to establish iron-deficiency anemia (IDA) model. After the model established, different iron supplements were given to the rats once a day by intragastric administration for 21 days. The results showed that REE-Fe had effective restorative action returning body weight, organ coefficients, and hematological parameters in IDA rats to normal level. In addition, comparing with FeSO4 or Fe-Gly, high-dose REE-Fe was more effective on improving the levels of renal coefficient, total iron-binding capacity, and transferrin. Furthermore, the liver hepcidin messenger RNA (mRNA) expression in the high-dose group was significantly higher (p < 0.05) than that in the FeSO4 or Fe-Gly group and showed no significant difference (p > 0.05) with the normal control group. The findings suggest that REE-Fe is an effective source of iron supplement for IDA rats and might be exploited as a new iron fortifier.

Vitamin C deficiency exerts paradoxical cardiovascular effects in osteogenic disorder Shionogi (ODS) rats.

PubMed

Vergely, Catherine; Goirand, Françoise; Ecarnot-Laubriet, Aline; Renard, Céline; Moreau, Daniel; Guilland, Jean-Claude; Dumas, Monique; Rochette, Luc

2004-04-01

Vitamin C is considered to be a very efficient water-soluble antioxidant, for which several new cardiovascular properties were recently described. The aim of this study was to determine in vivo the effects of a severe depletion of vitamin C on cardiac and vascular variables and reperfusion arrhythmias. For this purpose, we used a mutant strain of Wistar rats, osteogenic disorder Shionogi (ODS). After 15 d of consuming a vitamin C-deficient diet, ODS rats had a 90% decrease in plasma and tissue levels of ascorbate compared with ODS vitamin C-supplemented rats and normal Wistar rats. However, plasma antioxidant capacity, proteins, alpha-tocopherol, urate, catecholamines, lipids, and nitrate were not influenced by the vitamin C deficiency in ODS rats. Moreover, there was no difference between ODS vitamin C-deficient and -supplemented rats in heart rate and arterial pressure. After 5 min of an in vivo regional myocardial ischemia, various severe arrhythmias were observed, but their intensities were not modified by vitamin C in vitamin C-deficient ODS rats. The vascular reactivity, measured in vitro on thoracic arteries, was not altered by ascorbate deficiency in ODS rats. These unexpected results suggest that unidentified compensatory mechanisms play a role in maintaining normal cardiac function and vascular reactivity in vitamin C-deficient rats.

Dipeptidyl peptidase IV deficiency increases susceptibility to angiotensin-converting enzyme inhibitor-induced peritracheal edema.

PubMed

Byrd, James Brian; Shreevatsa, Ajai; Putlur, Pradeep; Foretia, Denis; McAlexander, Laurie; Sinha, Tuhin; Does, Mark D; Brown, Nancy J

2007-08-01

Serum dipeptidyl peptidase IV (DPPIV) activity is decreased in some individuals with ACE inhibitor-associated angioedema. ACE and DPPIV degrade substance P, an edema-forming peptide. The contribution of impaired degradation of substance P by DPPIV to the pathogenesis of ACE inhibitor-associated angioedema is unknown. We sought to determine whether DPPIV deficiency results in increased edema formation during ACE inhibition. We also sought to develop an animal model using magnetic resonance imaging to quantify ACE inhibitor-induced edema. The effect of genetic DPPIV deficiency on peritracheal edema was assessed in F344 rats after treatment with saline, captopril (2.5 mg/kg), or captopril plus the neurokinin receptor antagonist spantide (100 mug/kg) by using serial T2-weighted magnetic resonance imaging. Serum dipeptidyl peptidase activity was dramatically decreased in DPPIV-deficient rats (P < .001). The volume of peritracheal edema was significantly greater in captopril-treated DPPIV-deficient rats than in saline-treated DPPIV-deficient rats (P = .001), saline-treated rats of the normal substrain (P < .001), or captopril-treated rats of the normal substrain (P = .001). Cotreatment with spantide attenuated peritracheal edema in captopril-treated DPPIV-deficient rats (P = .005 vs captopril-treated DPPIV-deficient rats and P = .57 vs saline-treated DPPIV-deficient rats). DPPIV deficiency predisposes to peritracheal edema formation when ACE is inhibited through a neurokinin receptor-dependent mechanism. Magnetic resonance imaging is useful for modeling ACE inhibitor-associated angioedema in rats. Genetic or environmental factors that decrease DPPIV activity might increase the risk of ACE inhibitor-associated angioedema.

Copper uptake and retention in liver parenchymal cells isolated from nutritionally copper-deficient rats

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van den Berg, G.J.; de Goeij, J.J.; Bock, I.

1991-08-01

Copper uptake and retention were studied in primary cultures of liver parenchymal cells isolated from copper-deficient rats. Male Sprague-Dawley rats were fed a copper-deficient diet (less than 1 mg Cu/kg) for 10 wk. Copper-deficient rats were characterized by low copper concentrations in plasma and liver, anemia, low plasma ceruloplasmin oxidase activity and increased 64Cu whole-body retention. Freshly isolated liver parenchymal cells from copper-deficient rats showed a higher 64Cu influx, which was associated with a higher apparent Vmax of 45 {plus minus} 4 pmol Cu.mg protein-1.min-1 as compared with 30 {plus minus} 3 pmol Cu.mg protein-1.min-1 for cells isolated from copper-sufficientmore » rats. No significant difference in the apparent Km (approximately 30 mumol/L) was observed. Relative 64Cu efflux from cells from copper-deficient rats was significantly smaller than the efflux from cells from copper-sufficient rats after prelabeling as determined by 2-h efflux experiments. Analysis of the medium after efflux from cells from copper-deficient rats showed elevated protein-associated 64Cu, suggesting a higher incorporation of radioactive copper during metalloprotein synthesis. Effects of copper deficiency persist in primary cultures of parenchymal cells derived from copper-deficient rats, and short-term cultures of these cells offer a prospect for the study of cell biological aspects of the metabolic adaptation of the liver to copper deficiency.« less

Interaction of tributyltin with 3,3',4,4',5-pentachlorobiphenyl-induced ethoxyresorufin O-deethylase activity in rat hepatoma cells.

PubMed

Kannan, K; Villeneuve, D L; Blankenship, A L; Giesy, J P

1998-11-13

Interaction of tributyltin (TBT) with 3,3',4,4',5-pentachlorobiphenyl (PCB-126)-induced ethoxyresorufin O-deethylase (EROD) activity was examined in vitro using H4IIE rat hepatoma cells. H4IIE cells were exposed to TBT and PCB-126, individually or in combination, at different concentrations. TBT was cytotoxic at concentrations greater than 98 nM. PCB-126 was not cytotoxic in the concentration range of 49 to 3140 pM. At concentrations greater than 49 nM, PCB-126 enhanced the cytotoxicity of TBT in the 24-98 nM range. In the absence of inducers of EROD activity, TBT significantly inhibited constitutive EROD activity in H4IIE cells in a concentration-dependent manner. EROD activity in H4IIE cells was significantly increased by exposure to PCB-126 alone. This effect was potentiated by coexposure to low, noncytotoxic concentrations of TBT. The induction of cytochrome P-4501A (CYP1A) activity in the presence of both an inducer (PCB-126) and low concentrations of an inhibitor (TBT) indicates that TBT does not interfere with the Ah receptor binding, but acts at the transcriptional level. Potentiation of EROD activity and cytotoxicity as a consequence of coexposure to PCB-126 and TBT is of considerable toxicological significance, given their coaccumulation in a variety of marine organisms.

The effects of iron deficiency on rat liver enzymes.

PubMed Central

Bailey-Wood, R.; Blayney, L. M.; Muir, J. R.; Jacobs, A.

1975-01-01

The effect of iron deficiency on a number or iron containing enzymes in rat liver has been examined. In addition, 6-phosphogluconate dehydrogenase and glucose 6-phosphate dehydrogenase have been assayed. Of the mitochondrial electron transport reactions only succinate-cytochrome C reductase activity was decreased in iron deficient animals. Microsomal reductase enzymes associated with the NADPH-oxidase system were also markedly decreased although cytochrome P450 concentrations were unaffected. Both 6-phosphogluconate dehydrogenase and glucose 6-phosphate dehydrogenase were reduced in young iron deficient rats but the former had returned to control levels at the age of 14 weeks. PMID:172099

Preweaning iron deficiency increases non-contingent responding during cocaine self-administration in rats.

PubMed

Jenney, Christopher B; Alexander, Danielle N; Jones, Byron C; Unger, Erica L; Grigson, Patricia S

2016-12-01

Iron deficiency (ID) is the most prevalent single-nutrient deficiency worldwide. There is evidence that ID early in development (preweaning in rat) causes irreversible neurologic, behavioral, and motor development deficits. Many of these effects have been attributed to damage to dopamine systems, including ID-induced changes in transporter and receptor numbers in the striatum and nucleus accumbens. These mesolimbic dopaminergic neurons are, in part, responsible for mediating reward and thus play a key role in addiction. However, there has been relatively little investigation into the behavioral effects of ID on drug addiction. In 2002, we found that rats made ID from weaning (postnatal day 21) and throughout the experiment acquired cocaine self-administration significantly more slowly than controls and failed to increase responding when the dose of the drug was decreased. In the present study, we assessed addiction for self-administered cocaine in rats with a history of preweaning ID only during postnatal days 4 through 21, and iron replete thereafter. The results showed that while ID did not affect the number of cocaine infusions or the overall addiction-like behavior score, ID rats scored higher on a measure of continued responding for drug than did iron replete controls. This increase in responding, however, was less goal-directed as ID rats also responded more quickly to the non-rewarded manipulandum than did control rats. Thus, while ID early in infancy did not significantly increase addiction-like behaviors for cocaine in this small study, the pattern of data suggests a possible underlying learning or performance impairment. Future studies will be needed to elucidate the exact neuro-behavioral deficits that lead to the increase in indiscriminate responding for drug in rats with a history of perinatal ID. Copyright © 2016. Published by Elsevier Inc.

Parkin Deficiency Reduces Hippocampal Glutamatergic Neurotransmission by Impairing AMPA Receptor Endocytosis.

PubMed

Cortese, Giuseppe P; Zhu, Mei; Williams, Damian; Heath, Sarah; Waites, Clarissa L

2016-11-30

Mutations in the gene encoding Parkin, an E3 ubiquitin ligase, lead to juvenile-onset Parkinson's disease by inducing the selective death of midbrain dopaminergic neurons. Accumulating evidence indicates that Parkin also has an important role in excitatory glutamatergic neurotransmission, although its precise mechanism of action remains unclear. Here, we investigate Parkin's role at glutamatergic synapses of rat hippocampal neurons. We find that Parkin-deficient neurons exhibit significantly reduced AMPA receptor (AMPAR)-mediated currents and cell-surface expression, and that these phenotypes result from decreased postsynaptic expression of the adaptor protein Homer1, which is necessary for coupling AMPAR endocytic zones with the postsynaptic density. Accordingly, Parkin loss of function leads to the reduced density of postsynaptic endocytic zones and to impaired AMPAR internalization. These findings demonstrate a novel and essential role for Parkin in glutamatergic neurotransmission, as a stabilizer of postsynaptic Homer1 and the Homer1-linked endocytic machinery necessary for maintaining normal cell-surface AMPAR levels. Mutations in Parkin, a ubiquitinating enzyme, lead to the selective loss of midbrain dopaminergic neurons and juvenile-onset Parkinson's disease (PD). Parkin loss of function has also been shown to alter hippocampal glutamatergic neurotransmission, providing a potential explanation for PD-associated cognitive impairment. However, very little is known about Parkin's specific sites or mechanisms of action at glutamatergic synapses. Here, we show that Parkin deficiency leads to decreased AMPA receptor-mediated activity due to disruption of the postsynaptic endocytic zones required for maintaining proper cell-surface AMPA receptor levels. These findings demonstrate a novel role for Parkin in synaptic AMPA receptor internalization and suggest a Parkin-dependent mechanism for hippocampal dysfunction that may explain cognitive deficits associated with

CRF1 receptor-deficiency increases cocaine reward.

PubMed

Contarino, Angelo; Kitchener, Pierre; Vallée, Monique; Papaleo, Francesco; Piazza, Pier-Vincenzo

2017-05-01

Stimulant drugs produce reward but also activate stress-responsive systems. The corticotropin-releasing factor (CRF) and the related hypothalamus-pituitary-adrenal (HPA) axis stress-responsive systems are activated by stimulant drugs. However, their role in stimulant drug-induced reward remains poorly understood. Herein, we report that CRF 1 receptor-deficient (CRF 1 -/-), but not wild-type, mice show conditioned place preference (CPP) responses to a relatively low cocaine dose (5 mg/kg, i.p.). Conversely, wild-type, but not CRF 1 -/-, mice display CPP responses to a relatively high cocaine dose (20 mg/kg, i.p.), indicating that CRF 1 receptor-deficiency alters the rewarding effects of cocaine. Acute pharmacological antagonism of the CRF 1 receptor by antalarmin also eliminates cocaine reward. Nevertheless, CRF 1 -/- mice display higher stereotypy responses to cocaine than wild-type mice. Despite the very low plasma corticosterone concentration, CRF 1 -/- mice show higher nuclear glucocorticoid receptor (GR) levels in the brain region of the hippocampus than wild-type mice. Full rescue of wild-type-like corticosterone and GR circadian rhythm and level in CRF 1 -/- mice by exogenous corticosterone does not affect CRF 1 receptor-dependent cocaine reward but induces stereotypy responses to cocaine. These results indicate a critical role for the CRF 1 receptor in cocaine reward, independently of the closely related HPA axis activity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effects of zinc deficiency on the vallate papillae and taste buds in rats.

PubMed

Chou, H C; Chien, C L; Huang, H L; Lu, K S

2001-05-01

Zinc deficiency is associated with multiple clinical complications, including taste disturbance, anorexia, growth retardation, skin changes, and hypogonadism. We investigated the zinc-deficiency-induced morphologic changes in the vallate taste buds of weanling and young adult male Wistar rats. A total of 24 weanling and 30 young adult rats were used. Each age group was further divided into a control group fed a zinc-adequate (50 ppm) diet, a zinc-deficient (< 1 ppm) diet group, and a zinc-adequate pair-fed group who were fed the same amount of food as that taken by the zinc-deficient group. Weanling rats were fed for 4 weeks and young adult rats were fed for 6 weeks. The morphometry and morphologic changes of vallate taste buds were analyzed using light and transmission electron microscopy. Light microscopy revealed no significant difference in papilla size and morphology among the various groups. In both weanling and young adult rats in the zinc-deficient diet and pair-fed groups, the number of taste buds per papilla (per animal) and the average profile area of the taste bud were significantly smaller than those of the corresponding controls (p < 0.05). Ultrastructural changes were seen only in the taste buds of weanling rats fed the zinc-deficient diet, with derangement of the architecture of the taste bud and widening of the intercellular space between taste bud cells. The proportion of type I taste bud cells in the taste buds of weanling rats fed the zinc-deficient diet decreased from 59% to 39%, and that of type II taste bud cells decreased from 25% to 12%. No obvious changes in the ultrastructure of type III taste bud cells were observed. The main effects of zinc deficiency in weanling and young adult rats and in adequate diet pair-fed rats were changes in the number and size of taste buds, and fine structure changes in the taste bud cells, especially during the accelerated growth stage after weaning.

Facial morphometry of Ecuadorian patients with growth hormone receptor deficiency/Laron syndrome.

PubMed Central

Schaefer, G B; Rosenbloom, A L; Guevara-Aguirre, J; Campbell, E A; Ullrich, F; Patil, K; Frias, J L

1994-01-01

Facial morphometry using computerised image analysis was performed on patients with growth hormone receptor deficiency (Laron syndrome) from an inbred population of southern Ecuador. Morphometrics were compared for 49 patients, 70 unaffected relatives, and 14 unrelated persons. Patients with growth hormone receptor deficiency showed significant decreases in measures of vertical facial growth as compared to unaffected relatives and unrelated persons with short stature from other causes. This report validates and quantifies the clinical impression of foreshortened facies in growth hormone receptor deficiency. Images PMID:7815422

The selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen improve ANP levels and decrease nuclear translocation of NF-kB in estrogen-deficient rats.

PubMed

Lamas, Aline Z; Nascimento, Andrews M; Medeiros, Ana Raquel S; Caliman, Izabela F; Dalpiaz, Polyana L M; Firmes, Luciana B; Sousa, Glauciene J; Oliveira, Phablo Wendell C; Andrade, Tadeu U; Reis, Adelina M; Gouvea, Sônia A; Bissoli, Nazaré S

2017-08-01

The selective estrogen receptor modulators (SERMs) raloxifene and tamoxifen are used for the treatment of osteoporosis and cancer, respectively, in women. The impairment of both the Atrial Natriuretic Peptide (ANP) cell signaling system and the translocation of nuclear factor-kappa B (NF-kB) to the cell nucleus are associated with detrimental cardiovascular effects and inflammation. The effects of SERMs on these parameters in the cardiac tissue of estrogen-deficient rats has not been reported. We investigated the effects of raloxifene and tamoxifen on ANP signaling, p65 NF-kB nuclear translocation, cardiac histology and contractility. Female rats were divided into five groups: control (SHAM), ovariectomized (OVX), OVX-treated 17-β-estradiol (E), OVX-treated raloxifene (RLX) and OVX-treated tamoxifen (TAM). The treatments started 21days after ovariectomy and continued for 14days. Ovariectomy reduced ANP mRNA in the left atrium (LA), decreased the content of ANP protein in the LA and in plasma, and increased the level of p65 NF-kB nuclear translocation in the left ventricle. Both 17-β-estradiol and SERMs were able to reverse these alterations, which were induced by the estrogen deficient state. The hemodynamic and cardiac structural parameters analyzed in the present work were not modified by the interventions. Our study demonstrates, for the first time, the additional benefits of raloxifene and tamoxifen in an estrogen-deficient state. These include the normalization of plasmatic and cardiac ANP levels and cardiac p65 NF-kB translocation. Therefore, these treatments promote cardiovascular protection and may contribute to the prevention of cardiac dysfunction observed long-term in postmenopausal women. Copyright © 2017. Published by Elsevier Urban & Partner Sp. z o.o.

Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice

PubMed Central

Otten, Jeroen J. T.; de Jager, Saskia C. A.; Kavelaars, Annemieke; Seijkens, Tom; Bot, Ilze; Wijnands, Erwin; Beckers, Linda; Westra, Marijke M.; Bot, Martine; Busch, Matthias; Bermudez, Beatriz; van Berkel, Theo J. C.; Heijnen, Cobi J.; Biessen, Erik A. L.

2013-01-01

Leukocyte chemotaxis is deemed instrumental in initiation and progression of atherosclerosis. It is mediated by G-protein-coupled receptors (e.g., CCR2 and CCR5), the activity of which is controlled by G-protein-coupled receptor kinases (GRKs). In this study, we analyzed the effect of hematopoietic deficiency of a potent regulator kinase of chemotaxis (GRK2) on atherogenesis. LDL receptor-deficient (LDLr−/−) mice with heterozygous hematopoietic GRK2 deficiency, generated by bone marrow transplantation (n=15), displayed a dramatic attenuation of plaque development, with 79% reduction in necrotic core and increased macrophage content. Circulating monocytes decreased and granulocytes increased in GRK2+/− chimeras, which could be attributed to diminished granulocyte colony-forming units in bone marrow. Collectively, these data pointed to myeloid cells as major mediators of the impaired atherogenic response in GRK2+/− chimeras. LDLr−/− mice with macrophage/granulocyte-specific GRK2 deficiency (LysM-Cre GRK2flox/flox; n=8) failed to mimic the aforementioned phenotype, acquitting these cells as major responsible subsets for GRK2 deficiency-associated atheroprotection. To conclude, even partial hematopoietic GRK2 deficiency prevents atherosclerotic lesion progression beyond the fatty streak stage, identifying hematopoietic GRK2 as a potential target for intervention in atherosclerosis.—Otten, J. J. T., de Jager, S. C. A., Kavelaars, A., Seijkens, T., Bot, I., Wijnands, E., Beckers, L., Westra, M. M., Bot, M., Busch, M., Bermudez, B., van Berkel, T. J. C., Heijnen, C. J., Biessen, E. A. L. Hematopoietic G-protein-coupled receptor kinase 2 deficiency decreases atherosclerotic lesion formation in LDL receptor-knockout mice. PMID:23047899

Renal sodium transport in renin-deficient Dahl salt-sensitive rats

PubMed Central

Pavlov, Tengis S; Levchenko, Vladislav; Ilatovskaya, Daria V; Moreno, Carol; Staruschenko, Alexander

2016-01-01

Objective: The Dahl salt-sensitive rat is a well-established model of salt-sensitive hypertension. The goal of this study was to assess the expression and activity of renal sodium channels and transporters in the renin-deficient salt-sensitive rat. Methods: Renin knockout (Ren−/−) rats created on the salt-sensitive rat background were used to investigate the role of renin in the regulation of ion transport in salt-sensitive hypertension. Western blotting and patch-clamp analyses were utilized to assess the expression level and activity of Na+ transporters. Results: It has been described previously that Ren−/− rats exhibit severe kidney underdevelopment, polyuria, and lower body weight and blood pressure compared to their wild-type littermates. Here we found that renin deficiency led to decreased expression of sodium-hydrogen antiporter (NHE3), the Na+/H+ exchanger involved in Na+ absorption in the proximal tubules, but did not affect the expression of Na-K-Cl cotransporter (NKCC2), the main transporter in the loop of Henle. In the distal nephron, the expression of sodium chloride cotransporter (NCC) was lower in Ren−/− rats. Single-channel patch clamp analysis detected decreased ENaC activity in Ren−/− rats which was mediated via changes in the channel open probability. Conclusion: These data illustrate that renin deficiency leads to significant dysregulation of ion transporters. PMID:27443990

Omega-3 Fatty Acid Deficient Male Rats Exhibit Abnormal Behavioral Activation in the Forced Swim Test Following Chronic Fluoxetine Treatment: Association with Altered 5-HT1A and Alpha2A Adrenergic Receptor Expression

PubMed Central

Able, Jessica A.; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; McNamara, Robert K.

2014-01-01

Omega-3 fatty acid deficiency during development leads to enduing alterations in central monoamine neurotransmission in rat brain. Here we investigated the effects of omega-3 fatty acid deficiency on behavioral and neurochemical responses to chronic fluoxetine (FLX) treatment. Male rats were fed diets with (CON, n=34) or without (DEF, n=30) the omega-3 fatty acid precursor alpha-linolenic acid (ALA) during peri-adolescent development (P21-P90). A subset of CON (n=14) and DEF (n=12) rats were administered FLX (10 mg/kg/d) through their drinking water for 30 d beginning on P60. The forced swimming test (FST) was initiated on P90, and regional brain mRNA markers of serotonin and noradrenaline neurotransmission were determined. Dietary ALA depletion led to significant reductions in frontal cortex docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (−26%, p=0.0001) and DEF+FLX (−32%, p=0.0001) rats. Plasma FLX and norfluoxetine concentrations did not different between FLX-treated DEF and CON rats. During the 15-min FST pretest, DEF+FLX rats exhibited significantly greater climbing behavior compared with CON+FLX rats. During the 5-min test trial, FLX treatment reduced immobility and increased swimming in CON and DEF rats, and only DEF+FLX rats exhibited significant elevations in climbing behavior. DEF+FLX rats exhibited greater midbrain, and lower frontal cortex, 5-HT1A mRNA expression compared with all groups including CON+FLX rats. DEF+FLX rats also exhibited greater midbrain alpha2A adrenergic receptor mRNA expression which was positively correlated with climbing behavior in the FST. These preclinical data demonstrate that low omega-3 fatty acid status leads to abnormal behavioral and neurochemical responses to chronic FLX treatment in male rats. PMID:24360505

Resistance of essential fatty acid-deficient rats to endotoxin-induced increases in vascular permeability

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, E.J.; Cook, J.A.; Spicer, K.M.

Resistance to endotoxin in essential fatty acid-deficient (EFAD) rats is associated with reduced synthesis of certain arachidonic acid metabolites. It was hypothesized that EFAD rats would manifest decreased vascular permeability changes during endotoxemia as a consequence of reduced arachidonic acid metabolism. To test this hypothesis, changes in hematocrit (HCT) and mesenteric localization rate of technetium-labeled human serum albumin (99mTc-HSA) and red blood cells (99mTc-RBC) were assessed in EFAD and normal rats using gamma-camera imaging. Thirty minutes after Salmonella enteritidis endotoxin, EFAD rats exhibited less hemoconcentration as determined by % HCT than normal rats. Endotoxin caused a less severe change inmore » permeability index in the splanchnic region in EFAD rats than in normal rats (1.2 +/- 0.6 x 10(-3)min-1 vs. 4.9 +/- 1.7 x 10(-3)min-1 respectively, P less than 0.05). In contrast to 99mTc-HSA, mesenteric localization of 99mTc-RBC was not changed by endotoxin in control or EFAD rats. Supplementation with ethyl-arachidonic acid did not enhance susceptibility of EFAD rats to endotoxin-induced splanchnic permeability to 99mTc-HSA. Leukotrienes have been implicated as mediators of increased vascular permeability in endotoxin shock. Since LTC3 formation has been reported to be increased in EFA deficiency, we hypothesized that LTC3 may be less potent than LTC4. Thus the effect of LTC3 on mean arterial pressure and permeability was compared to LTC4 in normal rats. LTC3-induced increases in peak mean arterial pressure were less than LTC4 at 10 micrograms/kg (39 +/- 5 mm Hg vs. 58 +/- 4 mm Hg respectively, P less than 0.05) and at 20 micrograms/kg (56 +/- 4 mm Hg vs. 75 +/- 2 mm Hg respectively, P less than 0.05). LY171883 (30 mg/kg), an LTD4/E4 receptor antagonist, attenuated the pressor effect of LTC4, LTD4, and LTC3.« less

An Ω-3 fatty acid-deficient diet during gestation induces depressive-like behavior in rats: the role of the hypothalamo-pituitary-adrenal (HPA) system.

PubMed

Tang, Mimi; Liu, Yiping; Wang, Lu; Li, Huande; Cai, Hualin; Zhang, Min; Dang, Ruili; Xue, Ying; Wu, Yanqin

2018-06-08

Low intake of omega-3 (Ω-3) polyunsaturated fatty acids (PUFAs) especially docosahexaenoic acid (DHA) is associated with postpartum depression. DHA deficiency is accompanied by impaired attention and cognition, and will precipitate psychiatric symptoms. However, the effects of dietary DHA on postpartum depression remain unclear. We established a normal pregnancy model to evaluate whether an Ω-3 PUFA-deficient diet during gestation could induce depressive-like behavior and aggravate dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in rats. A between-group design was used to assess the effects of Ω-3 PUFA content (deficiency, control and supplementary) and reproductive status (virgin or parous). We assessed depressive-like behavior and measured the fatty acid composition in the liver. The protein expressions of glucocorticoid receptor (GR) and mineralocorticoid receptor (MCR) were also measured to evaluate the HPA activity. Exposure to the Ω-3 PUFA-deficient diet resulted in an increased immobility time in a forced swimming test (FST). Additionally, our results firstly showed the decreased expression of GR in the hippocampus of parous rats that were exposed to Ω-3 PUFA-deficient diets, which may partly facilitate the hyperactivity of the HPA axis and exert detrimental effects. Moreover, the reduction of GR was ameliorated by Ω-3 PUFA supplementation, providing new evidence for Ω-3 PUFAs in the progression of postpartum depression.

A diet containing the soy phytoestrogen genistein causes infertility in female rats partially deficient in UDP glucuronyltransferase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Seppen, Jurgen, E-mail: j.seppen@amc.uva.nl

Soy beans contain genistein, a natural compound that has estrogenic effects because it binds the estrogen receptor with relatively high affinity. Genistein is therefore the most important environmental estrogen in the human diet. Detoxification of genistein is mediated through conjugation by UDP-glucuronyltransferase 1 and 2 (UGT1 and UGT2) isoenzymes. Gunn rats have a genetic deficiency in UGT1 activity, UGT2 activities are not affected. Because our Gunn rats stopped breeding after the animal chow was changed to a type with much higher soy content, we examined the mechanism behind this soy diet induced infertility. Gunn and control rats were fed dietsmore » with and without genistein. In these rats, plasma levels of genistein and metabolites, fertility and reproductive parameters were determined. Enzyme assays showed reduced genistein UGT activity in Gunn rats, as compared to wild type rats. Female Gunn rats were completely infertile on a genistein diet, wild type rats were fertile. Genistein diet caused a persistent estrus, lowered serum progesterone and inhibited development of corpora lutea in Gunn rats. Concentrations of total genistein in Gunn and control rat plasma were identical and within the range observed in humans after soy consumption. However, Gunn rat plasma contained 25% unconjugated genistein, compared to 3.6% in control rats. This study shows that, under conditions of reduced glucuronidation, dietary genistein exhibits a strongly increased estrogenic effect. Because polymorphisms that reduce UGT1 expression are prevalent in the human population, these results suggest a cautionary attitude towards the consumption of large amounts of soy or soy supplements. -- Highlights: ► Gunn rats are partially deficient in detoxification by UDP glucuronyltransferases. ► Female Gunn rats are infertile on a soy containing diet. ► Soy contains genistein, a potent phytoestrogen. ► Inefficient glucuronidation of genistein causes female infertility.« less

Abolition of reperfusion-induced arrhythmias in hearts from thiamine-deficient rats.

PubMed

Oliveira, Fernando A; Guatimosim, Silvia; Castro, Carlos H; Galan, Diogo T; Lauton-Santos, Sandra; Ribeiro, Angela M; Almeida, Alvair P; Cruz, Jader S

2007-07-01

Extensive work has been done regarding the impact of thiamine deprivation on the nervous system. In cardiac tissue, chronic thiamine deficiency is described to cause changes in the myocardium that can be associated with arrhythmias. However, compared with the brain, very little is known about the effects of thiamine deficiency on the heart. Thus this study was undertaken to explore whether thiamine deprivation has a role in cardiac arrhythmogenesis. We examined hearts isolated from thiamine-deprived and control rats. We measured heart rate, diastolic and systolic tension, and contraction and relaxation rates. Whole cell voltage clamp was performed in rat isolated cardiac myocytes to measure L-type Ca(2+) current. In addition, we investigated the global intracellular calcium transients by using confocal microscopy in the line-scan mode. The hearts from thiamine-deficient rats did not degenerate into ventricular fibrillation during 30 min of reperfusion after 15 min of coronary occlusion. The antiarrhythmogenic effects were characterized by the arrhythmia severity index. Our results suggest that hearts from thiamine-deficient rats did not experience irreversible arrhythmias. There was no change in L-type Ca(2+) current density. Inactivation kinetics of this current in Ca(2+)-buffered cells was retarded in thiamine-deficient cardiac myocytes. The global Ca(2+) release was significantly reduced in thiamine-deficient cardiac myocytes. The amplitude of caffeine-releasable Ca(2+) was lower in thiamine-deficient myocytes. In summary, we have found that thiamine deprivation attenuates the incidence and severity of postischemic arrhythmias, possibly through a mechanism involving a decrease in global Ca(2+) release.

Development of antibodies against the rat brain somatostatin receptor.

PubMed

Theveniau, M; Rens-Domiano, S; Law, S F; Rougon, G; Reisine, T

1992-05-15

Somatostatin (SRIF) is a neurotransmitter in the brain involved in the regulation of motor activity and cognition. It induces its physiological actions by interacting with receptors. We have developed antibodies against the receptor to investigate its structural properties. Rabbit polyclonal antibodies were generated against the rat brain SRIF receptor. These antibodies (F4) were able to immunoprecipitate solubilized SRIF receptors from rat brain and the cell line AtT-20. The specificity of the interaction of these antibodies with SRIF receptors was further demonstrated by immunoblotting. F4 detected SRIF receptors of 60 kDa from rat brain and adrenal cortex and the cell lines AtT-20, GH3, and NG-108, which express high densities of SRIF receptors. They did not detect immunoreactive material from rat liver or COS-1, HEPG, or CRL cells, which do not express functional SRIF receptors. In rat brain, 60-kDa immunoreactivity was detected by F4 in the hippocampus, cerebral cortex, and striatum, which have high densities of SRIF receptors. However, F4 did not interact with proteins from cerebellum and brain stem, which express few SRIF receptors. Immunoreactive material cannot be detected in rat pancreas or pituitary, which have been reported to express a 90-kDa SRIF receptor subtype. The selective detection of 60-kDa SRIF receptors by F4 indicates that the 60- and 90-kDa SRIF receptor subtypes are immunologically distinct. The availability of antibodies that selectively detect native and denatured brain SRIF receptors provides us with a feasible approach to clone the brain SRIF receptor gene(s).

Endothelin-1-induced focal cerebral ischemia in the growth hormone/IGF-1 deficient Lewis Dwarf rat.

PubMed

Yan, Han; Mitschelen, Matthew; Toth, Peter; Ashpole, Nicole M; Farley, Julie A; Hodges, Erik L; Warrington, Junie P; Han, Song; Fung, Kar-Ming; Csiszar, Anna; Ungvari, Zoltan; Sonntag, William E

2014-11-01

Aging is a major risk factor for cerebrovascular disease. Growth hormone (GH) and its anabolic mediator, insulin-like growth factor (IGF)-1, decrease with advancing age and this decline has been shown to promote vascular dysfunction. In addition, lower GH/IGF-1 levels are associated with higher stroke mortality in humans. These results suggest that decreased GH/IGF-1 level is an important factor in increased risk of cerebrovascular diseases. This study was designed to assess whether GH/IGF-1-deficiency influences the outcome of cerebral ischemia. We found that endothelin-1-induced middle cerebral artery occlusion resulted in a modest but nonsignificant decrease in cerebral infarct size in GH/IGF-1 deficient dw/dw rats compared with control heterozygous littermates and dw/dw rats with early-life GH treatment. Expression of endothelin receptors and endothelin-1-induced constriction of the middle cerebral arteries were similar in the three experimental groups. Interestingly, dw/dw rats exhibited reduced brain edema and less astrocytic infiltration compared with their heterozygous littermates and this effect was reversed by GH-treatment. Because reactive astrocytes are critical for the regulation of poststroke inflammatory processes, maintenance of the blood-brain barrier and neural repair, further studies are warranted to determine the long-term functional consequences of decreased astrocytic activation in GH/IGF-1 deficient animals after cerebral ischemia. Published by Oxford University Press on behalf of the Gerontological Society of America 2014.

Intrauterine Zn Deficiency Favors Thyrotropin-Releasing Hormone-Increasing Effects on Thyrotropin Serum Levels and Induces Subclinical Hypothyroidism in Weaned Rats.

PubMed

Alcántara-Alonso, Viridiana; Alvarez-Salas, Elena; Matamoros-Trejo, Gilberto; de Gortari, Patricia

2017-10-18

Individuals who consume a diet deficient in zinc (Zn-deficient) develop alterations in hypothalamic-pituitary-thyroid axis function, i.e., a low metabolic rate and cold insensitivity. Although those disturbances are related to primary hypothyroidism, intrauterine or postnatal Zn-deficient adults have an increased thyrotropin (TSH) concentration, but unchanged thyroid hormone (TH) levels and decreased body weight. This does not support the view that the hypothyroidism develops due to a low Zn intake. In addition, intrauterine or postnatal Zn-deficiency in weaned and adult rats reduces the activity of pyroglutamyl aminopeptidase II (PPII) in the medial-basal hypothalamus (MBH). PPII is an enzyme that degrades thyrotropin-releasing hormone (TRH). This hypothalamic peptide stimulates its receptor in adenohypophysis, thereby increasing TSH release. We analyzed whether earlier low TH is responsible for the high TSH levels reported in adults, or if TRH release is enhanced by Zn deficiency at weaning. Dams were fed a 2 ppm Zn-deficient diet in the period from one week prior to gestation and up to three weeks after delivery. We found a high release of hypothalamic TRH, which along with reduced MBH PPII activity, increased TSH levels in Zn-deficient pups independently of changes in TH concentration. We found that primary hypothyroidism did not develop in intrauterine Zn-deficient weaned rats and we confirmed that metal deficiency enhances TSH levels since early-life, favoring subclinical hypothyroidism development which remains into adulthood.

The impact of adult vitamin D deficiency on behaviour and brain function in male Sprague-Dawley rats.

PubMed

Byrne, Jacqueline H; Voogt, Meggie; Turner, Karly M; Eyles, Darryl W; McGrath, John J; Burne, Thomas H J

2013-01-01

Vitamin D deficiency is common in the adult population, and this has been linked to depression and cognitive outcomes in clinical populations. The aim of this study was to investigate the effects of adult vitamin D (AVD) deficiency on behavioural tasks of relevance to neuropsychiatric disorders in male Sprague-Dawley rats. Ten-week old male Sprague-Dawley rats were fed a control or vitamin D deficient diet for 6 weeks prior to, and during behavioural testing. We first examined a range of behavioural domains including locomotion, exploration, anxiety, social behaviour, learned helplessness, sensorimotor gating, and nociception. We then assessed locomotor response to the psychomimetic drugs, amphetamine and MK-801. Attention and vigilance were assessed using the 5 choice serial reaction time task (5C-SRT) and the 5 choice continuous performance task (5C-CPT) and, in a separate cohort, working memory was assessed using the delay match to sample (DMTS) task. We also examined excitatory and inhibitory neurotransmitters in prefrontal cortex and striatum. AVD-deficient rats were deficient in vitamin D3 (<10 nM) and had normal calcium and phosphate levels after 8-10 weeks on the diet. Overall, AVD deficiency was not associated with an altered phenotype across the range of behavioural domains tested. On the 5C-SRT AVD-deficient rats made more premature responses and more head entries during longer inter-trial intervals (ITI) than control rats. On the 5C-CPT AVD-deficient rats took longer to make false alarm (FA) responses than control rats. AVD-deficient rats had increases in baseline GABA levels and the ratio of DOPAC/HVA within the striatum. AVD-deficient rats exhibited no major impairments in any of the behavioural domains tested. Impairments in premature responses in AVD-deficient rats may indicate that these animals have specific alterations in striatal systems governing compulsive or reward-seeking behaviour.

Dietary deficiency of vitamin E aggravates retinal ganglion cell death in experimental glaucoma of rats.

PubMed

Ko, Mei-Lan; Peng, Pai-Huei; Hsu, Shens-Yao; Chen, Chau-Fong

2010-09-01

Investigate the effect of dietary vitamin E (Vit E) on the retinas of a rat model of induced glaucoma, in which surgically induced elevation of intraocular pressure (IOP) is associated with an increase in reactive oxygen species. Rats were fed a standard chow, Vit E-supplemented diet, or Vit E-deficient diet and subjected to surgically induced IOP elevation (or sham surgery) for five weeks. The retinal ganglion cells (RGCs) were subjected to retrograde fluorescent tracer labeling. The mean number of RGCs of rats on the standard chow, Vit E-supplemented diet, and Vit E-deficient diet were 79.6%, 78.6%, and 71.3% of controls, respectively. Lipid peroxidation of the retinas of rats given a Vit E-deficient diet were significantly higher after IOP elevation for three days (14.42 +/- 0.25 microM, P = 0.016) and five weeks (10.46 +/- 0.11 microM, p = 0.042), compared to rats given standard chow (11.37 +/- 0.31 microM; 8.95 +/- 0.16 microM). Compared with rats given standard chow, rats given a Vit E-deficient diet had significantly elevated concentrations of glutathione (p = 0.032), but no significant differences in the levels of total superoxide dismutase (SOD), Cu/Zn SOD, or catalase activities three days after IOP elevation. Rats fed a Vit E-deficient diet with surgically induced IOP elevation experience significantly more RGC death than rats fed a normal diet. This phenomenon may be related to the increased level of lipid peroxidation in Vit E-deficient rats.

Liver-enriched transcription factors uncoupled from expression of hepatic functions in hepatoma cell lines.

PubMed Central

Chaya, D; Fougère-Deschatrette, C; Weiss, M C

1997-01-01

Among the liver-enriched transcription factors identified to date, only expression of hepatocyte nuclear factor 4 (HNF4) and hepatocyte nuclear factor 1 (HNF1) is in strict correlation with hepatic differentiation in cultured rat hepatoma cells. Indeed, differentiated hepatoma cells that stably express an extensive set of adult hepatic functions express liver-enriched transcription factors, while dedifferentiated cells that have lost expression of all these hepatic functions no longer express HNF4 and HNF1. We describe a new heritable phenotype, designated as uncoupled, in which there is a spontaneous dissociation between the expression of these transcription factors and that of the hepatic functions. Cells presenting this phenotype, isolated from differentiated hepatoma cells, cease to accumulate all transcripts coding for hepatic functions but nevertheless maintain expression of HNF4 and HNF1. Transitory transfection experiments indicate that these two factors present in these cells have transcriptional activity similar to that of differentiated hepatoma cells. Characterization of the appropriate intertypic cell hybrids demonstrates that this new phenotype is recessive to the dedifferentiated state and fails to be complemented by differentiated cells. These results indicate the existence of mechanisms that inhibit transcription of genes coding for hepatocyte functions in spite of the presence of functional HNF4 and HNF1. Cells of the uncoupled phenotype present certain properties of oval cells described for pathological states of the liver. PMID:9343392

Liver-enriched transcription factors uncoupled from expression of hepatic functions in hepatoma cell lines.

PubMed

Chaya, D; Fougère-Deschatrette, C; Weiss, M C

1997-11-01

Among the liver-enriched transcription factors identified to date, only expression of hepatocyte nuclear factor 4 (HNF4) and hepatocyte nuclear factor 1 (HNF1) is in strict correlation with hepatic differentiation in cultured rat hepatoma cells. Indeed, differentiated hepatoma cells that stably express an extensive set of adult hepatic functions express liver-enriched transcription factors, while dedifferentiated cells that have lost expression of all these hepatic functions no longer express HNF4 and HNF1. We describe a new heritable phenotype, designated as uncoupled, in which there is a spontaneous dissociation between the expression of these transcription factors and that of the hepatic functions. Cells presenting this phenotype, isolated from differentiated hepatoma cells, cease to accumulate all transcripts coding for hepatic functions but nevertheless maintain expression of HNF4 and HNF1. Transitory transfection experiments indicate that these two factors present in these cells have transcriptional activity similar to that of differentiated hepatoma cells. Characterization of the appropriate intertypic cell hybrids demonstrates that this new phenotype is recessive to the dedifferentiated state and fails to be complemented by differentiated cells. These results indicate the existence of mechanisms that inhibit transcription of genes coding for hepatocyte functions in spite of the presence of functional HNF4 and HNF1. Cells of the uncoupled phenotype present certain properties of oval cells described for pathological states of the liver.

Different response to choline deficiency of the serum ornithine carbamoyltransferase activity in four strains of rats.

PubMed

Nocianitri, K A; Aoyama, Y

2001-04-01

Rats of the Donryu, Wistar, Fischer, and Sprague-Dawley strains were examined for the effects of choline deficiency on liver lipids, serum lipids, and serum ornithine carbamoyltransferase. The liver total lipid, triacylglycerol, cholesterol and phospholipid contents in the choline-deficient rats were significantly higher than those in choline-sufficient rats. The contents of total lipids and phospholipids in the liver of the Wistar and Fischer rats fed on a choline-deficient diet were significantly higher than those of the Donryu and Sprague-Dawley rats. The levels of triacylglycerol, cholesterol and phospholipids in the serum were significantly decreased by feeding with the choline-deficient diet. The serum ornithine carbamoyltransferase activity was increased in the Wistar and Fischer strains by feeding with the choline-deficient diet. The Wistar and Fischer strains were consequently the most sensitive to both lipid accumulation and liver lesions induced by the choline deficiency.

Developmental vitamin D deficiency alters multiple neurotransmitter systems in the neonatal rat brain.

PubMed

Kesby, James P; Turner, Karly M; Alexander, Suzanne; Eyles, Darryl W; McGrath, John J; Burne, Thomas H J

2017-11-01

Epidemiological evidence suggests that developmental vitamin D (DVD) deficiency is a risk factor for neuropsychiatric disorders, such as schizophrenia. DVD deficiency in rats is associated with altered brain structure and adult behaviours indicating alterations in dopamine and glutamate signalling. Developmental alterations in dopamine neurotransmission have also been observed in DVD-deficient rats but a comprehensive assessment of brain neurochemistry has not been undertaken. Thus, the current study determined the regional concentrations of dopamine, noradrenaline, serotonin, glutamine, glutamate and γ-aminobutyric acid (GABA), and associated metabolites, in DVD-deficient neonates. Sprague-Dawley rats were fed a vitamin D deficient diet or control diet six weeks prior to mating until birth and housed under UVB-free lighting conditions. Neurotransmitter concentration was assessed by high-performance liquid chromatography on post-mortem neonatal brain tissue. Ubiquitous reductions in the levels of glutamine (12-24%) were observed in DVD-deficient neonates compared with control neonates. Similarly, in multiple brain regions DVD-deficient neonates had increased levels of noradrenaline and serine compared with control neonates. In contrast, increased levels of dopamine and decreased levels of serotonin in DVD-deficient neonates were limited to striatal subregions compared with controls. Our results confirm that DVD deficiency leads to changes in multiple neurotransmitter systems in the neonate brain. Importantly, this regionally-based assessment in DVD-deficient neonates identified both widespread neurotransmitter changes (glutamine/noradrenaline) and regionally selective neurotransmitter changes (dopamine/serotonin). Thus, vitamin D may have both general and local actions depending on the neurotransmitter system being investigated. Taken together, these data suggest that DVD deficiency alters neurotransmitter systems relevant to schizophrenia in the developing rat

Hepatoma targeting peptide conjugated bio-reducible polymer complexed with oncolytic adenovirus for cancer gene therapy

PubMed Central

Choi, Joung-Woo; Kim, Hyun Ah; Nam, Kihoon; Na, Youjin; Yun, Chae-Ok; Kim, SungWan

2015-01-01

Despite adenovirus (Ad) vector’s numerous advantages for cancer gene therapy, such as high ability of endosomal escape, efficient nuclear entry mechanism, and high transduction, and therapeutic efficacy, tumor specific targeting and antiviral immune response still remain as a critical challenge in clinical setting. To overcome these obstacles and achieve cancer-specific targeting, we constructed tumor targeting bioreducible polymer, an arginine grafted bio-reducible polymer (ABP)-PEG-HCBP1, by conjugating PEGylated ABP with HCBP1 peptides which has high affinity and selectivity towards hepatoma. The ABP-PEG-HCBP1-conjugated replication incompetent GFP-expressing ad, (Ad/GFP)-ABP-PEG-HCBP1, showed a hepatoma cancer specific uptake and transduction compared to either naked Ad/GFP or Ad/GFP-ABP. Competition assays demonstrated that Ad/GFP-ABP-PEG-HCBP1-mediated transduction was specifically inhibited by HCBP1 peptide rather than coxsackie and adenovirus receptor specific antibody. In addition, ABP-PEG-HCBP1 can protect biological activity of Ad against serum, and considerably reduced both innate and adaptive immune response against Ad. shMet-expressing oncolytic Ad (oAd; RdB/shMet) complexed with ABP-PEG-HCBP1 delivered oAd efficiently into hepatoma cancer cells. The oAd/ABP-PEG-HCBP1 demonstrated enhanced cancer cell killing efficacy in comparison to oAd/ABP complex. Furthermore, Huh7 and HT1080 cancer cells treated with oAd/shMet-ABP-PEG-HCBP1 complex had significantly decreased Met and VEGF expression in hepatoma cancer, but not in non-hepatoma cancer. In sum, these results suggest that HCBP1-conjugated bioreducible polymer could be used to deliver oncolytic Ad safely and efficiently to treat hepatoma. PMID:26437261

Physical Activity, Energy Expenditure, and Defense of Body Weight in Melanocortin 4 Receptor-Deficient Male Rats

PubMed Central

Almundarij, Tariq I.; Smyers, Mark E.; Spriggs, Addison; Heemstra, Lydia A.; Beltz, Lisa; Dyne, Eric; Ridenour, Caitlyn; Novak, Colleen M.

2016-01-01

Melanocortin 4 receptor (MC4R) variants contribute to human obesity, and rats lacking functional MC4R (Mc4rK314X/K314X) are obese. We investigated the hypothesis that low energy expenditure (EE) and physical activity contribute to this obese phenotype in male rats, and determined whether lack of functional MC4R conferred protection from weight loss during 50% calorie restriction. Though Mc4rK314X/K314X rats showed low brown adipose Ucp1 expression and were less physically active than rats heterozygous for the mutation (Mc4r+/K314X) or wild-type (Mc4r+/+) rats, we found no evidence of lowered EE in Mc4rK314X/K314X rats once body weight was taken into account using covariance. Mc4rK314X/K314X rats had a significantly higher respiratory exchange ratio. Compared to Mc4r+/+ rats, Mc4rK314X/K314X and Mc4r+/K314X rats lost less lean mass during calorie restriction, and less body mass when baseline weight was accounted for. Limited regional overexpression of Mc3r was found in the hypothalamus. Although lower physical activity levels in rats with nonfunctional MC4R did not result in lower total EE during free-fed conditions, rats lacking one or two functional copies of Mc4r showed conservation of mass, particularly lean mass, during energy restriction. This suggests that variants affecting MC4R function may contribute to individual differences in the metabolic response to food restriction. PMID:27886210

Restoration of peripheral V2 receptor vasopressin signaling fails to correct behavioral changes in Brattleboro rats.

PubMed

Balázsfi, Diána; Pintér, Ottó; Klausz, Barbara; Kovács, Krisztina B; Fodor, Anna; Török, Bibiána; Engelmann, Mario; Zelena, Dóra

2015-01-01

Beside its hormonal function in salt and water homeostasis, vasopressin released into distinct brain areas plays a crucial role in stress-related behavior resulting in the enhancement of an anxious/depressive-like state. We aimed to investigate whether correction of the peripheral symptoms of congenital absence of AVP also corrects the behavioral alterations in AVP-deficient Brattleboro rats. Wild type (WT) and vasopressin-deficient (KO) male Brattleboro rats were tested. Half of the KO animals were treated by desmopressin (V2-receptor agonist) via osmotic minipump (subcutaneous) to eliminate the peripheral symptoms of vasopressin-deficiency. Anxiety was studied by elevated plus maze (EPM), defensive withdrawal (DW) and marble burying (MB) tests, while depressive-like changes were monitored in forced swimming (FS) and anhedonia by sucrose preference test. Cell activity was examined in septum and amygdala by c-Fos immunohistochemistry after 10 min FS. KO rats spent more time in the open arm of the EPM, spent less time at the periphery of DW and showed less burying behavior in MB suggesting a reduced anxiety state. KO animals showed less floating behavior during FS revealing a less depressive phenotype. Desmopressin treatment compensated the peripheral effects of vasopressin-deficiency without a significant influence on the behavior. The FS-induced c-Fos immunoreactivity in the medial amygdala was different in WT and KO rats, with almost identical levels in KO and desmopressin treated animals. There were no differences in central and basolateral amygdala as well as in lateral septum. Our data confirmed the role of vasopressin in the development of affective disorders through central mechanisms. The involvement of the medial amygdala in the behavioral alterations of vasopressin deficient animals deserves further attention. Copyright © 2014 Elsevier Ltd. All rights reserved.

FAD-induced in vitro activation of glutathione reductase in the lens of B2 deficient rats.

PubMed

Ono, S; Hirano, H

1984-04-01

We studied the FAD-induced in vitro stimulation of lenticular glutathione reductase in riboflavin-deficient rats. The stimulatory effect of FAD on lenticular glutathione reductase in rats fed a B2-deficient diet for 4 weeks was remarkably higher than in paired control rats fed a B2-supplemented basal diet and control rats had ad libitum access to a B2-supplemented basal diet. The in vitro FAD stimulation effect on rat lenticular glutathione reductase represents a sensitive indicator of the B2 deficient status.

Physical activity prevents augmented body fat accretion in moderately iron-deficient rats.

PubMed

McClung, James P; Andersen, Nancy E; Tarr, Tyson N; Stahl, Chad H; Young, Andrew J

2008-07-01

Recent studies describe an association between poor iron status and obesity in humans, although the mechanism explaining this relationship is unclear. The present study aimed to determine the effect of moderate iron deficiency and physical activity (PA) on body composition in an animal model. Male Sprague-Dawley rats consumed iron-adequate (IA; 40 mg/kg) or moderately iron-deficient (ID; 9 mg/kg) diets ad libitum for 12 wk. Rats were assigned to 4 treatment groups (n = 10 per group): IA, sedentary (IAS); IA, PA (IAPA); ID, sedentary (IDS); or ID, PA (IDPA). Activity involved running on motorized running wheels at 4 m/min for 1 h/d for 5 d/wk. After 12 wk, ID rats were not anemic, but body iron stores were reduced as indicated by diminished (P < 0.05) femur iron compared with IA rats. Treatment group did not affect body weight or feed consumption. However, fat mass was greater (P < 0.05) in IDS rats (38.6 +/- 6.7%) than IAS (31.8 +/- 2.9%), IAPA (31.8 +/- 2.0%), and IDPA (32.8 +/- 4.5%) rats. Furthermore, lean body mass was diminished in IDS rats (58.7 +/- 6.8%) compared with IAS (65.6 +/- 3.0%), IAPA (65.6 +/- 2.1%), and IDPA (64.7 +/- 4.5%) rats. Thus, moderate iron deficiency may cause increased body fat accretion in rats and PA attenuates that effect.

Time course and pattern of compensatory ingestive behavioral adjustments to lysine deficiency in rats.

PubMed

Markison, S; Thompson, B L; Smith, J C; Spector, A C

2000-05-01

We and others have demonstrated that rats deficient in an essential amino acid (EAA) will consume sufficient quantities of the lacking nutrient to produce repletion when it is made available in solution. In the current series of experiments, we made rats deficient in lysine (LYS) by limiting the level of this EAA in the diet. We then examined licking behavior during approximately 23-h two-bottle intake tests over 4 consecutive days. In three separate experiments, rats were presented with the following: 1) 0.1 mol/L LYS and water, 2) 0.2 mol/L threonine (THR) and water and 3) 0.1 mol/L LYS and 0.2 mol/L THR. Lysine-deficient (LYS-DEF) rats drink significantly more LYS than did nondepleted controls (CON) when this amino acid was available. Meal pattern analysis revealed that the enhanced intake of LYS occurred as a function of a greater number of ingestive bouts, not changes in bout size. A cumulative analysis of LYS intake between CON and LYS-DEF rats revealed that a potentiation of intake developed within 30 min of sampling the solution when LYS and water were available and within 90 min when LYS and THR were the contrasting choices. In conclusion, increased LYS intake in the deficient rats occurs relatively rapidly and appears to be at least somewhat specific. Moreover, LYS deficiency does not seem to enhance the palatability of the limiting amino acid as judged by behaviors such as lick rate and bout size. Instead, LYS-DEF rats relieve the deficiency by increasing the number of drinking episodes initiated.

Omega-3 fatty acid deficient male rats exhibit abnormal behavioral activation in the forced swim test following chronic fluoxetine treatment: association with altered 5-HT1A and alpha2A adrenergic receptor expression.

PubMed

Able, Jessica A; Liu, Yanhong; Jandacek, Ronald; Rider, Therese; Tso, Patrick; McNamara, Robert K

2014-03-01

Omega-3 fatty acid deficiency during development leads to enduing alterations in central monoamine neurotransmission in rat brain. Here we investigated the effects of omega-3 fatty acid deficiency on behavioral and neurochemical responses to chronic fluoxetine (FLX) treatment. Male rats were fed diets with (CON, n = 34) or without (DEF, n = 30) the omega-3 fatty acid precursor alpha-linolenic acid (ALA) during peri-adolescent development (P21-P90). A subset of CON (n = 14) and DEF (n = 12) rats were administered FLX (10 mg/kg/d) through their drinking water for 30 d beginning on P60. The forced swimming test (FST) was initiated on P90, and regional brain mRNA markers of serotonin and noradrenaline neurotransmission were determined. Dietary ALA depletion led to significant reductions in frontal cortex docosahexaenoic acid (DHA, 22:6n-3) composition in DEF (-26%, p = 0.0001) and DEF + FLX (-32%, p = 0.0001) rats. Plasma FLX and norfluoxetine concentrations did not different between FLX-treated DEF and CON rats. During the 15-min FST pretest, DEF + FLX rats exhibited significantly greater climbing behavior compared with CON + FLX rats. During the 5-min test trial, FLX treatment reduced immobility and increased swimming in CON and DEF rats, and only DEF + FLX rats exhibited significant elevations in climbing behavior. DEF + FLX rats exhibited greater midbrain, and lower frontal cortex, 5-HT1A mRNA expression compared with all groups including CON + FLX rats. DEF + FLX rats also exhibited greater midbrain alpha2A adrenergic receptor mRNA expression which was positively correlated with climbing behavior in the FST. These preclinical data demonstrate that low omega-3 fatty acid status leads to abnormal behavioral and neurochemical responses to chronic FLX treatment in male rats. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of Zinc Supplementation on DNA Damage in Rats with Experimental Kidney Deficiency.

PubMed

Yegin, Sevim Çiftçi; Dede, Semiha; Mis, Leyla; Yur, Fatmagül

2017-04-01

This study was carried out to determine the effect of zinc on oxidative DNA damage in rats with experimental acute and chronic kidney deficiency. Six groups of five Wistar-Albino rats each were assigned as controls (C), acute kidney deficiency (AKD), zinc-supplemented (+Zn), acute kidney deficiency, zinc-supplemented (AKD + Zn), chronic kidney deficiency (CKD) and zinc-supplemented chronic kidney deficiency (CKD + Zn). The levels of 8-Oxo-2'-deoxyguanosine (8-OHdG) were determined, being the lowest in the CKD group (p < 0.05), higher in the C group than those of rats with CKD but lower than that of all the other groups (p < 0.05). There were no significant differences between the controls and the CKD + Zn group, or between the AKD and the +Zn groups. Among all groups, the highest 8-OHdG level was found in the AKD + Zn group (p < 0.05). DNA damage was greater in acute renal failure than in rats with chronic renal failure. The DNA damage in the zinc group was significantly higher than in the controls.

Impaired local immune response in vitamin A-deficient rats.

PubMed Central

Sirisinha, S; Darip, M D; Moongkarndi, P; Ongsakul, M; Lamb, A J

1980-01-01

The functional integrity of the local immune system in vitamin A-deficient (A-) rats was investigated. Secretory IgA levels in the intestinal fluid of A- rats were significantly lower than in controls. This and the decrease in intensity of immunofluorescent staining for secretory component (SC) in the intestinal cells was related to the duration of vitamin A deprivation. IgG levels in the intestinal fluid, and serum IgA and IgG levels were unaffected in deficiency. Moreover, when the response of animals to DNP50-BGG was evaluated, the local anti-DNP response in the intestine was markedly depressed. These defects may result from impaired synthesis of SC by epithelial cells. On the other hand, the serum antibody response in deficient animals was not noticeably different from that of the controls; if any, htere was a slight reduction in the affinity of antibody. PMID:7389210

Hepatoma targeting peptide conjugated bio-reducible polymer complexed with oncolytic adenovirus for cancer gene therapy.

PubMed

Choi, Joung-Woo; Kim, Hyun Ah; Nam, Kihoon; Na, Youjin; Yun, Chae-Ok; Kim, SungWan

2015-12-28

Despite adenovirus (Ad) vector's numerous advantages for cancer gene therapy, such as high ability of endosomal escape, efficient nuclear entry mechanism, and high transduction, and therapeutic efficacy, tumor specific targeting and antiviral immune response still remain as a critical challenge in clinical setting. To overcome these obstacles and achieve cancer-specific targeting, we constructed tumor targeting bioreducible polymer, an arginine grafted bio-reducible polymer (ABP)-PEG-HCBP1, by conjugating PEGylated ABP with HCBP1 peptides which has high affinity and selectivity towards hepatoma. The ABP-PEG-HCBP1-conjugated replication incompetent GFP-expressing ad, (Ad/GFP)-ABP-PEG-HCBP1, showed a hepatoma cancer specific uptake and transduction compared to either naked Ad/GFP or Ad/GFP-ABP. Competition assays demonstrated that Ad/GFP-ABP-PEG-HCBP1-mediated transduction was specifically inhibited by HCBP1 peptide rather than coxsackie and adenovirus receptor specific antibody. In addition, ABP-PEG-HCBP1 can protect biological activity of Ad against serum, and considerably reduced both innate and adaptive immune response against Ad. shMet-expressing oncolytic Ad (oAd; RdB/shMet) complexed with ABP-PEG-HCBP1 delivered oAd efficiently into hepatoma cancer cells. The oAd/ABP-PEG-HCBP1 demonstrated enhanced cancer cell killing efficacy in comparison to oAd/ABP complex. Furthermore, Huh7 and HT1080 cancer cells treated with oAd/shMet-ABP-PEG-HCBP1 complex had significantly decreased Met and VEGF expression in hepatoma cancer, but not in non-hepatoma cancer. In sum, these results suggest that HCBP1-conjugated bioreducible polymer could be used to deliver oncolytic Ad safely and efficiently to treat hepatoma. Copyright © 2015 Elsevier B.V. All rights reserved.

Effect of Daytime Blue-enriched LED Light on the Nighttime Circadian Melatonin Inhibition of Hepatoma 7288CTC Warburg Effect and Progression.

PubMed

Dauchy, Robert T; Wren-Dail, Melissa A; Dupepe, Lynell M; Hill, Steven M; Xiang, Shulin; Anbalagan, Muralidharan; Belancio, Victoria P; Dauchy, Erin M; Blask, David E

2018-06-06

Liver cancer is the second leading cause of cancer death worldwide. Metabolic pathways within the liver and liver cancersare highly regulated by the central circadian clock in the suprachiasmatic nuclei (SCN). Daily light and dark cycles regulate the SCN-driven pineal production of the circadian anticancer hormone melatonin and temporally coordinate circadianrhythms of metabolism and physiology in mammals. In previous studies, we demonstrated that melatonin suppresses linoleicacid metabolism and the Warburg effect (aerobic glycolysis)in human breast cancer xenografts and that blue-enriched light(465-485 nm) from light-emitting diode lighting at daytime (bLAD) amplifies nighttime circadian melatonin levels in ratsby 7-fold over cool white fluorescent (CWF) lighting. Here we tested the hypothesis that daytime exposure of tissue-isolatedMorris hepatoma 7288CTC-bearing male rats to bLAD amplifies the nighttime melatonin signal to enhance the inhibition oftumor growth. Compared with rats housed under a 12:12-h light:dark cycle in CWF light, rats in bLAD light evinced a 7-fold higher peak plasma melatonin level at the mid-dark phase; in addition, high melatonin levels were prolonged until 4 h intothe light phase. After implantation of tissue-isolated hepatoma 7288CTC xenografts, tumor growth rates were markedly delayed,and tumor cAMP levels, LA metabolism, the Warburg effect, and growth signaling activities were decreased in rats inbLAD compared with CWF daytime lighting. These data show that the increased nighttime circadian melatonin levels dueto bLAD exposure decreases hepatoma metabolic, signaling, and proliferative activities beyond what occurs after normalmelatonin signaling under CWF light.

Pregnancy and maternal iron deficiency stimulate hepatic CRBPII expression in rats.

PubMed

Cottin, Sarah C; Gambling, Lorraine; Hayes, Helen E; Stevens, Valerie J; McArdle, Harry J

2016-06-01

Iron deficiency impairs vitamin A (VA) metabolism in the rat but the mechanisms involved are unknown and the effect during development has not been investigated. We investigated the effect of pregnancy and maternal iron deficiency on VA metabolism in the mother and fetus. 54 rats were fed either a control or iron deficient diet for 2weeks prior to mating and throughout pregnancy. Another 15 female rats followed the same diet and were used as non-pregnant controls. Maternal liver, placenta and fetal liver were collected at d21 for total VA, retinol and retinyl ester (RE) measurement and VA metabolic gene expression analysis. Iron deficiency increased maternal hepatic RE (P<.05) and total VA (P<.0001), fetal liver RE (P<.05), and decreased placenta total VA (P<.05). Pregnancy increased Cellular Retinol Binding Protein (CRBP)-II gene expression by 7 fold (P=.001), decreased VA levels (P=.0004) and VA metabolic gene expression (P<.0001) in the liver. Iron deficiency increased hepatic CRBPII expression by a further 2 fold (P=.044) and RBP4 by~20% (P=.005), increased RBPR2 and decreased CRBPII, LRAT, and TTR in fetal liver, while it had no effect on VA metabolic gene expression in the placenta. Hepatic CRBPII expression is increased by pregnancy and further increased by iron deficiency, which may play an important role in VA metabolism and homeostasis. Maternal iron deficiency also alters VA metabolism in the fetus, which is likely to have consequences for development. Copyright © 2016 Elsevier Inc. All rights reserved.

[Effect of AÇaí (Euterpe oleracea) on lipid metabolism, immune substances and endocrine hormone in rats with deficiency-heat and deficiency-cold syndrome].

PubMed

Wang, Zi-Chen; Zhang, Jian-Jun; Zhu, Ying-Li; Qu, Yan; Fei, Wen-Ting; Wang, Sha; Wang, Jing-Xia; Wang, Lin-Yuan

2017-07-01

To study the effects of AÇaí(Euterpe oleracea) on lipid metabolism, immune substances and endocrine hormone level in rats with deficiency-heat and deficiency-cold syndrome. SD rats were divided into blank control group, deficiency-heat model group, deficiency-heat & Phellodendri Cortex group, deficiency-heat & AÇaí high dose and low dose groups, deficiency-cold model group, deficiency-cold & Cinnamomi Cortex group, deficiency-cold & AÇaí high dose and low dose groups. The rats received intramuscular injection of dexamethasone sodium phosphate (0.35 mg) or hydrocortisone sodium succinate (20 mg) for 21 days to set up deficiency-heat models and deficiency-cold models. Then the changes in fatmetabolism levels (FFA, LPL, HL) and immune indexes (IgG, IgM, C3 and C4) were detected by colorimeter; and the levels of endocrine hormone indexes (CORT, E2 and T) were detected by radioimmunoassay. The levels of FFA, LPL and HL in serum were reduced (P<0.01 or P<0.001); levels of IgG, IgM and C3 in serum were increased (P<0.05 or P<0.001); level of CORT in serum was increased (P<0.05) and the level of E2, E2/T in serum were reduced in the AÇaí high dose group (P<0.05). The effect of high dose AÇaí on fat metabolism was not obvious in deficiency-cold models, but the levels of IgG, IgM, C3 and CORT in serum were increased (P<0.05 or P<0.001). AÇaí was showed the same effect trend with Phellodendri Cortex in adjusting the levels of deficiency-heat rats; but unlike Cinnamomi Cortex, AÇaí was showed no obvious effect in adjusting the levels of deficiency-cold rats. In this experiment, homogeneous comparison and heterogeneous disproof were used to verify the cold nature of Çaí. Copyright© by the Chinese Pharmaceutical Association.

Voluntary wheel running is beneficial to the amino acid profile of lysine-deficient rats.

PubMed

Nagao, Kenji; Bannai, Makoto; Seki, Shinobu; Kawai, Nobuhiro; Mori, Masato; Takahashi, Michio

2010-06-01

Rats voluntarily run up to a dozen kilometers per night when their cages are equipped with a running wheel. Daily voluntary running is generally thought to enhance protein turnover. Thus, we sought to determine whether running worsens or improves protein degradation caused by a lysine-deficient diet and whether it changes the utilization of free amino acids released by proteolysis. Rats were fed a lysine-deficient diet and were given free access to a running wheel or remained sedentary (control) for 4 wk. Amino acid levels in plasma, muscle, and liver were measured together with plasma insulin levels and tissue weight. The lysine-deficient diet induced anorexia, skeletal muscle loss, and serine and threonine aminoacidemia, and it depleted plasma insulin and essential amino acids in skeletal muscle. Allowing rats to run voluntarily improved these symptoms; thus, voluntary wheel running made the rats less susceptible to dietary lysine deficiency. Amelioration of the declines in muscular leucine and plasma insulin observed in running rats could contribute to protein synthesis together with the enhanced availability of lysine and other essential amino acids in skeletal muscle. These results indicate that voluntary wheel running under lysine-deficient conditions does not enhance protein catabolism; on the contrary, it accelerates protein synthesis and contributes to the maintenance of muscle mass. The intense nocturnal voluntary running that characterizes rodents might be an adaptation of lysine-deficient grain eaters that allows them to maximize opportunities for food acquisition.

Deficient prepulse inhibition of acoustic startle in Hooded-Wistar rats compared with Sprague-Dawley rats.

PubMed

van den Buuse, Maarten

2003-04-01

1. Prepulse inhibition of acoustic startle has been suggested as a model of sensorimotor gating and central sensory information processing. Prepulse inhibition is impaired in patients with schizophrenia and responses can be restored by antipsychotic drug treatment. In the present study, startle and prepulse inhibition of startle were compared in different rat strains. 2. Sprague-Dawley rats showed robust inhibition of startle responses by increasing intensities of prepulse delivered just before the startle stimulus. In contrast, at both 4 and 10 weeks of age, rats of the Hooded-Wistar line had markedly reduced prepulse inhibition, although startle responses were not different. 3. Treatment with the dopamine receptor agonist apomorphine (0.1 mg/kg) or the N-methyl-d-aspartate (NMDA) receptor antagonist MK-801 (0.1 mg/kg) caused disruption of prepulse inhibition in Sprague-Dawley rats. In Hooded-Wistar rats, apomorphine further reduced the already low level of prepulse inhibition, but MK-801 treatment had no significant effect. This suggests that the impaired prepulse inhibition in Hooded-Wistar rats could be caused by changes in glutamatergic activity and/or NMDA receptors in these rats. 4. In photocell cages, spontaneous exploratory activity and inner zone activity were significantly lower in Hooded-Wistar rats than in Sprague-Dawley rats. Similarly, on the elevated plus-maze, Hooded-Wistar rats showed a lower propensity to visit the open arms. In contrast, amphetamine (0.5 mg/kg)-induced locomotor hyperactivity, an animal model of psychosis, was enhanced in Hooded-Wistar rats. 5. These data suggest that the Hooded-Wistar line could be a useful genetic animal model to study the interaction of glutamatergic and dopaminergic mechanisms in anxiety and schizophrenia.

Galactose-functionalized multi-responsive nanogels for hepatoma-targeted drug delivery

NASA Astrophysics Data System (ADS)

Lou, Shaofeng; Gao, Shan; Wang, Weiwei; Zhang, Mingming; Zhang, Ju; Wang, Chun; Li, Chen; Kong, Deling; Zhao, Qiang

2015-02-01

We report here a hepatoma-targeting multi-responsive biodegradable crosslinked nanogel, poly(6-O-vinyladipoyl-d-galactose-ss-N-vinylcaprolactam-ss-methacrylic acid) P(ODGal-VCL-MAA), using a combination of enzymatic transesterification and emulsion copolymerization for intracellular drug delivery. The nanogel exhibited redox, pH and temperature-responsive properties, which can be adjusted by varying the monomer feeding ratio. Furthermore, the volume phase transition temperature (VPTT) of the nanogels was close to body temperature and can result in rapid thermal gelation at 37 °C. Scanning electron microscopy also revealed that the P(ODGal-VCL-MAA) nanogel showed uniform spherical monodispersion. With pyrene as a probe, the fluorescence excitation spectra demonstrated nanogel degradation in response to glutathione (GSH). X-ray diffraction (XRD) showed an amorphous property of DOX within the nanogel, which was used in this study as a model anti-cancer drug. Drug-releasing characteristics of the nanogel were examined in vitro. The results showed multi-responsiveness of DOX release by the variation of environmental pH values, temperature or the availability of GSH, a biological reductase. An in vitro cytotoxicity assay showed a higher anti-tumor activity of the galactose-functionalized DOX-loaded nanogels against human hepatoma HepG2 cells, which was, at least in part, due to specific binding between the galactose segments and the asialoglycoprotein receptors (ASGP-Rs) in hepatic cells. Confocal laser scanning microscopy (CLSM) and flow cytometric profiles further confirmed elevated cellular uptake of DOX by the galactose-functionalised nanogels. Thus, we report here a multi-responsive P(ODGal-VCL-MAA) nanogel with a hepatoma-specific targeting ability for anti-cancer drug delivery.We report here a hepatoma-targeting multi-responsive biodegradable crosslinked nanogel, poly(6-O-vinyladipoyl-d-galactose-ss-N-vinylcaprolactam-ss-methacrylic acid) P(ODGal-VCL-MAA), using

Developmental Vitamin D (DVD) Deficiency Reduces Nurr1 and TH Expression in Post-mitotic Dopamine Neurons in Rat Mesencephalon.

PubMed

Luan, Wei; Hammond, Luke Alexander; Cotter, Edmund; Osborne, Geoffrey William; Alexander, Suzanne Adele; Nink, Virginia; Cui, Xiaoying; Eyles, Darryl Walter

2018-03-01

Developmental vitamin D (DVD) deficiency has been proposed as an important risk factor for schizophrenia. Our previous study using Sprague Dawley rats found that DVD deficiency disrupted the ontogeny of mesencephalic dopamine neurons by decreasing the mRNA level of a crucial differentiation factor of dopamine cells, the nuclear receptor related 1 protein (Nurr1). However, it remains unknown whether this reflects a reduction in dopamine cell number or in Nurr1 expression. It is also unclear if any particular subset of developing dopamine neurons in the mesencephalon is selectively affected. In this study, we employed state-of-the-art spinning disk confocal microscopy optimized for the imaging of tissue sections and 3D segmentation to assess post-mitotic dopamine cells on a single-cell basis in the rat mesencephalon at embryonic day 15. Our results showed that DVD deficiency did not alter the number, morphology, or positioning of post-mitotic dopamine cells. However, the ratio of Nurr1+TH+ cells in the substantia nigra pars compacta (SNc) compared with the ventral tegmental area (VTA) was increased in DVD-deficient embryos. In addition, the expression of Nurr1 in immature dopamine cells and mature dopamine neurons in the VTA was decreased in DVD-deficient group. Tyrosine hydroxylase was selectively reduced in SNc of DVD-deficient mesencephalon. We conclude that DVD deficiency induced early alterations in mesencephalic dopamine development may in part explain the abnormal dopamine-related behaviors found in this model. Our findings may have broader implications for how certain environmental risk factors for schizophrenia may shape the ontogeny of dopaminergic systems and by inference increase the risk of schizophrenia.

Characteristics of recombinantly expressed rat and human histamine H3 receptors.

PubMed

Wulff, Birgitte S; Hastrup, Sven; Rimvall, Karin

2002-10-18

Human and rat histamine H(3) receptors were recombinantly expressed and characterized using receptor binding and a functional cAMP assay. Seven of nine agonists had similar affinities and potencies at the rat and human histamine H(3) receptor. S-alpha-methylhistamine had a significantly higher affinity and potency at the human than rat receptor, and for 4-[(1R*,2R*)-2-(5,5-dimethyl-1-hexynyl)cyclopropyl]-1H-imidazole (Perceptin) the preference was the reverse. Only two of six antagonists had similar affinities and potencies at the human and the rat histamine H(3) receptor. Ciproxifan, thioperamide and (1R*,2R*)-trans-2-imidazol-4 ylcyclopropyl) (cyclohexylmethoxy) carboxamide (GT2394) had significantly higher affinities and potencies at the rat than at the human histamine H(3) receptor, while for N-(4-chlorobenzyl)-N-(7-pyrrolodin-1-ylheptyl)guanidine (JB98064) the preference was the reverse. All antagonists also showed potent inverse agonism properties. Iodoproxyfan, Perceptin, proxyfan and GR175737, compounds previously described as histamine H(3) receptor antagonists, acted as full or partial agonists at both the rat and the human histamine H(3) receptor. Copyright 2002 Elsevier Science B.V.

Functional properties of internalization-deficient P2X4 receptors reveal a novel mechanism of ligand-gated channel facilitation by ivermectin.

PubMed

Toulmé, Estelle; Soto, Florentina; Garret, Maurice; Boué-Grabot, Eric

2006-02-01

Although P2X receptors within the central nervous system mediate excitatory ATP synaptic transmission, the identity of central ATP-gated channels has not yet been elucidated. P2X(4), the most widely expressed subunit in the brain, was previously shown to undergo clathrin-dependent constitutive internalization by direct interaction between activator protein (AP)2 adaptors and a tyrosine-based sorting signal specifically present in the cytosolic C-terminal tail of mammalian P2X(4) sequences. In this study, we first used internalization-deficient P2X(4) receptor mutants to show that suppression of the endocytosis motif significantly increased the apparent sensitivity to ATP and the ionic permeability of P2X(4) channels. These unique properties, observed at low channel density, suggest that interactions with AP2 complexes may modulate the function of P2X(4) receptors. In addition, ivermectin, an allosteric modulator of several receptor channels, including mammalian P2X(4), did not potentiate the maximal current of internalization-deficient rat or human P2X(4) receptors. We demonstrated that binding of ivermectin onto wild-type P2X(4) channels increased the fraction of plasma membrane P2X(4) receptors, whereas surface expression of internalization-deficient P2X(4) receptors remained unchanged. Disruption of the clathrin-mediated endocytosis with the dominant-negative mutants Eps15 or AP-50 abolished the ivermectin potentiation of wild-type P2X(4) channel currents. Likewise, ivermectin increased the membrane fraction of nicotinic alpha7 acetylcholine (nalpha7ACh) receptors and the potentiation of acetylcholine current by ivermectin was suppressed when the same dominant-negative mutants were expressed. These data showed that potentiation by ivermectin of both P2X(4) and nalpha7ACh receptors was primarily caused by an increase in the number of cell surface receptors resulting from a mechanism dependent on clathrin/AP2-mediated endocytosis.

Cytotoxicity of the dicarboximide fungicides, vinclozolin and iprodione, in rat hepatoma-derived Fa32 cells.

PubMed

Dierickx, Paul J

2004-10-01

Dicarboximide fungicides are widely used to control various fungal species. Their primary action is not known, due to a lack of knowledge concerning the mechanism of action of the dicarboximide group. The cytotoxicities of vinclozolin and iprodione in rat hepatoma-derived Fa32 cells were investigated. Cytotoxicity was measured by neutral red uptake inhibition after treatment for 24 hours. Iprodione was more toxic than vinclozolin. Vinclozolin was less toxic in glutathione-depleted cells than in control cells. This was also true for iprodione at lower concentrations, but iprodione became more toxic at higher concentrations. Both the fungicides increased the endogenous glutathione content by 20% after 1 hour. After 24 hours, the glutathione content was doubled by vinclozolin, but was not affected by iprodione. No effect on glutathione S-transferase activity or reactive oxygen species formation could be observed. Cytochrome P450-dependent ethoxyresorufin-O-deethylase and pentoxyresorufin-O-depentylase activities were moderately activated by iprodione and strongly activated by vinclozolin. A glutathione-related cytochrome P450-dependent metabolic attack of vinclozolin and iprodione could be responsible for their cytotoxicity in Fa32 cells. Further research is needed to fully elucidate these (or other) mechanisms.

Attenuation of acoustic and tactile startle responses of vitamin B-6 deficient rats.

PubMed

Schaeffer, M C

1987-01-01

Vitamin B-6 deficient rats exhibit changes in behavior, sensory function, and other nervous system abnormalities such as convulsive seizures and motor disturbances. Sensorimotor reactivity was evaluated quantitatively by measuring auditory and tactile startle responses in 12 week old female Long-Evans rats fed a diet devoid of added vitamin B-6 (DEF) or a control diet, either ad lib (AL-CON) or pair-fed to deficient rats (PF-CON). Deficiency was confirmed with a tryptophan-load test administered to a separate group of rats fed simultaneously according to the same protocol. At week 18, body weight and feed efficiency were different among groups (p less than 0.001), and were lowest in DEF. Amplitude of response to both acoustic and tactile stimuli was depressed in DEF compared to both control groups, which generally did not differ in response. This effect was seen most dramatically in responses to the acoustic stimulus (p = 0.034), and especially to the first presentation (p = 0.017). Latency to maximum response was not affected by diet. Possible mechanisms for this nervous system abnormality, not previously reported in vitamin B-6 deficiency, are discussed.

Unopposed Estrogen Supplementation/Progesterone Deficiency in Post-Reproductive Age Affects the Secretory Profile of Resident Macrophages in a Tissue-Specific Manner in the Rat.

PubMed

Stanojević, Stanislava; Kovačević-Jovanović, Vesna; Dimitrijević, Mirjana; Vujić, Vesna; Ćuruvija, Ivana; Blagojević, Veljko; Leposavić, Gordana

2015-11-01

The influence of unopposed estrogen replacement/isolated progesterone deficiency on macrophage production of pro-inflammatory/anti-inflammatory mediators in the post-reproductive age was studied. Considering that in the rats post-ovariectomy the circulating estradiol, but not progesterone level rises to the values in sham-operated controls, 20-month-old rats ovariectomized at the age of 10 months served as an experimental model. Estrogen and progesterone receptor expression, secretion of pro- and anti-inflammatory cytokines, and arginine metabolism end-products were examined in splenic and peritoneal macrophages under basal conditions and following lipopolysaccharide (LPS) stimulation in vitro. Almost all peritoneal and a subset of splenic macrophages expressed the intracellular progesterone receptor. Ovariectomy diminished cytokine production by splenic (IL-1β) and peritoneal (TNF-α, IL-1β, IL-10) macrophages and increased the production of IL-10 by splenic and TGF-β by peritoneal cells under basal conditions. Following LPS stimulation, splenic macrophages from ovariectomized rats produced less TNF-α and more IL-10, whereas peritoneal macrophages produced less IL-1β and TGF-β than the corresponding cells from sham-operated rats. Ovariectomy diminished urea production in both subpopulations of LPS-stimulated macrophages. Although long-lasting isolated progesterone deficiency in the post-reproductive age differentially affects cytokine production in the macrophages from distinct tissue compartments, in both subpopulations, it impairs the pro-inflammatory/anti-inflammatory cytokine secretory balance. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Magnesium attenuates chronic hypersensitivity and spinal cord NMDA receptor phosphorylation in a rat model of diabetic neuropathic pain

PubMed Central

Rondón, L J; Privat, A M; Daulhac, L; Davin, N; Mazur, A; Fialip, J; Eschalier, A; Courteix, C

2010-01-01

Neuropathic pain is a common diabetic complication affecting 8–16% of diabetic patients. It is characterized by aberrant symptoms of spontaneous and stimulus-evoked pain including hyperalgesia and allodynia. Magnesium (Mg) deficiency has been proposed as a factor in the pathogenesis of diabetes-related complications, including neuropathy. In the central nervous system, Mg is also a voltage-dependant blocker of the N-methyl-d-aspartate receptor channels involved in abnormal processing of sensory information. We hypothesized that Mg deficiency might contribute to the development of neuropathic pain and the worsening of clinical and biological signs of diabetes and consequently, that Mg administration could prevent or improve its complications. We examined the effects of oral Mg supplementation (296 mg l−1 in drinking water for 3 weeks) on the development of neuropathic pain and on biological and clinical parameters of diabetes in streptozocin (STZ)-induced diabetic rats. STZ administration induced typical symptoms of type 1 diabetes. The diabetic rats also displayed mechanical hypersensitivity and tactile and thermal allodynia. The level of phosphorylated NMDA receptor NR1 subunit (pNR1) was higher in the spinal dorsal horn of diabetic hyperalgesic/allodynic rats. Magnesium supplementation failed to reduce hyperglycaemia, polyphagia and hypermagnesiuria, or to restore intracellular Mg levels and body growth, but increased insulinaemia and reduced polydipsia. Moreover, it abolished thermal and tactile allodynia, delayed the development of mechanical hypersensitivity, and prevented the increase in spinal cord dorsal horn pNR1. Thus, neuropathic pain symptoms can be attenuated by targeting the Mg-mediated blockade of NMDA receptors, offering new therapeutic opportunities for the management of chronic neuropathic pain. PMID:20837644

Antidiuretic effects of a nonpeptide vasopressin V(2)-receptor agonist, OPC-51803, administered orally to rats.

PubMed

Nakamura, S; Hirano, T; Tsujimae, K; Aoyama, M; Kondo, K; Yamamura, Y; Mori, T; Tominaga, M

2000-12-01

OPC-51803 is the first nonpeptide vasopressin (AVP) V(2)-receptor-selective agonist. Its pharmacological profile, including antidiuretic action and receptor binding, was characterized using conscious Brattleboro rats with hereditary diabetes insipidus and Sprague-Dawley rats. In membrane preparations from the liver and kidney, OPC-51803 displaced the [(3)H]AVP binding to V(2)-receptors (K(i) = 49.8 +/- 8.1 nM) more greatly than that to V(1a)-receptors (K(i) = 1061 +/- 60 nM), showing a 21 times higher affinity for V(2)-receptors. At single oral doses of 0.003 to 0.3 mg/kg in female Brattleboro rats, OPC-51803 decreased urine volume (from 10.8 +/- 1.1 to 0.5 +/- 0.2 ml during 0-2 h postdosing) and increased urinary osmolality (from 114 +/- 9 to 432 +/- 114 mOsm/kg) in a dose-dependent manner. During the period of 4-week treatment with OPC-51803, significant and constant antidiuresis was observed. In male Sprague-Dawley rats with normal plasma AVP levels, OPC-51803 at 0.03 to 0.3 mg/kg also produced a dose-dependent antidiuretic action (urine volume: from 2.6 +/- 0.6 to 1.1 +/- 0.2 ml at 0-4 h postdosing). Few changes in urinary parameters, serum parameters, or plasma hormone levels were observed. OPC-51803 did not change blood pressure or heart rate, or inhibit AVP-induced pressor response even at 30 mg/kg p.o. These results demonstrate that OPC-51803 is a V(2)-selective agonist that produces a significant antidiuretic action after single and multiple oral dosing in AVP-deficient and normal AVP states. The data suggest that OPC-51803 is a useful therapeutic drug in the treatment of hypothalamic diabetes insipidus, nocturnal enuresis, and some kinds of urinary incontinence.

Ascorbic acid deficiency stimulates hepatic expression of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1, in scurvy-prone ODS rats.

PubMed

Horio, Fumihiko; Kiyama, Keiichiro; Kobayashi, Misato; Kawai, Kaori; Tsuda, Takanori

2006-02-01

ODS rat has a hereditary defect in ascorbic acid biosynthesis and is a useful animal model for elucidating the physiological role of ascorbic acid. We previously demonstrated by using ODS rats that ascorbic acid deficiency changes the hepatic gene expression of acute phase proteins, as seen in acute inflammation. In this study, we investigated the effects of ascorbic acid deficiency on the production of inflammatory chemokine, cytokine-induced neutrophil chemoattractant-1 (CINC-1), in ODS rats. Male ODS rats (6 wk of age) were fed a basal diet containing ascorbic acid (300 mg/kg diet) or a diet without ascorbic acid for 14 d. Obvious symptoms of scurvy were not observed in the ascorbic acid-deficient rats. Ascorbic acid deficiency significantly elevated the serum concentration of CINC-1 on d 14. The liver and spleen CINC-1 concentrations in the ascorbic acid-deficient rats were significantly elevated to 600% and 180% of the respective values in the control rats. However, the lung concentration of CINC-1 was not affected by ascorbic acid deficiency. Ascorbic acid deficiency significantly elevated the hepatic mRNA level of CINC-1 (to 480% of the value in the control rats), but not the lung mRNA level. These results demonstrate that ascorbic acid deficiency elevates the serum, liver and spleen concentrations of CINC-1 as seen in acute inflammation, and suggest that ascorbic acid deficiency stimulate the hepatic CINC-1 gene expression.

Rats fed soy protein isolate (SPI) have impaired hepatic CYP1A1 induction by polycyclic aromatic hydrocarbons as a result of interference with aryl hydrocarbon receptor signaling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Singhal, Rohit; Badger, Thomas M.; Arkansas Children's Nutrition Center, Little Rock, AR 72202

2008-03-01

Consumption of soy diets has been found to reduce cancer incidence in animals and is associated with reduced cancer risk in humans. Previously, we have demonstrated that female Sprague-Dawley rats fed purified AIN-93G diets with soy protein isolate (SPI) as the sole protein source had reduced CYP1A1 induction and basal aryl hydrocarbon receptor (AhR) levels relative to those fed the same diet containing casein (CAS). In the present study, the molecular mechanisms underlying reduced AhR expression have been studied. The SPI-effect on AhR was not observed after feeding diets containing the purified soy isoflavones genistein or daidzein. Rat hepatoma FGC-4more » cells were treated with the serum obtained from rats fed CAS- or SPI-containing diets. Reduced AhR levels (P < 0.05) were observed after 24 h exposure to SPI-serum without any changes in the overall expression of chaperone proteins-HSP90 and XAP2. SPI-serum-stimulated AhR degradation was inhibited by treating the cells with the proteasome inhibitor, MG132, and was observed to be preceded by ubiquitination of the receptor. A reduced association of XAP2 with the immunoprecipitated AhR complex was observed. SPI-serum-mediated AhR degradation was preceded by nuclear translocation of the receptor. However, the translocated receptor was found to be unable to heterodimerize with ARNT or to bind to XRE elements on the CYP1A1 enhancer. These data suggest that feeding SPI-containing diets antagonizes AhR signaling by a novel mechanism which differs from those established for known AhR antagonists.« less

Tachykinin receptors in the rat isolated uterus.

PubMed

Fisher, L; Pennefather, J N; Hall, S

1993-07-02

Tachykinin receptors mediating uterotonic effects were examined in preparations from oestrogen-primed rats. In the absence of peptidase inhibitors [Lys5-MeLeu9-Nle10] NKA (4-10) was 14-fold more potent than neurokinin A (NKA), but the two peptides were equipotent in the presence of phosphoramidon alone and in combination with amastatin. The NK-2 receptor antagonist SR 48968 antagonised responses to the tachykinins. These findings indicate that an NK-2 receptor is present in the oestrogen-primed rat uterus and that endopeptidase 24.11 plays a major role to inactivate NKA in this tissue.

Release of overexpressed CypB activates ERK signaling through CD147 binding for hepatoma cell resistance to oxidative stress.

PubMed

Kim, Kiyoon; Kim, Hunsung; Jeong, Kwon; Jung, Min Hyung; Hahn, Bum-Soo; Yoon, Kyung-Sik; Jin, Byung Kwan; Jahng, Geon-Ho; Kang, Insug; Ha, Joohun; Choe, Wonchae

2012-08-01

Cyclophilin, a cytosolic receptor for the immunosuppressive drug cyclosporin A, plays a role in diverse pathophysiologies along with its receptor, CD147. Although the interaction between cyclophilin A and CD147 is well established in inflammatory disease, that of cyclophilin B (CypB) with CD147 has not been fully explored, especially in cancer cell biology, and the exact molecular mechanism underlying such an association is poorly understood. In this study, we first identified high expression levels of CypB in 54 % of hepatocellular carcinoma patient tissues but in only 12.5 % of normal liver tissues. Then, we demonstrated that CypB overexpression protects human hepatoma cells against oxidative stress through its binding to CD147; this protective effect depends on the peptidyl prolyl isomerase activity of CypB. siRNA-mediated knockdown of CypB expression rendered hepatoma cells more vulnerable to ROS-mediated apoptosis. Furthermore, we also determined that a direct interaction between secreted CypB and CD147 regulates the extracellular signal-regulated kinase intracellular signaling pathway and is indispensible for the protective functions of CypB. For the first time, we demonstrated that CypB has an essential function in protecting hepatoma cells against oxidative stress through binding to CD147 and regulating the ERK pathway.

The ghrelin receptor agonist HM01 mimics the neuronal effects of ghrelin in the arcuate nucleus and attenuates anorexia-cachexia syndrome in tumor-bearing rats.

PubMed

Borner, Tito; Loi, Laura; Pietra, Claudio; Giuliano, Claudio; Lutz, Thomas A; Riediger, Thomas

2016-07-01

The gastric hormone ghrelin positively affects energy balance by increasing food intake and reducing energy expenditure. Ghrelin mimetics are a possible treatment against cancer anorexia-cachexia syndrome (CACS). This study aimed to characterize the action of the nonpeptidergic ghrelin receptor agonist HM01 on neuronal function, energy homeostasis and muscle mass in healthy rats and to evaluate its possible usefulness for the treatment of CACS in a rat tumor model. Using extracellular single-unit recordings, we tested whether HM01 mimics the effects of ghrelin on neuronal activity in the arcuate nucleus (Arc). Furthermore, we assessed the effect of chronic HM01 treatment on food intake (FI), body weight (BW), lean and fat volumes, and muscle mass in healthy rats. Using a hepatoma model, we investigated the possible beneficial effects of HM01 on tumor-induced anorexia, BW loss, muscle wasting, and metabolic rate. HM01 (10(-7)-10(-6) M) mimicked the effect of ghrelin (10(-8) M) by increasing the firing rate in 76% of Arc neurons. HM01 delivered chronically for 12 days via osmotic minipumps (50 μg/h) increased FI in healthy rats by 24%, paralleled by increased BW, higher fat and lean volumes, and higher muscle mass. Tumor-bearing rats treated with HM01 had 30% higher FI than tumor-bearing controls and were protected against BW loss. HM01 treatment resulted in higher muscle mass and fat mass. Moreover, tumor-bearing rats reduced their metabolic rate following HM01 treatment. Our studies substantiate the possible therapeutic usefulness of ghrelin receptor agonists like HM01 for the treatment of CACS and possibly other forms of disease-related anorexia and cachexia. Copyright © 2016 the American Physiological Society.

Effect of Zinc-Deficient Diet on Oral Tissues and Periodontal Indices in Rats

PubMed Central

Seyedmajidi, Seyed Ali; Seyedmajidi, Maryam; Moghadamnia, Aliakbar; Khani, Zohreh; Zahedpasha, Samir; Jenabian, Niloofar; Jorsaraei, Gholamali; Halalkhor, Sohrab; Motallebnejad, Mina

2014-01-01

Zinc (Zn) as a nutritional factor affects the health of the oral tissues. This study was done for the evaluation of the effects of zinc deficiency on the oral tissues of rats. The study was carried out on 14 male Wistar rats, cessation of lactation on the 24th day after birth. The rats were randomly divided into two groups. Zinc deficient (ZD) diet was used for one group and another group was fed with a zinc-containing (ZC) diet. The alterations of the oral tissues in both groups were evaluated clinically after four weeks. Also the gingival index and periodontal pocket depth were recorded. The measurement of serum zinc level was done by atomic absorption spectrophotometry. The microscopic slides of oral tissue specimen were evaluated quantitatively. The serum zinc level of the ZD rats was lower than the ZC group (p< 0.001). According clinical findings, the gingival index was lower in ZC rat (p=0.001), but there was no significant difference regarding the periodontal pocket depth between two groups (p=0.07). Aphthous ulcer was observed in ZD rats on the floor of the mouth. There was no significant difference regarding the epithelial and keratin thickening between two groups. This study indicated that oral and periodontal health was better in ZC rats than in ZD rats. Aphthous lesions were more prominent in ZD rats. This study confirmed that zinc deficiency may endanger oral and periodo ntal structures. PMID:25035857

Establishment of a rat hepatoma-derived cell line proliferating in D-phenylalanine medium and expressing D-amino-acid oxidase.

PubMed

Yoda, N; Konno, R; Nagashima, S

2001-01-01

A cell line (R-Y121B.DF) has been established from a cell line (R-Y121B) derived from a rat hepatoma line (H4-II-E). The R-Y121B.DF cells have been continuously cultured in a serum-free modified Eagle's minimum essential medium in which L-phenylalanine was replaced by D-phenylalanine. They had D-amino-acid oxidase (DAO) activity which is essential for the growth in the medium containing D-amino acids. The enzyme activity of the R-Y121B.DF cells was approximately one-fourth of that of the rat liver. Northern hybridization using a DAO cDNA probe detected a hybridizing signal in the R-Y121B.DF cells and the rat liver but not in the parental R-Y121B and H4-II-E cells. Reverse transcription-polymerase chain reaction using DAO-specific primers amplified a DNA fragment of the expected size in the R-Y121B.DF cells but not in the R-Y121B and H4-II-E cells. This fragment was confirmed to be DAO cDNA by nucleotide sequencing. Western blotting showed that DAO protein was present in the R-Y121B.DF cells and the rat liver but not in the R-Y121B and H4-II-E cells. Southern hybridization showed that the DAO gene structure was not different among the R-Y121B.DF cells, R-Y121B cells, H4-II-E cells, and the rat liver. These results indicate that the R-Y121B.DF is a unique cell line which proliferates in the medium containing D-phenylalanine and explicitly expresses DAO. This line is useful for the study of DAO in vitro.

Molokhia (Corchorus olitorius L.) extract suppresses transformation of the aryl hydrocarbon receptor induced by dioxins.

PubMed

Nishiumi, Shin; Yabushita, Yoshiyuki; Fukuda, Itsuko; Mukai, Rie; Yoshida, Ken-Ichi; Ashida, Hitoshi

2006-02-01

Dioxins enter the body mainly through diet and cause the various toxicological effects by binding to the cytosolic aryl hydrocarbon receptor (AhR) followed by its transformation. In recent reports, it has been shown that certain natural compounds suppress AhR transformation in vitro. In this study, we demonstrated that ethanolic extract from molokhia, known as Egyptian spinach, showed the strongest suppressive effect on AhR transformation induced by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in cell-free system using rat hepatic cytosol among 41 kinds of extracts from vegetables and fruits. The molokhia extract also suppressed TCDD-induced AhR transformation in mouse hepatoma Hepa-1c1c7 cells and in intestinal permeability system constructed with human colon adenocarcinoma Caco-2 cells and human hepatoma HepG2 cells. Moreover, oral administration of the molokhia extract (100mg/kg body weight) decreased 3-methylcholanthrene-induced AhR transformation to the control level by inhibiting translocation of the AhR from cytosol into the nucleus in the liver of rats. The molokhia extract-administered rat liver showed a tolerance to TCDD-induced AhR transformation by ex vivo experiment. These results indicate that molokhia is an attractive food for isolation and identification of a natural antagonist for the AhR.

[Correction of isoproterenol-induced myocardial injury with magnesium salts in magnesium-deficient rats].

PubMed

Kharitonova, M V; Zheltova, A A; Spasov, A A; Smirnov, A V; Pan'shin, N G; Iezhitsa, I N

2013-01-01

The effect of Mg L-asparaginate (Mg-L-Asp), Mg chloride (MgCl2) and Mg sulfate (MgSO4) on the severity of isoproterenol-induced myocardial injury in Mg-deficient rats has been evaluated. To induce Mg deficiency, twenty-eight rats were placed on a low Mg diet (Mg content < 15 mg/kg) and demineralized water for 10 weeks. Twelve control rats were fed a basal control diet (Mg content = 500 mg/kg) and water (with Mg content 20 mg/l) for equal duration. On day 49 of low Mg diet, Mg-deficient rats were randomly divided into four groups: 1) group that continued to receive low Mg diet; 2) low Mg diet plus oral MgSO4; 3) low Mg diet plus oral Mg-L-Asp and 4) low Mg diet plus oral MgCl2 (50 mg of Mg per kg of body weight). Isoproterenol was injected subcutaneously (30 mg/kg BW, twice, at an interval of 24 hours) on the day 70 of the study, when plasma and erythrocyte Mg level in rats fed a low Mg diet were significantly decreased by 47% and 45% compared to intact animals. Twenty-four hours after second injection of isoproterenol, tests for activities of creatine kinase (CK), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) were run and histopathological study was carried out. Administration of isoproterenol to rats resulted in significantly elevated plasma CK, LDH and AST, however analyses in Mg deficient group demonstrated more dramatically increased activity of CK and AST compared to control rats (3,06 and 4,67 fold in Mg-deficient group vs. 1,91 and 3,92 fold in intact group). Increased leakage of cardiac injury markers was concomitant to increased volume of fuchsinophilic cardiomyocytes (54.2 +/- 1.7% in Mg-deficient group and 38.9 +/- 1.9% in intact group, p < 0.05). However, pretreatment with of MgCl2, MgSO4 and Mg-L-Asp during 21 days favorably decreased sensitivity of myocardium to isoproterenol-induced ischemic injury. All evaluated salts significantly decreased myocyte marker enzymes as well as protected myocardium against isoproterenol

In vivo detection of c-MET expression in a rat hepatocarcinogenesis model using molecularly targeted magnetic resonance imaging.

PubMed

Towner, Rheal A; Smith, Nataliya; Tesiram, Yasvir A; Abbott, Andrew; Saunders, Debbie; Blindauer, Rebecca; Herlea, Oana; Silasi-Mansat, Robert; Lupu, Florea

2007-01-01

The multifunctional growth factor scatter factor/hepatocyte growth factor and its tyrosine kinase receptor, c-MET, have been implicated in the genesis and malignant progression of numerous human malignancies, including hepatocellular carcinomas. The incidence of hepatocellular carcinomas in the United States has increased noticeably over the past two decades and is listed as the fifth major cancer in men worldwide. In this study, we used a choline-deficient l-amino acid (CDAA)-defined rat hepatocarcinogenesis model to visualize increased in vivo expression of the c-MET antigen in neoplastic lesion formation with the use of a super paramagnetic iron oxide (SPIO)-anti-c-MET molecularly targeted magnetic resonance imaging (MRI) contrast agent. SPIO-anti-c-MET was used for the first time to detect overexpression of c-MET in neoplastic nodules and tumors within the livers of CDAA-treated rats, as determined by a decrease in MRI signal intensity and a decrease in regional T(2) values. Specificity for the binding of the molecularly targeted anti-c-MET contrast agent was determined using rat hepatoma (H4-II-E-C3) cell cultures and immunofluorescence microscopic imaging of the targeting agents within neoplastic liver tissue 1 to 2 hours following intravenous administration of SPIO-anti-c-MET and MRI investigation. This method has the ability to visualize in vivo the overexpression of c-MET at early developmental stages of tumor formation.

Impaired responses to sweet taste in vitamin A-deficient rats.

PubMed

Reifen, R; Agami, O; Weiser, H; Biesalski, H; Naim, M

1998-01-01

In brief-exposure, two-choice preference tests (sucrose solution v water), vitamin A-deficient (VAD) rats exhibited a decreased preference for sucrose relative to control rats. There was no difference in total fluid intake from both choices between the two groups, nor was any significant difference found in circumvallate taste papilla keratin size. It is concluded that the impaired preference for sucrose in VAD rats is due to a specific impairment in taste sensation rather than general malaise.

In male rats with concurrent iron and (n-3) fatty acid deficiency, provision of either iron or (n-3) fatty acids alone alters monoamine metabolism and exacerbates the cognitive deficits associated with combined deficiency.

PubMed

Baumgartner, Jeannine; Smuts, Cornelius M; Malan, Linda; Arnold, Myrtha; Yee, Benjamin K; Bianco, Laura E; Boekschoten, Mark V; Müller, Michael; Langhans, Wolfgang; Hurrell, Richard F; Zimmermann, Michael B

2012-08-01

Concurrent deficiencies of iron (Fe) (ID) and (n-3) fatty acids [(n-3)FAD)] in rats can alter brain monoamine pathways and impair learning and memory. We examined whether repletion with Fe and DHA/EPA, alone and in combination, corrects the deficits in brain monoamine activity (by measuring monoamines and related gene expression) and spatial working and reference memory [by Morris water maze (MWM) testing] associated with deficiency. Using a 2 × 2 design, male rats with concurrent ID and (n-3)FAD [ID+(n-3)FAD] were fed an Fe+DHA/EPA, Fe+(n-3)FAD, ID+DHA/EPA, or ID+(n-3)FAD diet for 5 wk [postnatal d 56-91]. Biochemical measures and MWM performance after repletion were compared to age-matched control rats. The provision of Fe in combination with DHA/EPA synergistically increased Fe concentrations in the olfactory bulb (OB) (Fe x DHA/EPA interaction). Similarly, provision of DHA/EPA in combination with Fe resulted in higher brain DHA concentrations than provision of DHA alone in the frontal cortex (FC) and OB (P < 0.05). Dopamine (DA) receptor D1 was upregulated in the hippocampus of Fe+DHA/EPA rats (fold-change = 1.25; P < 0.05) and there were significant Fe x DHA/EPA interactions on serotonin (5-HT) in the OB and on the DA metabolite dihydroxyphenylacetic acid in the FC and striatum. Working memory performance was impaired in ID+DHA/EPA rats compared with controls (P < 0.05). In the reference memory task, Fe+DHA/EPA improved learning behavior, but Fe or DHA/EPA alone did not. These findings suggest that feeding either Fe or DHA/EPA alone to adult rats with both ID and (n-3)FAD affects the DA and 5-HT pathways differently than combined repletion and exacerbates the cognitive deficits associated with combined deficiency.

Direct stimulation of immediate-early genes by intranuclear insulin in trypsin-treated H35 hepatoma cells.

PubMed Central

Lin, Y J; Harada, S; Loten, E G; Smith, R M; Jarett, L

1992-01-01

H35 hepatoma cells were treated with trypsin to abolish insulin binding and insulin-stimulated receptor kinase activity. Insulin was, however, internalized by fluid-phase endocytosis in trypsin-treated cells. Furthermore, nuclear accumulation of insulin was similar in control and trypsin-treated hepatoma cells. Northern blot analysis revealed insulin increased g33 and c-fos mRNA concentrations identically in control and trypsin-treated cells but had no effect on beta 2-microglobulin mRNA. Actinomycin D treatment prior to or after insulin addition demonstrated that insulin increased gene transcription and had no effect on mRNA degradation. These studies suggest that the accumulation of intact insulin in cell nuclei may be directly involved in the increased transcription of immediate-early genes. Images PMID:1409684

Physiologic regulation of atrial natriuretic peptide receptors in rat renal glomeruli.

PubMed Central

Ballermann, B J; Hoover, R L; Karnovsky, M J; Brenner, B M

1985-01-01

Isolated rat renal glomeruli and cultured glomerular mesangial and epithelial cells were examined for atrial natriuretic peptide (ANP) receptors, and for ANP-stimulated cyclic guanosine monophosphate (cGMP) generation. In glomeruli from normal rats, human (1-28) 125I-ANP bound to a single population of high affinity receptors with a mean equilibrium dissociation constant of 0.46 nM. Human (1-28) ANP markedly stimulated cGMP generation, but not cAMP generation in normal rat glomeruli. Analogues of ANP that bound to the glomerular ANP receptor with high affinity stimulated cGMP accumulation, whereas the (13-28) ANP fragment, which failed to bind to the receptor, was devoid of functional activity. Cell surface receptors for ANP were expressed on cultured glomerular mesangial but not epithelial cells, and appreciable ANP-stimulated cGMP accumulation was elicited only in mesangial cells. Approximately 12,000 ANP receptor sites were present per mesangial cell, with an average value for the equilibrium dissociation constant of 0.22 nM. Feeding of a low-salt diet to rats for 2 wk resulted in marked up regulation of the glomerular ANP receptor density to a mean of 426 fmol/mg protein, compared with 116 fmol/mg in rats given a high-salt diet. A modest reduction in the affinity of glomerular ANP receptors was also observed in rats fed the low-salt diet. ANP-stimulated cGMP generation in glomeruli did not change with alterations in salt intake. We conclude that high salt feeding in the rat results in reduced glomerular ANP receptor density relative to values in salt restricted rats. Furthermore, the mesangial cell is a principal target for ANP binding in the glomerulus. Images PMID:3001139

INHIBITORY EFFECT OF CHITOSAN OLIGOSACCHARIDE ON HUMAN HEPATOMA CELLS IN VITRO.

PubMed

Liu, Likun; Xin, Yi; Liu, Jia; Zhang, Ershao; Li, Weiling

2017-01-01

Chitosan oligosaccharide, the degradation products of chitin, was reported to have a wide range of physiological functions and biological activities. In this study, we explored the inhibitory effect of Chitosan oligosaccharide on human hepatoma cells. MTT assay was applied to detect cell viability of the human hepatoma cells treated with Chitosan oligosaccharide. Flow cytometric analysis was used to investigate the apoptosis of the human hepatoma cells treated with Chitosan oligosaccharide. We employed western blot to investigate the underlying mechanisms involved in the apoptosis. Our data indicated that chitosan oligosaccharide dose-dependently inhibited the growth of hepatoma cells and induced apoptosis. On the molecular level, chitosan oligosaccharide decreased Bcl-2 and increased Caspase-3 expression which may be related to the apoptosis of hepatoma cells. Our results provide an experimental basis for the clinical development of Chitosan oligosaccharide as a novel anti-hepatoma drug.

Tracing of Zinc Nanocrystals in the Anterior Pituitary of Zinc-Deficient Wistar Rats.

PubMed

Kuldeep, Anjana; Nair, Neena; Bedwal, Ranveer Singh

2017-06-01

The aim of this study was to trace zinc nanocrystals in the anterior pituitary of zinc-deficient Wistar rats by using autometallographic technique. Male Wistar rats (30-40 days of age, pre-pubertal period) of 40-50 g body weight were divided into the following: the ZC (zinc control) group-fed with 100 ppm zinc in diet, the ZD (zinc-deficient) group-fed with zinc-deficient (1.00 ppm) diet and the PF (pair-fed) group-received 100 ppm zinc in diet. The experiments were set for 2 and 4 weeks. Pituitary was removed and processed for the autometallographic technique. The control and pair-fed groups retained their normal morphological features. However, male Wistar rats fed on zinc-deficient diet for 2 and 4 weeks displayed a wide range of symptoms such as significant (P < 0.05) decrease in diet consumption, body weight and pituitary weight and decrease in gradation of intensity of zinc nanocrystals in the nuclei. The present findings suggest that the dietary zinc deficiency causes decreased intensity of zinc nanocrystals localization and their distribution in the pituitary thereby contributing to the dysfunction of the pituitary of the male Wistar rats. The severity of zinc deficiency symptoms progressed after the second week of the experiment. Decreased intensity of zinc nanocrystals attenuates the pituitary function which would exert its affect on other endocrine organs impairing their functions indicating that the metabolic regulation of pituitary is mediated to a certain extent by zinc and/or hypothalamus-hypophysial system which also reflects its essentiality during the period of growth.

Telmisartan prevents hepatic fibrosis and enzyme-altered lesions in liver cirrhosis rat induced by a choline-deficient L-amino acid-defined diet

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jin Haiyan; Department of Gastroenterology and Hepatology, Yanbian University Hospital, Yanji, Jilin; Yamamoto, Naoki

2007-12-28

Rennin-angiotensin system is involved in liver fibrogenesis through activating hepatic stellate cells (HSCs). Telmisartan (Tel) is an angiotensin II type 1 receptor antagonist, could function as a selective peroxisome proliferator-activated receptor {gamma} activator. Here we studied the effect of Tel on liver fibrosis, pre-neoplastic lesions in vivo and primary HSCs in vitro. In vivo study, we used the choline-deficient L-amino acid-defined (CDAA)-diet induced rat NASH model. The rats were fed the CDAA diet for 8 weeks to induce liver fibrosis and pre-neoplastic lesions, and then co-administrated with Tel for another 10 weeks. Tel prevented liver fibrogenesis and pre-neoplastic lesions bymore » down-regulating TGF{beta}1 and TIMP-1, 2 and increasing MMP-13 expression. Tel inhibited HSCs activation and proliferation. These results suggested that Tel could be a promising drug for NASH related liver fibrosis.« less

Telmisartan prevents hepatic fibrosis and enzyme-altered lesions in liver cirrhosis rat induced by a choline-deficient L-amino acid-defined diet.

PubMed

Jin, Haiyan; Yamamoto, Naoki; Uchida, Koichi; Terai, Shuji; Sakaida, Isao

2007-12-28

Rennin-angiotensin system is involved in liver fibrogenesis through activating hepatic stellate cells (HSCs). Telmisartan (Tel) is an angiotensin II type 1 receptor antagonist, could function as a selective peroxisome proliferator-activated receptor gamma activator. Here we studied the effect of Tel on liver fibrosis, pre-neoplastic lesions in vivo and primary HSCs in vitro. In vivo study, we used the choline-deficient L-amino acid-defined (CDAA)-diet induced rat NASH model. The rats were fed the CDAA diet for 8 weeks to induce liver fibrosis and pre-neoplastic lesions, and then co-administrated with Tel for another 10 weeks. Tel prevented liver fibrogenesis and pre-neoplastic lesions by down-regulating TGFbeta1 and TIMP-1, 2 and increasing MMP-13 expression. Tel inhibited HSCs activation and proliferation. These results suggested that Tel could be a promising drug for NASH related liver fibrosis.

Melatonin modulates rat myotube-acetylcholine receptors by inhibiting calmodulin.

PubMed

de Almeida-Paula, Lidiana Duarte; Costa-Lotufo, Leticia V; Silva Ferreira, Zulma; Monteiro, Amanda Elisa G; Isoldi, Mauro Cesar; Godinho, Rosely O; Markus, Regina P

2005-11-21

Melatonin, the pineal gland hormone, modulates alpha-bungarotoxin sensitive nicotinic acetylcholine receptors in sympathetic nerve terminals, cerebellum and chick retina imposing a diurnal variation in functional responses [Markus, R.P., Zago, W.M., Carneiro, R.C., 1996. Melatonin modulation of presynaptic nicotinic acetylcholine receptors in the rat vas deferens. J. Pharmacol. Exp. Ther. 279, 18-22; Markus, R.P., Santos, J.M., Zago, W., Reno, L.A., 2003. Melatonin nocturnal surge modulates nicotinic receptors and nicotine-induced [3HI] glutamate release in rat cerebellum slices. J. Pharmacol. Exp. Ther. 305, 525-530; Sampaio, L.F.S., Hamassaki-Britto, D.E., Markus, R.P., 2005. Influence of melatonin on the development of functional nicotinic acetylcholine receptors in cultured chick retinal cells. Braz. J. Med. Biol. Res. 38, 603-613]. Here we show that in rat myotubes forskolin and melatonin reduced the number of nicotinic acetylcholine receptors expressed in plasma membrane. In addition, these cells expressed melatonin MT1 receptors, which are known to be coupled to G(i)-protein. However, the pharmacological profile of melatonin analogs regarding the reduction in cyclic AMP accumulation and number of nicotinic acetylcholine receptors did not point to a mechanism mediated by activation of G(i)-protein coupled receptors. On the other hand, calmidazolium, a classical inhibitor of calmodulin, reduced in a similar manner both effects. Considering that one isoform of adenylyl cyclase present in rat myotubes is regulated by Ca2+/calmodulin, we propose that melatonin modulates the number of nicotinic acetylcholine receptors via reduction in cyclic AMP accumulation.

High mortality rates occur in copper deficient rats exposed to a normally nonlethal endotoxin treatment

DOE Office of Scientific and Technical Information (OSTI.GOV)

DiSilvestro, R.; Joseph, E.; Yang, F.L.

Endotoxin hepatotoxicity is proposed to occur by processes which could be retarded by 3 copper enzymes: ceruloplasmin, Cu-Zn superoxide dismutase (SOD), and extracellular (EC) SOD. Weanling rats fed low copper for 40 days showed low activity levels of these enzymes, and a very high mortality rate 20 h after endotoxin injection. No rats fed adequate copper died from this treatment. In addition, serum transaminase activities, indicators of liver damage, were elevated by 3 h to a greater extent in the deficient rats than in the adequates. The high susceptibility to endotoxemia in the deficient rats was not associated with lowmore » hepatic glutathione, high liver malondialedhyde, nor restricted metallothionein induction 3 h after endotoxin injection. Endotoxin reduced serum EC SOD activities in adequate and deficient rats, but final values were lower in the latter. Studies on roles of specific copper enzymes in resistance to endotoxemia are currently underway.« less

INHIBITORY EFFECT OF CHITOSAN OLIGOSACCHARIDE ON HUMAN HEPATOMA CELLS IN VITRO

PubMed Central

Liu, Likun; Xin, Yi; Liu, Jia; Zhang, Ershao; Li, Weiling

2017-01-01

Background: Chitosan oligosaccharide, the degradation products of chitin, was reported to have a wide range of physiological functions and biological activities. In this study, we explored the inhibitory effect of Chitosan oligosaccharide on human hepatoma cells Materials and Methods: MTT assay was applied to detect cell viability of the human hepatoma cells treated with Chitosan oligosaccharide. Flow cytometric analysis was used to investigate the apoptosis of the human hepatoma cells treated with Chitosan oligosaccharide. We employed western blot to investigate the underlying mechanisms involved in the apoptosis. Results: Our data indicated that chitosan oligosaccharide dose-dependently inhibited the growth of hepatoma cells and induced apoptosis. On the molecular level, chitosan oligosaccharide decreased Bcl-2 and increased Caspase-3 expression which may be related to the apoptosis of hepatoma cells. Conclusion: Our results provide an experimental basis for the clinical development of Chitosan oligosaccharide as a novel anti-hepatoma drug. PMID:28638890

Expression of sulfonylurea receptors in rat taste buds.

PubMed

Liu, Dian-Xin; Liu, Xiao-Min; Zhou, Li-Hong; Feng, Xiao-Hong; Zhang, Xiao-Juan

2011-07-01

To test the possibility that a fast-onset promoting agent repaglinide may initiate prandial insulin secretion through the mechanism of cephalic-phase insulin release, we explored the expression and distribution character of sulfonylurea receptors in rat taste buds. Twenty male Wistar rats aged 10 weeks old were killed after general anesthesia. The circumvallate papillae, fungiform papillae and pancreas tissues were separately collected. Immunohistochemical staining was used to detect the expression and distribution of sulfonylurea receptor 1 (SUR1) or sulfonylurea receptor 2 (SUR2) in rat taste buds. Reverse transcriptase polymerase chain reaction (RT-PCR) was used to analyze the expression of SUR1 or SUR2 mRNA. The pancreatic tissues from the same rat were used as positive control. This is the first study to report that SUR1 is uniquely expressed in the taste buds of fungiform papillae of each rat tongue, while the expression of SUR1 or SUR2 was not detected in the taste buds of circumvallate papillae. SUR1 is selectively expressed in rat taste buds, and its distribution pattern may be functionally relevant, suggesting that the rapid insulin secretion-promoting effect of repaglinide may be exerted through the cephalic-phase secretion pathway mediated by taste buds. Copyright © 2010 Elsevier GmbH. All rights reserved.

PAR2 (Protease-Activated Receptor 2) Deficiency Attenuates Atherosclerosis in Mice.

PubMed

Jones, Shannon M; Mann, Adrien; Conrad, Kelsey; Saum, Keith; Hall, David E; McKinney, Lisa M; Robbins, Nathan; Thompson, Joel; Peairs, Abigail D; Camerer, Eric; Rayner, Katey J; Tranter, Michael; Mackman, Nigel; Owens, A Phillip

2018-06-01

PAR2 (protease-activated receptor 2)-dependent signaling results in augmented inflammation and has been implicated in the pathogenesis of several autoimmune conditions. The objective of this study was to determine the effect of PAR2 deficiency on the development of atherosclerosis. PAR2 mRNA and protein expression is increased in human carotid artery and mouse aortic arch atheroma versus control carotid and aortic arch arteries, respectively. To determine the effect of PAR2 deficiency on atherosclerosis, male and female low-density lipoprotein receptor-deficient ( Ldlr -/- ) mice (8-12 weeks old) that were Par2 +/+ or Par2 -/- were fed a fat- and cholesterol-enriched diet for 12 or 24 weeks. PAR2 deficiency attenuated atherosclerosis in the aortic sinus and aortic root after 12 and 24 weeks. PAR2 deficiency did not alter total plasma cholesterol concentrations or lipoprotein distributions. Bone marrow transplantation showed that PAR2 on nonhematopoietic cells contributed to atherosclerosis. PAR2 deficiency significantly attenuated levels of the chemokines Ccl2 and Cxcl1 in the circulation and macrophage content in atherosclerotic lesions. Mechanistic studies using isolated primary vascular smooth muscle cells showed that PAR2 deficiency is associated with reduced Ccl2 and Cxcl1 mRNA expression and protein release into the supernatant resulting in less monocyte migration. Our results indicate that PAR2 deficiency is associated with attenuation of atherosclerosis and may reduce lesion progression by blunting Ccl2 - and Cxcl1 -induced monocyte infiltration. © 2018 American Heart Association, Inc.

Clinical and molecular genetic spectrum of congenital deficiency of the leptin receptor.

PubMed

Farooqi, I Sadaf; Wangensteen, Teresia; Collins, Stephan; Kimber, Wendy; Matarese, Giuseppe; Keogh, Julia M; Lank, Emma; Bottomley, Bill; Lopez-Fernandez, Judith; Ferraz-Amaro, Ivan; Dattani, Mehul T; Ercan, Oya; Myhre, Anne Grethe; Retterstol, Lars; Stanhope, Richard; Edge, Julie A; McKenzie, Sheila; Lessan, Nader; Ghodsi, Maryam; De Rosa, Veronica; Perna, Francesco; Fontana, Silvia; Barroso, Inês; Undlien, Dag E; O'Rahilly, Stephen

2007-01-18

A single family has been described in which obesity results from a mutation in the leptin-receptor gene (LEPR), but the prevalence of such mutations in severe, early-onset obesity has not been systematically examined. We sequenced LEPR in 300 subjects with hyperphagia and severe early-onset obesity, including 90 probands from consanguineous families, and investigated the extent to which mutations cosegregated with obesity and affected receptor function. We evaluated metabolic, endocrine, and immune function in probands and affected relatives. Of the 300 subjects, 8 (3%) had nonsense or missense LEPR mutations--7 were homozygotes, and 1 was a compound heterozygote. All missense mutations resulted in impaired receptor signaling. Affected subjects were characterized by hyperphagia, severe obesity, alterations in immune function, and delayed puberty due to hypogonadotropic hypogonadism. Serum leptin levels were within the range predicted by the elevated fat mass in these subjects. Their clinical features were less severe than those of subjects with congenital leptin deficiency. The prevalence of pathogenic LEPR mutations in a cohort of subjects with severe, early-onset obesity was 3%. Circulating levels of leptin were not disproportionately elevated, suggesting that serum leptin cannot be used as a marker for leptin-receptor deficiency. Congenital leptin-receptor deficiency should be considered in the differential diagnosis in any child with hyperphagia and severe obesity in the absence of developmental delay or dysmorphism. Copyright 2007 Massachusetts Medical Society.

Role of hypothalamic cannabinoid receptors in post-stroke depression in rats.

PubMed

Wang, Shanshan; Sun, Hong; Liu, Sainan; Wang, Ting; Guan, Jinqun; Jia, Jianjun

2016-03-01

One of the most common psychological consequences of stroke is post-stroke depression (PSD). While more than 30 percent of stroke patients eventually develop PSD, the neurobiological mechanisms underlying such a phenomenon have not been well investigated. Given the critical involvement of hypothalamic-pituitary-adrenal axis and endocannabinoid system in response to stressful stimuli, we evaluated the hypothesis that cannabinoid receptors in the hypothalamus are critical for modulation of post-stroke depression-like behaviors in rats. To this end, rats were treated with middle cerebral artery occlusion (MCAO) followed by chronic unpredictable mild stress (CUMS) treatment procedure. We then assessed the expression of CB1 and CB2 receptors in the hypothalamus, and evaluated the effects of pharmacological stimulations of CB1 or CB2 receptors on the expression and development of depression-like behaviors in PSD rats. We found that PSD rats exhibited decreased the expression of CB1 receptor, but not CB2 receptor, in the ventral medial hypothalamus (VMH). Such an effect was not observed in the dorsally adjacent brain regions. Furthermore, intra-VMH injections of CB2 receptor agonist, but not CB1 receptor agonist, attenuated the expression of depression-like behaviors in PSD rats. Finally, repeated intraperitoneal injections of CB1 or CB2 receptor agonists during CUMS treatment inhibited the development of depression-like behaviors in PSD rats. Taken together, these results suggest that decreased CB1 receptor expression is likely associated with the development of post-stroke depression, and CB2 receptor may be a potential therapeutic target for the treatment post-stroke depressive disorders. Copyright © 2016 Elsevier Inc. All rights reserved.

V1-receptor mediated GSH efflux by vasopressin from rat hepatocytes.

PubMed

Sato, C; Liu, J H; Uchihara, M; Izumi, N; Yauchi, T; Sakaj, Y; Asahina, Y; Fukuma, T; Takano, T; Marumo, F

1992-01-01

Vasopression increases sinusoidal efflux of GSH in the perfused rat liver. The mechanism of this effect was studied in the perfused rat liver and in isolated rat hepatocytes. Vasopressin stimulated GSH efflux in both systems and a V1-receptor antagonist (OPC-21268) significantly inhibited the effect of vasopressin suggesting that vasopressin stimulates GSH efflux from rat hepatocytes via V1-receptor.

Mandibular bone remodeling under a choline-deficient diet: a histomorphometric study in rats.

PubMed

Gorustovich, Alejandro A; Espósito, María A; Guglielmotti, María B; Giglio, Máximo J

2003-06-01

A deficiency of lipotropic factors in the rat induces renal, hepatic, and/or hematic damage. The aim of the present study was to evaluate the effect of a choline-deficient diet and refeeding on mandibular bone remodeling. Fifty Wistar rats were divided into 5 groups: group 1 (G1): control diet for 15 days; group 2 (G2): choline-deficient diet for 15 days; group 3 (G3): control diet for 30 days; group 4 (G4): choline-deficient diet for 30 days; and group 5 (G5): choline-deficient diet for 15 days and control diet for 15 days. All animals were sacrificed by ether overdose. The mandibles were resected, radiographed, decalcified, processed, and embedded in paraffin. Bucco-lingually oriented sections were obtained at the level of the interradicular bone of the medial roots of the left first molar, and stained with hematoxylin and eosin (H & E). Bone tissue density and bone remodeling were determined histomorphometrically. Body weight, food intake, hematocrit, and hemoglobinemia were also recorded. Microscopic observation revealed that osteogenesis was lower in rats fed a choline-deficient diet, at both 15 and 30 days, and that this decrease did not revert with a control diet. Histomorphometric evaluation showed 37% and 27% reduction in bone tissue density at 15 and 30 days, respectively, and a 30% decrease in bone formation at 30 days, compared to controls. In this experimental model, a choline-deficient diet led to altered bone remodeling as observed by a marked reduction in osteogenesis.

GC-TOF/MS-based metabolomic profiling of estrogen deficiency-induced obesity in ovariectomized rats

PubMed Central

Ma, Bo; Zhang, Qi; Wang, Guang-ji; A, Ji-ye; Wu, Di; Liu, Ying; Cao, Bei; Liu, Lin-sheng; Hu, Ying-ying; Wang, Yong-lu; Zheng, Ya-ya

2011-01-01

Aim: To explore the alteration of endogenous metabolites and identify potential biomarkers using metabolomic profiling with gas chromatography coupled a time-of-flight mass analyzer (GC/TOF-MS) in a rat model of estrogen-deficiency-induced obesity. Methods: Twelve female Sprague-Dawley rats six month of age were either sham-operated or ovariectomized (OVX). Rat blood was collected, and serum was analyzed for biomarkers using standard colorimetric methods with commercial assay kits and a metabolomic approach with GC/TOF-MS. The data were analyzed using multivariate statistical techniques. Results: A high body weight and body mass index inversely correlated with serum estradiol (E2) in the OVX rats compared to the sham rats. Estrogen deficiency also significantly increased serum total cholesterol, triglycerides, and low-density lipoprotein cholesterol. Utilizing GC/TOF-MS-based metabolomic analysis and the partial least-squares discriminant analysis, the OVX samples were discriminated from the shams. Elevated levels of cholesterol, glycerol, glucose, arachidonic acid, glutamic acid, glycine, and cystine and reduced alanine levels were observed. Serum glucose metabolism, energy metabolism, lipid metabolism, and amino acid metabolism were involved in estrogen-deficiency-induced obesity in OVX rats. Conclusion: The series of potential biomarkers identified in the present study provided fingerprints of rat metabolomic changes during obesity and an overview of multiple metabolic pathways during the progression of obesity involving glucose metabolism, lipid metabolism, and amino acid metabolism. PMID:21293480

Innate immune reactivity of the liver in rats fed a choline-deficient L-amino-acid-defined diet.

PubMed

Kawaratani, Hideto; Tsujimoto, Tatsuhiro; Kitazawa, Toshiyuki; Kitade, Mitsuteru; Yoshiji, Hitoshi; Uemura, Masahito; Fukui, Hiroshi

2008-11-21

To investigate the innate immune reactivity of tumor necrosis factor-alpha (TNF-alpha), Toll-like receptor 4 (TLR4), and CD14 in the liver of non-alcoholic steatohepatitis (NASH) model rats. Male F344 rats were fed a choline-deficient L-amino-acid-defined (CDAA) diet. The rats were killed after 4 or 8 wk of the diet, and their livers were removed for immunohistochemical investigation and RNA extraction. The liver specimens were immunostained for TNF-alpha, TLR4, and CD14. The gene expressions of TNF-alpha, TLR4, and CD14 were determined by reverse-transcriptase polymerase chain reaction (RT-PCR). Kupffer cells were isolated from the liver by Percoll gradient centrifugation, and were then cultured to measure TNF-alpha production. The serum and liver levels of TNF-alpha in the CDAA-fed rats increased significantly as compared with the control group, as did the immunohistochemical values and gene expressions of TNF-alpha, TLR4, and CD14 with the progression of steatohepatitis. TNF-alpha production from the isolated Kupffer cells of the CDAA-fed rats was elevated by lipopolysaccharide stimulation. The expressions of TNF-alpha, TLR4, and CD14 increased in the NASH model, suggesting that TLR4 and CD14-mediated endotoxin liver damage may also occur in NASH.

Treatment with geraniol ameliorates methionine-choline-deficient diet-induced non-alcoholic steatohepatitis in rats.

PubMed

Chen, Jun; Fan, Xiaoxia; Zhou, Lin; Gao, Xiaogang

2016-07-01

Non-alcoholic steatohepatitis (NASH) is one of the most common causes of chronic liver disease and is considered to be a causative factor of cryptogenic cirrhosis and hepatocellular carcinoma. The aim of this work was to investigate whether treatment with geraniol (a monoterpene) attenuated NASH induced by methionine-choline-deficient (MCD) diet in rats. Rats were fed with MCD diet to induce NASH and treated with geraniol (200 mg/kg/day) for 10 weeks. Treatment with geraniol reduced histological scores, fibrosis, and apoptosis in livers, lowered activities of alanine aminotransferase and aspartate aminotransferase in serum, and attenuated hepatic fat accumulation in rats fed with MCD diet. Treatment with geraniol preserved hepatic mitochondrial function, evidenced by reduced mitochondrial reactive oxygen species formation, enhanced adenosine triphosphate formation and membrane integrity, restored mitochondrial electron transport chain enzyme activity, and increased mitochondrial DNA content in rats fed with MCD diet. Treatment with geraniol reduced uncoupling protein 2 protein expression, and enhanced protein expression of prohibitin, mRNA expression of peroxisome proliferator-activated receptor α, and activity of mitochondrial carnitine palmitoyl transferase-I in livers of rats fed with MCD diet. Treatment with geraniol abated oxidative stress, evidenced by reduced malondialdehyde and 3-nitrotyrosine formation, enhanced activity of glutathione S-epoxide transferase, and down-regulated expression of inducible nitric oxide synthase and cytochrome P450 2E1 in livers of rats fed with MCD diet. Treatment with geraniol reduced myeloperoxidase activity and protein expression of tumor necrosis factor alpha and IL-6 in livers of rats fed with MCD diet. Treatment with geraniol attenuated MCD-induced NASH in rats. © 2015 Journal of Gastroenterology and Hepatology Foundation and John Wiley & Sons Australia, Ltd.

Aberrant T-cell function in vitro and impaired T-cell dependent antibody response in vivo in vitamin A-deficient rats.

PubMed Central

Wiedermann, U; Hanson, L A; Kahu, H; Dahlgren, U I

1993-01-01

We have previously reported that vitamin A deficiency resulted in a reduced IgA antibody response to cholera toxin (CT) after per-oral immunization. In the present investigation we have studied the in vivo and in vitro immune response in vitamin A-deficient rats to two parenterally applied antigens, beta-lactoglobulin (beta-LG) and picrylsulphonic acid (TNP)-Ficoll. The serum IgG and IgM antibody responses to the T-cell dependent antigen beta-LG were significantly lower in the vitamin A-deficient rats than in the pair-fed control rats. No such differences were seen with the IgG and IgM responses to the T-cell independent antigen TNP-Ficoll. However, the biliary IgA and the serum IgE antibodies against both antigens were decreased in the vitamin A-deficient rats. In vitro lymphocyte stimulation with concanavalin A (Con A) or beta-LG gave higher T-cell proliferation rates in the vitamin A-deficient than in the control rats. Interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) levels in supernatants from Con A-stimulated mesenteric lymph node cells were also higher in the vitamin A-deficient rats, while IL-6 levels were decreased, which is consistent with an up-regulated Th1 activity. Proliferation studies on purified accessory cells and T cells from the deficient and the control rats, mixed in different combinations, showed that the T cells, but not the accessory cells, were disturbed in the vitamin A-deficient rats. Despite the increased T-cell activity in vitro the vitamin A-deficient rats had a lower delayed-type hypersensitivity (DTH) reaction than the pair-fed control rats. In conclusion, the increased IL-2 and IFN-gamma levels may reflect an up-regulation of Th1 cell function, while the decreased IgA, IgE and IL-6 levels indicate a suppression of Th2 cells. The disturbed T-lymphocyte function is manifested in vivo as a decreased DTH reaction and suppressed antibody production, the latter possibly due to a lack of B-cell switching and proliferation factors in

BWTG3 hepatoma cells can acquire phenylalanine hydroxylase, cystathionine synthase and CPS-I without genetic manipulation, but activation of the silent OTC gene requires cell fusion with hepatocytes.

PubMed

Farmer, A A; Goss, S J

1991-04-01

The mouse hepatoma BWTG3 has been tested for its ability to grow in three different media that select for traits normally expressed in adult liver: homocysteine medium to select for cystathionine synthase (CS), tyrosine-free medium for phenylalanine hydroxylase (PH), and ornithine medium for carbamylphosphate synthetase-I (CPS-I) and ornithine transcarbamylase (OTC). In no case were the cells immediately capable of bulk growth, showing that all these traits were in some degree deficient. However, the cultures in homocysteine medium and in tyrosine-free medium both gave rise, spontaneously, to growing clones with frequencies of approximately 10(-3) and 10(-5), respectively. The deficiencies of CS and PH were accordingly excluded from further study, in view of their inherent instability. In contrast, no colonies ever formed in ornithine medium. Though neither CPS-I nor OTC were detectable in stock BWTG3 cells, it was found that CPS-I was readily inducible by hormones. The deficiency of OTC, however, appeared to be totally stable showing no reversion in response either to hormones or to azacytidine treatment. This deficiency was investigated by fusing the hepatoma to OTC+ liver cells prepared from normal or sparse-fur (spf) mice. Sparse-fur mice were used because their OTC is mutant and has a distinctive pH-dependence. OTC+ hybrids were readily produced, without the need for any specific selection for OTC, and, in one case at least, with only minimal chromosome segregation. In all the OTC+ hybrids made with spf cells, there was clear reactivation of the wild-type, hepatoma-derived OTC gene.(ABSTRACT TRUNCATED AT 250 WORDS)

Production of large numbers of hybridomas producing monoclonal antibodies against rat IgE using mast cell-deficient w/wv and sl/sld strains of mice.

PubMed

Rup, B J

1989-08-15

A number of different mouse strains and immunization protocols were used to attempt to make monoclonal antibodies against rat IgE for use in studies of the structure, biological activities and regulation of this class of antibody. Successful production of large numbers of monoclonal antibodies was achieved when mast cell deficient (w/wv and sl/sld) but not conventional (BALB/c, CAF1 or SJL) mice were used. These results suggest that the poor response of conventional strains of mice to rat IgE may be due to the presence of mast cells bearing high affinity receptors for IgE in these mice.

Isolated Flinders Sensitive Line rats have decreased dopamine D2 receptor mRNA.

PubMed

Bjørnebekk, Astrid; Mathé, Aleksander A; Brené, Stefan

2007-07-02

Social isolation has profound effects on animal behavior and dopamine systems. We investigated the effect of social isolation on the dopamine receptor and neuropeptide mRNAs in the brain reward system in an animal model of depression, the Flinders Sensitive Line rats and Sprague-Dawley controls. We demonstrate that socially isolated but not group housed Flinders sensitive line rats had lower dopamine D2 receptor mRNA levels compared with Sprague-Dawley rats. Isolated and group housed Flinders Sensitive Line rats had higher levels of dopamine D1 receptor and substance P and enkephalin but not dynorphin mRNAs when compared with Sprague-Dawley rats. Our findings of decreased dopamine D2 receptor levels in socially isolated Flinders Sensitive Line rats suggest that low D2 receptor expression may play a role in pathophysiology of depression.

[Influence of combined vitamin deficiency on unconditioned reflexes and learning in growing rats].

PubMed

Vrzhesinskaya, O A; Kodentsova, V M; Beketova, N A; Pereverzeva, O G; Kosheleva, O V; Sidorova, Yu S; Zorin, S N; Mazo, V K

2015-01-01

The aim of this study was to investigate the effect of combined deficiency of all vitamins on the manifestation of unconditioned reflex and learning (in response to an electric current) in growing Wistar rats with initial body weight 53.4 ± 1.2 g (45.5-62.0 g). 20 of 46 tested male rats (latent period of transition from the illuminated chamber to the dark compartment did not exceed 60 s) were included in the experiment. Rats were randomly divided into 2 groups (control and experimental) for the duration of the latent period and body mass. Within 23 days the rats of the control group received a complete semisynthetic diet. Combined vitamin deficiency in tested rats was caused by 5-fold diet decrease of the amount of vitamin mixture without vitamin E. On the 12th day the second phase of testing was performed, during which the rat received electrocutaneous irritation on paws (current 0.4 mA, 8 seconds) after transition to the dark compartment of the chamber. Preservation of the conducted reflex was performed 24 h and 9 days after training. On the 23rd day pre-anesthetized with ether rats were taken out from the experiment by decapitation. The content of vitamin A (retinol and retinol palmitate) and E (tocopherols) in plasma and liver and in the sunflower oil was analyzed by HPLC, the level of vitamins B1 and B2 in liver and casein by fluorimetric method, blood serum malondialdehyde content--by spectrophotometric method. Reducing of vitamin mixture amount of the diet lead to significant reduction in liver vitamin A, E, B1, and B2 level and in blood plasma vitamin A and E concentration by the end of the experiment, but had no effect on blood plasma MDA concentration. On the 12th day of vitamin deficiency in rats manifestation of unconditioned reflex (photophobia) has been deteriorated, as evidenced by the significant 3,2-fold increase of latent period of transition to the dark compartment compared with animals fed a complete diet (47.8 ± 15.8 vs 14.8 ± 3.6 sec), but

Hypothyroxinemia induced by maternal mild iodine deficiency impairs hippocampal myelinated growth in lactational rats.

PubMed

Wei, Wei; Wang, Yi; Dong, Jing; Wang, Yuan; Min, Hui; Song, Binbin; Shan, Zhongyan; Teng, Weiping; Xi, Qi; Chen, Jie

2015-11-01

Hypothyroxinemia induced by maternal mild iodine deficiency causes neurological deficits and impairments of brain function in offspring. Hypothyroxinemia is prevalent in developing and developed countries alike. However, the mechanism underlying these deficits remains less well known. Given that the myelin plays an important role in learning and memory function, we hypothesize that hippocampal myelinated growth may be impaired in rat offspring exposed to hypothyroxinemia induced by maternal mild iodine deficiency. To test this hypothesis, the female Wistar rats were used and four experimental groups were prepared: (1) control; (2) maternal mild iodine deficiency diet inducing hypothyroxinemia; (3) hypothyroidism induced by maternal severe iodine deficiency diet; (4) hypothyroidism induced by maternal methimazole water. The rats were fed the diet from 3 months before pregnancy to the end of lactation. Our results showed that the physiological changes occuring in the hippocampal myelin were altered in the mild iodine deficiency group as indicated by the results of immunofluorescence of myelin basic proteins on postnatal day 14 and postnatal day 21. Moreover, hypothyroxinemia reduced the expressions of oligodendrocyte lineage transcription factor 2 and myelin-related proteins in the treatments on postnatal day 14 and postnatal day 21. Our data suggested that hypothyroxinemia induced by maternal mild iodine deficiency may impair myelinated growth of the offspring. © 2014 Wiley Periodicals, Inc.

Clinical and Molecular Genetic Spectrum of Congenital Deficiency of the Leptin Receptor

PubMed Central

Farooqi, I. Sadaf; Wangensteen, Teresia; Collins, Stephan; Kimber, Wendy; Matarese, Giuseppe; Keogh, Julia M.; Lank, Emma; Bottomley, Bill; Lopez-Fernandez, Judith; Ferraz-Amaro, Ivan; Dattani, Mehul T.; Ercan, Oya; Myhre, Anne Grethe; Retterstol, Lars; Stanhope, Richard; Edge, Julie A.; McKenzie, Sheila; Lessan, Nader; Ghodsi, Maryam; De Rosa, Veronica; Perna, Francesco; Fontana, Silvia; Barroso, Inês; Undlien, Dag E.; O'Rahilly, Stephen

2009-01-01

BACKGROUND A single family has been described in which obesity results from a mutation in the leptin-receptor gene (LEPR), but the prevalence of such mutations in severe, early-onset obesity has not been systematically examined. METHODS We sequenced LEPR in 300 subjects with hyperphagia and severe early-onset obesity, including 90 probands from consanguineous families, and investigated the extent to which mutations cosegregated with obesity and affected receptor function. We evaluated metabolic, endocrine, and immune function in probands and affected relatives. RESULTS Of the 300 subjects, 8 (3%) had nonsense or missense LEPR mutations — 7 were homozygotes, and 1 was a compound heterozygote. All missense mutations resulted in impaired receptor signaling. Affected subjects were characterized by hyperphagia, severe obesity, alterations in immune function, and delayed puberty due to hypogonadotropic hypogonadism. Serum leptin levels were within the range predicted by the elevated fat mass in these subjects. Their clinical features were less severe than those of subjects with congenital leptin deficiency. CONCLUSIONS The prevalence of pathogenic LEPR mutations in a cohort of subjects with severe, early-onset obesity was 3%. Circulating levels of leptin were not disproportionately elevated, suggesting that serum leptin cannot be used as a marker for leptin-receptor deficiency. Congenital leptin-receptor deficiency should be considered in the differential diagnosis in any child with hyperphagia and severe obesity in the absence of developmental delay or dysmorphism. PMID:17229951

Fetal iron deficiency induces chromatin remodeling at the Bdnf locus in adult rat hippocampus.

PubMed

Tran, Phu V; Kennedy, Bruce C; Lien, Yu-Chin; Simmons, Rebecca A; Georgieff, Michael K

2015-02-15

Fetal and subsequent early postnatal iron deficiency causes persistent impairments in cognitive and affective behaviors despite prompt postnatal iron repletion. The long-term cognitive impacts are accompanied by persistent downregulation of brain-derived neurotrophic factor (BDNF), a factor critical for hippocampal plasticity across the life span. This study determined whether early-life iron deficiency epigenetically modifies the Bdnf locus and whether dietary choline supplementation during late gestation reverses these modifications. DNA methylation and histone modifications were assessed at the Bdnf-IV promoter in the hippocampus of rats [at postnatal day (PND) 65] that were iron-deficient (ID) during the fetal-neonatal period. Iron deficiency was induced in rat pups by providing pregnant and nursing dams an ID diet (4 mg/kg Fe) from gestational day (G) 2 through PND7, after which iron deficiency was treated with an iron-sufficient (IS) diet (200 mg/kg Fe). This paradigm resulted in about 60% hippocampal iron loss on PND15 with complete recovery by PND65. For choline supplementation, pregnant rat dams were given dietary choline (5 g/kg) from G11 through G18. DNA methylation was determined by quantitative sequencing of bisulfite-treated DNA, revealing a small alteration at the Bdnf-IV promoter. Chromatin immunoprecipitation analysis showed increased HDAC1 binding accompanied by reduced binding of RNA polymerase II and USF1 at the Bdnf-IV promoter in formerly ID rats. These changes were correlated with altered histone methylations. Prenatal choline supplementation reverses these epigenetic modifications. Collectively, the findings identify epigenetic modifications as a potential mechanism to explicate the long-term repression of Bdnf following fetal and early postnatal iron deficiency. Copyright © 2015 the American Physiological Society.

Fetal iron deficiency induces chromatin remodeling at the Bdnf locus in adult rat hippocampus

PubMed Central

Kennedy, Bruce C.; Lien, Yu-Chin; Simmons, Rebecca A.; Georgieff, Michael K.

2014-01-01

Fetal and subsequent early postnatal iron deficiency causes persistent impairments in cognitive and affective behaviors despite prompt postnatal iron repletion. The long-term cognitive impacts are accompanied by persistent downregulation of brain-derived neurotrophic factor (BDNF), a factor critical for hippocampal plasticity across the life span. This study determined whether early-life iron deficiency epigenetically modifies the Bdnf locus and whether dietary choline supplementation during late gestation reverses these modifications. DNA methylation and histone modifications were assessed at the Bdnf-IV promoter in the hippocampus of rats [at postnatal day (PND) 65] that were iron-deficient (ID) during the fetal-neonatal period. Iron deficiency was induced in rat pups by providing pregnant and nursing dams an ID diet (4 mg/kg Fe) from gestational day (G) 2 through PND7, after which iron deficiency was treated with an iron-sufficient (IS) diet (200 mg/kg Fe). This paradigm resulted in about 60% hippocampal iron loss on PND15 with complete recovery by PND65. For choline supplementation, pregnant rat dams were given dietary choline (5 g/kg) from G11 through G18. DNA methylation was determined by quantitative sequencing of bisulfite-treated DNA, revealing a small alteration at the Bdnf-IV promoter. Chromatin immunoprecipitation analysis showed increased HDAC1 binding accompanied by reduced binding of RNA polymerase II and USF1 at the Bdnf-IV promoter in formerly ID rats. These changes were correlated with altered histone methylations. Prenatal choline supplementation reverses these epigenetic modifications. Collectively, the findings identify epigenetic modifications as a potential mechanism to explicate the long-term repression of Bdnf following fetal and early postnatal iron deficiency. PMID:25519736

Hyperphagia and obesity in OLETF rats lacking CCK-1 receptors

PubMed Central

Moran, Timothy H; Bi, Sheng

2006-01-01

The brain–gut peptide cholecystokinin (CCK) inhibits food intake following peripheral or site directed central administration. Peripheral exogenous CCK inhibits food intake by reducing the size and duration of a meal. Antagonist studies have demonstrated that the actions of the exogenous peptide mimic those of endogenous CCK. Antagonist administration results in increased meal size and meal duration. The feeding inhibitory actions of CCK are mediated through interactions with CCK-1 receptors. The recent identification of the Otsuka–Long–Evans–Tokushima Fatty (OLETF) rat as a spontaneous CCK-1 receptor knockout model has allowed a more comprehensive evaluation of the feeding actions of CCK. OLETF rats become obese and develop non-insulin dependent diabetes mellitus (NIDDM). Consistent with the absence of CCK-1 receptors, OLETF rats do not respond to exogenous CCK. OLETF rats are hyperphagic and their increased food intake is characterized by a large increase in meal size with a decrease in meal frequency that is not sufficient to compensate for the meal size increase. Deficits in meal size control are evident in OLETF rats as young as 2 days of age. OLETF obesity is secondary to the increased food intake. Pair feeding to amounts consumed by intact control rats normalizes body weight, body fat and elevated insulin and glucose levels. Hypothalamic arcuate nucleus peptide mRNA expression in OLETF rats is appropriate to their obesity and is normalized by pair feeding. In contrast, pair fed and young pre-obese OLETF rats have greatly elevated dorsomedial hypothalamic (DMH) neuropeptide Y (NPY) mRNA expression. Elevated DMH NPY in OLETF rats appears to be a consequence of the absence of CCK-1 receptors. In intact rats NPY and CCK-1 receptors colocalize to neurons within the compact subregion of the DMH and local CCK administration reduces food intake and decreases DMH NPY mRNA expression. We have proposed that the absence of DMH CCK-1 receptors significantly

Brain and Hepatic Mt mRNA Is Reduced in Response to Mild Energy Restriction and n-3 Polyunsaturated Fatty Acid Deficiency in Juvenile Rats

PubMed Central

Mehus, Aaron A.; Picklo, Sr, Matthew J.

2017-01-01

Metallothioneins (MTs) perform important regulatory and cytoprotective functions in tissues including the brain. While it is known that energy restriction (ER) and dietary n-3 polyunsaturated fatty acid (PUFA) deficiency impact postnatal brain growth and development, little data exist regarding the impact of undernutrition upon MT expression in growing animals. We tested the hypothesis that ER with and without dietary n-3 PUFA deficiency reduces MT expression in juvenile rats. ER rats were individually pair-fed at 75% of the ad libitum (AL) intake of control rats provided diets consisting of either soybean oil (SO) that is α-linolenic acid (ALA; 18:3n-3) sufficient or corn oil (CO; ALA-deficient). Fatty acids (FA) and metal concentrations of liver and brain regions were analyzed. Tissue expression of MTs (Mt1-3) and modulators of MT expression including glucocorticoid receptors (Nr3c1 and Nr3c2) and several mediators of thyroid hormone regulation (Dio1-3, Mct8, Oatp1c1, Thra, and Thrb) were measured. Plasma corticosterone and triiodothyronine levels were also evaluated. ER, but not metal deficiency, reduced Mt2 expression in the cerebellum (50%) and cerebral cortex (23%). In liver, a reduction in dietary n-3 PUFA reduced Mt1, Mt2, Nr3c1, Mct8, and Thrb. ER elevated Nr3c1, Dio1, and Thrb and reduced Thra in the liver. Given MT’s role in cellular protection, further studies are needed to evaluate whether ER or n-3 PUFA deficiency may leave the juvenile brain and/or liver more susceptible to endogenous or environmental stressors. PMID:29048374

Brain and Hepatic Mt mRNA Is Reduced in Response to Mild Energy Restriction and n-3 Polyunsaturated Fatty Acid Deficiency in Juvenile Rats.

PubMed

Mehus, Aaron A; Picklo, Matthew J

2017-10-19

Metallothioneins (MTs) perform important regulatory and cytoprotective functions in tissues including the brain. While it is known that energy restriction (ER) and dietary n -3 polyunsaturated fatty acid (PUFA) deficiency impact postnatal brain growth and development, little data exist regarding the impact of undernutrition upon MT expression in growing animals. We tested the hypothesis that ER with and without dietary n -3 PUFA deficiency reduces MT expression in juvenile rats. ER rats were individually pair-fed at 75% of the ad libitum (AL) intake of control rats provided diets consisting of either soybean oil (SO) that is α-linolenic acid (ALA; 18:3 n -3) sufficient or corn oil (CO; ALA-deficient). Fatty acids (FA) and metal concentrations of liver and brain regions were analyzed. Tissue expression of MTs ( Mt1-3 ) and modulators of MT expression including glucocorticoid receptors ( Nr3c1 and Nr3c2 ) and several mediators of thyroid hormone regulation ( Dio1-3 , Mct8 , Oatp1c1 , Thra , and Thrb ) were measured. Plasma corticosterone and triiodothyronine levels were also evaluated. ER, but not metal deficiency, reduced Mt2 expression in the cerebellum (50%) and cerebral cortex (23%). In liver, a reduction in dietary n -3 PUFA reduced Mt1 , Mt2 , Nr3c1 , Mct8 , and Thrb . ER elevated Nr3c1 , Dio1 , and Thrb and reduced Thra in the liver. Given MT's role in cellular protection, further studies are needed to evaluate whether ER or n -3 PUFA deficiency may leave the juvenile brain and/or liver more susceptible to endogenous or environmental stressors.

Cardiac catecholamines in rats fed copper deficient or copper adequate diets containing fructose or starch

DOE Office of Scientific and Technical Information (OSTI.GOV)

Scholfield, D.J.; Fields, M.; Beal, T.

1989-02-09

The symptoms of copper (Cu) deficiency are known to be more severe when rats are fed a diet with fructose (F) as the principal carbohydrate. Mortality, in males, due to cardiac abnormalities usually occurs after five weeks of a 62% F, 0.6 ppm Cu deficient diet. These effects are not observed if cornstarch (CS) is the carbohydrate (CHO) source. Studies with F containing diets have shown increased catecholamine (C) turnover rates while diets deficient in Cu result in decreased norepinephrine (N) levels in tissues. Dopamine B-hydroxylase (EC 1.14.17.1) is a Cu dependent enzyme which catalyzes the conversion of dopamine (D)more » to N. An experiment was designed to investigate the effects of CHO and dietary Cu on levels of three C in cardiac tissue. Thirty-two male and female Sprague-Dawley rats were fed Cu deficient or adequate diets with 60% of calories from F or CS for 6 weeks. N, epinephrine (E) and D were measured by HPLC. Statistical analysis indicates that Cu deficiency tends to decrease N levels, while having the reverse effect on E. D did not appear to change. These findings indicate that Cu deficiency but not dietary CHO can affect the concentration of N and E in rat cardiac tissue.« less

Testosterone Deficiency Causes Endothelial Dysfunction via Elevation of Asymmetric Dimethylarginine and Oxidative Stress in Castrated Rats.

PubMed

Kataoka, Tomoya; Hotta, Yuji; Maeda, Yasuhiro; Kimura, Kazunori

2017-12-01

Testosterone is believed to mediate the penile erectile response by producing adequate nitric oxide; therefore, testosterone deficiency results in erectile dysfunction through decreased nitric oxide bioavailability. However, the mechanisms underlying endothelial dysfunction in testosterone deficiency remain unclear. To investigate the mechanism of endothelial dysfunction in a rat model of testosterone deficiency. Rats were distributed into 3 groups: castrated (Cast), castrated and supplemented with testosterone (Cast + T), and sham (Sham). In the Cast + T group, castrated rats were treated daily with subcutaneous testosterone (3 mg/kg daily) for 4 weeks; Sham and Cast rats received only the vehicle. Erectile function using intracavernosal pressure and mean arterial pressure measurements after electrical stimulation of the cavernous nerve, endothelial function using isometric tension, asymmetric dimethylarginine (ADMA) levels using ultra-performance liquid chromatography and tandem mass spectrometry, and inflammatory biomarker expression were performed 4 weeks after the operation. In the Cast group, the ratio of intracavernosal pressure to mean arterial pressure significantly decreased, acetylcholine-induced relaxation was lower, and serum ADMA, oxidative stress, and inflammation biomarker levels were significantly increased (P < .01). Testosterone injection significantly improved each of these parameters (P < .01). The present results provide scientific evidence of the effect of testosterone deficiency on erectile function and the effect of testosterone replacement therapy. This study provides evidence of the influence of testosterone deficiency on endothelial function by investigating ADMA and oxidative stress. A major limitation of this study is the lack of a direct link of increased ADMA by oxidative stress to inflammation. Testosterone deficiency increased not only ADMA levels but also oxidative stress and inflammation in castrated rats, which can cause

The effects of dietary vitamin B12 deficiency on sperm maturation in developing and growing male rats.

PubMed

Watanabe, Toshiaki; Ohkawa, Keiko; Kasai, Shigenobu; Ebara, Shuhei; Nakano, Yoshihisa; Watanabe, Yoshitaka

2003-03-01

To evaluate the role of vitamin B12 on spermatogenesis, the effects of dietary vitamin B12 deficiency on sperm maturation in developing rat fetuses and young growing rats were examined. The vitamin B12-deficient diet was given to all the animals for three different periods: whole period (gestation to mature), gestation period (gestation to weaning), or immature period (3-12 weeks postnatal). Sperm examination revealed that the sperm count was markedly lower in male progeny (F1) that were vitamin B12-deficient during the whole period. In addition, a significantly higher number of abnormal sperm, such as tailless and amorphous sperm, was observed. In male rats that were vitamin B12-deficient during the immature period, the incidence of abnormal sperms was 14.4% and 4.8% for tailless and short tail, respectively. The motion rates, such as path velocity and straight line velocity, were decreased to 20-40% of the control value in rats that were vitamin B12-deficient both during the whole and gestation periods. However, no effects of vitamin B12 deficiency on sperm motility were observed during the immature and mature periods. From these findings, we suggest that dietary vitamin B12 deficiency during pregnancy may induce irreversible damage in the germ cells of embryos and affect the maturation of spermatozoa.

Functional Characteristics of the Naked Mole Rat μ-Opioid Receptor

PubMed Central

Roth, Clarisse A.

2013-01-01

While humans and most animals respond to µ-opioid receptor (MOR) agonists with analgesia and decreased aggression, in the naked mole rat (NMR) opioids induce hyperalgesia and severe aggression. Single nucleotide polymorphisms in the human mu-opioid receptor gene (OPRM1) can underlie altered behavioral responses to opioids. Therefore, we hypothesized that the primary structure of the NMR MOR may differ from other species. Sequencing of the NMR oprm1 revealed strong homology to other mammals, but exposed three unique amino acids that might affect receptor-ligand interactions. The NMR and rat oprm1 sequences were cloned into mammalian expression vectors and transfected into HEK293 cells. Radioligand binding and 3'-5'-cyclic adenosine monophosphate (cAMP) enzyme immunoassays were used to compare opioid binding and opioid-mediated cAMP inhibition. At normalized opioid receptor protein levels we detected significantly lower [3H]DAMGO binding to NMR compared to rat MOR, but no significant difference in DAMGO-induced cAMP inhibition. Strong DAMGO-induced MOR internalization was detectable using radioligand binding and confocal imaging in HEK293 cells expressing rat or NMR receptor, while morphine showed weak or no effects. In summary, we found minor functional differences between rat and NMR MOR suggesting that other differences e.g. in anatomical distribution of MOR underlie the NMR's extreme reaction to opioids. PMID:24312175

Inhibition of growth of Morris hepatomas 7777 and 7800 by corn oil.

PubMed

Gilbertson, J R; Gelman, R A; Ove, P; Coetzee, M L

1977-01-01

Intraperitoneal injection of trace amounts of corn oil prior to and following the injection of 40-50 mg of tissue from hepatoma 7777 or 7800 into the thigh of adult male Buffalo rats resulted in a marked decrease in the growth rate of both tumors. Exhaustive extraction of the corn oil with water indicated that the active component was not water soluble. Similar injections of safflower oil or isotonic saline had no effect on tumor growth rate. Analysis of the tissue phospholipid fatty acids revealed that the injected corn oil caused no change in the esterified fatty acids in this lipid fraction.

Impulsivity and AMPA receptors: aniracetam ameliorates impulsive behavior induced by a blockade of AMPA receptors in rats.

PubMed

Nakamura, K; Kurasawa, M; Shirane, M

2000-04-17

The study aimed to ascertain the involvement of central AMPA receptors in impulsive behaviors of aged rats and to examine the effects of aniracetam. Premature response in the two-lever choice reaction task was assessed as an index of impulsivity. Intracerebroventricular injection of 2, 3-dihydroxy-6-nitro-7-sulfamoyl-benzo(F)quinoxaline (NBQX), an AMPA receptor antagonist, dose-dependently (10.1-1009 ng/rat) increased only premature response without altering responding speed and choice accuracy 30 min after the injection. Aniracetam (30 mg/kg p.o.), a positive allosteric modulator of AMPA receptors, or AMPA (55.9 ng/rat, co-injected with NBQX) completely restored the NBQX-induced increase in impulsivity. These results indicate that AMPA receptors are tonically involved in the regulation of impulsivity.

[Effect of selenium deficiency on the F344 inbred line offspring rats' neuro-behavior, ability of learning and memory].

PubMed

Hong, Liang-Li; Tian, Dong-Ping; Su, Min; Shen, Xiu-Na; Gao, Yuxia

2006-01-01

To establish the selenium (Se) deficient animal model on F344 inbred line rats and observe the effects of a long-term Se-deficiency on the offspring's neuro-behavior, abilities of learning and memory. Feeding F344 inbred line rats on Se-deficient diet to establish Se-deficient animal model. For the offspring, the body weight, physiological indexes nervous reflections for growth and development were monitored during the early postnatal period. The Se-deficient diet contained less than 0.01 mg/kg and the glutathione peroxidase (GSH-Px) activity in blood of the Se-deficient group rats is lower than the Se-normal group after feeding on Se-deficient diet for 4 weeks. For the offspring, the birth weight and the body weight of Se-deficient group were obviously lower than the Se-normal group before weaning. Se-deficient offspring rats differed from Se-normal controls in lower scores in surface righting reflex (RR) test at postnatal 4th day after delivery, cliff avoidance test at postnatal 7th day and auditory acuity trial at postnatal 10th day respectively. But these differences disappear after a few days in the same tests. In addition, no significant differences between two groups in suspending test and walking ability test at postnatal 12th and 14th day. In open field test, Se-deficient male offspring stayed less time in the middle grid and moved less. In Morris water maze test, the Se-deficient offspring spent more time to find the hidden platform at the 6th and 9th training tests in the place navigation trial. Furthermore, the Se-deficient group spent less time in target quadrant when giving the spatial probe trial. A Se-deficient animal model have been established on F344 inbred line rats successfully. A long-term Se deficiency could retard the development of the offspring in uterus and after delivery. Se deficiency also decreased the offspring's abilities of spatial learning and memory in Morris water maze test and resulted in the male offspring's nervousness to new

Choline and betaine ameliorate liver lipid accumulation induced by vitamin B6 deficiency in rats.

PubMed

Kitagawa, Erina; Yamamoto, Tatsuya; Fujishita, Mayuko; Ota, Yuki; Yamamoto, Kohei; Nakagawa, Tomoyuki; Hayakawa, Takashi

2017-02-01

We investigated the efficacy of supplementing the diet with choline or betaine in ameliorating lipid accumulation induced by vitamin B 6 (B 6 ) deficiency in rat liver. Male Wistar rats were fed a control, B 6 -deficient, choline-supplemented (2, 4, or 6 g choline bitartrate/kg diet) B 6 -deficient diet or betaine-supplemented (1, 2, or 4 g betaine anhydrous/kg diet) B 6 -deficient diet for 35 d; all diets contained 9 g L-methionine (Met)/kg diet. Choline or betaine supplementation attenuated liver lipid deposition and restored plasma lipid profiles to control levels. These treatments restored the disruptions in Met metabolism and the phosphatidylcholine (PC)/phosphatidylethanolamine (PE) ratio induced by B 6 deficiency in liver microsomes. These results suggest that choline and betaine ameliorated liver lipid accumulation induced by B 6 deficiency via recovery of Met metabolism and very low-density lipoprotein secretion by restoring the supply of PC derived from PE.

Studies on gonadotropin receptor of rat ovary and testis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Q.

1989-01-01

The subunit structure of the testicular LH/hCG receptor was studied by a chemical cross-linking technique. Leydig cells isolated from rat testis were incubated with {sup 125}I-hCG, following which the bound {sup 125}I-hCG was covalently cross-linked to the receptor on the cell surface with a cleavable or a non-cleavable cross-linking reagent. The hormone-receptor complex was extracted and then either subjected to gel permeation chromatography under nondenaturing conditions, or resolved by SDS-polyacrylamide gel electrophoresis, followed by autoradiographic analysis. The ovarian LH/hCG receptor was studied with luteal cells from pseudopregnant rats. Purification of the receptor was achieved by ligand affinity chromatography following detergentmore » solubilization of the plasma membrane. The purified hCG receptor displayed properties identical to the membrane bound receptor with regard to binding specificity and affinity, and exhibited a molecular weight of approximately 130,000 dalton.« less

Protease-Activated Receptor-2 Deficiency Attenuates Atherosclerotic Lesion Progression and Instability in Apolipoprotein E-Deficient Mice

PubMed Central

Zuo, Pengfei; Zuo, Zhi; Zheng, Yueyue; Wang, Xin; Zhou, Qianxing; Chen, Long; Ma, Genshan

2017-01-01

Inflammatory mechanisms are involved in the process of atherosclerotic plaque formation and rupture. Accumulating evidence suggests that protease-activated receptor (PAR)-2 contributes to the pathophysiology of chronic inflammation on the vasculature. To directly examine the role of PAR-2 in atherosclerosis, we generated apolipoprotein E/PAR-2 double-deficient mice. Mice were fed with high-fat diet for 12 weeks starting at ages of 6 weeks. PAR-2 deficiency attenuated atherosclerotic lesion progression with reduced total lesion area, reduced percentage of stenosis and reduced total necrotic core area. PAR-2 deficiency increased fibrous cap thickness and collagen content of plaque. Moreover, PAR-2 deficiency decreased smooth muscle cell content, macrophage accumulation, matrix metallopeptidase-9 expression and neovascularization in plaque. Relative quantitative PCR assay using thoracic aorta revealed that PAR-2 deficiency reduced mRNA expression of inflammatory molecules, such as vascular cell adhesion molecule-1, intercellular adhesion molecule-1, tumor necrosis factor (TNF)-α and monocyte chemoattractant protein (MCP)-1. In vitro experiment, we found that PAR-2 deficiency reduced mRNA expression of interferon-γ, interleukin-6, TNF-α and MCP-1 in macrophage under unstimulated and lipopolysaccharide-stimulated conditions. These results suggest that PAR-2 deficiency attenuates the progression and instability of atherosclerotic plaque. PMID:28959204

The effect of insulin deficiency on the plasma clearance and exchange of high-density-lipoprotein phosphatidylcholine in rats.

PubMed Central

Martins, I J; Redgrave, T G

1992-01-01

Triolein/cholesteryl oleate/cholesterol/phosphatidylcholine emulsions designed to model the lipid composition of chylomicrons were injected intravenously into control and streptozotocin-treated insulin-deficient rats. As previously described for lymph chylomicrons, the emulsion triolein was hydrolysed and phosphatidylcholine was transferred to the plasma high-density lipoproteins (HDL). This mechanism was used to introduce a phospholipid label into HDL in vivo. The subsequent clearance of phospholipid radioactivity from the plasma of insulin-deficient rats was significantly slower than in controls (P less than 0.025). Plasma clearance was similarly slower in insulin-deficient rats after injection of HDL that was previously labelled with radioactive phospholipids. After injection, the phospholipid label redistributed rapidly between the large-particle fraction of plasma lipoproteins (very-low- and low-density lipoproteins), and the lighter and heavier fractions of HDL. Compared with control rats, in insulin-deficient rats less of the phospholipid label was distributed to the lighter HDL fraction and more to the heavier HDL fraction, and this difference was not due to changes in activity of lecithin: cholesterol acyltransferase or in the apparent activity of phospholipid transfer protein. In insulin-deficient rats the changes in HDL phospholipid clearance and exchange appeared to be secondary to the associated hypertriglyceridaemia and the related changes in distribution of phospholipids between classes of plasma lipoproteins. PMID:1536661

Synergistic effects of acyclic retinoid and OSI-461 on growth inhibition and gene expression in human hepatoma cells.

PubMed

Shimizu, Masahito; Suzui, Masumi; Deguchi, Atsuko; Lim, Jin T E; Xiao, Danhua; Hayes, Julia H; Papadopoulos, Kyriakos P; Weinstein, I Bernard

2004-10-01

Hepatoma is one of the most frequently occurring cancers worldwide. However, effective chemotherapeutic agents for this disease have not been developed. Acyclic retinoid, a novel synthetic retinoid, can reduce the incidence of postsurgical recurrence of hepatoma and improve the survival rate. OSI-461, a potent derivative of exisulind, can increase intracellular levels of cyclic GMP, which leads to activation of protein kinase G and induction of apoptosis in cancer cells. In the present study, we examined the combined effects of acyclic retinoid plus OSI-461 in the HepG2 human hepatoma cell line. We found that the combination of as little as 1.0 micromol/L acyclic retinoid and 0.01 micromol/L OSI-461 exerted synergistic inhibition of the growth of HepG2 cells. Combined treatment with low concentrations of these two agents also acted synergistically to induce apoptosis in HepG2 cells through induction of Bax and Apaf-1, reduction of Bcl-2 and Bcl-xL, and activation of caspase-3, -8, and -9. OSI-461 enhanced the G0-G1 arrest caused by acyclic retinoid, and the combination of these agents caused a synergistic decrease in the levels of expression of cyclin D1 protein and mRNA, inhibited cyclin D1 promoter activity, decreased the level of hyperphosphorylated forms of the Rb protein, induced increased cellular levels of the p21(CIP1) protein and mRNA, and stimulated p21(CIP1) promoter activity. Moreover, OSI-461 enhanced the ability of acyclic retinoid to induce increased cellular levels of retinoic acid receptor beta and to stimulate retinoic acid response element-chloramphenicol acetyltransferase activity. A hypothetical model involving concerted effects on p21(CIP1) and retinoic acid receptor beta expression is proposed to explain these synergistic effects. Our results suggest that the combination of acyclic retinoid plus OSI-461 might be an effective regimen for the chemoprevention and chemotherapy of human hepatoma and possibly other malignancies.

Impairment of the liver insulin receptor autoactivation cascade at full-term pregnancy in the rat.

PubMed

Martinez, C; Molero, J C; Ruiz, P; Del Arco, A; Andres, A; Carrascosa, J M

1995-10-15

Partially purified liver insulin receptors from full-term pregnant rats show decreased autophosphorylation rates if compared with receptors from virgins. We studied the molecular mechanism of this phenomenon, looking at possible structural and functional changes of several domains. The ATP-binding domain seems to be unaltered in receptors from pregnant rats since Km for ATP was similar to that observed in virgins. In contrast, the Vmax. is decreased some 45%, suggesting changes in the kinase domain. Truncation of a fragment of 10 kDa from the C-terminal tail does not normalize the kinase activity in receptors from pregnant rats, suggesting that this domain is not involved in the inhibitory regulation. Treatment with alkaline phosphatase increases the [32P]Pi incorporation into receptors from pregnant rats; however, the autophosphorylation remains lower than that observed in virgin rats. Tryptic phosphopeptide maps of phosphorylated receptors show that the same phosphopeptides are present in receptors from virgin and pregnant rats. However, the progression through the autoactivation cascade in the kinase domain is impaired in receptors from pregnant rats. Differences in the cleavage by trypsin at the two alternative sites in the kinase domain were observed, indicating possible structural changes in receptors from pregnant rats that could be related to the impairment of the autoactivation cascade. Integrity of the alpha- and beta-subunits, as well as differential expression of the two receptor isotypes, were shown to be unaltered. We conclude that (1) the decreased autophosphorylation rate of the liver insulin receptor from pregnant rats is associated with the impairment of its autoactivation cascade, probably as a consequence of the basal Ser/Thr phosphorylation; and (2) the inhibition of the autoactivation cascade does not account for the overall inhibition of autophosphorylation observed in receptors from pregnant rats.

Inhibition of Hepatitis B Virus and Induction of Hepatoma Cell Apoptosis by ASGPR-Directed Delivery of shRNAs

PubMed Central

Yao, Xinxin; Shi, Chuan; Sun, Lifang; Yuan, Lu; Lei, Ping; Zhu, Huifen; Liu, Hongbo; Wu, Xiongwen; Ning, Qin; Zhou, Chun; Shen, Guanxin

2012-01-01

Hepatitis B virus (HBV) infection is a worldwide liver disease and nearly 25% of chronic HBV infections terminate in hepatocellular carcinoma (HCC). Currently, there is no effective therapy to inhibit HBV replication and to eliminate hepatoma cells, making it highly desired to develop novel therapies for these two stages of the HBV-caused detrimental disease. Recently, short hairpin RNA (shRNA) has emerged as a potential therapy for virus-infected disease and cancer. Here, we have generated a shRNA, pGenesil-siHBV4, which effectively inhibits HBV replication in the human hepatoma cell line HepG2.2.15. The inhibitory effects of pGenesil-siHBV4 are manifested by the decrease of both the HBV mRNA level and the protein levels of the secreted HBV surface antigen (HBsAg) and HBV e antigen (HBeAg), and by the reduction of secreted HBV DNA. Using mouse hydrodynamic tail vein injection, we demonstrate that pGenesil-siHBV4 is effective in inhibiting HBV replication in vivo. Because survivin plays a key role in cancer cell escape from apoptosis, we further generated pGenesil-siSurvivin, a survivin-silencing shRNA, and showed its effect of triggering apoptosis of HBV-containing hepatoma cells. To develop targeted shRNA therapy, we have identified that as a specific binder of the asialoglycoprotein receptor (ASGPR), jetPEI-Hepatocyte delivers pGenesil-siHBV4 and pGenesil-siSurvivin specifically to hepatocytes, not other types of cells. Finally, co-transfection of pGenesil-siHBV4 and pGenesil-siSurvivin exerts synergistic effects in inducing hepatoma cell apoptosis, a novel approach to eliminate hepatoma by downregulating survivin via multiple mechanisms. The application of these novel shRNAs with the jetPEI-Hepatocyte targeting strategy demonstrates the proof-of-principle for a promising approach to inhibit HBV replication and eliminate hepatoma cells with high specificity. PMID:23094023

[Effects of vitamins deficiency on the cytochrome P450 inducibility in rats].

PubMed

Trusov, N V; Guseva, G V; Beketova, N A; Aksenov, I V; Avrent'eva, L I; Kravchenko, L V

2014-01-01

The purpose of the study was to determine multi-vitamin deficiency effects on the inducibility of main isoforms of cytochrome P450 in the rat liver. The study was carried out on 4 groups of Wistar rats. Rats of the 1st and 3rd group received semi-synthetic diets containing adequate (100% of recommended vitamin level) level of vitamins, the 2nd and 4th--the semi-synthetic diet containing vitamins in the amount of 20% from adequate level. The duration of the experiment was 4 weeks. During the last week indole-3-carbinol (I-3-C) in dose of 20 mg/kg body weight was added to the diet of the 3rd and 4th group of rats. Vitamin E content in liver and blood serum declined by 59 and 34%, respectively in rats which were fed vitamin-deficient diet (2nd group); vitamin A level decreased by 5 times in the liver, but was not changed in blood serum. Multi-vitamin deficiency in the diet led to the increase in the liver ethoxyresorufin O-dealkylase (EROD) activity of CYP1A1, methoxyresorufin O-dealkylase (MROD) activity of CYP1A2 and testosteron 6beta-hydroxylase (6beta-TG) activity of CYP3A by 11, 80 and 53%, respectively, and gene expression of CYP1A1, CYP1A2, CYP3A and AhR by 8,5; 1,6; 2,4 and 3,6 fold. In rats fed diet with adequate levels of vitamins (3rd group) I-3-C increased activity of EROD and MROD by 4,4 and 5,5 fold, and the expression of CYP1A1, CYP1A2 and AhR genes by 148; 3 and 3,5 fold compared to the parameters of the 1st group (without I-3-C). Multi-vitamin deficiency increased I-3-C-related induction of EROD activity and expression of CYP1A1 and CYP1A2 genes, but decreased I-3-C-related induction of the MROD activity. Thus, 5-fold reducing of vitamin content in rat diet lead to significant changes in activity and inducibility of cytochrome P450 of CYP1A and 3A family, which play a key role in the detoxification and metabolism of drugs.

Dioxin-like activity of brominated dioxins as individual compounds or mixtures in in vitro reporter gene assays with rat and mouse hepatoma cell lines.

PubMed

Suzuki, G; Nakamura, M; Michinaka, C; Tue, N M; Handa, H; Takigami, H

2017-10-01

In vitro reporter gene assays detecting dioxin-like compounds have been developed and validated since the middle 1990's, and applied to the determination of dioxin-like activities in various samples for their risk management. Data on characterizing the potency of individual brominated dioxins and their activity in mixture with chlorinated dioxins are still limited on the cell-based assay. This study characterized the dioxin-like activities of the 32 brominated dioxins, such as polybrominated dibenzo-p-dioxins, polybrominated dibenzofurans (PBDFs), coplanar polybrominated biphenyls, mixed halogenated dibenzo-p-dioxins and dibenzofurans (PXDFs), as a sole component or in a mixture by DR-CALUX (dioxin-responsive chemically activated luciferase expression) using the rat hepatoma H4IIE cell line and XDS-CALUX (xenobiotic detection systems-chemically activated luciferase expression) assays using the mouse hepatoma H1L6.1 cell line. The 2,3,7,8-TCDD-relative potencies (REPs) of most of the brominated dioxins were within a factor of 10 of the WHO toxicity equivalency factor (WHO-TEF) for the chlorinated analogues. The REPs of a few PXDFs were an order of magnitude higher than the corresponding WHO-TEFs, indicating their toxicological importance. Results with reconstituted mixtures suggest that the activity of brominated and chlorinated dioxins in both CALUX assays was dose-additive. Thus, obtained results indicated the applicability of the CALUX assays as screening tools of brominated dioxins together with their chlorinated analogues. Copyright © 2017 Elsevier Ltd. All rights reserved.

Nuclear receptor coactivators function in estrogen receptor- and progestin receptor-dependent aspects of sexual behavior in female rats

PubMed Central

Molenda-Figueira, Heather A.; Williams, Casey A.; Griffin, Andreana L.; Rutledge, Eric M.; Blaustein, Jeffrey D.; Tetel, Marc J.

2008-01-01

The ovarian hormones, estradiol (E) and progesterone (P) facilitate the expression of sexual behavior in female rats. E and P mediate many of these behavioral effects by binding to their respective intracellular receptors in specific brain regions. Nuclear receptor coactivators, including Steroid Receptor Coactivator-1 (SRC-1) and CREB Binding Protein (CBP), dramatically enhance ligand-dependent steroid receptor transcriptional activity in vitro. Previously, our lab has shown that SRC-1 and CBP modulate estrogen receptor (ER)-mediated induction of progestin receptor (PR) gene expression in the ventromedial nucleus of the hypothalamus (VMN) and hormone-dependent sexual receptivity in female rats. Female sexual behaviors can be activated by high doses of E alone in ovariectomized rats, and thus are believed to be ER-dependent. However, the full repertoire of female sexual behavior, in particular, proceptive behaviors such as hopping, darting and ear wiggling, are considered to be PR-dependent. In the present experiments, the function of SRC-1 and CBP in distinct ER- (Exp. 1) and PR- (Exp. 2) dependent aspects of female sexual behavior was investigated. In Exp. 1, infusion of antisense oligodeoxynucleotides to SRC-1 and CBP mRNA into the VMN decreased lordosis intensity in rats treated with E alone, suggesting that these coactivators modulate ER-mediated female sexual behavior. In Exp. 2, antisense to SRC-1 and CBP mRNA around the time of P administration reduced PR-dependent ear wiggling and hopping and darting. Taken together, these data suggest that SRC-1 and CBP modulate ER and PR action in brain and influence distinct aspects of hormone-dependent sexual behaviors. These findings support our previous studies and provide further evidence that SRC-1 and CBP function together to regulate ovarian hormone action in behaviorally-relevant brain regions. PMID:16769066

Skeletal response to corticosteroid deficiency and excess in growing male rats

NASA Technical Reports Server (NTRS)

Li, M.; Shen, Y.; Halloran, B. P.; Baumann, B. D.; Miller, K.; Wronski, T. J.

1996-01-01

The study was designed to investigate bone histomorphometric changes induced by corticosteroid deficiency and supplementation at different dose levels in the rat skeleton. Male rats were adrenalectomized (ADX) or sham-operated and divided into six groups. At 2 days after surgery, sham-operated control rats (CON + PLA) and one group of ADX rats (ADX + PLA) were implanted subcutaneously (s.c.) with placebo pellets. ADX rats in the remaining four groups (ADX + C25, ADX + C50, ADX + C100, and ADX + C300) were implanted sc with corticosterone pellets designed to release 25, 50, 100, or 300 mg of the hormone over a 60 day period. Each ADX rat was also implanted sc with an aldosterone pellet (2.5 mg) similarly designed to release its contents over the same time period. All rats were killed at 3 weeks after implantation of pellets. Terminal blood samples were collected for serum biochemistry and the proximal tibial metaphyses (PTM), tibial diaphyses, and first lumbar vertebrae (LV) were processed undecalcified for quantitative bone histomorphometry. A dose-dependent increase in serum corticosterone concentration was observed in ADX rats implanted with hormone pellets. In comparison to CON + PLA rats, ADX + PLA rats had lower cancellous bone volume associated with a stimulation in longitudinal bone growth, an increase in mineral apposition rate, and a trend for increased osteoclast and osteoblast surfaces in PTM. In contrast, cancellous bone of ADX + C25 rats was preserved at nearly the CON + PLA level. However, the higher doses of corticosterone increased cancellous bone mass, but decreased longitudinal bone growth and all indices of bone resorption and formation in a dose-dependent manner in PTM. Similar cancellous bone changes were observed in the LV of corticosterone-treated rats, with the exception of a lack of an hormonal effect on cancellous bone mass. In the tibial diaphysis, corticosterone inhibited periosteal bone formation in a dose-dependent manner, but did not

Prenatal choline supplementation ameliorates the long-term neurobehavioral effects of fetal-neonatal iron deficiency in rats.

PubMed

Kennedy, Bruce C; Dimova, Jiva G; Siddappa, Asha J M; Tran, Phu V; Gewirtz, Jonathan C; Georgieff, Michael K

2014-11-01

Gestational iron deficiency in humans and rodents produces long-term deficits in cognitive and socioemotional function and alters expression of plasticity genes in the hippocampus that persist despite iron treatment. Prenatal choline supplementation improves cognitive function in other rodent models of developmental insults. The objective of this study was to determine whether prenatal choline supplementation prevents the long-term effects of fetal-neonatal iron deficiency on cognitive and social behaviors and hippocampal gene expression. Pregnant rat dams were administered an iron-deficient (2-6 g/kg iron) or iron-sufficient (IS) (200 g/kg iron) diet from embryonic day (E) 3 to postnatal day (P) 7 with or without choline supplementation (5 g/kg choline chloride, E11-18). Novel object recognition (NOR) in the test vs. acquisition phase, social approach (SA), and hippocampal mRNA expression were compared at P65 in 4 male adult offspring groups: formerly iron deficient (FID), FID with choline supplementation (FID-C), IS, and IS with choline supplementation. Relative to the intact NOR in IS rats (acquisition: 47.9%, test: 60.2%, P < 0.005), FID adult rats had impaired recognition memory at the 6-h delay (acquisition: 51.4%, test: 55.1%, NS), accompanied by a 15% reduction in hippocampal expression of brain-derived neurotrophic factor (Bdnf) (P < 0.05) and myelin basic protein (Mbp) (P < 0.05). Prenatal choline supplementation in FID rats restored NOR (acquisition: 48.8%, test: 64.4%, P < 0.0005) and increased hippocampal gene expression (FID-C vs. FID group: Bdnf, Mbp, P < 0.01). SA was also reduced in FID rats (P < 0.05 vs. IS rats) but was only marginally improved by prenatal choline supplementation. Deficits in recognition memory, but not social behavior, resulting from gestational iron deficiency are attenuated by prenatal choline supplementation, potentially through preservation of hippocampal Bdnf and Mbp expression. Prenatal choline supplementation may be a

Atrial natriuretic factor receptor heterogeneity in rat tissues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andresen, J.W.; Kuno, T.; Kamisaki, Y.

1986-03-01

Rat /sup 125/I-atrial natriuretic factor (ANF, 8-33) was used to identify ANF receptors in membrane preparations from rat adrenal gland and lung. When solubilized with Lubrol-PX, the receptors retained a binding profile and properties that correspond to the high affinity and specificity found in crude membranes. Single peaks of binding activity were observed in gel permeation HPLC and density gradient centrifugation analysis of the solubilized preparations. However, when membranes and solubilized preparations were labeled with /sup 125/I-ANF, treated with crosslinking reagent (disuccinimidyl suberate), and analyzed by SDS gel electrophoresis several specifically labeled bands (120,000, 70,000, and 60,000 daltons) were identifiedmore » by autoradiography. The relative distribution of the specifically labeled proteins varied significantly between rat adrenal gland and lung. In adrenal glands the 120K dalton band was the most prominent specifically labeled protein, while the 60K and 70K dalton proteins were labeled to a lesser degree. In lung membranes the lower molecular weight proteins were more prominent. These results suggest the presence of multiple ANF receptor subtypes, the distribution of which varies among tissues. Chromatographic separation and further characterization of these receptors are currently in progress, and preliminary purification studies support this hypothesis.« less

Cell surface GRP78 facilitates hepatoma cells proliferation and migration by activating IGF-IR.

PubMed

Yin, Yancun; Chen, Chen; Chen, Jinliang; Zhan, Renhui; Zhang, Qiang; Xu, Xiaoyan; Li, Defang; Li, Minjing

2017-07-01

The 78kDa glucose regulated protein (GRP78) is a multifunctional chaperone that is involved in a variety of cellular processes. Insulin like growth factor I receptor (IGF-IR) often aberrant expresses in many types of tumor cells. The IGF-IR signaling plays key roles in carcinogenesis and maintenance of the malignant phenotype. The crosstalk between GRP78 and IGF-IR molecules has not well been illuminated. Here, we demonstrated a reciprocal regulation of GRP78 expression and IGF-IR pathway activation. IGF-I induced GRP78 expression in hepatoma cells. IGF-IR knockdown or IGF-IR inhibitor repressed GRP78 expression. Both phosphatidylinositol 3-kianase (PI3K) and mitogen-activated protein kinase (MAPK) pathways involved in IGF-I induction of GRP78 expression. Interestingly, treatment of hepatoma cells with IGF-I re-distributes GRP78 from endoplasmic reticulum (ER) to cell surface and promotes its physical interaction with IGF-IR. Also, GRP78 promotes IGF-IR phosphorylation and activation. Blocked of GRP78 by small interfering RNA or inhibition of GRP78 function by (-)-epigallocatechin gallate (EGCG) blocks IGF-I induced IGF-IR phosphorylation and its downstream signaling. Further, blocked cell surface GRP78 with antibody inhibits IGF-I stimulated cellular proliferation and migration. These data reveal an essential role for the molecular chaperone GRP78 in IGF-IR signaling and implicate the use of GRP78 inhibitors in blocking IGF-IR signaling in hepatoma cells. Copyright © 2017 Elsevier Inc. All rights reserved.

Cobalamin Deficiency Results in Increased Production of Formate Secondary to Decreased Mitochondrial Oxidation of One-Carbon Units in Rats.

PubMed

MacMillan, Luke; Tingley, Garrett; Young, Sara K; Clow, Kathy A; Randell, Edward W; Brosnan, Margaret E; Brosnan, John T

2018-03-01

Formate is produced in mitochondria via the catabolism of serine, glycine, dimethylglycine, and sarcosine. Formate produced by mitochondria may be incorporated into the cytosolic folate pool where it can be used for important biosynthetic reactions. Previous studies from our lab have shown that cobalamin deficiency results in increased plasma formate concentrations. Our goal was to determine the basis for elevated formate in vitamin B-12 deficiency. Male Sprague Dawley rats were randomly assigned to consume either a cobalamin-replete (50 μg cobalamin/kg diet) or -deficient (no added cobalamin) diet for 6 wk. Formate production was measured in vivo and in isolated liver mitochondria from a variety of one-carbon precursors. We also measured the oxidation of [3-14C]-l-serine to 14CO2 in isolated rat liver mitochondria and the expression of hepatic genes involved in one-carbon unit and formate metabolism. Cobalamin-deficient rats produce formate at a rate 55% higher than that of replete rats. Formate production from serine was increased by 60% and from dimethylglycine and sarcosine by ∼200% in liver mitochondria isolated from cobalamin-deficient rats compared with cobalamin-replete rats. There was a 26% decrease in the 14CO2 produced by mitochondria from cobalamin-deficient rats. Gene expression analysis showed that 10-formyltetrahydrofolate dehydrogenase-cytosolic (Aldh1l1) and mitochondrial (Aldh1l2) expression were decreased by 40% and 60%, respectively, compared to control, while 10-formyltetrahydrofolate synthetase, mitochondrial, monofunctional (Mthfd1l) expression was unchanged. We propose that a bifurcation in mitochondrial one-carbon metabolism is a key control mechanism in determining the fate of one-carbon units, to formate or CO2. During cobalamin deficiency in rats the disposition of 10-formyl-tetrahydrofolate carbon is shifted in favor of formate production. This may represent a mechanism to generate more one-carbon units for the replenishment of the S

Leptin Receptor Deficiency is Associated With Upregulation of Cannabinoid 1 Receptors in Limbic Brain Regions

PubMed Central

THANOS, PANAYOTIS K.; RAMALHETE, ROBERTO C.; MICHAELIDES, MICHAEL; PIYIS, YIANNI K.; WANG, GENE-JACK; VOLKOW, NORA D.

2009-01-01

Leptin receptor dysfunction results in overeating and obesity. Leptin regulates hypothalamic signaling that underlies the motivation to hyperphagia, but the interaction between leptin and cannabinoid signaling is poorly understood. We evaluated the role of cannabinoid 1 receptors (CB1R) in overeating and the effects of food deprivation on CB1R in the brain. One-month-old Zucker rats were divided into unrestricted and restricted (fed 70% of unrestricted rats) diet groups and maintained until adulthood (4 months). Levels of relative binding sites of CB1R (CB1R binding levels) were assessed using [3H] SR141716A in vitro autoradiography. These levels were higher (except cerebellum and hypothalamus) at 4 months than at 1 month of age. One month CB1R binding levels for most brain regions did not differ between Ob and Lean (Le) rats (except in frontal and cingulate cortices in Le and in the hypothalamus in Ob). Four month Ob rats had higher CB1R binding levels than Le in most brain regions and food restriction was associated with higher CB1R levels in all brain regions in Ob, but not in Le rats. CB1R binding levels increased between adolescence and young adulthood which we believe was influenced by leptin and food availability. The high levels of CB1R in Ob rats suggest that leptin's inhibition of food-intake is in part mediated by downregulation of CB1R and that leptin interferes with CB1R upregulation under food-deprivation conditions. These results are consistent with prior findings showing increased levels of endogenous cannabinoids in the Ob rats corroborating the regulation of cannabinoid signaling by leptin. PMID:18563836

Leptin receptor deficiency is associated with upregulation of cannabinoid 1 receptors in limbic brain regions.

PubMed

Thanos, Panayotis K; Ramalhete, Roberto C; Michaelides, Michael; Piyis, Yianni K; Wang, Gene-Jack; Volkow, Nora D

2008-09-01

Leptin receptor dysfunction results in overeating and obesity. Leptin regulates hypothalamic signaling that underlies the motivation to hyperphagia, but the interaction between leptin and cannabinoid signaling is poorly understood. We evaluated the role of cannabinoid 1 receptors (CB(1)R) in overeating and the effects of food deprivation on CB(1)R in the brain. One-month-old Zucker rats were divided into unrestricted and restricted (fed 70% of unrestricted rats) diet groups and maintained until adulthood (4 months). Levels of relative binding sites of CB(1)R (CB(1)R binding levels) were assessed using [(3)H] SR141716A in vitro autoradiography. These levels were higher (except cerebellum and hypothalamus) at 4 months than at 1 month of age. One month CB(1)R binding levels for most brain regions did not differ between Ob and Lean (Le) rats (except in frontal and cingulate cortices in Le and in the hypothalamus in Ob). Four month Ob rats had higher CB(1)R binding levels than Le in most brain regions and food restriction was associated with higher CB(1)R levels in all brain regions in Ob, but not in Le rats. CB(1)R binding levels increased between adolescence and young adulthood which we believe was influenced by leptin and food availability. The high levels of CB(1)R in Ob rats suggest that leptin's inhibition of food-intake is in part mediated by downregulation of CB(1)R and that leptin interferes with CB(1)R upregulation under food-deprivation conditions. These results are consistent with prior findings showing increased levels of endogenous cannabinoids in the Ob rats corroborating the regulation of cannabinoid signaling by leptin. Published 2008 Wiley-Liss, Inc.

Comparison of nicotinic receptor binding and biotransformation of coniine in the rat and chick.

PubMed

Forsyth, C S; Speth, R C; Wecker, L; Galey, F D; Frank, A A

1996-12-31

Coniine, an alkaloid from Conium maculatum (poison hemlock), is a known teratogen in many domestic species with maternal ingestion resulting in arthrogryposis of the offspring. We have previously shown that rats are not susceptible and rabbits only weakly susceptible to coniine-induced arthrogryposis. However, the chick embryo does provide a reproducible laboratory animal model of coniine-induced teratogenesis. The reason for this cross-species variation is unknown. The purpose of this study was to evaluate coniine binding to nicotinic receptors and to measure coniine metabolism in vitro between susceptible and non-susceptible species. Using the chick model, neither the peripheral nicotinic receptor antagonist d-tubocurarine chloride nor the central nicotinic receptor antagonist trimethaphan camsylate blocked the teratogenesis or lethality of 1.5% coniine (50 microliters/egg). Trimethaphan camsylate enhanced coniine-induced lethality in a dose-dependent manner. Neither nicotinic receptor blocker prevented nicotine sulfate-induced malformations but d-tubocurarine chloride did block lethality in a dose-dependent manner. Competition by coniine for [125I]-alpha-bungarotoxin to nicotinic receptors isolated from adult rat diaphragm and chick thigh muscle and competition by coniine for [3H]-cytisine to receptors from rat and chick brain were used to assess coniine binding to nicotinic receptors. The IC50 for coniine in rat diaphragm was 314 microM while that for chick leg muscle was 70 microM. For neuronal nicotinic receptors, the IC50s of coniine for maternal rat brain, fetal rat brain, and chick brain were 1100 microM, 820 microM, and 270 microM, respectively. There were no differences in coniine biotransformation in vitro by microsomes from rat or chick livers. Differences in apparent affinity of coniine for nicotinic receptors or differences in the quantity of the nicotinic receptor between the rat and chick may explain, in part, the differences in susceptibility of

DAILY PATTERNS OF CLOCK AND COGNITION-RELATED FACTORS ARE MODIFIED IN THE HIPPOCAMPUS OF VITAMIN A-DEFICIENT RATS

PubMed Central

Golini, Rebeca S.; Delgado, Silvia M.; Navigatore Fonzo, Lorena S.; Ponce, Ivana T.; Lacoste, María G.; Anzulovich, Ana C.

2012-01-01

The circadian expression of clock and clock-controlled cognition-related genes in the hippocampus would be essential to achieve an optimal daily cognitive performance. There is some evidence that retinoid nuclear receptors (RARs and RXRs) can regulate circadian gene expression in different tissues. In this study, Holtzman male rats from control and vitamin A-deficient groups were sacrificed throughout a 24-h period and hippocampus samples were isolated every 4 or 5 h. RARα and RXRβ expression level was quantified and daily expression patterns of clock BMAL1, PER1, RORα and REVERB genes, RORα and REVERB proteins, as well as temporal expression of cognition-related RC3 and BDNF genes were determined in the hippocampus of the two groups of rats. Our results show significant daily variations of BMAL1, PER1, RORα and REVERB genes, RORα and REVERB proteins and, consequently, daily oscillating expression of RC3 and BDNF genes in the rat hippocampus. Vitamin A deficiency reduced RXRβ mRNA level as well as the amplitude of PER1, REVERB gene and REVERB protein rhythms, and phase-shifted the daily peaks of BMAL1 and RORα mRNA, RORα protein and RC3 and BDNF mRNA levels. Thus, nutritional factors, such as vitamin A and its derivatives the retinoids, might modulate daily patterns of BDNF and RC3 expression in the hippocampus and they could be essential to maintain an optimal daily performance at molecular level in this learning-and-memory-related brain area. PMID:22434687

Histomorphometric study of alveolar bone healing in rats fed a boron-deficient diet.

PubMed

Gorustovich, Alejandro A; Steimetz, Tammy; Nielsen, Forrest H; Guglielmotti, María B

2008-04-01

Bone healing after tooth extraction in rats is a suitable experimental model to study bone formation. Thus, we performed a study to determine the effects of boron (B) deficiency on bone healing by using this model. The first lower right molar of weanling Wistar rats was extracted under anesthesia. The animals were divided into two groups: +B (adequate; 3 mg B/kg diet), and -B (boron-deficient; 0.07 mg/kg diet). The animals in both groups were killed in groups of 10 at 7 and 14 days after surgery. The guidelines of the NIH for the care and use of laboratory animals were observed. The mandibles were resected, fixed, decalcified, and embedded in paraffin. Buccolingually oriented sections were obtained at the level of the mesial alveolus and used for histometric evaluations. Total alveolar volume (TAV) and trabecular bone volume per total volume (BV/TV) in the apical third of the alveolus were determined. Percentages of osteoblast surface (ObS), eroded surface (ES), and quiescent surface (QS) were determined. No statistical significant differences in food intake and body weight were observed. Histomorphometric evaluation found -B rats had 36% and 63% reductions in BV/TV at 7 and 14 days, respectively. When compared with +B rats, -B rats had significant reductions (57% and 87%) in ObS concomitantly with increases (120% and 126%) in QS at 7 and 14 days, respectively. The findings show that boron deficiency results in altered bone healing because of a marked reduction in osteogenesis. 2008 Wiley-Liss, Inc

Changes of imidazoline receptors in spontaneously hypertensive rats

PubMed Central

Mar, Guang-Yuan; Chou, Ming-Ting; Chung, Hsien-Hui; Chiu, Nien-Hua; Chen, Mei-Fen; Cheng, Juei-Tang

2013-01-01

The role of imidazoline receptors in the regulation of vascular function remains unclear. In this study, we evaluated the effect of agmatine, an imidazoline receptor agonist, on systolic blood pressure (SBP) in spontaneously hypertensive rats (SHRs) and investigated the expressions of imidazoline receptors by Western blot. The isometric tension of aortic rings isolated from male SHRs was also estimated. Agmatine decreased SBP in a dose-dependent manner in SHRs but not in the normal group [Wistar–Kyoto (WKY) rats]. This reduction in SBP in SHRs was abolished by BU224, a selective antagonist of imidazoline I2-receptors. Higher expression of imidazoline receptors in SHR was observed. Moreover, agmatine-induced relaxation in isolated aortic rings precontracted with phenylephrine or KCl. This relaxation was also abolished by BU224 but was not modified by efaroxan, an imidazoline I1-receptor antagonist. Agmatine-induced relaxation was also attenuated by PNU 37883, a selective blocker of vascular ATP-sensitive potassium (KATP) channels. Additionally, vasodilatation by agmatine was reduced by an inhibitor of protein kinase A (PKA). We suggest that agmatine can lower blood pressure in SHRs through activation of the peripheral imidazoline I2-receptor, which is expressed more highly in SHRs. PMID:23176371

Benzodiazepine and kainate receptor binding sites in the RCS rat retina.

PubMed

Stasi, Kalliopi; Naskar, Rita; Thanos, Solon; Kouvelas, Elias D; Mitsacos, Ada

2003-02-01

The effect of age and photoreceptor degeneration on the kainate subtype of glutamate receptors and on the benzodiazepine-sensitive gamma-aminobutyric acid-A receptors (GABA(A)) in normal and RCS (Royal College of Surgeons) rats were investigated. [(3)H]Kainate and [(3)H]flunitrazepam were used as radioligands for kainate and GABA(A)/benzodiazepine()receptors, respectively, using the quantitative receptor autoradiography technique. In both normal and RCS rat retina we observed that [(3)Eta]flunitrazepam and [(3)Eta]kainate binding levels were several times higher in inner plexiform layer (IPL) than in outer plexiform layer (OPL) at all four ages studied (P17, P35, P60 and P180). Age-related changes in receptor binding were observed in normal rat retina: [(3)Eta]flunitrazepam binding showed a significant decrease of 25% between P17 and P60 in IPL,and [(3)Eta]kainate binding showed significant decreases between P17 and P35 in both synaptic layers (71% in IPL and 63% in OPL). Degeneration-related changes in benzodiazepine and kainate receptor binding were observed in RCS rat retina. In IPL, [(3)Eta]flunitrazepam and [(3)Eta]kainate binding levels were higher than in normal retina at P35 (by 24% and 86%, respectively). In OPL, [(3)Eta]flunitrazepam binding was higher in RCS than in normal retina on P35 (74%) and also on P60 (62%). The results indicate that postnatal changes occur in kainate and benzodiazepine receptor binding sites in OPL and IPL of the rat retina up to 6 months of age. The data also suggest that the receptor binding changes observed in the RCS retina could be a consequence of the primary photoreceptor degeneration.

Extrasynaptic GABAA receptors in rat pontine reticular formation increase wakefulness.

PubMed

Vanini, Giancarlo; Baghdoyan, Helen A

2013-03-01

Gamma-aminobutyric acid (GABA) causes phasic inhibition via synaptic GABAA receptors and tonic inhibition via extrasynaptic GABAA receptors. GABA levels in the extracellular space regulate arousal state and cognition by volume transmission via extrasynaptic GABAA receptors. GABAergic transmission in the pontine reticular formation promotes wakefulness. No previous studies have determined whether an agonist at extrasynaptic GABAA receptors administered into the pontine reticular formation alters sleep and wakefulness. Therefore, this study used gaboxadol (THIP; agonist at extrasynaptic GABAA receptors that contain a δ subunit) to test the hypothesis that extrasynaptic GABAA receptors within the pontine reticular formation modulate sleep and wakefulness. Within/between subjects. University of Michigan. Adult male Crl:CD*(SD) (Sprague-Dawley) rats (n = 10). Microinjection of gaboxadol, the nonsubtype selective GABAA receptor agonist muscimol (positive control), and saline (negative control) into the rostral pontine reticular formation. Gaboxadol significantly increased wakefulness and decreased both nonrapid eye movement sleep and rapid eye movement sleep in a concentration-dependent manner. Relative to saline, gaboxadol did not alter electroencephalogram power. Microinjection of muscimol into the pontine reticular formation of the same rats that received gaboxadol increased wakefulness and decreased sleep. Tonic inhibition via extrasynaptic GABAA receptors that contain a δ subunit may be one mechanism by which the extracellular pool of endogenous GABA in the rostral pontine reticular formation promotes wakefulness. Vanini G; Baghdoyan HA. Extrasynaptic GABAA receptors in rat pontine reticular formation increase wakefulness. SLEEP 2013;36(3):337-343.

Dietary fructose but not starch is responsible for hyperlipidemia associated with copper deficiency in rats: effect of high-fat diet.

PubMed

Fields, M; Lewis, C G

1999-02-01

To test the hypothesis that copper deficiency in rats may be hyperlipidemic only when the diets consumed contain nutrients which contribute to blood lipids such as fructose and high fat. Weanling male Sprague Dawley rats were fed diets which contained either starch or fructose as their sole carbohydrate source. The diets were either inadequate (0.6 microg Cu/g) or adequate (6.0 microg Cu/g) in copper and contained either high (300 g/kg) or low (60 g/kg) fat. At the end of the 4th week the rats were killed. Livers were analyzed for copper content. Plasma was analyzed for cholesterol and triglyceride concentrations. High-fat diet did not increase blood lipids in rats fed a copper-deficient diet containing starch. In contrast, the combination of high-fat diet with fructose increased blood triglycerides and fructose with copper deficiency resulted in a significant increases in blood cholesterol. Hyperlipidemia of copper deficiency in rats is dependent on synergistic effects between dietary fructose and copper deficiency and fructose and amount of dietary fat. Hyperlipidemia does not develop if starch is the main source of dietary carbohydrate in a copper-deficient diet even if a high-fat diet is fed.

Developmental programming of vascular dysfunction by prenatal and postnatal zinc deficiency in male and female rats.

PubMed

Mendes Garrido Abregú, Facundo; Gobetto, María Natalia; Juriol, Lorena Vanesa; Caniffi, Carolina; Elesgaray, Rosana; Tomat, Analía Lorena; Arranz, Cristina

2018-06-01

Micronutrient malnutrition during intrauterine and postnatal growth may program cardiovascular diseases in adulthood. We examined whether moderate zinc restriction in male and female rats throughout fetal life, lactation and/or postweaning growth induces alterations that can predispose to the onset of vascular dysfunction in adulthood. Female Wistar rats were fed low- or control zinc diets from pregnancy to offspring weaning. After weaning, offspring were fed either a low- or a control zinc diet until 81 days. We evaluated systolic blood pressure (SBP), thoracic aorta morphology, nitric oxide (NO) system and vascular reactivity in 6- and/or 81-day-old offspring. At day 6, zinc-deficient male and female offspring showed a decrease in aortic NO synthase (NOS) activity accompanied by an increase in oxidative stress. Zinc-deficient 81-day-old male rats exhibited an increase in collagen deposition in tunica media, as well as lower activity of endothelial NOS (eNOS) that could not be reversed with an adequate zinc diet during postweaning life. Zinc deficiency programmed a reduction in eNOS protein expression and higher SBP only in males. Adult zinc-deficient rats of both sexes showed reduced vasodilator response dependent on eNOS activity and impaired aortic vasoconstrictor response to angiotensin-II associated with alterations in intracellular calcium mobilization. Female rats were less sensitive to the effects of zinc deficiency and exhibited higher eNOS activity and/or expression than males, without alterations in SBP or aortic histology. This work strengthens the importance of a balanced intake of micronutrients during perinatal growth to ensure adequate vascular function in adult life. Copyright © 2018 Elsevier Inc. All rights reserved.

The effects of Cordyceps sinensis phytoestrogen on estrogen deficiency-induced osteoporosis in ovariectomized rats.

PubMed

Zhang, Da-wei; Wang, Zhen-lin; Qi, Wei; Zhao, Guang-yue

2014-12-13

Isoflavones are naturally occurring plant chemicals belonging to the "phytoestrogen" class. The aim of the present study was to examine the effects of isoflavones obtained from Cordyceps sinensis (CSIF) on development of estrogen deficiency-induced osteoporosis in ovariectomized rats. After the rats were treated orally with CSIF, serum alkaline phosphatase (ALP), tartarate resistant acid phosphatase (TRAP), serum osteocalcin (OC), homocysteine (HCY), C-terminal crosslinked telopeptides of collagen type I (CTX), estradiol and interferonγ (IFN-γ) level were examined. At the same time, the urine calcium, plasma calcium, plasma phosphorus and the mass of uterus, thymus and body were also examined. The beneficial effects of CSIF on improvement of osteoporosis in rats were attributable mainly to decrease ALP activity, TRAP activity, CTX level and IFN-γ level. At the same time, CSIF also increase the OC and estradiol level in ovariectomized osteopenic rats. The histological examination clearly showed that dietary CSIF can prevent bone loss caused by estrogen deficiency. The significant estrogenic activity of CSIF demonstrated that CSIF has significant estrogenic effects in OVX rats.

Thyroid hormone receptor inhibits hepatoma cell migration through transcriptional activation of Dickkopf 4

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chi, Hsiang-Cheng; Liao, Chen-Hsin; Huang, Ya-Hui

Highlights: •T{sub 3} affects DKK4 mRNA and protein expression in HepG2-TR cells. •Regulation of DKK4 by T{sub 3} is at transcriptional level. •DKK4 overexpression suppresses hepatoma cell metastasis. -- Abstract: Triiodothyronine (T{sub 3}) is a potent form of thyroid hormone mediates several physiological processes including cellular growth, development, and differentiation via binding to the nuclear thyroid hormone receptor (TR). Recent studies have demonstrated critical roles of T{sub 3}/TR in tumor progression. Moreover, long-term hypothyroidism appears to be associated with the incidence of human hepatocellular carcinoma (HCC), independent of other major HCC risk factors. Dickkopf (DKK) 4, a secreted protein thatmore » antagonizes the canonical Wnt signaling pathway, is induced by T{sub 3} at both mRNA and protein levels in HCC cell lines. However, the mechanism underlying T{sub 3}-mediated regulation of DKK4 remains unknown. In the present study, the 5′ promoter region of DKK4 was serially deleted, and the reporter assay performed to localize the T{sub 3} response element (TRE). Consequently, we identified an atypical direct repeat TRE between nucleotides −1645 and −1629 conferring T{sub 3} responsiveness to the DKK4 gene. This region was further validated using chromatin immunoprecipitation (ChIP) and electrophoretic mobility shift assay (EMSA). Stable DKK4 overexpression in SK-Hep-1 cells suppressed cell invasion and metastatic potential, both in vivo andin vitro, via reduction of matrix metalloproteinase-2 (MMP-2) expression. Our findings collectively suggest that DKK4 upregulated by T{sub 3}/TR antagonizes the Wnt signal pathway to suppress tumor cell progression, thus providing new insights into the molecular mechanism underlying thyroid hormone activity in HCC.« less

Decoy receptor 3 analogous supplement protects steatotic rat liver from ischemia-reperfusion injury.

PubMed

Li, Tzu-Hao; Liu, Chih-Wei; Lee, Pei-Chang; Huang, Chia-Chang; Lee, Kuei-Chuan; Hsieh, Yun-Cheng; Yang, Ying-Ying; Hsieh, Shie-Liang; Lin, Han-Chieh; Tsai, Chang-Youh

2017-07-01

For steatotic livers, pharmacological approaches to minimize the hepatic neutrophil and macrophage infiltration, and cytokine and chemokine release in ischemia-reperfusion (IR) injury are still limited. Tumor necrosis factor (TNF)-α superfamily-stimulated pathogenic cascades and M1 macrophage/Kupffer cells (KC) polarization from Th1 cytokines are important in the pathogenesis of IR liver injury with hepatic steatosis (HS). Conversely, anti-inflammatory M2 macrophages produce Th2 cytokine (interleukin-4), which reciprocally enhances M2 polarization. Toll-like receptor 4-activated KCs can release proinflammatory mediators, skew M1 polarization and escalate liver IR injury. Decoy receptor 3 (DcR 3 ) could be potential agents simultaneously blocking the IR liver injury-related pathogenic changes and extend the survival of steatotic graft. Rats were fed with methionine and choline-deficient high-fat diet (MCD HFD) for 6 weeks to induce HS. Preliminary experiments with HS group and IR group were conducted, and either immunoglobulin G Fc protein or DcR3 analogue was treated for 14 days in all groups to evaluate the severity. In the Zucker rat-focused experiments, various serum and hepatic substances, M1 polarization, and hepatic microcirculation were assessed. We found that serum/hepatic DcR 3 levels were lower in nonalcoholic fatty liver disease patients with HS. DcR 3 a protected Zucker rats with HS from IR liver injury. The beneficial effects of DcR 3 a supplement were mediated by inhibiting hepatic M1 polarization of KCs, decreasing serum/hepatic TNFα, nitric oxide, nitrotyrosine, soluble TNF-like cytokine 1A, Fas ligand, and interferon-γ levels, neutrophil infiltration, and improving hepatic microcirculatory failure among rats with IR-injured steatotic livers. Additionally, downregulated hepatic TNF-like cytokine 1A/Fas-ligand and toll-like receptor 4/nuclear factor-κB signals were found to mediate the DcR 3 a-related protective effects of steatotic livers from

Folate-deficiency induced cell-specific changes in the distribution of lymphocytes and granulocytes in rats.

PubMed

Abe, Ikumi; Shirato, Ken; Hashizume, Yoko; Mitsuhashi, Ryosuke; Kobayashi, Ayumu; Shiono, Chikako; Sato, Shogo; Tachiyashiki, Kaoru; Imaizumi, Kazuhiko

2013-01-01

Folate (vitamin B(9)) plays key roles in cell growth and proliferation through regulating the synthesis and stabilization of DNA and RNA, and its deficiency leads to lymphocytopenia and granulocytopenia. However, precisely how folate deficiency affects the distribution of a variety of white blood cell subsets, including the minor population of basophils, and the cell specificity of the effects remain unclear. Therefore, we examined the effects of a folate-deficient diet on the circulating number of lymphocyte subsets [T-lymphocytes, B-lymphocytes, and natural killer (NK) cells] and granulocyte subsets (neutrophils, eosinophils, and basophils) in rats. Rats were divided into two groups, with one receiving the folate-deficient diet (FAD group) and the other a control diet (CON group). All rats were pair-fed for 8 weeks. Plasma folate level was dramatically lower in the FAD group than in the CON group, and the level of homocysteine in the plasma, a predictor of folate deficiency was significantly higher in the FAD group than in the CON group. The number of T-lymphocytes, B-lymphocytes, and NK cells was significantly lower in the FAD group than in the CON group by 0.73-, 0.49-, and 0.70-fold, respectively, indicating that B-lymphocytes are more sensitive to folate deficiency than the other lymphocyte subsets. As expected, the number of neutrophils and eosinophils was significantly lower in the FAD group than in the CON group. However, the number of basophils, the least common type of granulocyte, showed transiently an increasing tendency in the FAD group as compared with the CON group. These results suggest that folate deficiency induces lymphocytopenia and granulocytopenia in a cell-specific manner.

Pantothenic acid deficiency may increase the urinary excretion of 2-oxo acids and nicotinamide catabolites in rats.

PubMed

Shibata, Katsumi; Inomoto, Kasumi; Nakata, Chifumi; Fukuwatari, Tsutomu

2013-01-01

Pantothenic acid (PaA) is involved in the metabolism of amino acids as well as fatty acid. We investigated the systemic metabolism of amino acids in PaA-deficient rats. For this purpose, urine samples were collected and 2-oxo acids and L-tryptophan (L-Trp) and its metabolites including nicotinamide were measured. Group 1 was freely fed a conventional chemically-defined complete diet and used as an ad lib-fed control, which group was used for showing reference values. Group 2 was freely fed the complete diet without PaA (PaA-free diet) and used as a PaA-deficient group. Group 3 was fed the complete diet, but the daily food amount was equal to the amount of the PaA-deficient group and used as a pair-fed control group. All rats were orally administered 100 mg of L-Trp/kg body weight at 09:00 on day 34 of the experiment and the following 24-h urine samples were collected. The urinary excretion of the sum of pyruvic acid and oxaloacetic acid was higher in rats fed the PaA-free diets than in the rats fed pair-fed the complete diet. PaA deficiency elicited the increased urinary excretion of anthranilic acid and kynurenic acid, while the urinary excretion of xanthurenic acid decreased. The urinary excretion of L-Trp itself, 3-hydroxyanthranilic acid, and quinolinic acid revealed no differences between the rats fed the PaA-free and pair-fed the complete diets. PaA deficiency elicited the increased excretion of N(1)-methylnicotinamide, N(1)-methyl-2-pyridone-5-carboxamide, and N(1)-methyl-4-pyridone-3-carboxamide. These findings suggest that PaA deficiency disturbs the amino acid catabolism.

Prenatal Choline Supplementation Ameliorates the Long-Term Neurobehavioral Effects of Fetal-Neonatal Iron Deficiency in Rats123

PubMed Central

Kennedy, Bruce C.; Dimova, Jiva G.; Siddappa, Asha J. M.; Tran, Phu V.; Gewirtz, Jonathan C.; Georgieff, Michael K.

2014-01-01

Background: Gestational iron deficiency in humans and rodents produces long-term deficits in cognitive and socioemotional function and alters expression of plasticity genes in the hippocampus that persist despite iron treatment. Prenatal choline supplementation improves cognitive function in other rodent models of developmental insults. Objective: The objective of this study was to determine whether prenatal choline supplementation prevents the long-term effects of fetal-neonatal iron deficiency on cognitive and social behaviors and hippocampal gene expression. Methods: Pregnant rat dams were administered an iron-deficient (2–6 g/kg iron) or iron-sufficient (IS) (200 g/kg iron) diet from embryonic day (E) 3 to postnatal day (P) 7 with or without choline supplementation (5 g/kg choline chloride, E11–18). Novel object recognition (NOR) in the test vs. acquisition phase, social approach (SA), and hippocampal mRNA expression were compared at P65 in 4 male adult offspring groups: formerly iron deficient (FID), FID with choline supplementation (FID-C), IS, and IS with choline supplementation. Results: Relative to the intact NOR in IS rats (acquisition: 47.9%, test: 60.2%, P < 0.005), FID adult rats had impaired recognition memory at the 6-h delay (acquisition: 51.4%, test: 55.1%, NS), accompanied by a 15% reduction in hippocampal expression of brain-derived neurotrophic factor (Bdnf) (P < 0.05) and myelin basic protein (Mbp) (P < 0.05). Prenatal choline supplementation in FID rats restored NOR (acquisition: 48.8%, test: 64.4%, P < 0.0005) and increased hippocampal gene expression (FID-C vs. FID group: Bdnf, Mbp, P < 0.01). SA was also reduced in FID rats (P < 0.05 vs. IS rats) but was only marginally improved by prenatal choline supplementation. Conclusions: Deficits in recognition memory, but not social behavior, resulting from gestational iron deficiency are attenuated by prenatal choline supplementation, potentially through preservation of hippocampal Bdnf and Mbp

The effect of developmental vitamin D deficiency in male and female Sprague-Dawley rats on decision-making using a rodent gambling task.

PubMed

Peak, J N; Turner, K M; Burne, T H J

2015-01-01

Developmental vitamin D (DVD) deficiency is a plausible risk factor for schizophrenia that has been associated with behavioural alterations including disruptions in latent inhibition and response inhibition. The rodent gambling task (rGT) assesses risk-based decision-making, which is a key cognitive deficit observed in schizophrenia patients. The primary aim of this study was to examine risk-based decision-making in DVD-deficient and control rats on the rGT. We also evaluated the performance of female Sprague-Dawley rats on the rGT for the first time. Adult male and female Sprague-Dawley rats from control and vitamin D deficient dams were trained to perform the rGT in standard operant chambers and their performance and choice-preferences were assessed. Female rats were significantly faster to reach rGT training criteria compared with male rats and DVD-deficient rats were faster to reach training criteria than control animals. After reaching stable performance on the rGT DVD-deficient and control rats showed a significant preference for the optimal choice-option in the rGT, but there were no significant effects of sex or diet on these responses. DVD deficiency did not alter the decision-making processes on the rGT because no significant changes in choice-preferences were evident. This is the first study to demonstrate that once established, the performance of females is comparable to male Sprague-Dawley rats on the rGT. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.

Extrasynaptic GABAA Receptors in Rat Pontine Reticular Formation Increase Wakefulness

PubMed Central

Vanini, Giancarlo; Baghdoyan, Helen A.

2013-01-01

Study Objectives: Gamma-aminobutyric acid (GABA) causes phasic inhibition via synaptic GABAA receptors and tonic inhibition via extrasynaptic GABAA receptors. GABA levels in the extracellular space regulate arousal state and cognition by volume transmission via extrasynaptic GABAA receptors. GABAergic transmission in the pontine reticular formation promotes wakefulness. No previous studies have determined whether an agonist at extrasynaptic GABAA receptors administered into the pontine reticular formation alters sleep and wakefulness. Therefore, this study used gaboxadol (THIP; agonist at extrasynaptic GABAA receptors that contain a δ subunit) to test the hypothesis that extrasynaptic GABAA receptors within the pontine reticular formation modulate sleep and wakefulness. Design: Within/between subjects. Setting: University of Michigan. Patients or Participants: Adult male Crl:CD*(SD) (Sprague-Dawley) rats (n = 10). Interventions: Microinjection of gaboxadol, the nonsubtype selective GABAA receptor agonist muscimol (positive control), and saline (negative control) into the rostral pontine reticular formation. Measurements and Results: Gaboxadol significantly increased wakefulness and decreased both nonrapid eye movement sleep and rapid eye movement sleep in a concentration-dependent manner. Relative to saline, gaboxadol did not alter electroencephalogram power. Microinjection of muscimol into the pontine reticular formation of the same rats that received gaboxadol increased wakefulness and decreased sleep. Conclusion: Tonic inhibition via extrasynaptic GABAA receptors that contain a δ subunit may be one mechanism by which the extracellular pool of endogenous GABA in the rostral pontine reticular formation promotes wakefulness. Citation: Vanini G; Baghdoyan HA. Extrasynaptic GABAA receptors in rat pontine reticular formation increase wakefulness. SLEEP 2013;36(3):337-343. PMID:23450652

Kinin B1 receptor deficiency leads to leptin hypersensitivity and resistance to obesity.

PubMed

Mori, Marcelo A; Araújo, Ronaldo C; Reis, Felipe C G; Sgai, Daniela G; Fonseca, Raphael G; Barros, Carlos C; Merino, Vanessa F; Passadore, Mariana; Barbosa, Ana M; Ferrari, Bernard; Carayon, Pierre; Castro, Charlles H M; Shimuta, Suma I; Luz, Jacqueline; Bascands, Jean-Loup; Schanstra, Joost P; Even, Patrick C; Oliveira, Suzana M; Bader, Michael; Pesquero, João B

2008-06-01

Kinins mediate pathophysiological processes related to hypertension, pain, and inflammation through the activation of two G-protein-coupled receptors, named B(1) and B(2). Although these peptides have been related to glucose homeostasis, their effects on energy balance are still unknown. Using genetic and pharmacological strategies to abrogate the kinin B(1) receptor in different animal models of obesity, here we present evidence of a novel role for kinins in the regulation of satiety and adiposity. Kinin B(1) receptor deficiency in mice (B(1)(-/-)) resulted in less fat content, hypoleptinemia, increased leptin sensitivity, and robust protection against high-fat diet-induced weight gain. Under high-fat diet, B(1)(-/-) also exhibited reduced food intake, improved lipid oxidation, and increased energy expenditure. Surprisingly, B(1) receptor deficiency was not able to decrease food intake and adiposity in obese mice lacking leptin (ob/ob-B(1)(-/-)). However, ob/ob-B(1)(-/-) mice were more responsive to the effects of exogenous leptin on body weight and food intake, suggesting that B(1) receptors may be dependent on leptin to display their metabolic roles. Finally, inhibition of weight gain and food intake by B(1) receptor ablation was pharmacologically confirmed by long-term administration of the kinin B(1) receptor antagonist SSR240612 to mice under high-fat diet. Our data suggest that kinin B(1) receptors participate in the regulation of the energy balance via a mechanism that could involve the modulation of leptin sensitivity.

Postprandial fatty acid uptake and adipocyte remodeling in angiotensin type 2 receptor-deficient mice fed a high-fat/high-fructose diet

PubMed Central

Noll, Christophe; Labbé, Sébastien M.; Pinard, Sandra; Shum, Michael; Bilodeau, Lyne; Chouinard, Lucie; Phoenix, Serge; Lecomte, Roger; Carpentier, André C.; Gallo-Payet, Nicole

2016-01-01

ABSTRACT The role of the angiotensin type-2 receptor in adipose physiology remains controversial. The aim of the present study was to demonstrate whether genetic angiotensin type-2 receptor-deficiency prevents or worsens metabolic and adipose tissue morphometric changes observed following a 6-week high-fat/high-fructose diet with injection of a small dose of streptozotocin. We compared tissue uptake of nonesterified fatty acid and dietary fatty acid in wild-type and angiotensin type-2 receptor-deficient mice by using the radiotracer 14(R,S)-[18F]-fluoro-6-thia-heptadecanoic acid in mice fed a standard or high-fat diet. Postprandial fatty acid uptake in the heart, liver, skeletal muscle, kidney and adipose tissue was increased in wild-type mice after a high-fat diet and in angiotensin type-2 receptor-deficient mice on both standard and high-fat diets. Compared to the wild-type mice, angiotensin type-2 receptor-deficient mice had a lower body weight, an increase in fasting blood glucose and a decrease in plasma insulin and leptin levels. Mice fed a high-fat diet exhibited increased adipocyte size that was prevented by angiotensin type-2 receptor-deficiency. Angiotensin type-2 receptor-deficiency abolished the early hypertrophic adipocyte remodeling induced by a high-fat diet. The small size of adipocytes in the angiotensin type-2 receptor-deficient mice reflects their inability to store lipids and explains the increase in fatty acid uptake in non-adipose tissues. In conclusion, a genetic deletion of the angiotensin type-2 receptor is associated with metabolic dysfunction of white adipose depots, and indicates that adipocyte remodeling occurs before the onset of insulin resistance in the high-fat fed mouse model. PMID:27144096

P2Y receptors and atherosclerosis in apolipoprotein E-deficient mice

PubMed Central

Guns, Pieter-Jan DF; Hendrickx, Jan; Van Assche, Tim; Fransen, Paul; Bult, Hidde

2010-01-01

Background and purpose: P2Y nucleotide receptors are involved in the regulation of vascular tone, smooth muscle cell (SMC) proliferation and inflammatory responses. The present study investigated whether they are involved in atherosclerosis. Experimental approach: mRNA of P2Y receptors was quantified (RT-PCR) in atherosclerotic and plaque-free aorta segments of apolipoprotein E-deficient (apoE–/–) mice. Macrophage activation was assessed in J774 macrophages, and effects of non-selective purinoceptor antagonists on atherosclerosis were evaluated in cholesterol-fed apoE–/– mice. Key results: P2Y6 receptor mRNA was consistently elevated in segments with atherosclerosis, whereas P2Y2 receptor expression remained unchanged. Expression of P2Y1 or P2Y4 receptor mRNA was low or undetectable, and not influenced by atherosclerosis. P2Y6 mRNA expression was higher in cultured J774 macrophages than in cultured aortic SMCs. Furthermore, immunohistochemical staining of plaques demonstrated P2Y6-positive macrophages, but few SMCs, suggesting that macrophage recruitment accounted for the increase in P2Y6 receptor mRNA during atherosclerosis. In contrast to ATP, the P2Y6-selective agonist UDP increased mRNA expression and activity of inducible nitric oxide synthase and interleukin-6 in J774 macrophages; this effect was blocked by suramin (100–300 µM) or pyridoxal-phosphate-6-azophenyl-2′-4′-disulphonic acid (PPADS, 10–30 µM). Finally, 4-week treatment of cholesterol-fed apoE–/– mice with suramin or PPADS (50 and 25 mg·kg−1·day−1 respectively) reduced plaque size, without changing plaque composition (relative SMC and macrophage content) or cell replication. Conclusions and implications: These results suggest involvement of nucleotide receptors, particularly P2Y6 receptors, during atherosclerosis, and warrant further research with selective purinoceptor antagonists or P2Y6 receptor-deficient mice. PMID:20050854

Testing the hypothesis that vitamin C deficiency is a risk factor for clozapine-induced agranulocytosis using guinea pigs and ODS rats.

PubMed

Ip, Julia; Wilson, John X; Uetrecht, Jack P

2008-04-01

The use of clozapine is limited by a relatively high incidence of drug-induced agranulocytosis. Clozapine is oxidized by bone marrow cells to a reactive nitrenium ion. Although many idiosyncratic drug reactions are immune-mediated, the fact that patients with a history of clozapine-induced agranulocytosis do not immediately develop agranulocytosis on rechallenge suggests that some other factor may be responsible for the idiosyncratic nature of this reaction. The reactive nitrenium ion is very rapidly reduced back to clozapine by vitamin C, and many schizophrenic patients are vitamin C deficient. We set out to test the hypothesis that vitamin C deficiency is a major risk factor for clozapine-induced agranulocytosis using a vitamin C deficient guinea pig model. Although the vitamin C deficient guinea pigs did not develop agranulocytosis, the amount of clozapine covalent binding in these animals was less than we had previously observed in samples from rats and humans. Therefore, we studied ODS rats that also cannot synthesize vitamin C. Vitamin C deficient ODS rats also did not develop agranulocytosis, and furthermore, although covalent binding in the bone marrow was greater than that in the guinea pig, it was not increased in the vitamin C deficient ODS rats relative to ODS rats that had adequate vitamin C in their diet. Therefore, it is very unlikely that vitamin C deficiency is a major risk factor for clozapine-induced agranulocytosis.

Thymic involution in the suspended rat model for weightlessness - Decreased glucocorticoid receptor concentration

NASA Technical Reports Server (NTRS)

Steffen, J. M.; Musacchia, X. J.

1984-01-01

Hindlimb muscle atrophy, thymic involution and adrenal hypertrophy in rats during spaceflight can be simulated using suspension models. Skeletal muscle and thymus are sensitive to gluco-corticoids (GC), and previous studies have demonstrated that muscle atrophy in suspended rats is associated with increased GC receptor concentration. The objectives were to confirm thymic involution during suspension, and determine if involution correlated with increased GC receptor concentration. Seven days of antiorthostatic (AO) suspension of rats produced a significant (P less than 0.001) reduction in thymic wet weight not associated with an alteration of percent water content. GC receptor concentration (pmol/mg protein) decreased 20 percent (P less than 0.025) in thymus glands from 7 day AO suspended rats. Suspension, therefore, is associated with involution of the thymus, but this is not dependent upon AO positioning. Thymus GC receptor concentrations were depressed in 7-day suspended rats, in contrast with previous observations on skeletal muscle, suggesting that different mechanisms may underlie these responses.

Fetal and neonatal iron deficiency but not copper deficiency increases vascular complexity in the developing rat brain

PubMed Central

Bastian, Thomas W.; Santarriaga, Stephanie; Nguyen, Thu An; Prohaska, Joseph R.; Georgieff, Michael K.; Anderson, Grant W.

2015-01-01

Objectives Anemia caused by nutritional deficiencies, such as iron and copper deficiencies, is a global health problem. Iron and copper deficiencies have their most profound effect on the developing fetus/infant, leading to brain development deficits and poor cognitive outcomes. Tissue iron depletion or chronic anemia can induce cellular hypoxic signaling. In mice, chronic hypoxia induces a compensatory increase in brain blood vessel outgrowth. We hypothesized that developmental anemia, due to iron or copper deficiencies, induces angiogenesis/vasculogenesis in the neonatal brain. Methods To test our hypothesis, three independent experiments were performed where pregnant rats were fed iron- or copper-deficient diets from gestational day 2 through mid-lactation. Effects on the neonatal brain vasculature were determined using qPCR to assess mRNA levels of angiogenesis/vasculogenesis-associated genes and GLUT1 immunohistochemistry (IHC) to assess brain blood vessel density and complexity. Results Iron deficiency, but not copper deficiency, increased mRNA expression of brain endothelial cell- and angiogenesis/vasculogenesis-associated genes (i.e. Glut1, Vwf, Vegfa, Ang2, Cxcl12, and Flk1) in the neonatal brain, suggesting increased cerebrovascular density. Iron deficiency also increased hippocampal and cerebral cortical blood vessel branching by 62% and 78%, respectively. Discussion This study demonstrates increased blood vessel complexity in the neonatal iron-deficient brain, which is likely due to elevated angiogenic/vasculogenic signaling. At least initially, this is probably an adaptive response to maintain metabolic substrate homeostasis in the developing iron-deficient brain. However, this may also contribute to long-term neurodevelopmental deficits. PMID:26177275

Muscarinic receptors mediate cold stress-induced detrusor overactivity in type 2 diabetes mellitus rats.

PubMed

Imamura, Tetsuya; Ishizuka, Osamu; Ogawa, Teruyuki; Yamagishi, Takahiro; Yokoyama, Hitoshi; Minagawa, Tomonori; Nakazawa, Masaki; Gautam, Sudha Silwal; Nishizawa, Osamu

2014-10-01

This study determined if muscarinic receptors could mediate the cold stress-induced detrusor overactivity induced in type 2 diabetes mellitus rats. Ten-week-old female Goto-Kakizaki diabetic rats (n = 12) and Wister Kyoto non-diabetic rats (n = 12) were maintained on a high-fat diet for 4 weeks. Cystometric investigations of the unanesthetized rats were carried out at room temperature (27 ± 2°C) for 20 min. They were intravenously administered imidafenacin (0.3 mg/kg, n = 6) or vehicle (n = 6). After 5 min, the rats were transferred to a low temperature (4 ± 2°C) for 40 min where the cystometry was continued. The rats were then returned to room temperature for the final cystometric measurements. Afterwards, expressions of bladder muscarinic receptor M3 and M2 messenger ribonucleic acids and proteins were assessed by reverse transcription polymerase chain reaction and immunohistochemistry. In non-diabetic Wister Kyoto rats, imidafenacin did not reduce cold stress-induced detrusor overactivity. In diabetic Goto-Kakizaki rats, just after transfer to a low temperature, the cold stress-induced detrusor overactivity in imidafenacin-treated rats was reduced compared with vehicle-treated rats. Within the urinary bladders, the ratio of M3 to M2 receptor messenger ribonucleic acid in the diabetic Goto-Kakizaki rats was significantly higher than that of the non-diabetic Wister Kyoto rats. The proportion of muscarinic M3 receptor-positive area within the detrusor in diabetic Goto-Kakizaki rats was also significantly higher than that in non-diabetic Wister Kyoto rats. Imidafenacin partially inhibits cold stress-induced detrusor overactivity in diabetic Goto-Kakizaki rats. In this animal model, muscarinic M3 receptors partially mediate cold stress-induced detrusor overactivity. © 2014 The Japanese Urological Association.

Cocaine- and amphetamine-regulated transcript (CART) peptide immunoreactivity in the brain of the CCK-1 receptor deficient obese OLETF rat

PubMed Central

Abraham, Hajnalka; Covasa, Mihai; Hajnal, Andras

2013-01-01

Cocaine- and amphetamine regulated transcript (CART) peptide is expressed in brain areas involved in homeostatic regulation and reward. CART has been shown to reduce food intake but the underlying mechanisms and the relevance of this effect to obesity yet remain unknown. Therefore, we used immunohistochemistry to investigate expression of CART peptide in various brain regions of the obese Otsuka Long Evans Tokushima Fatty (OLETF) rats lacking the CCK-1 receptor. Analysis revealed that whereas the distribution of CART peptide-immunoreactive neurons and axonal networks was identical in OLETF rats and lean controls, intensity of CART immunoreactivity was significantly reduced in the rostral part of the nucleus accumbens (p<0.01), the basolateral complex of the amygdala (p<0.05), and the rostro-medial nucleus of solitary tract (p<0.001) of the OLETF rats. These areas are involved in reward and integration of taste and viscerosensory information and have been previously associated with altered functions in this strain. The findings suggest that in addition to previously described deficits in peripheral satiety signals and augmented orexigenic regulation, the anorectic effect of CART peptide may also be diminished in OLETF rats. PMID:19533109

Species differences in the localization and number of CNS beta adrenergic receptors: Rat versus guinea pig

DOE Office of Scientific and Technical Information (OSTI.GOV)

Booze, R.M.; Crisostomo, E.A.; Davis, J.N.

1989-06-01

The localization and number of beta adrenergic receptors were directly compared in the brains of rats and guinea pigs. The time course of association and saturability of (125I)cyanopindolol (CYP) binding to slide-mounted tissue sections was similar in rats (Kd = 17 pM) and guinea pigs (Kd = 20 pM). The beta-1 and beta-2 receptor subtypes were examined through the use of highly selective unlabeled receptor antagonists, ICI 118,551 (50 nM) and ICI 89,406 (70 nM). Dramatic species differences between rats and guinea pigs were observed in the neuroanatomical regional localization of the beta adrenergic receptor subtypes. For example, in themore » thalamus prominent beta-1 and beta-2 receptor populations were identified in the rat; however, the entire thalamus of the guinea pig had few, if any, beta adrenergic receptors of either subtype. Hippocampal area CA1 had high levels of beta-2 adrenergic receptors in both rats and guinea pigs but was accompanied by a widespread distribution of beta-2 adrenergic receptors only in rats. Quantitative autoradiographic analyses of 25 selected neuroanatomical regions (1) confirmed the qualitative differences in CNS beta adrenergic receptor localization, (2) determined that guinea pigs had significantly lower levels of beta adrenergic receptors than rats and (3) indicated a differential pattern of receptor subtypes between the two species. Knowledge of species differences in receptor patterns may be useful in designing effective experiments as well as in exploring the relationships between receptor and innervation patterns. Collectively, these data suggest caution be used in extrapolation of the relationships of neurotransmitters and receptors from studies of a single species.« less

Expression of glutathione peroxidase I gene in selenium-deficient rats.

PubMed Central

Reddy, A P; Hsu, B L; Reddy, P S; Li, N Q; Thyagaraju, K; Reddy, C C; Tam, M F; Tu, C P

1988-01-01

We have characterized a cDNA pGPX1211 encoding rat glutathione peroxidase I. The selenocysteine in the protein corresponded to a TGA codon in the coding region of the cDNA, similar to earlier findings in mouse and human genes, and a gene encoding the formate dehydrogenase from E. coli, another selenoenzyme. The rat GSH peroxidase I has a calculated subunit molecular weight of 22,155 daltons and shares 95% and 86% sequence homology with the mouse and human subunits, respectively. The 3'-noncoding sequence (greater than 930 bp) in pGPX1211 is much longer than that of the human sequences. We found that glutathione peroxidase I mRNA, but not the polypeptide, was expressed under nutritional stress of selenium deficiency where no glutathione peroxidase I activity can be detected. The failure of detecting any apoprotein for the glutathione peroxidase I under selenium deficiency and results published from other laboratories supports the proposal that selenium may be incorporated into the glutathione peroxidase I co-translationally. Images PMID:2838821

Ascorbic acid deficiency increases endotoxin influx to portal blood and liver inflammatory gene expressions in ODS rats.

PubMed

Tokuda, Yuki; Miura, Natsuko; Kobayashi, Misato; Hoshinaga, Yukiko; Murai, Atsushi; Aoyama, Hiroaki; Ito, Hiroyuki; Morita, Tatsuya; Horio, Fumihiko

2015-02-01

The aim of this study was to determine whether ascorbic acid (AsA) deficiency-induced endotoxin influx into portal blood from the gastrointestinal tract contributes to the inflammatory changes in the liver. The mechanisms by which AsA deficiency provokes inflammatory changes in the liver were investigated in Osteogenic Disorder Shionogi (ODS) rats (which are unable to synthesize AsA). Male ODS rats (6-wk-old) were fed a diet containing sufficient (300 mg/kg) AsA (control group) or a diet without AsA (AsA-deficient group) for 14 or 18 d. On day 14, the hepatic mRNA levels of acute-phase proteins and inflammation-related genes were significantly higher in the AsA-deficient group than the control group, and these elevations by AsA deficiency were exacerbated on day 18. The serum concentrations of interleukin (IL)-1β and IL-6, which induce acute-phase proteins in the liver, were also significantly elevated on day 14 in the AsA-deficient group compared with the respective values in the control group. IL-1β mRNA levels in the liver, spleen, and lung were increased by AsA deficiency. Moreover, on both days 14 and 18, the portal blood endotoxin concentration was significantly higher in the AsA-deficient group than in the control group, and a significant correlation between serum IL-1β concentrations and portal endotoxin concentrations was found in AsA-deficient rats. In the histologic analysis of the ileum tissues, the number of goblet cells per villi was increased by AsA deficiency. These results suggest that AsA deficiency-induced endotoxin influx into portal blood from the gastrointestinal tract contributes to the inflammatory changes in the liver. Copyright © 2015 Elsevier Inc. All rights reserved.

Presynaptic selectivity of a ligand for serotonin 1A receptors revealed by in vivo PET assays of rat brain.

PubMed

Saijo, Takeaki; Maeda, Jun; Okauchi, Takashi; Maeda, Jun-ichi; Morio, Yasunori; Kuwahara, Yasuhiro; Suzuki, Masayuki; Goto, Nobuharu; Fukumura, Toshimitsu; Suhara, Tetsuya; Higuchi, Makoto

2012-01-01

A novel investigational antidepressant with high affinity for the serotonin transporter and the serotonin 1A (5-HT(1A)) receptor, called Wf-516 (structural formula: (2S)-1-[4-(3,4-dichlorophenyl)piperidin-1-yl]-3-[2-(5-methyl-1,3,4-oxadiazol-2-yl)benzo[b]furan-4-yloxy]propan-2-ol monohydrochloride), has been found to exert a rapid therapeutic effect, although the mechanistic basis for this potential advantage remains undetermined. We comparatively investigated the pharmacokinetics and pharmacodynamics of Wf-516 and pindolol by positron emission tomographic (PET) and autoradiographic assays of rat brains in order to elucidate their molecular interactions with presynaptic and postsynaptic 5-HT(1A) receptors. In contrast to the full receptor occupancy by pindolol in PET measurements, the binding of Wf-516 to 5-HT(1A) receptors displayed limited capacity, with relatively high receptor occupancy being achieved in regions predominantly containing presynaptic receptors. This selectivity was further proven by PET scans of neurotoxicant-treated rats deficient in presynaptic 5-HT(1A) receptors. In addition, [(35)S]guanosine 5'-O-[γ-thio]triphosphate autoradiography indicated a partial agonistic ability of Wf-516 for 5-HT(1A) receptors. This finding has lent support to reports that diverse partial agonists for 5-HT(1A) receptors exert high sensitivity for presynaptic components. Thus, the present PET data suggest a relatively high capacity of presynaptic binding sites for partial agonists. Since our in vitro and ex vivo autoradiographies failed to illustrate these distinct features of Wf-516, in vivo PET imaging is considered to be, thus far, the sole method capable of pharmacokinetically demonstrating the unique actions of Wf-516 and similar new-generation antidepressants.

Presynaptic Selectivity of a Ligand for Serotonin 1A Receptors Revealed by In Vivo PET Assays of Rat Brain

PubMed Central

Okauchi, Takashi; Maeda, Jun-ichi; Morio, Yasunori; Kuwahara, Yasuhiro; Suzuki, Masayuki; Goto, Nobuharu; Fukumura, Toshimitsu; Suhara, Tetsuya; Higuchi, Makoto

2012-01-01

A novel investigational antidepressant with high affinity for the serotonin transporter and the serotonin 1A (5-HT1A) receptor, called Wf-516 (structural formula: (2S)-1-[4-(3,4-dichlorophenyl)piperidin-1-yl]-3-[2-(5-methyl-1,3,4-oxadiazol-2-yl)benzo[b]furan-4-yloxy]propan-2-ol monohydrochloride), has been found to exert a rapid therapeutic effect, although the mechanistic basis for this potential advantage remains undetermined. We comparatively investigated the pharmacokinetics and pharmacodynamics of Wf-516 and pindolol by positron emission tomographic (PET) and autoradiographic assays of rat brains in order to elucidate their molecular interactions with presynaptic and postsynaptic 5-HT1A receptors. In contrast to the full receptor occupancy by pindolol in PET measurements, the binding of Wf-516 to 5-HT1A receptors displayed limited capacity, with relatively high receptor occupancy being achieved in regions predominantly containing presynaptic receptors. This selectivity was further proven by PET scans of neurotoxicant-treated rats deficient in presynaptic 5-HT1A receptors. In addition, [35S]guanosine 5′-O-[γ-thio]triphosphate autoradiography indicated a partial agonistic ability of Wf-516 for 5-HT1A receptors. This finding has lent support to reports that diverse partial agonists for 5-HT1A receptors exert high sensitivity for presynaptic components. Thus, the present PET data suggest a relatively high capacity of presynaptic binding sites for partial agonists. Since our in vitro and ex vivo autoradiographies failed to illustrate these distinct features of Wf-516, in vivo PET imaging is considered to be, thus far, the sole method capable of pharmacokinetically demonstrating the unique actions of Wf-516 and similar new-generation antidepressants. PMID:22880045

Comparative Study of Light Scattering from Hepatoma Cells and Hepatocytes

NASA Astrophysics Data System (ADS)

Lin, Xiaogang; Wang, Rongrong; Guo, Yongcai; Gao, Chao; Guo, Xiaoen

2012-11-01

Primary liver cancer is one of the highest mortality malignant tumors in the world. China is a high occurrence area of primary liver cancer. Diagnosis of liver cancer, especially early diagnosis, is essential for improving patients' survival. Light scattering and measuring method is an emerging technology developed in recent decades, which has attracted a large number of biomedical researchers due to its advantages, such as fast, simple, high accuracy, good repeatability, and non-destructive. The hypothesis of this project is that there may be some different light scattering information between hepatoma cells and hepatocyte. Combined with the advantages of the dynamic light scattering method and the biological cytology, an experimental scheme to measure the light scattering information of cells was formulated. Hepatoma cells and hepatic cells were irradiated by a semiconductor laser (532 nm). And the Brookhaven BI-200SM wide-angle light scattering device and temperature control apparatus were adopted. The light scattering information of hepatoma cells and hepatic cells in vitro within the 15°C to 30°C temperature range was processed by a BI-9000AT digital autocorrelator. The following points were found: (a) the scattering intensities of human hepatic cells and hepatoma cells are nearly not affected by the temperature factor, and the former is always greater than the latter and (b) the relaxation time of hepatoma cells is longer than that of hepatic cells, and both the relaxation time are shortened with increasing temperature from 15°C to 25°C. It can be concluded that hepatoma cells could absorb more incident light than hepatic cells. The reason may be that there exists more protein and nucleic acid in cancerous cells than normal cells. Furthermore, based on the length relaxation time, a conclusion can be inferred that the Brownian movement of cancer cells is greater.

A calcium-deficient diet in pregnant, nursing rats induces hypomethylation of specific cytosines in the 11β-hydroxysteroid dehydrogenase-1 promoter in pup liver.

PubMed

Takaya, Junji; Iharada, Anna; Okihana, Hiroyuki; Kaneko, Kazunari

2013-11-01

Prenatal undernutrition affects offspring phenotype via changes in the epigenetic regulation of specific genes. We hypothesized that pregnant females that were fed a calcium (Ca)-deficient diet would have offspring with altered hepatic glucocorticoid-related gene expression and altered epigenetic gene regulation. Female Wistar rats ate either a Ca-deficient or control diet from 3 weeks before conception to 21 days after parturition. Pups were allowed to nurse from their original mothers and then euthanized on day 21. Methylation of individual cytosine-guanine dinucleotides in the phosphoenolpyruvate carboxykinase (Pck1), peroxisome proliferator-activated receptor α (Ppara), glucocorticoid receptor (Nr3c1), 11β-hydroxysteroid dehydrogenase-1 (Hsd11b1), and 11β-hydroxysteroid dehydrogenase-2 (Hsd11b2) promoters was measured in liver tissue using pyrosequencing. For each gene, quantitative real-time polymerase chain reaction was used to assess mRNA levels in liver tissue. Overall Hsd11b1 methylation was lower in the Ca-deficient group than in the control group; however, overall methylation of each other gene did not differ between groups. Serum corticosterone levels in male pups from Ca-deficient dams were higher than those in control pups. Expression of Pck1 and Nr3c1 was lower in the Ca-deficient group than in the control group. A Ca-deficient diet for a dam during gestation and early nursing may alter glucocorticoid metabolism and lead to higher intracellular glucocorticoid concentrations in the hepatic cells of her offspring; moreover, this abnormal glucocorticoid metabolism may induce the metabolic complications that are associated with Ca deficiency. These findings indicated that prenatal nutrition affected glucocorticoid metabolism in offspring in part by affecting the epigenome of offspring. © 2013.

Protein disulfide isomerase regulates renal AT1 receptor function and blood pressure in rats.

PubMed

Wang, Xitao; Asghar, Mohammad

2017-08-01

The role and mechanism of renal protein disulfide isomerase (PDI) in blood pressure regulation has not been tested before. Here, we test this possibility in Sprague-Dawley rats. Rats were treated with PDI inhibitor bacitracin (100 mg·kg -1 ip·day -1 for 14 days), and then blood pressure and renal angiotensin II type 1 (AT 1 ) receptor function were determined in anesthetized rats. Renal AT 1 receptor function was determined as the ability of candesartan (an AT 1 receptor blocker) to increase diuresis and natriuresis. A second set of vehicle- and bacitracin-treated rats was used to determine biochemical parameters. Systolic blood pressure as well as diastolic blood pressure increased in bacitracin-treated compared with vehicle-treated rats. Compared with vehicle, bacitracin-treated rats showed increased diuresis and natriuresis in response to candesartan (10-µg iv bolus dose) suggesting higher AT 1 receptor function in these rats. These were associated with higher renin activities in the plasma and renal tissues. Furthermore, urinary 8-isoprostane and kidney injury molecule-1 levels were higher and urinary antioxidant capacity was lower in bacitracin-treated rats. Renal protein carbonyl and nitrotyrosine levels also were higher in bacitracin- compared with vehicle-treated rats, suggesting oxidative stress burden in bacitracin-treated rats. Moreover, PDI activity decreased and its protein levels increased in renal tissues of bacitracin-treated rats. Also, nuclear levels of Nrf2 transcription factor, which regulates redox homeostasis, were decreased in bacitracin-treated rats. Furthermore, tissue levels of Keap1, an Nrf2 inhibitory molecule, and tyrosine 216-phosphorylated GSK3β protein, an Nrf2 nuclear export protein, were increased in bacitracin-treated rats. These results suggest that renal PDI by regulating Keap1-Nrf2 pathway acts as an antioxidant, maintaining redox balance, renal AT 1 receptor function, and blood pressure in rats. Copyright © 2017 the

4PS/insulin receptor substrate (IRS)-2 is the alternative substrate of the insulin receptor in IRS-1-deficient mice.

PubMed

Patti, M E; Sun, X J; Bruening, J C; Araki, E; Lipes, M A; White, M F; Kahn, C R

1995-10-20

Insulin receptor substrate-1 (IRS-1) is the major cytoplasmic substrate of the insulin and insulin-like growth factor (IGF)-1 receptors. Transgenic mice lacking IRS-1 are resistant to insulin and IGF-1, but exhibit significant residual insulin action which corresponds to the presence of an alternative high molecular weight substrate in liver and muscle. Recently, Sun et al. (Sun, X.-J., Wang, L.-M., Zhang, Y., Yenush, L. P., Myers, M. G., Jr., Glasheen, E., Lane, W.S., Pierce, J. H., and White, M. F. (1995) Nature 377, 173-177) purified and cloned 4PS, the major substrate of the IL-4 receptor-associated tyrosine kinase in myeloid cells, which has significant structural similarity to IRS-1. To determine if 4PS is the alternative substrate of the insulin receptor in IRS-1-deficient mice, we performed immunoprecipitation, immunoblotting, and phosphatidylinositol (PI) 3-kinase assays using specific antibodies to 4PS. Following insulin stimulation, 4PS is rapidly phosphorylated in liver and muscle, binds to the p85 subunit of PI 3-kinase, and activates the enzyme. Insulin stimulation also results in the association of 4PS with Grb 2 in both liver and muscle. In IRS-1-deficient mice, both the phosphorylation of 4PS and associated PI 3-kinase activity are enhanced, without an increase in protein expression. Immunodepletion of 4PS from liver and muscle homogenates removes most of the phosphotyrosine-associated PI 3-kinase activity in IRS-1-deficient mice. Thus, 4PS is the primary alternative substrate, i.e. IRS-2, which plays a major role in physiologic insulin signal transduction via both PI 3-kinase activation and Grb 2/Sos association. In IRS-1-deficient mice, 4PS/IRS-2 provides signal transduction to these two major pathways of insulin signaling.

Increased ethanol preference and serotonin 1A receptor-dependent attenuation of ethanol-induced hypothermia in PACAP-deficient mice.

PubMed

Tanaka, Kazuhiro; Kunishige-Yamamoto, Akiko; Hashimoto, Hitoshi; Shintani, Norihito; Hayata, Atsuko; Baba, Akemichi

2010-01-01

Pituitary adenylate cyclase-activating polypeptide (PACAP)-deficient mice display remarkable behavioral changes including increased novelty-seeking behavior and reduced hypothermia induced by either serotonin (5-HT)(1A) receptor agonists or ethanol. Because 5-HT(1A) receptors have been implicated in the development of alcohol dependence, we have examined ethanol preference in PACAP-deficient mice using a two-bottle choice and a conditioned place preference test, as well as additive effects of ethanol and 5-HT(1A) receptor agents on hypothermia. PACAP-deficient mice showed an increased preference towards ethanol compared with wild-type mice. However, they showed no preference for the ethanol compartment after conditioning and neither preference nor aversion to sucrose or quinine. The 5-HT(1A) receptor agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT) restored the attenuated hypothermic response to ethanol in the mutants to similar levels in wild-type mice, with no effect in wild-types. In contrast, the 5-HT(1A) receptor antagonist WAY-100635 attenuated the ethanol-induced hypothermia in wild-type mice, with no effect in the mutants. These results demonstrate increased ethanol preference in PACAP-deficient mice that may be mediated by 5-HT(1A) receptor-dependent attenuation of ethanol-induced central inhibition. Copyright 2009 Elsevier Inc. All rights reserved.

The GH-IGF1 axis and longevity. The paradigm of IGF1 deficiency.

PubMed

Laron, Zvi

2008-01-01

Primary or secondary IGF1 deficiency has been implicated in shortening of lifespan. This paper reviews available data on the influence of IGF1 deficiency on lifespan and longevity in animals and man. It has been shown that inactivation of the IGF1 gene or of the GH receptor in both invertebrates (C-elegans, flies-Drosphila) and rodents (mice and rats), leading to IGF1 deficiency, prolong life, particularly in females. In man, evaluation of the 2 largest cohorts of patients with Laron syndrome (inactive GH receptor resulting in IGF1 deficiency) in Israel and Ecuador revealed that despite their dwarfism and marked obesity, patients are alive at the ages of 75-78 years, with some having reached even more advanced ages. It is assumed that a major contributing factor is their protection from cancer, a major cause of death in the general population.

Prenatal iron deficiency causes sex-dependent mitochondrial dysfunction and oxidative stress in fetal rat kidneys and liver.

PubMed

Woodman, Andrew G; Mah, Richard; Keddie, Danae; Noble, Ronan M N; Panahi, Sareh; Gragasin, Ferrante S; Lemieux, Hélène; Bourque, Stephane L

2018-06-01

Prenatal iron deficiency alters fetal developmental trajectories, which results in persistent changes in organ function. Here, we studied the effects of prenatal iron deficiency on fetal kidney and liver mitochondrial function. Pregnant Sprague-Dawley rats were fed partially or fully iron-restricted diets to induce a state of moderate or severe iron deficiency alongside iron-replete control rats. We assessed mitochondrial function via high-resolution respirometry and reactive oxygen species generation via fluorescence microscopy on gestational d 21. Hemoglobin levels were reduced in dams in the moderate (-31%) and severe groups (-54%) compared with controls, which was accompanied by 55% reductions in fetal hemoglobin levels in both moderate and severe groups versus controls. Male iron-deficient kidneys exhibited globally reduced mitochondrial content and respiration, as well as increased cytosolic superoxide and decreased NO. Female iron-deficient kidneys exhibited complex II down-regulation and increased mitochondrial oxidative stress. Male iron-deficient livers exhibited reduced complex IV respiration and increased cytosolic superoxide, whereas female liver tissues exhibited no alteration in oxidant levels or mitochondrial function. These findings indicate that prenatal iron deficiency causes changes in mitochondrial content and function as well as oxidant status in a sex- and organ-dependent manner, which may be an important mechanism that underlies the programming of cardiovascular disease.-Woodman, A. G., Mah, R., Keddie, D., Noble, R. M. N., Panahi, S., Gragasin, F. S., Lemieux, H., Bourque, S. L. Prenatal iron deficiency causes sex-dependent mitochondrial dysfunction and oxidative stress in fetal rat kidneys and liver.

Nicotinamide megadosing increases hepatic poly(ADP-ribose) levels in choline-deficient rats.

PubMed

ApSimon, M M; Rawling, J M; Kirkland, J B

1995-07-01

Previous work in our laboratory has shown that dietary megadoses of nicotinamide, used in the prevention of diabetes, cause increases in hepatic poly(ADP-ribose). Poly(ADP-ribose) is synthesized from NAD+ by a nuclear enzyme, poly(ADP-ribose)polymerase, which is activated by DNA strand breaks. The nicotinamide-induced increase in poly(ADP-ribose) could result from an increase in substrate, NAD+, or the induction of strand breaks in DNA. Strand breaks may result from the depletion of single carbon groups, through the excretion of methylated derivatives of nicotinamide. To differentiate between these mechanisms, a 3 x 3 factorial experiment was conducted in which rats were fed diets containing various supplements of choline bitartrate (0, 2, 20 g/kg diet) and nicotinamide (0, 1, 2 g/kg diet). At the conclusion of treatments, blood NAD+ and liver lipid, NAD+ and poly(ADP-ribose) levels were determined. Choline deficiency caused the characteristic accumulation of fat in the liver at all levels of nicotinamide. In choline deficient rats, nicotinamide supplements further increased liver lipid concentration. Blood and liver NAD+ concentrations were increased by nicotinamide supplementation, irrespective of choline status. In contrast, liver poly(ADP-ribose) levels were increased by nicotinamide supplementation only in choline deficient rats. These results show that nicotinamide-induced increases in poly(ADP-ribose) levels appear to be dependent on decreased methyl donor status and suggest that adequate choline status is important for preventing some deleterious effects of nicotinamide treatment.

Age-related changes in the thermoregulatory capacity of tryptophan-deficient rats.

PubMed

Segall, P E; Timiras, P S

1975-01-01

From a larger study seeking to develop indexes of physiological aging, the present experiment was designed 1) to test thermoregulatory capacity in the aging and old rat subjected to 3 minutes of whole-body ice water immersion, and 2) using this index of physiological age, to determine whether tryptophan deficiency from time of weaning can retard the onset of senescence. Results indicate a progressive prolongation of temperature recovery time from young to middle age to old, and tryptophan-deficient animals restored to commercial diet at middle age show the thermoregulatory capacity of young adults. The implications of tryptophan deficiency with respect to brain development, serotonin metabolism, and temperature regulation are also discussed in terms of the possibility of intervening with the aging process.

The distribution of the orphan bombesin receptor subtype-3 in the rat CNS.

PubMed

Jennings, C A; Harrison, D C; Maycox, P R; Crook, B; Smart, D; Hervieu, G J

2003-01-01

Bombesin receptor subtype 3 (BRS-3) is an orphan G-protein coupled receptor that shares between 47 and 51% homology with other known bombesin receptors. The natural ligand for BRS-3 is currently unknown and little is known about the mechanisms regulating BRS-3 gene expression. Unlike other mammalian bombesin receptors that have been shown to be predominantly expressed in the CNS and gastrointestinal tract, expression of the BRS-3 receptor in the rat brain has previously not been observed. To gain further understanding of the biology of BRS-3, we have studied the distribution of BRS-3 mRNA and protein in the rat CNS. The mRNA expression pattern was studied using reverse transcription followed by quantitative polymerase chain reaction. Using immunohistological techniques, the distribution of BRS-3 protein in the rat brain was investigated using a rabbit affinity-purified polyclonal antiserum raised against an N-terminal peptide. The BRS-3 receptor was found to be widely expressed in the rat brain at both mRNA and protein levels. Particularly strong immunosignals were observed in the cerebral cortex, hippocampal formation, hypothalamus and thalamus. Other regions of the brain such as the basal ganglia, midbrain and reticular formation were also immunopositive for BRS-3. In conclusion, our neuroanatomical data provide evidence that BRS-3 is as widely expressed in the rat brain as other bombesin-like peptide receptors and suggest that this receptor may also have important roles in the CNS, mediating the functions of a so far unidentified ligand.

Normocalcemia without hyperparathyroidism in vitamin D-deficient rats.

PubMed

Kollenkirchen, U; Fox, J; Walters, M R

1991-03-01

Despite numerous attempts, no reliable dietary regimen exists to achieve vitamin D deficiency (-D) in rats without attendant changes in plasma parathyroid hormone (PTH), Ca, or phosphate. This represents an important obstacle to proper investigations of the physiologic role(s) of vitamin D metabolites in the function of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] target tissues. This paper describes the successful development of such a diet, which uses a combination of high Ca content, properly controlled Ca/P ratio, and lactose. Normal weanling rats were fed diets containing A, 0.8% Ca, 0.5% P, +D3, or -D diets containing B, 0.8% Ca and 0.5% P; C, 2.0% Ca and 1.25% P; or D, 2.0% Ca, 1.25% P, and 20% lactose. After 6 diet weeks group D rats remained normocalcemic and normophosphatemic, but diet groups B and C became hypocalcemic (6.9 +/- 0.8 and 7.2 +/- 0.4 mg/dl, respectively). Thus high dietary Ca and P was incapable of maintaining normal plasma Ca levels in the absence of dietary lactose. The normocalcemia in group D was not maintained by elevated PTH secretion because N-terminal PTH levels were also normal (14 +/- 3 versus 20 +/- 5 pg/ml). In contrast, PTH levels were markedly elevated in hypocalcemic groups B and C (47 +/- 7 and 48 +/- 10 pg/ml, respectively). Plasma 25-OHD3 and 1,25-(OH)2D3 levels were reduced to less than 120 and less than 12 pg/ml, respectively, in all -D groups. Thus the high-Ca diet and the use of normal weanlings did not impede the development of vitamin D deficiency.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of group II metabotropic glutamate receptor (mGlu2) elicits common changes in rat and mice sleep-wake architecture.

PubMed

Ahnaou, Abdellah; Dautzenberg, Frank M; Geys, Helena; Imogai, Hassan; Gibelin, Antoine; Moechars, Dieder; Steckler, Thomas; Drinkenburg, Wilhelmus H I M

2009-01-28

Compiling pharmacological evidence implicates metabotropic glutamate mGlu(2) receptors in the regulation of emotional states and suggests positive modulators as a novel therapeutic approach of Anxiety/Depression and Schizophrenia. Here, we investigated subcutaneous effects of the metabotropic glutamate mGlu(2/3) agonist (LY354740) on sleep-wake architecture in rat. To confirm the specific effects on rapid eye movement (REM) sleep were mediated via metabotropic glutamate mGlu(2) receptors, we characterized the sleep-wake cycles in metabotropic glutamate mGlu(2) receptor deficient mice (mGlu(2)R(-/-)) and their arousal response to LY354740. We furthermore examined effects on sleep behavior in rats of the positive allosteric modulator, biphenyl-indanone A (BINA) alone and in combination with LY354740 at sub-effective doses. LY354740 (1, 3 and 10 mg/kg) dose-dependently suppressed REM sleep and prolonged its onset latency. Metabotropic glutamate mGlu(2)R(-/-) and their wild type (WT) littermates exhibited similar spontaneous sleep-wake phenotype, while LY354740 (10 mg/kg) significantly affected REM sleep variables in WT but not in the mutant. In rats, BINA (1, 3, 10, 20, 40 mg/kg) dose-dependently suppressed REM sleep, lengthened its onset latency and slightly enhanced passive waking. Additionally, combined treatment elicited a synergistic action on REM sleep variables. Our findings show common changes of REM sleep variables following modulation of metabotropic glutamate mGlu(2) receptor and support an active role of this receptor in the regulation of REM sleep. The synergistic action of BINA on LY354740's effects on sleep pattern implies that positive modulators would tune the endogenous glutamate tone suggesting potential benefit in the treatment of psychiatric disorders, in which REM sleep overdrive is manifested.

Subtle abnormalities of gait detected early in vitamin B6 deficiency in aged and weanling rats with hind leg gait analysis.

PubMed

Schaeffer, M C; Cochary, E F; Sadowski, J A

1990-04-01

Motor abnormalities have been observed in every species made vitamin B6 deficient, and have been detected and quantified early in vitamin B6 deficiency in young adult female Long-Evans rats with hind leg gait analysis. Our objective was to determine if hind leg gait analysis could be used to detect vitamin B6 deficiency in weanling (3 weeks) and aged (23 months) Fischer 344 male rats. Rats (n = 10 per group) were fed: the control diet ad libitum (AL-CON); the control diet devoid of added pyridoxine hydrochloride (DEF); or the control diet pair-fed to DEF (PF-CON). At 10 weeks, plasma pyridoxal phosphate concentration confirmed deficiency in both age groups. Gait abnormalities were detected in the absence of gross motor disturbances in both aged and weanling DEF rats at 2-3 weeks. Width of step was significantly reduced (16%, p less than 0.003) in DEF aged rats compared to AL- and PF-CON. This pattern of response was similar to that reported previously in young adult rats. In weanling rats, pair feeding alone reduced mean width of step (+/- SEM) by 25% compared to ad libitum feeding (2.7 +/- 0.1 vs 3.6 +/- 0.1 cm for PF- vs AL-CON, respectively, p less than 0.05). In DEF weanling rats, width (3.0 +/- 0.1 cm) was increased compared to PF-CON (11%, p less than 0.05) but decreased compared to AL-CON (16%, p less than 0.05). Width of step was significantly altered early in B6 deficiency in rats of different ages and strains and in both sexes.(ABSTRACT TRUNCATED AT 250 WORDS)

Serotonin receptor 5-HT5A in rat hippocampus decrease by leptin treatment.

PubMed

García-Alcocer, Guadalupe; Rodríguez, Angelina; Moreno-Layseca, Paulina; Berumen, Laura C; Escobar, Jesica; Miledi, Ricardo

2010-12-17

5-Hydroxytryptamine (5-HT) is involved in a variety of different physiological processes and behaviors through the activation of equally diverse receptors subtypes. In this work we studied the changes on the expression of 5-HT(5A) receptors in rat hippocampus induced by leptin, an adipocyte-derived hormone that has been reported to participate in the modulation of food intake and in adult hippocampal neurogenesis. To study the effect of leptin on the 5-HT(5A) receptor gene expression a qRT-PCR was used and the distribution of those receptors in the hippocampus was visualized by immunohistochemistry. Rats were separated in four groups: control (untreated rats), leptin-treated, serotonin-treated and leptin+serotonin treated. The results showed that even though the 5-HT(5A) gene expression did not change in the hippocampus of any of the treated groups, in the rats treated with leptin and serotonin, the specific immunostaining for the 5-HT(5A) serotonin receptor decreased significantly in the dentate gyrus. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

In Vivo Evaluation of Transdermal Iodide Microemulsion for Treating Iodine Deficiency Using Sprague Dawley Rats.

PubMed

Alayoubi, Alaadin; Sullivan, Ryan D; Lou, Hao; Patel, Hemlata; Mandrell, Timothy; Helms, Richard; Almoazen, Hassan

2016-06-01

The objective of this study was to evaluate the transdermal efficiency of iodide microemulsion in treating iodine deficiency using rats as an animal model. Animals were fed either iodine-deficient diet (20 μg/kg iodide) or control diet (200 μg/kg iodide) over a 17-month period. At month 14, iodide microemulsion was applied topically in iodine-deficient group and physiological evaluations of thyroid gland functions were characterized by monitoring the thyroid hormones (T3, T4), thyroid-stimulating hormone (TSH), iodide ion excretion in urine, and the overall rat body weights in both groups. Moreover, morphological evaluations of thyroid gland before and after treatment were performed by ultrasound imaging and through histological assessment. Prior to microemulsion treatment, the levels of T3, T4, and TSH in iodine-deficient group were statistically significant as compared to that in the control group. The levels of T3 and T4 increased while TSH level decreased significantly in iodine-deficient group within the first 4 weeks of treatment. After treatment, iodide concentration in urine increased significantly. There was no statistical difference in weight between the two groups. Ultrasound imaging and histological evaluations showed evidence of hyperplasia in iodine-deficient group. Topical iodide microemulsion has shown a promising potential as a novel delivery system to treat iodine deficiency.

Cardiac structural changes and electrical remodeling in a thiamine-deficiency model in rats.

PubMed

Roman-Campos, D; Campos, A C; Gioda, C R; Campos, P P; Medeiros, M A A; Cruz, J S

2009-06-05

Thiamine is an important cofactor present in many biochemical reactions, and its deprivation can lead to heart dysfunction. Little is known about the influence of thiamine deprivation on the electrophysiological behavior of the isolated heart cells and information about thiamine deficiency in heart morphology is controversial. Thus, we decided to investigate the major repolarizing conductances and their influence in the action potential (AP) waveform as well as the changes in the heart structure in a set of thiamine deficiency in rats. Using the patch-clamp technique, we investigated inward (I(K1)) and outward K(+) currents (I(to)), T-type and L-type Ca(2+) currents and APs. To evaluate heart morphology we used hematoxylin and eosin in transversal heart sections. Thiamine deficiency caused a marked decrease in left ventricle thickness, cardiomyocyte number, cell length and width, and membrane capacitance. When evaluating I(to) we did not find difference in current amplitude; however an acceleration of I(to) inactivation was observed. I(K1) showed a reduction in the amplitude and slope conductance, which implicated a less negative resting membrane potential in cardiac myocytes isolated from thiamine-deficient rats. We did not find any difference in L-type Ca(2+) current density. T-type Ca(2+) current was not observed. In addition, we did not observe significant changes in AP repolarization. Based on our study we can conclude that thiamine deficiency causes heart hypotrophy and not heart hypertrophy. Moreover, we provided evidence that there is no major electrical remodeling during thiamine deficiency, a feature of heart failure models.

A comparative study of functional 5-HT4 receptors in human colon, rat oesophagus and rat ileum.

PubMed

McLean, P G; Coupar, I M; Molenaar, P

1995-05-01

1. The pharmacological properties of 5-hydroxytryptamine (5-HT), the 5-HT4 receptor agonists, DAU 6236 and SC 53116 and the 5-HT4 receptor antagonist, GR 1130808, were studied in the rat oesophagus, rat ileum and human colon. 2. 5-HT relaxed the longitudinal muscle of the rat oesophagus and rat ileum and the circular muscle of the human colon. Absolute values of relaxation were measured and showed the order of the maximum responses, rat oesophagus > human colon > rat ileum with EC50 values of 189 +/- 15 nM, 157 +/- 4 nM, 306 +/- 72 nM, respectively. 5-HT also inhibited the spontaneous contractions of the human colon with an EC50 value of 119 +/- 1 nM. The effect of 5-HT on the human colon was not affected by methysergide (10 microM) or ondansetron (1 microM). 3. The use of the uptake and metabolism inhibitors, cocaine (30 microM) and pargyline (100 microM), did not increase the potency of 5-HT in the rat oesophagus or human colon. In the rat oesophagus, cocaine (30 microM) produced a reduction in carbachol-induced tone of 22.2 +/- 0.6% and reduced the 5-HT maximum effect by 52.0 +/- 0.4%. 4. The compounds, DAU 6236 and SC 53116, showed a different pattern of potencies and efficacies in the rat oesophagus, rat ileum and human colon compared to 5-HT. DAU 6236 relaxed the human colonic circular muscle with an EC50 value of 129 +/- 16 nM but its efficacy was less than that of 5-HT. DAU 6236 (1 microM) also antagonized the 5-HT-induced relaxation of the human colon with a dose-ratio of 9.9. In the rat oesophagus and rat ileum, DAU 6236 was inactive in the majority of tissues. In the minority of oesophagus tissues that did respond the EC50 value was 1.2 +/- 0.7 microM. DAU 6236 also antagonized the effect of 5-HT in the rat oesophagus in a non-surmountable fashion. SC 53116 relaxed the rat oesophagus with an EC50 value of 91 +/- 4 nM, with an efficacy less than that observed to 5-HT; however, at 200 nM it did not antagonize the 5-HT-induced relaxation of the rat

[Altered ability to learn of rat offspring with iodine deficiency].

PubMed

Tsintsadze, T G; Gabrichidze, G O; Lazrishvili, N I; Metreveli, D S; Mitagvariia, N P

2006-01-01

Experimental data demonstrate that hypothyroidism could result in depressive behavior and subsequently thyroid hormones could act as antidepressants. Postnatal changes in learning ability, memory and emotional status in posterity of rats, which have experienced different level of iodine deficiency before conception and during all gestation period were investigated in this study. Results obtained suggest that sudden iodine deprivation before and during gestation led to a significant neurological defect, which was represented by loss of ability to learn, one of the most important functions of brain in newborn and by evidence of depression. Iodine supply to the diet of female rats eliminates these effects completely.

Effects of Biotin Deficiency on Biotinylated Proteins and Biotin-Related Genes in the Rat Brain.

PubMed

Yuasa, Masahiro; Aoyama, Yuki; Shimada, Ryoko; Sawamura, Hiromi; Ebara, Shuhei; Negoro, Munetaka; Fukui, Toru; Watanabe, Toshiaki

2016-01-01

Biotin is a water-soluble vitamin that functions as a cofactor for biotin-dependent carboxylases. The biochemical and physiological roles of biotin in brain regions have not yet been investigated sufficiently in vivo. Thus, in order to clarify the function of biotin in the brain, we herein examined biotin contents, biotinylated protein expression (e.g. holocarboxylases), and biotin-related gene expression in the brain of biotin-deficient rats. Three-week-old male Wistar rats were divided into a control group, biotin-deficient group, and pair-fed group. Rats were fed experimental diets from 3 wk old for 8 wk, and the cortex, hippocampus, striatum, hypothalamus, and cerebellum were then collected. In the biotin-deficient group, the maintenance of total biotin and holocarboxylases, increases in the bound form of biotin and biotinidase activity, and the expression of an unknown biotinylated protein were observed in the cortex. In other regions, total and free biotin contents decreased, holocarboxylase expression was maintained, and bound biotin and biotinidase activity remained unchanged. Biotin-related gene (pyruvate carboxylase, sodium-dependent multivitamin transporter, holocarboxylase synthetase, and biotinidase) expression in the cortex and hippocampus also remained unchanged among the dietary groups. These results suggest that biotin may be related to cortex functions by binding protein, and the effects of a biotin deficiency and the importance of biotin differ among the different brain regions.

Toll-Like Receptor 4 Deficiency Impairs Motor Coordination

PubMed Central

Zhu, Jian-Wei; Li, Yi-Fei; Wang, Zhao-Tao; Jia, Wei-Qiang; Xu, Ru-Xiang

2016-01-01

The cerebellum plays an essential role in balance and motor coordination. Purkinje cells (PCs) are the sole output neurons of the cerebellar cortex and are critical for the execution of its functions, including motor coordination. Toll-like receptor (TLR) 4 is involved in the innate immune response and is abundantly expressed in the central nervous system; however, little is known about its role in cerebellum-related motor functions. To address this question, we evaluated motor behavior in TLR4 deficient mice. We found that TLR4−∕− mice showed impaired motor coordination. Morphological analyses revealed that TLR4 deficiency was associated with a reduction in the thickness of the molecular layer of the cerebellum. TLR4 was highly expressed in PCs but not in Bergmann glia or cerebellar granule cells; however, loss of TLR4 decreased the number of PCs. These findings suggest a novel role for TLR4 in cerebellum-related motor coordination through maintenance of the PC population. PMID:26909014

Administration of an oxytocin receptor antagonist attenuates sexual motivation in male rats.

PubMed

Blitzer, D S; Wells, T E; Hawley, W R

2017-08-01

In male rats, oxytocin impacts both sexual arousal and certain types of consummatory sexual behaviors. However, the role of oxytocin in the motivational aspects of sexual behavior has received limited attention. Given the role that oxytocin signaling plays in consummatory sexual behaviors, it was hypothesized that pharmacological attenuation of oxytocin signaling would reduce sexual motivation in male rats. Sexually experienced Long-Evans male rats were administered either an oxytocin receptor antagonist (L368,899 hydrochloride; 1mg/kg) or vehicle control into the intraperitoneal cavity 40min prior to placement into the center chamber of a three-chambered arena designed to assess sexual motivation. During the 20-minute test, a sexually experienced stimulus male rat and a sexually receptive stimulus female rat were separately confined to smaller chambers that were attached to the larger end chambers of the arena. However, physical contact between test and stimulus rats was prevented by perforated dividers. Immediately following the sexual motivation test, test male rats were placed with a sexually receptive female to examine consummatory sexual behaviors. Although both drug and vehicle treated rats exhibited a preference for the female, treatment with an oxytocin receptor antagonist decreased the amount of time spent with the female. There were no differences between drug and vehicle treated rats in either general activity, exploratory behaviors, the amount of time spent near the stimulus male rat, or consummatory sexual behaviors. Extending previous findings, these results indicate that oxytocin receptors are involved in sexual motivation in male rats. Copyright © 2017 Elsevier Inc. All rights reserved.

[Stimulation of D2-receptors improves passive avoidance learning in female rats].

PubMed

Fedotova, Iu O

2012-01-01

The involvement of D2-receptors in learning/memory processes during ovary cycle was assessed in the adult female rats. Quinperole (0,1 mg/kg, i.p.), D2-receptor agonist and sulpiride (10,0 mg/kg, i.p.), D2-receptor antagonist were injected chronically to adult female rats. Learning of these animals was assessed in different models: passive avoidance performance and Morris water maze. Chronic quinperole administration to females resulted in the appearance of the passive avoidance performance in proestrous and estrous, as distinct from the control animals. Also, quinperole improved spatial learning in proestrous and stimulated it in estrous in Morris water maze. Chronic sulpiride administration similarly impaired non-spatial and spatial learning in females during all phases of ovary cycle. The results of the study suggest modulating role of D2-receptors in learning/memory processes during ovary cycle in the adult female rats.

Soyasaponin I Improved Neuroprotection and Regeneration in Memory Deficient Model Rats

PubMed Central

Hong, Sung-Woon; Heo, Hwon; Yang, Jeong-hwa; Han, Maeum; Kim, Dong-Hyun; Kwon, Yunhee Kim

2013-01-01

Soy (Glycine Max Merr, family Leguminosae) has been reported to possess anti-cancer, anti-lipidemic, estrogen-like, and memory-enhancing effects. We investigated the memory-enhancing effects and the underlying mechanisms of soyasaponin I (soya-I), a major constituent of soy. Impaired learning and memory were induced by injecting ibotenic acid into the entorhinal cortex of adult rat brains. The effects of soya-I were evaluated by measuring behavioral tasks and neuronal regeneration of memory-deficient rats. Oral administration of soya-I exhibited significant memory-enhancing effects in the passive avoidance, Y-maze, and Morris water maze tests. Soya-Ι also increased BrdU incorporation into the dentate gyrus and the number of cell types (GAD67, ChAT, and VGluT1) in the hippocampal region of memory-deficient rats, whereas the number of reactive microglia (OX42) decreased. The mechanism underlying memory improvement was assessed by detecting the differentiation and proliferation of neural precursor cells (NPCs) prepared from the embryonic hippocampus (E16) of timed-pregnant Sprague-Dawley rats using immunocytochemical staining and immunoblotting analysis. Addition of soya-Ι in the cultured NPCs significantly elevated the markers for cell proliferation (Ki-67) and neuronal differentiation (NeuN, TUJ1, and MAP2). Finally, soya-I increased neurite lengthening and the number of neurites during the differentiation of NPCs. Soya-Ι may improve hippocampal learning and memory impairment by promoting proliferation and differentiation of NPCs in the hippocampus through facilitation of neuronal regeneration and minimization of neuro-inflammation. PMID:24324703

Activation of D4 dopamine receptor decreases AT1 angiotensin II receptor expression in rat renal proximal tubule cells

PubMed Central

Chen, Ken; Deng, Kun; Wang, Xiaoyan; Wang, Zhen; Zheng, Shuo; Ren, Hongmei; He, Duofen; Han, Yu; Asico, Laureano D.; Jose, Pedro A.; Zeng, Chunyu

2014-01-01

The dopaminergic and renin angiotensin systems interact to regulate blood pressure. Disruption of the D4 dopamine receptor gene in mice produces hypertension that is associated with increased renal AT1 receptor expression. We hypothesize that the D4 receptor can inhibit AT1 receptor expression and function in renal proximal tubules (RPTs) cells from Wistar-Kyoto (WKY) rats but the D4 receptor regulation of AT1 receptor is aberrant in RPT cells from spontaneously hypertensive rats (SHRs). The D4 receptor agonist, PD168077, decreased AT1 receptor protein expression in a time and concentration-dependent manner in WKY cells. By contrast, in SHR cells, PD168077 increased AT1 receptor protein expression. The inhibitory effect of D4 receptor on AT1 receptor expression in WKY cells was blocked by a calcium channel blocker, nicardipine, or calcium-free medium, indicating that calcium is involved in the D4 receptor-mediated signaling pathway. Angiotensin II increased Na+-K+ ATPase activity in WKY cells. Pretreatment with PD168077 decreased the stimulatory effect of angiotensin II on Na+-K+ ATPase activity in WKY cells. In SHR cells, the inhibitory effect of D4 receptor on angiotensin II-mediated stimulation of Na+-K+ ATPase activity was aberrant; pretreatment with PD168077 augmented the stimulatory effect of AT1 receptor on Na+-K+ ATPase activity in SHR cells. This was confirmed in vivo; pre-treatment with PD128077 for one week augmented the anti-hypertensive and natriuretic effect of losartan in SHRs but not in WKY rats. We suggest that an aberrant interaction between D4 and AT1 receptors may play a role in the abnormal regulation of sodium excretion in hypertension. PMID:25368031

The effect of ingested sulfite on visual evoked potentials, lipid peroxidation, and antioxidant status of brain in normal and sulfite oxidase-deficient aged rats.

PubMed

Ozsoy, Ozlem; Aras, Sinem; Ozkan, Ayse; Parlak, Hande; Aslan, Mutay; Yargicoglu, Piraye; Agar, Aysel

2016-07-01

Sulfite, commonly used as a preservative in foods, beverages, and pharmaceuticals, is a very reactive and potentially toxic molecule which is detoxified by sulfite oxidase (SOX). Changes induced by aging may be exacerbated by exogenous chemicals like sulfite. The aim of this study was to investigate the effects of ingested sulfite on visual evoked potentials (VEPs) and brain antioxidant statuses by measuring superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities. Brain lipid oxidation status was also determined via thiobarbituric acid reactive substances (TBARS) in normal- and SOX-deficient aged rats. Rats do not mimic the sulfite responses seen in humans because of their relatively high SOX activity level. Therefore this study used SOX-deficient rats since they are more appropriate models for studying sulfite toxicity. Forty male Wistar rats aged 24 months were randomly assigned to four groups: control (C), sulfite (S), SOX-deficient (D) and SOX-deficient + sulfite (DS). SOX deficiency was established by feeding rats with low molybdenum (Mo) diet and adding 200 ppm tungsten (W) to their drinking water. Sulfite in the form of sodium metabisulfite (25 mg kg(-1) day(-1)) was given by gavage. Treatment continued for 6 weeks. At the end of the experimental period, flash VEPs were recorded. Hepatic SOX activity was measured to confirm SOX deficiency. SOX-deficient rats had an approximately 10-fold decrease in hepatic SOX activity compared with the normal rats. The activity of SOX in deficient rats was thus in the range of humans. There was no significant difference between control and treated groups in either latence or amplitude of VEP components. Brain SOD, CAT, and GPx activities and brain TBARS levels were similar in all experimental groups compared with the control group. Our results indicate that exogenous administration of sulfite does not affect VEP components and the antioxidant/oxidant status of aged rat brains. © The Author

Human TRAF3 adaptor molecule deficiency leads to impaired Toll-like receptor 3 response and susceptibility to herpes simplex encephalitis

PubMed Central

de Diego, Rebeca Pérez; Sancho-Shimizu, Vanessa; Lorenzo, Lazaro; Puel, Anne; Plancoulaine, Sabine; Picard, Capucine; Herman, Melina; Cardon, Annabelle; Durandy, Anne; Bustamante, Jacinta; Vallabhapurapu, Sivakumar; Bravo, Jerónimo; Warnatz, Klaus; Chaix, Yves; Cascarrigny, Françoise; Lebon, Pierre; Rozenberg, Flore; Karin, Michael; Tardieu, Marc; Al-Muhsen, Saleh; Jouanguy, Emmanuelle; Zhang, Shen-Ying; Abel, Laurent; Casanova, Jean-Laurent

2010-01-01

Tumor necrosis factor (TNF) receptor-associated factor 3 (TRAF3) functions downstream of multiple receptors that induce interferon-α (IFN-α), IFN–β and IFN-λ production, including Toll-like receptor 3 (TLR3), which is deficient in some patients with herpes simplex virus-1 encephalitis (HSE). Mice lacking TRAF3 die in the neonatal period, preventing direct investigation of the role of TRAF3 in immune responses and host defenses in vivo. Here we reported the autosomal dominant, human TRAF3 deficiency in a young adult with a history of HSE in childhood. The TRAF3 mutant allele was a loss-of-expression, loss-of-function, dominant-negative phenotype, and was associated with impaired, but not abolished TRAF3-dependent responses upon stimulation of both TNF receptors and receptors that induce IFN production. TRAF3 deficiency was associated with a clinical phenotype limited to HSE resulting from the impairment of TLR3-dependent induction of IFN. Thus, TLR3-mediated immunity against primary infection by HSV-1 in the central nervous system is critically dependent on TRAF3. Highlight sentence Autosomal dominant TRAF3 deficiency is a genetic etiology of herpes simplex encephalitis. Highlight sentence R118W TRAF3 allele is loss-of-function, loss-of-expression, and dominant-negative. Highlight sentence Human TRAF3 deficiency impairs the TLR3-dependent induction of anti-viral interferons. PMID:20832341

Farnesoid X receptor deficiency induces nonalcoholic steatohepatitis in low-density lipoprotein receptor-knockout mice fed a high-fat diet.

PubMed

Kong, Bo; Luyendyk, James P; Tawfik, Ossama; Guo, Grace L

2009-01-01

Nonalcoholic steatohepatitis (NASH) comprises dysregulation of lipid metabolism and inflammation. Identification of the various genetic and environmental susceptibility factors for NASH may provide novel treatments to limit inflammation and fibrosis in patients. This study utilized a mouse model of hypercholesterolemia, low-density lipoprotein receptor knockout (LDLr(-/-)) mice fed a high-fat diet for 5 months, to test the hypothesis that farnesoid X receptor (FXR) deficiency contributed to NASH development. Either the high-fat diet or FXR deficiency increased serum alanine aminotransferase activity, whereas only FXR deficiency increased bile acid and alkaline phosphatase levels. FXR deficiency and high-fat feeding increased serum cholesterol and triglycerides. Although high fat led to macrosteatosis and hepatocyte ballooning in livers of mice regardless of genotype, no inflammatory infiltrate was observed in the livers of LDLr(-/-) mice. In contrast, in the livers of LDLr(-/-)/FXR(-/-) mice, foci of inflammatory cells were observed occasionally when fed the control diet and were greatly increased when fed the high-fat diet. Consistent with enhanced inflammatory cells, hepatic levels of tumor necrosis factor alpha and intercellular adhesion molecule-1 mRNA were increased by the high-fat diet in LDLr(-/-)/FXR(-/-) mice. In agreement with elevated levels of procollagen 1 alpha 1 and TGF-beta mRNA, type 1 collagen protein levels were increased in livers of LDLr(-/-)/FXR(-/-) mice fed a high-fat diet. In conclusion, FXR deficiency induces pathologic manifestations required for NASH diagnosis in a mouse model of hypercholesterolemia, including macrosteatosis, hepatocyte ballooning, and inflammation, which suggest a combination of FXR deficiency and high-fat diet is a risk factor for NASH development, and activation of FXR may be a therapeutic intervention in the treatment of NASH.

Age-dependent changes of presynaptic neuromodulation via A1-adenosine receptors in rat hippocampal slices.

PubMed

Sperlágh, B; Zsilla, G; Baranyi, M; Kékes-Szabó, A; Vizi, E S

1997-10-01

The presynaptic neuromodulation of stimulation-evoked release of [3H]-acetylcholine by endogenous adenosine, via A1-adenosine receptors, was studied in superfused hippocampal slices taken from 4-, 12- and 24-month-old rats. 8-Cyclopentyl-1,3-dimethylxanthine (0.25 microM), a selective A1-receptor antagonist, increased significantly the electrical field stimulation-induced release of [3H]-acetylcholine in slices prepared from 4- and 12-month-old rats, showing a tonic inhibitory action of endogenous adenosine via stimulation of presynaptic A1-adenosine receptors. In contrast, 8-cyclopentyl-1,3-dimethylxanthine had no effect in 24-month-old rats. 2-Chloroadenosine (10 microM), an adenosine receptor agonist decreased the release of [3H]-acetylcholine in slices taken from 4- and 12-month-old rats, and no significant change was observed in slices taken from 24-month-old rats. In order to show whether the number/or affinity of the A1-receptors was affected in aged rats, [3H]-8-cyclopentyl-1,3-dimethylxanthine binding was studied in hippocampal membranes prepared from rats of different ages. Whereas the Bmax value was significantly lower in 2-year-old rats than in younger counterparts, the dissociation constant (Kd) was not affected by aging, indicating that the density rather than the affinity of adenosine receptors was altered. Endogenous adenosine levels present in the extracellular space were also measured in the superfusate by high performance liquid chromatography (HPLC) coupled with ultraviolet detection, and an age-related increase in the adenosine level was found. In summary, our results indicate that during aging the level of adenosine in the extracellular fluid is increased in the hippocampus. There is a downregulation and reduced responsiveness of presynaptic adenosine A1-receptors, and it seems likely that these changes are due to the enhanced adenosine level in the extracellular space.

RNASeq-derived transcriptome comparisons reveal neuromodulatory deficiency in the CO2 insensitive brown Norway rat

PubMed Central

Puissant, Madeleine M; Echert, Ashley E; Yang, Chun; Mouradian, Gary C; Novotny, Tyler; Liu, Pengyuan; Liang, Mingyu; Hodges, Matthew R

2015-01-01

Raphé-derived serotonin (5-HT) and thyrotropin-releasing hormone (TRH) play important roles in fundamental, homeostatic control systems such as breathing and specifically the ventilatory CO2 chemoreflex. Brown Norway (BN) rats exhibit an inherent and severe ventilatory insensitivity to hypercapnia but also exhibit relatively normal ventilation at rest and during other conditions, similar to multiple genetic models of 5-HT system dysfunction in mice. Herein, we tested the hypothesis that the ventilatory insensitivity to hypercapnia in BN rats is due to altered raphé gene expression and the consequent deficiencies in raphé-derived neuromodulators such as TRH. Medullary raphé transcriptome comparisons revealed lower expression of multiple 5-HT neuron-specific genes in BN compared to control Dahl salt-sensitive rats, predictive of reduced central nervous system monoamines by bioinformatics analyses and confirmed by high-performance liquid chromatography measurements. In particular, raphé Trh mRNA and peptide levels were significantly reduced in BN rats, and injections of the stable TRH analogue Taltirelin (TAL) stimulated breathing dose-dependently, with greater effects in BN versus control Sprague–Dawley rats. Importantly, TAL also effectively normalized the ventilatory CO2 chemoreflex in BN rats, but TAL did not affect CO2 sensitivity in control Sprague–Dawley rats. These data establish a molecular basis of the neuromodulatory deficiency in BN rats, and further suggest an important functional role for TRH signalling in the mammalian CO2 chemoreflex. PMID:25630262

Mechanisms of Kappa Opioid Receptor Potentiation of Dopamine D2 Receptor Function in Quinpirole-Induced Locomotor Sensitization in Rats.

PubMed

Escobar, Angélica P; González, Marcela P; Meza, Rodrigo C; Noches, Verónica; Henny, Pablo; Gysling, Katia; España, Rodrigo A; Fuentealba, José A; Andrés, María E

2017-08-01

Increased locomotor activity in response to the same stimulus is an index of behavioral sensitization observed in preclinical models of drug addiction and compulsive behaviors. Repeated administration of quinpirole, a D2/D3 dopamine agonist, induces locomotor sensitization. This effect is potentiated and accelerated by co-administration of U69593, a kappa opioid receptor agonist. The mechanism underlying kappa opioid receptor potentiation of quinpirole-induced locomotor sensitization remains to be elucidated. Immunofluorescence anatomical studies were undertaken in mice brain slices and rat presynaptic synaptosomes to reveal kappa opioid receptor and D2R pre- and postsynaptic colocalization in the nucleus accumbens. Tonic and phasic dopamine release in the nucleus accumbens of rats repeatedly treated with U69593 and quinpirole was assessed by microdialysis and fast scan cyclic voltammetry. Anatomical data show that kappa opioid receptor and D2R colocalize postsynaptically in medium spiny neurons of the nucleus accumbens and the highest presynaptic colocalization occurs on the same dopamine terminals. Significantly reduced dopamine levels were observed in quinpirole, and U69593-quinpirole treated rats, explaining sensitization of D2R. Presynaptic inhibition induced by kappa opioid receptor and D2R of electrically evoked dopamine release was faster in U69593-quinpirole compared with quinpirole-repeatedly treated rats. Pre- and postsynaptic colocalization of kappa opioid receptor and D2R supports a role for kappa opioid receptor potentiating both the D2R inhibitory autoreceptor function and the inhibitory action of D2R on efferent medium spiny neurons. Kappa opioid receptor co-activation accelerates D2R sensitization by contributing to decrease dopamine release in the nucleus accumbens. © The Author 2017. Published by Oxford University Press on behalf of CINP.

Immunohistochemical localization of ionotropic glutamate receptors in the rat red nucleus

PubMed Central

Minbay, Zehra; Kocoglu, Sema Serter; Yurtseven, Duygu Gok; Eyigor, Ozhan

2017-01-01

In this study, we aimed to determine the presence as well as the diverse distribution of N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptor subunits in the rat red nucleus. Using adult Sprague-Dawley rats as the experimental animals, immunohistochemistry was performed on 30 µm thick coronal brain sections with antibodies against α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (GluA1-4), kainate (GluK1, GluK2/3, and GluK5), and NMDA (GluN1 and GluN2A) receptor subunits. The results showed that all ionotropic glutamate receptor subunits are expressed in the red nucleus. Specific staining was localized in the neuron bodies and processes. However, the pattern of immunoreactivity and the number of labeled neurons changed depending on the type of ionotropic glutamate receptor subunits and the localization of neurons in the red nucleus. The neurons localized in the magnocellular part of the red nucleus were particularly immunopositive for GluA2, GluA4, GluK2/3, GluK5, GluN1, and GluN2A receptor proteins. In the parvocellular part of the red nucleus, ionotropic glutamate receptor subunit immunoreactivity of variable intensity (lightly to moderately stained) was detected in the neurons. These results suggest that red nucleus neurons in rat heterogeneously express ionotropic glutamate receptor subunits to form functional receptor channels. In addition, the likelihood of the coexpression of different subunits in the same subgroup of neurons suggests the formation of receptor channels with diverse structure by way of different subunit combination, and the possibility of various neuronal functions through these channels in the red nucleus. PMID:28027456

Immunohistochemical localization of ionotropic glutamate receptors in the rat red nucleus.

PubMed

Minbay, Zehra; Serter Kocoglu, Sema; Gok Yurtseven, Duygu; Eyigor, Ozhan

2017-02-21

In this study, we aimed to determine the presence as well as the diverse distribution of N-methyl-D-aspartate (NMDA) and non-NMDA glutamate receptor subunits in the rat red nucleus. Using adult Sprague-Dawley rats as the experimental animals, immunohistochemistry was performed on 30 µm thick coronal brain sections with antibodies against α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (GluA1-4), kainate (GluK1, GluK2/3, and GluK5), and NMDA (GluN1 and GluN2A) receptor subunits. The results showed that all ionotropic glutamate receptor subunits are expressed in the red nucleus. Specific staining was localized in the neuron bodies and processes. However, the pattern of immunoreactivity and the number of labeled neurons changed depending on the type of ionotropic glutamate receptor subunits and the localization of neurons in the red nucleus. The neurons localized in the magnocellular part of the red nucleus were particularly immunopositive for GluA2, GluA4, GluK2/3, GluK5, GluN1, and GluN2A receptor proteins. In the parvocellular part of the red nucleus, ionotropic glutamate receptor subunit immunoreactivity of variable intensity (lightly to moderately stained) was detected in the neurons. These results suggest that red nucleus neurons in rat heterogeneously express ionotropic glutamate receptor subunits to form functional receptor channels. In addition, the likelihood of the coexpression of different subunits in the same subgroup of neurons suggests the formation of receptor channels with diverse structure by way of different subunit combination, and the possibility of various neuronal functions through these channels in the red nucleus.

Effects of multi-deficiencies-diet on bone parameters of peripheral bone in ovariectomized mature rat.

PubMed

El Khassawna, Thaqif; Böcker, Wolfgang; Govindarajan, Parameswari; Schliefke, Nathalie; Hürter, Britta; Kampschulte, Marian; Schlewitz, Gudrun; Alt, Volker; Lips, Katrin Susanne; Faulenbach, Miriam; Möllmann, Henriette; Zahner, Daniel; Dürselen, Lutz; Ignatius, Anita; Bauer, Natali; Wenisch, Sabine; Langheinrich, Alexander Claus; Schnettler, Reinhard; Heiss, Christian

2013-01-01

Many postmenopausal women have vitamin D and calcium deficiency. Therefore, vitamin D and calcium supplementation is recommended for all patients with osteopenia and osteoporosis. We used an experimental rat model to test the hypothesis that induction of osteoporosis is more efficiently achieved in peripheral bone through combining ovariectomy with a unique multi-deficiencies diet (vitamin D depletion and deficient calcium, vitamin K and phosphorus). 14-week-old Sprague-Dawley rats served as controls to examine the initial bone status. 11 rats were bilaterally ovariectomized (OVX) and fed with multi-deficiencies diet. Three months later the treated group and the Sham group (n = 8) were euthanized. Bone biomechanical competence of the diaphyseal bone was examined on both, tibia and femur. Image analysis was performed on tibia via µCT, and on femur via histological analysis. Lower torsional stiffness indicated inferior mechanical competence of the tibia in 3 month OVX+Diet. Proximal metaphyseal region of the tibia showed a diminished bone tissue portion to total tissue in the µCT despite the increased total area as evaluated in both µCT and histology. Cortical bone showed higher porosity and smaller cross sectional thickness of the tibial diaphysis in the OVX+Diet rats. A lower ALP positive area and elevated serum level of RANKL exhibited the unbalanced cellular interaction in bone remodeling in the OVX+Diet rat after 3 month of treatment. Interestingly, more adipose tissue area in bone marrow indicated an effect of bone loss similar to that observed in osteoporotic patients. Nonetheless, the presence of osteoid and elevated serum level of PTH, BGP and Opn suggest the development of osteomalacia rather than an osteoporosis. As the treatment and fracture management of both osteoporotic and osteomalacia patients are clinically overlapping, this study provides a preclinical animal model to be utilized in local supplementation of minerals, drugs and growth factors

Effects of Multi-Deficiencies-Diet on Bone Parameters of Peripheral Bone in Ovariectomized Mature Rat

PubMed Central

El Khassawna, Thaqif; Böcker, Wolfgang; Govindarajan, Parameswari; Schliefke, Nathalie; Hürter, Britta; Kampschulte, Marian; Schlewitz, Gudrun; Alt, Volker; Lips, Katrin Susanne; Faulenbach, Miriam; Möllmann, Henriette; Zahner, Daniel; Dürselen, Lutz; Ignatius, Anita; Bauer, Natali; Wenisch, Sabine; Langheinrich, Alexander Claus; Schnettler, Reinhard; Heiss, Christian

2013-01-01

Many postmenopausal women have vitamin D and calcium deficiency. Therefore, vitamin D and calcium supplementation is recommended for all patients with osteopenia and osteoporosis. We used an experimental rat model to test the hypothesis that induction of osteoporosis is more efficiently achieved in peripheral bone through combining ovariectomy with a unique multi-deficiencies diet (vitamin D depletion and deficient calcium, vitamin K and phosphorus). 14-week-old Sprague-Dawley rats served as controls to examine the initial bone status. 11 rats were bilaterally ovariectomized (OVX) and fed with multi-deficiencies diet. Three months later the treated group and the Sham group (n = 8) were euthanized. Bone biomechanical competence of the diaphyseal bone was examined on both, tibia and femur. Image analysis was performed on tibia via µCT, and on femur via histological analysis. Lower torsional stiffness indicated inferior mechanical competence of the tibia in 3 month OVX+Diet. Proximal metaphyseal region of the tibia showed a diminished bone tissue portion to total tissue in the µCT despite the increased total area as evaluated in both µCT and histology. Cortical bone showed higher porosity and smaller cross sectional thickness of the tibial diaphysis in the OVX+Diet rats. A lower ALP positive area and elevated serum level of RANKL exhibited the unbalanced cellular interaction in bone remodeling in the OVX+Diet rat after 3 month of treatment. Interestingly, more adipose tissue area in bone marrow indicated an effect of bone loss similar to that observed in osteoporotic patients. Nonetheless, the presence of osteoid and elevated serum level of PTH, BGP and Opn suggest the development of osteomalacia rather than an osteoporosis. As the treatment and fracture management of both osteoporotic and osteomalacia patients are clinically overlapping, this study provides a preclinical animal model to be utilized in local supplementation of minerals, drugs and growth factors

Heart dysfunction induced by choline-deficiency in adult rats: the protective role of L-carnitine.

PubMed

Strilakou, Athina A; Lazaris, Andreas C; Perelas, Apostolos I; Mourouzis, Iordanis S; Douzis, Ioannis Ch; Karkalousos, Petros L; Stylianaki, Aikaterini Th; Pantos, Costas I; Liapi, Charis A

2013-06-05

Choline is a B vitamin co-factor and its deficiency seems to impair heart function. Carnitine, a chemical analog of choline, has been used as adjunct in the management of cardiac diseases. The study investigates the effects of choline deficiency on myocardial performance in adult rats and the possible modifications after carnitine administration. Wistar Albino rats (n=24), about 3 months old, were randomized into four groups fed with: (a) standard diet (control-CA), (b) choline deficient diet (CDD), (c) standard diet and carnitine in drinking water 0.15% w/v (CARN) and (d) choline deficient diet and carnitine (CDD+CARN). After four weeks of treatment, we assessed cardiac function under isometric conditions using the Langendorff preparations [Left Ventricular Developed Pressure (LVDP-mmHg), positive and negative first derivative of LVDP were evaluated], measured serum homocysteine and brain natriuretic peptide (BNP) levels and performed histopathology analyses. In the CDD group a compromised myocardium contractility compared to control (P=0.01), as assessed by LVDP, was noted along with a significantly impaired diastolic left ventricular function, as assessed by (-) dp/dt (P=0.02) that were prevented by carnitine. Systolic force, assessed by (+) dp/dt, showed no statistical difference between groups. A significant increase in serum BNP concentration was found in the CDD group (P<0.004) which was attenuated by carnitine (P<0.05), whereas homocysteine presented contradictory results (higher in the CDD+CARN group). Heart histopathology revealed a lymphocytic infiltration of myocardium and valves in the CDD group that was reduced by carnitine. In conclusion, choline deficiency in adult rats impairs heart performance; carnitine acts against these changes. Copyright © 2013 Elsevier B.V. All rights reserved.

[Effects of total flavonoids in Astragali Complanati Semen on liver lipid level and ERα expression on liver in hyperlipidemia rats with kidney-Yang deficiency pattern].

PubMed

Tang, Xiao-Ran; Wang, Jing-Xia; Fu, Lu; Yao, Jun-Kai; Li, Si-Ming; Gao, Xue-Min; Zhang, Jian-Jun

2018-06-01

Menopausal women appear lipid metabolism disorder with the ovarian function decline and the estrogen levels decreased. Modern clinical usually use estrogen replacement therapy and with long time application with lots of side effect appear. Traditional Chinese medicine has more secure and effective methords,using warming Yang drugs and methods. And the previous study proves the Chinese medicine Astragali Complanati Semen water extraction has a good role in regulation of blood lipids. Because of the liver is the most important organ on regulating metabolism, therefore this study aimed to evaluate the effects of total flavonoids in Astragali Complanati Semen(TFS)on liverlipid level and ERα expressionon liver in hyperlipidemia rats with kidney-Yang deficiency pattern to explore the substance basis and mechanism of Astragali Complanati Semen in regulate lipid effect and clarify traditional Chinese medicine advantages and features. This experiment uses hyperlipidemia rats with kidney-Yang deficiency pattern with bilateral ovariectomized and fed with high fat diet for 6 weeks. And rats of sham operation group and model group rats were intragastrilly(ig) with saline, estrogen group were intragastrilly with estrogen(0.2 mg·kg⁻¹). And three TFS group were intragastrilly with TFS at dose 28.5, 57, 114 mg·kg⁻¹ for 8 weeks. At the same time, TC, TG, LDL-C,HDL-C liver weight, liver index, uterine weight, uterine index, serum estrogen level, FSH levels and liver pathology, liver estrogen receptor expression were detected, weighting and calculating their organ index. The experimental results compared with the model group, TFS 114 mg·kg⁻¹ decreased the level of liver TG ( P <0.05), TC ( P <0.001) and LDL-C ( P <0.001) and increased the level of HDL-C ( P <0.05). Compared with the model group, estrogen group increased the level of blood serum ( P <0.001) and decreased the level of FSH ( P <0.001). In addition, compared with sham operation group,model group decreased the

Thalamic Proteome Changes and Behavioral Impairments in Thiamine-deficient Rats.

PubMed

Nunes, Polliana Toledo; Gómez-Mendoza, Diana Paola; Rezende, Cristiana Perdigão; Figueiredo, Henrique César Pereira; Ribeiro, Angela Maria

2018-06-09

Thiamine deficiency (TD) has been used as an experimental model in rodents to study the molecular mechanisms of neurodegeneration and its association with behavioral changes. The aims of the present study were to investigate the spatial cognitive performance of pyrithiamine-induced thiamine deficiency (PTD) in adult male rats and disclose the thalamic proteome alterations caused by a severe TD episode. After the onset of the neurological signs, such as seizure and/or loss of righting reflex, the TD treatment was interrupted. Following 15 days of recovery, all rats were submitted to the spatial cognitive tasks in the Morris Water Maze (MWM). The results show that the PTD rats exhibited deficits during the learning process, which was reverted by repeated training. However, despite the spatial cognitive recovery, some protein changes were not reversible. The proteomic analysis, using label-free quantification, revealed deregulation of 183 thalamic proteins. Using bioinformatic tools, these proteins were categorized according to Gene Ontology functional annotation and metabolic pathways. We show that a severe TD affects proteins involved in different biological processes, such as, oxidative stress, neurotransmitter synthesis and synaptic vesicle cycle. These could explain the outcome in neurotransmitter release changes caused by TD, previously observed by our group and by other authors. These findings disclose the role of key proteins and metabolic pathways probably involved in the neurodegeneration process induced by TD. These proteins represent relevant molecular targets for future studies focusing also on the molecular basis of selective vulnerability of some brain areas to TD insult. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

A receptor autoradiographic and in situ hybridization analysis of the distribution of the 5-ht7 receptor in rat brain.

PubMed Central

Gustafson, E. L.; Durkin, M. M.; Bard, J. A.; Zgombick, J.; Branchek, T. A.

1996-01-01

1. Receptor autoradiography and in situ hybridization histochemistry have been used to delineate the distribution of the 5-ht7 receptor and its mRNA in rat brain. Receptor autoradiographic studies were performed using [3H]-5-carboxamidotryptamine (5-CT) as the radioligand. The binding characteristics of the masking compounds were determined in Cos-7 cells transfected with a panel of 5-HT receptor subtype cDNAs, including the rat 5-ht7 cDNA. In situ hybridization studies were carried out with 35S-labelled oligonucleotide probes to the rat 5-ht7 mRNA. 2. Specific binding of [3H]-5-CT was observed in many areas of the rat brain. Following co-incubation with 1 microM ergotamine, this binding was completely eliminated. After addition of the masking ligands, [3H]-5-CT binding remained in layers 1-3 of cortex, septum, globus pallidus, thalamus, hypothalamus, centromedial amygdala, substantia nigra, periaquaductal gray, and superior colliculus. Addition of the antagonist, methiothepin, to the incubation regimen eliminated most of the remaining [3H]-5-CT binding in the brain, with the exception of the globus pallidus and substantia nigra. 3. The 5-ht7 mRNA was discretely localized in rat brain. The most intense hybridization signals were observed over the thalamus, the anterior hippocampal rudiment, and over the CA3 region of the hippocampus. Other regions containing hybridization signals included the septum, the hypothalamus, the centromedial amygdala and the periaquaductal gray. The regions exhibiting a modest receptor binding signal after methiothepin incubation, the globus pallidus and the substantia nigra, contained no 5-ht7 hybridization signals, suggesting a non-5-ht7 subtype in these two related structures. 4. The distribution of the 5-ht7 receptor and its mRNA is suggestive of multiple roles for this novel 5-HT receptor, within several brain systems. The limbic system (centromedial amygdala, anterior hippocampal rudiment, hypothalamus) is particularly well

[Comparison of integration processing technology of origin and traditional cutting processing technology of Moslae Herba for lung-Yang deficiency rats].

PubMed

Sun, Dong-Yue; Wang, Xin-Ya; Wang, Xiao-Ting; Yan, Li; Liu, Xiao-Feng; Pang, Bo; Gao, Hui

2018-06-01

To compare the effect of integration processing technology of origin (IPTO) and traditional cutting processing technology (TCPT) of Moslae Herba for lung-Yang deficiency rats caused by complex factors, analyze the mechanism, and provide the modern pharmacology basis for the implementation of IPTO of Moslae Herba. The rat models of lung-Yang deficiency were established by smoking + swimming in ice water + drinking ice water. The model rats were randomly divided into different groups, and were treated with intragastric administration for 30 d. Then the general signs, anal temperature and autonomic activity of the rats were observed. The pathological morphology of lung tissues was observed, and the positive expression of tumor necrosis factor (TNF-α) was observed by immunohistochemical method, and the hematological indexes were determined. Enzyme linked immunosorbent assay (ELISA) method was used to detect serum nitric oxide (NO), immunoglobulin G (IGG), malondialdehyde (MDA), thromboxane B2 (TXB2) and interleukin-8 (IL-8) level, and the organ coefficients of heart, liver, spleen, lung, kidney and other organs were calculated. According to the results, Moslae Herba volatile oil and decoction could improve the general signs and autonomic activities of lung-Yang deficiency rats, improve the body weight, rectal temperature, and the content of IGG in serum of lung-Yang deficiency rats, reduce organ coefficients of heart, liver, spleen, lung and kidney, serum NO, MDA, TXB2, IL-8 contents, white blood cell and TNF-α mean optical density in the lung tissues of rats. witg statistically significant difference ( P <0.01 or P <0.05). The effects of IPTO volatile oil and water decoction were slightly higher. Therefore, Moslae Herba has therapeutic effect on lung-Yang deficiency rats, and ICPT has better effect, whose mechanism may be related to the intervention of TNF-α expression, improving the level of IGG, and inhibiting NO, MDA, IL-8, and TXB2 levels. Copyright© by the

Growth hormone and IGF-1 deficiency exacerbate high-fat diet-induced endothelial impairment in obese Lewis dwarf rats: implications for vascular aging.

PubMed

Bailey-Downs, Lora C; Sosnowska, Danuta; Toth, Peter; Mitschelen, Matthew; Gautam, Tripti; Henthorn, Jim C; Ballabh, Praveen; Koller, Akos; Farley, Julie A; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

2012-06-01

Previous studies suggest that the age-related decline in circulating growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels significantly contribute to vascular dysfunction in aging by impairing cellular oxidative stress resistance pathways. Obesity in elderly individuals is increasing at alarming rates, and there is evidence suggesting that elderly individuals are more vulnerable to the deleterious cardiovascular effects of obesity than younger individuals. However, the specific mechanisms through which aging, GH/IGF-1 deficiency, and obesity interact to promote the development of cardiovascular disease remain unclear. To test the hypothesis that low circulating GH/IGF-1 levels exacerbate the pro-oxidant and proinflammatory vascular effects of obesity, GH/IGF-1-deficient Lewis dwarf rats and heterozygous control rats were fed either a standard diet or a high-fat diet (HFD) for 7 months. Feeding an HFD resulted in similar relative weight gains and increases in body fat content in Lewis dwarf rats and control rats. HFD-fed Lewis dwarf rats exhibited a relative increase in blood glucose levels, lower insulin, and impaired glucose tolerance as compared with HFD-fed control rats. Analysis of serum cytokine expression signatures indicated that chronic GH/IGF-1 deficiency exacerbates HFD-induced inflammation. GH/IGF-1 deficiency also exacerbated HFD-induced endothelial dysfunction, oxidative stress, and expression of inflammatory markers (tumor necrosis factor-α, ICAM-1) in aortas of Lewis dwarf rats. Overall, our results are consistent with the available clinical and experimental evidence suggesting that GH/IGF-1 deficiency renders the cardiovascular system more vulnerable to the deleterious effects of obesity.

Growth Hormone and IGF-1 Deficiency Exacerbate High-Fat Diet–Induced Endothelial Impairment in Obese Lewis Dwarf Rats: Implications for Vascular Aging

PubMed Central

Bailey-Downs, Lora C.; Sosnowska, Danuta; Toth, Peter; Mitschelen, Matthew; Gautam, Tripti; Henthorn, Jim C.; Ballabh, Praveen; Koller, Akos; Farley, Julie A.; Sonntag, William E.; Csiszar, Anna

2012-01-01

Previous studies suggest that the age-related decline in circulating growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels significantly contribute to vascular dysfunction in aging by impairing cellular oxidative stress resistance pathways. Obesity in elderly individuals is increasing at alarming rates, and there is evidence suggesting that elderly individuals are more vulnerable to the deleterious cardiovascular effects of obesity than younger individuals. However, the specific mechanisms through which aging, GH/IGF-1 deficiency, and obesity interact to promote the development of cardiovascular disease remain unclear. To test the hypothesis that low circulating GH/IGF-1 levels exacerbate the pro-oxidant and proinflammatory vascular effects of obesity, GH/IGF-1–deficient Lewis dwarf rats and heterozygous control rats were fed either a standard diet or a high-fat diet (HFD) for 7 months. Feeding an HFD resulted in similar relative weight gains and increases in body fat content in Lewis dwarf rats and control rats. HFD-fed Lewis dwarf rats exhibited a relative increase in blood glucose levels, lower insulin, and impaired glucose tolerance as compared with HFD-fed control rats. Analysis of serum cytokine expression signatures indicated that chronic GH/IGF-1 deficiency exacerbates HFD-induced inflammation. GH/IGF-1 deficiency also exacerbated HFD-induced endothelial dysfunction, oxidative stress, and expression of inflammatory markers (tumor necrosis factor-α, ICAM-1) in aortas of Lewis dwarf rats. Overall, our results are consistent with the available clinical and experimental evidence suggesting that GH/IGF-1 deficiency renders the cardiovascular system more vulnerable to the deleterious effects of obesity. PMID:22080499

Overexpression of insulin-like growth factor-I receptor as a pertinent biomarker for hepatocytes malignant transformation

PubMed Central

Yan, Xiao-Di; Yao, Min; Wang, Li; Zhang, Hai-Jian; Yan, Mei-Juan; Gu, Xing; Shi, Yun; Chen, Jie; Dong, Zhi-Zhen; Yao, Deng-Fu

2013-01-01

AIM: To investigate the dynamic features of insulin-like growth factor-I receptor (IGF-IR) expression in rat hepatocarcinogenesis, and the relationship between IGF-IR and hepatocytes malignant transformation at mRNA or protein level. METHODS: Hepatoma models were made by inducing with 2-fluorenylacetamide (2-FAA) on male Sprague-Dawley rats. Morphological changes of hepatocytes were observed by pathological Hematoxylin and eosin staining, the dynamic expressions of liver and serum IGF-IR were quantitatively analyzed by an enzyme-linked immunosorbent assay. The distribution of hepatic IGF-IR was located by immunohistochemistry. The fragments of IGF-IR gene were amplified by reverse transcription-polymerase chain reaction, and confirmed by sequencing. RESULTS: Rat hepatocytes after induced by 2-FAA were changed dynamically from granule-like degeneration, precancerous to hepatoma formation with the progressing increasing of hepatic mRNA or IGF-IR expression. The incidences of liver IGF-IR, IGF-IR mRNA, specific IGF-IR concentration (ng/mg wet liver), and serum IGF-IR level (ng/mL) were 0.0%, 0.0%, 0.63 ± 0.17, and 1.33 ± 0.47 in the control; 50.0%, 61.1%, 0.65 ± 0.2, and 1.51 ± 0.46 in the degeneration; 88.9%, 100%, 0.66 ± 0.14, and 1.92 ± 0.29 in the precancerosis; and 100%, 100%, 0.96 ± 0.09, and 2.43 ± 0.57 in the cancerous group, respectively. IGF-IR expression in the cancerous group was significantly higher (P < 0.01) than that in any of other groups at mRNA or protein level. The closely positive IGF-IR relationship was found between livers and sera (r = 0.91, t = 14.222, P < 0.01), respectively. CONCLUSION: IGF-IR expression may participate in rat hepatocarcinogenesis and its abnormality should be an early marker for hepatocytes malignant transformation. PMID:24106410

[Correction of the combined vitamin deficiency in growing rats fed fiber enriched diets with different doses of vitamins].

PubMed

Beketova, N A; Kodentsova, V M; Vrzhesinskaia, O A; Kosheleva, O V; Pereverzeva, O G; Sokol'nikov, A A; Aksenov, I V

2014-01-01

The effect of 5% dietary wheat bran (WB) on the correction of combined vitamin deficiency by two doses of vitamins (physiological and enhanced) has been analyzed using a rat model (8 groups, n = 8/group). Vitamin deficiency in male weanling Wistar rats (58.1 ± 0.5 g) was induced by 5-fold reduction of vitamin mixture amount in the feed and complete vitamin E, B1 and B2 exclusion from the mixture for 30 days, then deficit was corrected within 5 days. Rats from control group were fed a complete semisynthetic diet containing microcrystalline cellulose 2%. Vitamin deficient diet for 35 days resulted in reduced (p < 0.05) levels of vitamin A in the liver by 25 fold, vitamin E and B1--2.0-2.3 fold, vitamin B2--by 40%, 25(OH)D blood plasma concentration--by 21% compared with the control. Feed consumption of the animals treated with vitamin deficient diet and WB was higher by 43% than in rats with vitamin deficit. Their rate of weight occupied the intermediate position between the rates of weight in deficit and in control animals, and they could not serve a full control to evaluate the WB impact on vitamin sufficiency. After filling the vitamin diet content to an adequate level vitamin E liver content was fully restored. To restore vitamins B1 and B2 liver level higher doses of vitamins (120-160% of adequate content) were required, and to restore the reduced levels of vitamin A in rat liver even 2-fold increased dose of vitamin A was insufficient. The diet enrichment with WB had no effect on vitamin B1 and B2 liver content, regardless of the amount of vitamins in the diet. Adding fiber to the diet of animals adequately provided with vitamins resulted in significantly 1,3-fold increase of 25(OH)D blood plasma concentration and a slight but significant decrease of α-tocopherol liver level by 16% as compared to rats not receiving WB. The enrichment of rat diet with dietary fibers worsened restoration of the reduced vitamin E status not only by filling vitamin content in the

Combined deficiency of iron and (n-3) fatty acids in male rats disrupts brain monoamine metabolism and produces greater memory deficits than iron deficiency or (n-3) fatty acid deficiency alone.

PubMed

Baumgartner, Jeannine; Smuts, Cornelius M; Malan, Linda; Arnold, Myrtha; Yee, Benjamin K; Bianco, Laura E; Boekschoten, Mark V; Müller, Michael; Langhans, Wolfgang; Hurrell, Richard F; Zimmermann, Michael B

2012-08-01

Deficiencies of iron (Fe) (ID) and (n-3) fatty acids (FA) [(n-3)FAD] may impair brain development and function through shared mechanisms. However, little is known about the potential interactions between these 2 common deficiencies. We studied the effects of ID and (n-3)FAD, alone and in combination, on brain monoamine pathways (by measuring monoamines and related gene expression) and spatial working and reference memory (by Morris water maze testing). Using a 2 × 2 design, male rats were fed an ID, (n-3)FAD, ID+(n-3)FAD, or control diet for 5 wk postweaning (postnatal d 21-56) after (n-3)FAD had been induced over 2 generations. The (n-3)FAD and ID diets decreased brain (n-3) FA by 70-76% and Fe by 20-32%, respectively. ID and (n-3)FAD significantly increased dopamine (DA) concentrations in the olfactory bulb (OB) and striatum, with an additive 1- to 2-fold increase in ID+(n-3)FAD rats compared with controls (P < 0.05). ID decreased serotonin (5-HT) levels in OB, with a significant decrease in ID+(n-3)FAD rats. Furthermore, norepinephrine concentrations were increased 2-fold in the frontal cortex (FC) of (n-3)FAD rats (P < 0.05). Dopa decarboxylase was downregulated in the hippocampus of ID and ID+(n-3)FAD rats (fold-change = -1.33; P < 0.05). ID and (n-3)FAD significantly impaired working memory performance and the impairment positively correlated with DA concentrations in FC (r = 0.39; P = 0.026). Reference memory was impaired in the ID+(n-3)FAD rats (P < 0.05) and was negatively associated with 5-HT in FC (r = -0.42; P = 0.018). These results suggest that the combined deficiencies of Fe and (n-3) FA disrupt brain monoamine metabolism and produce greater deficits in reference memory than ID or (n-3)FAD alone.

Histopathology of chondronecrosis development in knee articular cartilage in a rat model of Kashin-Beck disease using T-2 toxin and selenium deficiency conditions.

PubMed

Guan, Fang; Li, Siyuan; Wang, Zhi-Lun; Yang, Haojie; Xue, Senghai; Wang, Wei; Song, Daiqing; Zhou, Xiaorong; Zhou, Wang; Chen, Jing-Hong; Caterson, Bruce; Hughes, Clare

2013-01-01

The objective of this study is to observe pathogenic lesions of joint cartilages in rats fed with T-2 toxin under a selenium deficiency nutrition status in order to determine possible etiological factors causing Kashin-Beck disease (KBD). Sprague-Dawley rats were fed selenium-deficient or control diets for 4 weeks prior to their being exposed to T-2 toxin. Six dietary groups were formed and studied 4 weeks later, i.e., controls, selenium-deficient, low T-2 toxin, high T-2 toxin, selenium-deficient diet plus low T-2 toxin, and selenium-deficient diet plus high T-2 toxin. Selenium deficiencies were confirmed by the determination of glutathione peroxidase activity and selenium levels in serum. The morphology and pathology (chondronecrosis) of knee joint cartilage of experimental rats were observed using light microscopy and the expression of proteoglycans was determined by histochemical staining. Chondronecrosis in deep zone of articular cartilage of knee joints was seen in both the low and high T-2 toxin plus selenium-deficient diet groups, these chondronecrotic lesions being very similar to chondronecrosis observed in human KBD. However, the chondronecrosis observed in the rat epiphyseal growth plates of animals treated with T-2 toxin alone or T-2 toxin plus selenium-deficient diets were not similar to that found in human KBD. Our results indicate that the rat can be used as a suitable animal model for studying etiological factors contributing to the pathogenesis (chondronecrosis) observed in human KBD. However, those changes seen in epiphyseal growth plate differ from those seen in human KBD probably because of the absence of growth plate closure in the rat.

Colonic inflammation increases the contribution of muscarinic M2 receptors to carbachol-induced contraction of the rat colon.

PubMed

Jragh, Dina M; Khan, Islam; Oriowo, Mabayoje A

2011-01-01

Carbachol-induced contraction of the rat colon is impaired in rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. The main objective of this study was to examine the effect of colitis on the expression and function of muscarinic (M) receptor subtypes in the rat colon. Rats (n = 80) were treated with TNBS and used 5 days later for measurement of contractility, myeloperoxidase activity, histology and expression of muscarinic receptor isoforms using Western blot analysis. Carbachol produced concentration-dependent contractions of colonic segments from control (n = 40) and TNBS-treated (n = 40) rats with no significant difference in potency. However, the maximum response to carbachol was significantly reduced in colon segments of TNBS-treated rats. The selective muscarinic receptor antagonists 4-diphenylacetoxy-N-methyl piperidine (4-DAMP, M(3)), pirenzepine (M(1)) and methoctramine (M(2)) antagonized carbachol-induced contraction in control (9.1 ± 0.1, 6.7 ± 0.3 and 6.0 ± 0.1, respectively) and TNBS-treated rats (9.2 ± 0.2, 6.9 ± 0.2, 6.7 ± 0.2). The -logK(B) values in control rats are consistent with an action of carbachol on muscarinic M(3) receptors. There was no significant difference in -logK(B) values for 4-DAMP and pirenzepine in control and TNBS-treated rats, but methoctramine was fivefold more potent in TNBS-treated rats, possibly indicating an increased contribution of muscarinic M(2) receptors to carbachol-induced contraction in the inflamed colon. The expression of M(2) receptors was also significantly increased in colon segments from TNBS-treated rats, confirming the increased role of muscarinic M(2) receptors in the inflamed colon. The data show that while only M(3) receptors appeared to mediate carbachol-induced contraction in control segments, expression of both M(2) and M(3) receptors was increased in the inflamed rat colon. Copyright © 2011 S. Karger AG, Basel.

Mitogenic signaling of urokinase receptor-deficient kidney fibroblasts: actions of an alternative urokinase receptor and LDL receptor-related protein.

PubMed

Zhang, Guoqiang; Cai, Xiaohe; López-Guisa, Jesús M; Collins, Sarah J; Eddy, Allison A

2004-08-01

The urokinase receptor (uPAR) attenuates myofibroblast recruitment and fibrosis in the kidney. This study examined the role of uPAR and its co-receptor LDL receptor-related protein (LRP) in the regulation of kidney fibroblast proliferation and extracellular signal-regulated kinase (ERK) signaling. Compared with uPAR+/+ cells, uPAR-/- kidney fibroblasts were hyperproliferative. UPAR-/- fibroblast proliferation was 60% inhibited by an ERK kinase inhibitor. LRP protein was reduced and extracellular accumulation of urokinase-type plasminogen activator (uPA) and plasminogen activator inhibitor type 1 (PAI-1) proteins were greater in uPAR-/- cultures. Addition of functional uPA protein or LRP antisense RNA significantly increased ERK signaling and cell mitosis in both genotypes. Enhanced uPAR-/- fibroblast proliferation was reversed by a recombinant nonfunctional uPA peptide. The density of cell-bound fluor-uPA was similar between uPAR-/- and uPAR+/+ fibroblasts (78 +/- 6 versus 92 +/- 16 units). These data suggest that uPAR-deficient kidney fibroblasts express lower levels of its scavenger co-receptor LRP, resulting in greater extracellular accumulation of uPA and PAI-1. Enhanced proliferation of uPAR-/- fibroblasts seems to be mediated by uPA-dependent ERK signaling via an alternative urokinase receptor.

Lordosis facilitated by GPER-1 receptor activation involves GnRH-1, progestin and estrogen receptors in estrogen-primed rats.

PubMed

Domínguez-Ordóñez, R; Garcia-Juárez, M; Lima-Hernández, F J; Gómora-Arrati, P; Domínguez-Salazar, E; Blaustein, J D; Etgen, A M; González-Flores, O

2018-02-01

The present study assessed the participation of membrane G-protein coupled estrogen receptor 1 (GPER-1) and gonadotropin releasing hormone 1 (GnRH-1) receptor in the display of lordosis induced by intracerebroventricular (icv) administration of G1, a GPER-1 agonist, and by unesterified 17β-estradiol (free E 2 ). In addition, we assessed the participation of both estrogen and progestin receptors in the lordosis behavior induced by G1 in ovariectomized (OVX), E 2 -benzoate (EB)-primed rats. In Experiment 1, icv injection of G1 induced lordosis behavior at 120 and 240min. In Experiment 2, icv injection of the GPER-1 antagonist G15 significantly reduced lordosis behavior induced by either G1 or free E 2 . In addition, Antide, a GnRH-1 receptor antagonist, significantly depressed G1 facilitation of lordosis behavior in OVX, EB-primed rats. Similarly, icv injection of Antide blocked the stimulatory effect of E 2 on lordosis behavior. In Experiment 3, systemic injection of either tamoxifen or RU486 significantly reduced lordosis behavior induced by icv administration of G1 in OVX, EB-primed rats. The results suggest that GnRH release activates both estrogen and progestin receptors and that this activation is important in the chain of events leading to the display of lordosis behavior in response to activation of GPER-1 in estrogen-primed rats. Copyright © 2018 Elsevier Inc. All rights reserved.

Phosphorylation of the rat hepatic polymeric IgA receptor.

PubMed Central

Larkin, J M; Sztul, E S; Palade, G E

1986-01-01

In vivo labeling with [35S]cysteine has identified three transmembrane forms of the rat hepatic polymeric IgA receptor: (i) a 105-kDa core glycosylated precursor; (ii) a terminally glycosylated 116-kDa intermediate; and (iii) a mature 120-kDa form. In the current study we show that the 120-kDa form is phosphorylated. After in vivo labeling with [32P]orthophosphate, all receptor forms were immunoprecipitated from hepatic total microsomes (TM) (with an antireceptor antiserum), separated by NaDodSO4/PAGE, and detected by autoradiography. The 120-kDa form was selectively phosphorylated, whereas the 116- and 105-kDa forms incorporated no detectable 32P. To determine the topology of the phosphorylation sites, hepatic TM isolated from rats labeled in vivo with either [35S]cysteine or [32P]orthophosphate were treated with trypsin. TM were solubilized and receptors were immunoprecipitated from lysates. With increasing trypsin concentrations, the [35S]cysteine-labeled receptor triplet was degraded to a trypsin-resistant doublet of approximately 95 and 85 kDa, indicating that approximately 20 kDa was removed from the receptor endodomain by trypsin. The same treatment removed all detectable 32P from labeled receptors. Furthermore, no 32P was detected in the 80-kDa biliary form of the receptor. Serine was identified as the only phosphorylated residue in acid hydrolysates of 32P-labeled immunoprecipitated receptor. These findings indicate that (i) the 120-kDa form is the only phosphorylated species of the receptor; and (ii) the phosphorylated residues are serine(s) located in the endodomain of the protein. Images PMID:3460069

Oxytocin decreases colonic motility of cold water stressed rats via oxytocin receptors.

PubMed

Yang, Xiao; Xi, Tao-Fang; Li, Yu-Xian; Wang, Hai-Hong; Qin, Ying; Zhang, Jie-Ping; Cai, Wen-Ting; Huang, Meng-Ting; Shen, Ji-Qiao; Fan, Xi-Min; Shi, Xuan-Zheng; Xie, Dong-Ping

2014-08-21

To investigate whether cold water intake into the stomach affects colonic motility and the involvement of the oxytocin-oxytocin receptor pathway in rats. Female Sprague Dawley rats were used and some of them were ovariectomized. The rats were subjected to gastric instillation with cold (0-4 °C, cold group) or room temperature (20-25 °C, control group) saline for 14 consecutive days. Colon transit was determined with a bead inserted into the colon. Colonic longitudinal muscle strips were prepared to investigate the response to oxytocin in vitro. Plasma concentration of oxytocin was detected by ELISA. Oxytocin receptor expression was investigated by Western blot analysis. Immunohistochemistry was used to locate oxytocin receptors. Colon transit was slower in the cold group than in the control group (P < 0.05). Colonic smooth muscle contractile response to oxytocin decreased, and the inhibitory effect of oxytocin on muscle contractility was enhanced by cold water intake (0.69 ± 0.08 vs 0.88 ± 0.16, P < 0.05). Atosiban and tetrodotoxin inhibited the effect of oxytocin on colonic motility. Oxytocin receptors were located in the myenteric plexus, and their expression was up-regulated in the cold group (P < 0.05). Cold water intake increased blood concentration of oxytocin, but this effect was attenuated in ovariectomized rats (286.99 ± 83.72 pg/mL vs 100.56 ± 92.71 pg/mL, P < 0.05). However, in ovariectomized rats, estradiol treatment increased blood oxytocin, and the response of colonic muscle strips to oxytocin was attenuated. Cold water intake inhibits colonic motility partially through oxytocin-oxytocin receptor signaling in the myenteric nervous system pathway, which is estrogen dependent.

Characterization of the hypothermic effects of imidazoline I2 receptor agonists in rats

PubMed Central

Thorn, David A; An, Xiao-Fei; Zhang, Yanan; Pigini, Maria; Li, Jun-Xu

2012-01-01

BACKGROUND AND PURPOSE Imidazoline I2 receptors have been implicated in several CNS disorders. Although several I2 receptor agonists have been described, no simple and sensitive in vivo bioassay is available for studying I2 receptor ligands. This study examined I2 receptor agonist-induced hypothermia as a functional in vivo assay of I2 receptor agonism. EXPERIMENTAL APPROACH Different groups of rats were used to examine the effects of I2 receptor agonists on the rectal temperature and locomotion. The pharmacological mechanisms were investigated by combining I2 receptor ligands and different antagonists. KEY RESULTS All the selective I2 receptor agonists examined (2-BFI, diphenyzoline, phenyzoline, CR4056, tracizoline, BU224 and S22687, 3.2–56 mg·kg–1, i.p.) dose-dependently and markedly decreased the rectal temperature (hypothermia) in rats, with varied duration of action. Pharmacological mechanism of the observed hypothermia was studied by combining the I2 receptor agonists (2-BFI, BU224, tracizoline and diphenyzoline) with imidazoline I2 receptor/ α2 adrenoceptor antagonist idazoxan, selective I1 receptor antagonist efaroxan, α2 adrenoceptor antagonist/5-HT1A receptor agonist yohimbine. Idazoxan but not yohimbine or efaroxan attenuated the hypothermic effects of 2-BFI, BU224, tracizoline and diphenyzoline, supporting the I2 receptor mechanism. In contrast, both idazoxan and yohimbine attenuated hypothermia induced by the α2 adrenoceptor agonist clonidine. Among all the I2 receptor agonists studied, only S22687 markedly increased the locomotor activity in rats. CONCLUSIONS AND IMPLICATIONS Imidazoline I2 receptor agonists can produce hypothermic effects, which are primarily mediated by I2 receptors. These data suggest that I2 receptor agonist-induced hypothermia is a simple and sensitive in vivo assay for studying I2 receptor ligands. PMID:22324428

Non-NMDA receptor antagonist-induced drinking in rat

NASA Technical Reports Server (NTRS)

Xu, Z.; Johnson, A. K.

1998-01-01

Glutamate has been implicated in the central control of mechanisms that maintain body fluid homeostasis. The present studies demonstrate that intracerebroventricular (i.c.v.) injections of the non-N-methyl-d-aspartate (NMDA) receptor antagonists 6, 7-dinitroquinoxaline-2,3-dione (DNQX) and 6-cyano-7-nitroquinoxaline-2,3 dione (CNQX) induce drinking in rats. The dipsogenic effect of i.c.v. DNQX was antagonized by the non-NMDA receptor agonist alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA). The water intake induced by DNQX was also blocked by pretreatment with a NMDA receptor antagonist, MK-801, but not by angiotensin type 1 (AT1) or acetylcholine muscarinic receptor antagonists (losartan and atropine). The results indicate that non-NMDA receptors may exert a tonic inhibitory effect within brain circuits that control dipsogenic activity and that functional integrity of NMDA receptors may be required for the non-NMDA receptor antagonists to induce water intake. Copyright 1998 Published by Elsevier Science B.V.

Receptors for atrial natriuretic peptide are decreased in the kidney of rats with streptozotocin-induced diabetes mellitus.

PubMed Central

Sechi, L A; Valentin, J P; Griffin, C A; Lee, E; Bartoli, E; Humphreys, M H; Schambelan, M

1995-01-01

To determine whether decreased renal responsiveness to atrial natriuretic peptide (ANP) in diabetes is mediated by alterations in the renal ANP receptor, ANP receptor density and affinity were measured 17-20 d after streptozotocin injection and compared with values in vehicle-treated controls and streptozotocin-treated rats made euglycemic with insulin. Plasma ANP concentration was significantly greater in hyperglycemic diabetic rats than in control or euglycemic diabetic rats. Both in glomeruli and inner medulla, ANP receptor dissociation constant did not differ among the three study groups, whereas the maximum binding capacity was decreased significantly in hyperglycemic diabetics in comparison with controls and euglycemic diabetics. Glomerular clearance receptors were also decreased significantly in hyperglycemic diabetic rats in comparison with control and euglycemic diabetic rats. To determine whether the decreased number of renal ANP receptors in diabetic rats was associated with a decreased biological response, we measured ANP-dependent cyclic GMP (cGMP) accumulation by isolated glomeruli and inner medullary collecting duct cells in vitro. cGMP accumulation was significantly less in hyperglycemic diabetic rats than in controls or euglycemic diabetic rats both in the presence or absence of the phosphodiesterase inhibitor zaprinast. cGMP phosphodiesterase activity in inner medullary collecting duct cells obtained from control and hyperglycemic diabetic rats did not differ. Thus, the decreased number of biologically active ANP receptors in the kidneys of diabetic rats is accompanied by decreased biological responsiveness in vitro and provides a potential explanation for the reduction in renal sensitivity to ANP in this condition. Images PMID:7769090

Tissue distribution of manganese in iron-sufficient or iron-deficient rats after stainless steel welding-fume exposure.

PubMed

Park, Jung-Duck; Kim, Ki-Young; Kim, Dong-Won; Choi, Seong-Jin; Choi, Byung-Sun; Chung, Yong Hyun; Han, Jeong Hee; Sung, Jae Hyuck; Kwon, Il Hoon; Mun, Je-Hyeok; Yu, Il Je

2007-05-01

Welders can be exposed to high levels of manganese through welding fumes. Although it has already been suggested that excessive manganese exposure causes neurotoxicity, called manganism, the pathway of manganese transport to the brain with welding-fume exposure remains unclear. Iron is an essential metal that maintains a homeostasis in the body. The divalent metal transporter 1 (DMT1) transports iron and other divalent metals, such as manganese, and the depletion of iron is known to upregulate DMT1 expression. Accordingly, this study investigated the tissue distribution of manganese in iron-sufficient and iron-deficient rats after welding-fume exposure. The feeding of an iron-deficient diet for 4 wk produced a depletion of body iron, such as decreased iron levels in the serum and tissues, and upregulated the DMT1 expression in the rat duodenum. The iron-sufficient and iron-deficient rats were then exposed to welding fumes generated from manual metal arc stainless steel at a concentration of 63.5 +/- 2.3 mg/m3 for 2 h per day over a 30-day period. Animals were sacrificed on days 1, 15, and 30. The level of body iron in the iron-deficient rats was restored to the control level after the welding-fume exposure. However, the tissue distributions of manganese after the welding-fume exposure showed similar patterns in both the iron-sufficient and iron-deficient groups. The concentration of manganese increased in the lungs and liver on days 15 and 30, and increased in the olfactory bulb on day 30. Slight and heterogeneous increases of manganese were observed in different brain regions. Consequently, these findings suggest that the presence of Fe in the inhaled welding fumes may not have a significant effect on the uptake of Mn into the brain. Thus, the condition of iron deficiency did not seem to have any apparent effect on the transport of Mn into the brain after the inhalation of welding fumes.

Cannabinoid-mediated diversity of antinociceptive efficacy of parecoxib in Wistar and Sprague Dawley rats in the chronic constriction injury model of neuropathic pain.

PubMed

Becker, Axel; Geisslinger, Gerd; Murín, Radovan; Grecksch, Gisela; Höllt, Volker; Zimmer, Andreas; Schröder, Helmut

2013-05-01

We studied nociceptive behavior and the effects of analgesics in Wistar (Wist) and Sprague Dawley (SPD) rats and in CB1 receptor-deficient mice with neuropathic pain experimentally. Neuropathic pain was induced by loose ligation of the sciatic nerve (chronic constriction injury, CCI). In CCI rats from both strains, cold allodynia and a reduced thermal pain threshold were detected, whereas no effect was found in the hot plate test. Thermal pain threshold was used to study the antinociceptive effects of morphine, gabapentin, and parecoxib 5 days after surgery. Doses of gabapentin and morphine which had no effect on sham-operated animals provoked antinociceptive activity in CCI rats from both strains. An antinociceptive effect of parecoxib was only found in CCI Wist rats. No pharmacokinetic differences were detected between the two strains in parecoxib metabolism. Antinociceptive activity caused by parecoxib was attenuated by the CB1 antagonist rimonabant. To further clarify parecoxib-CB1 interaction, the effect of parecoxib was investigated in CB1-deficient mice and wild-type animals. CCI did not affect thermal pain threshold and mechanical pain threshold was decreased. Parecoxib normalized the altered mechanical pain threshold in CCI wild-type animals, whereas it had only a marginal effect in CB1 receptor deficient mice. Receptor binding experiments showed increased CB1 binding in parecoxib-treated CCI Wist rats. Levels of the CB1 receptor mRNA remained constant in both strains of rats 5 days after surgery. Differences in antinociceptive activity might be due to modification of the cannabinoid system.

The role of CCK2 receptors in energy homeostasis: insights from the CCK2 receptor-deficient mouse.

PubMed

Weiland, Tracey J; Voudouris, Nicholas J; Kent, Stephen

2004-09-15

The present study explored the contribution of type 2 cholecystokinin (CCK) receptors in energy regulation. A total of 78 CCK2 receptor-deficient mice and 80 wild-type controls were acclimated to a 12:12 light-dark cycle at 30 +/- 1 degrees C. Using a computer-monitored biotelemetry system, circadian patterns of body temperature, food intake, and activity were monitored for 4 days. Body weight and water consumption were manually recorded during this period. Results indicate that CCK2 receptor invalidation produces elevated body temperature during both the photophase and scotophase (by 0.38 and 0.12 degrees C, respectively), increased body weight (29.3 +/- 0.2 vs. 26.8 +/- 0.2 g) and water consumption (4.1 +/- 0.1 vs. 3.2 +/- 0.1 ml), and decreased scotophase locomotor activity (WT: 7.0 +/- 0.2 vs. KO: 6.1 +/- 0.2 counts/min). These findings suggest an important role for CCK2 receptors in processes underlying energy regulation during basal and possibly pathological states.

Nippostronglylus brasiliensis infection in the rat: effect of iron and protein deficiency and dexamethasone on the efficacy of benzimidazole anthelmintics.

PubMed Central

Duncombe, V M; Bolin, T D; Davis, A E; Kelly, J D

1977-01-01

Malnutrition, anaemia, and gut parasites are commonly interrelated. Using the Nippostrongylus brasiliensis-rat model, the effect of iron and protein deficiency on the efficacy of benzimidazole anthelmintics was studied. It was demonstrated that the anthelmintics mebendazole and fenbendazole were significantly less effective in eradicating parasites when animals were deficient in iron and protein. This decreased efficacy of anthelmintics in iron and protein deficiency could not be overcome by intraperitoneal administration of the drug. Since nutritional deficiencies may act via impairment of the immune response, anthelmintic efficacy was determined in adequately nourished rats treated with the immunosuppressive drug dexamethasone. A similar decrease in efficacy of mebendazole was shown when these animals were treated with dexamethasone. Thus it is possible that lowered anthelmintic efficacy in iron and protein deficient animals is mediated by immune deficiency. These findings may be relevant to anthelmintic programmes in malnourished communities. PMID:590849

Hematopoietic Sphingosine 1-Phosphate Lyase Deficiency Decreases Atherosclerotic Lesion Development in LDL-Receptor Deficient Mice

PubMed Central

Bot, Martine; Van Veldhoven, Paul P.; de Jager, Saskia C. A.; Johnson, Jason; Nijstad, Niels; Van Santbrink, Peter J.; Westra, Marijke M.; Van Der Hoeven, Gerd; Gijbels, Marion J.; Müller-Tidow, Carsten; Varga, Georg; Tietge, Uwe J. F.; Kuiper, Johan; Van Berkel, Theo J. C.; Nofer, Jerzy-Roch

2013-01-01

Aims Altered sphingosine 1-phosphate (S1P) homeostasis and signaling is implicated in various inflammatory diseases including atherosclerosis. As S1P levels are tightly controlled by S1P lyase, we investigated the impact of hematopoietic S1P lyase (Sgpl1−/−) deficiency on leukocyte subsets relevant to atherosclerosis. Methods and Results LDL receptor deficient mice that were transplanted with Sgpl1−/− bone marrow showed disrupted S1P gradients translating into lymphopenia and abrogated lymphocyte mitogenic and cytokine response as compared to controls. Remarkably however, Sgpl1−/− chimeras displayed mild monocytosis, due to impeded stromal retention and myelopoiesis, and plasma cytokine and macrophage expression patterns, that were largely compatible with classical macrophage activation. Collectively these two phenotypic features of Sgpl1 deficiency culminated in diminished atherogenic response. Conclusions Here we not only firmly establish the critical role of hematopoietic S1P lyase in controlling S1P levels and T cell trafficking in blood and lymphoid tissue, but also identify leukocyte Sgpl1 as critical factor in monocyte macrophage differentiation and function. Its, partly counterbalancing, pro- and anti-inflammatory activity spectrum imply that intervention in S1P lyase function in inflammatory disorders such as atherosclerosis should be considered with caution. PMID:23700419

Prostaglandin F2α receptor silencing attenuates vascular remodeling in rats with type 2 diabetes.

PubMed

Li, Ya; Han, Lu; Ding, Wen-Yuan; Ti, Yun; Li, Yi-Hui; Tang, Meng-Xiong; Wang, Zhi-Hao; Zhang, Yun; Zhang, Wei; Zhong, Ming

2015-12-01

Vascular remodeling is an important feature of diabetic macrovascular complications. The prostaglandin F2α receptor (FP), the expression of which is upregulated by insulin resistance and diabetes, is reportedly involved in myocardial remodeling. In this study, we aimed to investigate whether the FP receptor is implicated in diabetes-induced vascular remodeling. A type 2 diabetic rat model was induced through a high-fat diet and low-dose streptozotocin (STZ). Thirty-two rats were randomized into four groups: control, diabetes, diabetes treated with empty virus and diabetes treated with FP receptor-shRNA. Then, we evaluated the metabolic index, FP receptor expression and vascular remodeling. We used FP receptor gene silencing in vivo to investigate the role that the FP receptor plays in the pathophysiologic features of vascular remodeling. Diabetic rats displayed increased levels of blood glucose, cholesterol, and triglycerides, as well as severe insulin resistance and FP receptor overexpression. In addition, increased medial thickness, excessive collagen deposition and diminished elastic fibers were observed in the diabetic rats, resulting in vascular remodeling. In the FP receptor-shRNA group, the medial thickness, collagen content, elastin/collagen ratio, and collagen I/collagen III content ratio were markedly decreased. Additionally, with FP receptor gene silencing, the JNK phosphorylation level was markedly decreased. Silencing of the FP receptor exerts a protective effect on diabetes-induced vascular remodeling, thereby suggesting a new therapeutic target for vascular remodeling in diabetes. Copyright © 2015 Elsevier Inc. All rights reserved.

Muscarinic Receptor Binding in Rat Bladder Urothelium and Detrusor Muscle by Intravesical Solifenacin.

PubMed

Ito, Yoshihiko; Kashiwabara, Michishi; Yoshida, Akira; Hikiyama, Eriko; Onoue, Satomi; Yamada, Shizuo

2016-01-01

Solifenacin is an antimuscarinic agent used to treat symptoms of overactive bladder. Pharmacologically significant amounts of solifenacin were excreted in the urine of humans taking a clinical dose of this drug. The aim of this study is to measure muscarinic receptor binding in the bladder urothelium and detrusor muscles of rats following the intravesical instillation of solifenacin. Muscarinic receptors were measured by radioreceptor assay using [N-methyl-(3)H]scopolamine methyl chloride ([(3)H]NMS), a selective radioligand of muscarinic receptors. Solifenacin showed concentration-dependent inhibition of specific [(3)H]NMS binding in the bladder urothelium and detrusor muscle of rats, with no significant difference in Ki values or Hill coefficients between these tissues. Following the intravesical instillation of solifenacin, there was significant muscarinic receptor binding (increase in Kd for specific [(3)H]NMS binding) in the bladder urothelium and detrusor muscle of rats. Similar bladder muscarinic receptor binding was observed by the intravesical instillation of oxybutynin, but not with trospium. In conclusion, the present study has demonstrated that solifenacin binds muscarinic receptors not only in the detrusor muscle but also in the bladder urothelium with high affinity. These bladder muscarinic receptors may be significantly affected by solifenacin excreted in the urine.

Morphological assessment of bone mineralization in tibial metaphyses of ascorbic acid-deficient ODS rats.

PubMed

Hasegawa, Tomoka; Li, Minqi; Hara, Kuniko; Sasaki, Muneteru; Tabata, Chihiro; de Freitas, Paulo Henrique Luiz; Hongo, Hiromi; Suzuki, Reiko; Kobayashi, Masatoshi; Inoue, Kiichiro; Yamamoto, Tsuneyuki; Oohata, Noboru; Oda, Kimimitsu; Akiyama, Yasuhiro; Amizuka, Norio

2011-08-01

Osteogenic disorder shionogi (ODS) rats carry a hereditary defect in ascorbic acid synthesis, mimicking human scurvy when fed with an ascorbic acid-deficient (aa-def) diet. As aa-def ODS rats were shown to feature disordered bone formation, we have examined the bone mineralization in this rat model. A fibrous tissue layer surrounding the trabeculae of tibial metaphyses was found in aa-def ODS rats, and this layer showed intense alkaline phosphatase activity and proliferating cell nuclear antigen-immunopositivity. Many osteoblasts detached from the bone surfaces and were characterized by round-shaped rough endoplasmic reticulum (rER), suggesting accumulation of malformed collagen inside the rER. Accordingly, fine, fragile fibrillar collagenous structures without evident striation were found in aa-def bones, which may result from misassembling of the triple helices of collagenous α-chains. Despite a marked reduction in bone formation, ascorbic acid deprivation seemed to have no effect on mineralization: while reduced in number, normal matrix vesicles and mineralized nodules could be seen in aa-def bones. Fine needle-like mineral crystals extended from these mineralized nodules, and were apparently bound to collagenous fibrillar structures. In summary, collagen mineralization seems unaffected by ascorbic acid deficiency in spite of the fine, fragile collagenous fibrils identified in the bones of our animal model.

Hypoxia/hepatoma dual specific suicide gene expression plasmid delivery using bio-reducible polymer for hepatocellular carcinoma therapy.

PubMed

Kim, Hyun Ah; Nam, Kihoon; Lee, Minhyung; Kim, Sung Wan

2013-10-10

Gene therapy is suggested as a promising alternative strategy of hepatocellular carcinoma (HCC, also called hepatoma) therapy. To achieve a successful and safe gene therapy, tight regulation of gene expression is required to minimize side-effects in normal tissues. In this study, we developed a novel hypoxia and hepatoma dual specific gene expression vector. The constructed vectors were transfected into various cell lines using bio-reducible polymer, PAM-ABP. First, pAFPS-Luc or pAFPL-Luc vector was constructed with the alpha-fectoprotein (AFP) promoter and enhancer for hepatoma tissue specific gene expression. Then, pEpo-AFPL-Luc was constructed by insertion of the erythropoietin (Epo) enhancer for hypoxic cancer specific gene expression. In vitro transfection assay showed that pEpo-AFPL-Luc transfected hepatoma cell increased gene expression under hypoxic condition. To confirm the therapeutic effect of dual specific vector, herpes simplex virus thymidine kinase (HSV-TK) gene was introduced for cancer cell killing. The pEpo-AFPL-TK was transfected into hepatoma cell lines in the presence of ganciclovir (GCV) pro-drug. Caspase-3/7, MTT and TUNEL assays elucidated that pEpo-AFPL-TK transfected cells showed significant increasing of death rate in hypoxic hepatoma cells compared to controls. Therefore, the hypoxia/hepatoma dual specific gene expression vector with the Epo enhancer and AFP promoter may be useful for hepatoma specific gene therapy. © 2013.

Gonadectomy reduces the density of androgen receptor-immunoreactive neurons in male rat's hippocampus: testosterone replacement compensates it.

PubMed

Moghadami, Sajjad; Jahanshahi, Mehrdad; Sepehri, Hamid; Amini, Hossein

2016-01-28

In the present study, the role of gonadectomy on memory impairment and the density of androgen receptor-immunoreactive neurons in rats' hippocampus as well as the ability of testosterone to compensate of memory and the density of androgen receptors in the hippocampus was evaluated. Adult male rats (except intact-no testosterone group) were bilaterally castrated, and behavioral tests performed 2 weeks later. Animals bilaterally cannulated into lateral ventricles and then received testosterone (10, 40 and 120 µg/0.5 µl DMSO) or vehicle (DMSO; 0.5 µl) for gonadectomized-vehicle group, 30 min before training in water maze test. The androgen receptor-immunoreactive neurons were detected by immunohistochemical technique in the hippocampal areas. In the gonadectomized male rats, a memory deficit was found in Morris water maze test on test day (5th day) after DMSO administration. Gonadectomy decreased density of androgen receptor-immunoreactive neurons in the rats' hippocampus. The treatment with testosterone daily for 5 days attenuated memory deficits induced by gonadectomy. Testosterone also significantly increased the density of androgen receptor-immunoreactive neurons in the hippocampal areas. The intermediate dose of this hormone (40 µg) appeared to have a significant effect on spatial memory and the density of androgen receptor-immunoreactive neurons in gonadectomized rats' hippocampus. The present study suggests that testosterone can compensate memory failure in gonadectomized rats. Also testosterone replacement can compensate the reduction of androgen receptor-immunoreactive neurons density in the rats' hippocampus after gonadectomy.

Activity of xenobiotic-metabolizing enzymes in the liver of rats with multi-vitamin deficiency.

PubMed

Tutelyan, Victor A; Kravchenko, Lidia V; Aksenov, Ilya V; Trusov, Nikita V; Guseva, Galina V; Kodentsova, Vera M; Vrzhesinskaya, Oksana A; Beketova, Nina A

2013-01-01

The purpose of the study was to determine how multi-vitamin deficiency affects xenobiotic-metabolizing enzyme (XME) activities in the rat liver. Vitamin levels and XME activities were studied in the livers of male Wistar rats who were fed for 4 weeks with semi-synthetic diets containing either adequate (100 % of recommended vitamin intake) levels of vitamins (control), or decreased vitamin levels (50 % or 20 % of recommended vitamin intake). The study results have shown that moderate vitamin deficiency (50 %) leads to a decrease of vitamin A levels only, and to a slight increase, as compared with the control, in the following enzyme activities: methoxyresorufin O-dealkylase (MROD) activity of CYP1 A2 - by 34 % (p < 0.05), UDP-glucuronosyl transferase - by 26 % (p < 0.05), and quinone reductase - by 55 % (p < 0.05). Profound vitamin deficiency (20 %) led to a decrease of vitamins A, E, B1, B2, and C, and enzyme activities in the liver: MROD - to 78 % of the control level (p < 0.05), 4-nitrophenol hydroxylase - to 74 % (p < 0.05), heme oxygenase-1 - to 83 % (p < 0.05), and quinone reductase - to 60 % (p < 0.05). At the same time, the UDP-glucuronosyl transferase activity and ethoxyresorufin O-dealkylase activity of CYP1A1, pentoxyresorufin O-dealkylase activity of CYP2B1/2 and 6β-testosterone hydroxylase, as well as the total activity of glutathione transferase did not differ from the control levels. The study has demonstrated that profound multi-vitamin deficiency is associated with a decrease in the expression of CYP1A2 and CYP3A1 mRNAs to 62 % and 79 %, respectively. These data indicated that a short-term but profound multi-vitamin deficiency in rats leads to a decrease in the activities and expression of the some XME that play an important role in detoxification of xenobiotics and metabolism of drugs and antioxidant protection.

Glutathione peroxidase (EC 1.11.1.9) and superoxide dismutase (EC 1.15.1.1) activities in riboflavin-deficient rats infected with Plasmodium berghei malaria.

PubMed

Adelekan, D A; Thurnham, D I

1998-03-01

Riboflavin deficiency interferes with the growth and multiplication of malaria parasites as well as the host response to malaria. The objective of the present work was to determine the effects of riboflavin deficiency on erythrocyte glutathione peroxidase (EC 1.11.1.9; GPx) and superoxide dismutase (EC 1.15.1.1; SOD) in rats infected with Plasmodium berghei malaria. Riboflavin in its co-enzyme form, FAD, is required by glutathione reductase (EC 1.6.4.1) to regenerate GSH and GSH is an important cellular antioxidant both in its own right and also as a substrate for the enzyme GPx. Weanling rats were deprived of riboflavin for 8 weeks before intraperitoneal injection of 1 x 10(6) P. berghei parasites. Control animals were weight-matched to the respective riboflavin-deficient group. At 10 d post-infection, parasite counts were higher in the weight-matched control group than the riboflavin-deficient group (P = 0.004). GPx activity was higher in erythrocytes of rats parasitized with P. berghei than comparable non-infected rats regardless of riboflavin status (P < 0.05). As mature erythrocytes do not synthesize new protein, the higher GPx activities were probably due to the presence of the parasite protein. In erythrocytes from riboflavin-deficient rats, GPx activity tended to be lower than in those rats fed on diets adequate in riboflavin (weight-matched controls) whether parasitized or not, but the difference was not significant. Neither riboflavin deficiency nor malaria had any effect on erythrocyte SOD activity. It was concluded that riboflavin deficiency has no marked effect on erythrocyte GPx or SOD activity in the rat.

Postnatal growth hormone deficiency in growing rats causes marked decline in the activity of spinal cord acetylcholinesterase but not butyrylcholinesterase.

PubMed

Koohestani, Faezeh; Brown, Chester M; Meisami, Esmail

2012-11-01

The effects of growth hormone (GH) deficiency on the developmental changes in the abundance and activity of cholinesterase enzymes were studied in the developing spinal cord (SC) of postnatal rats by measuring the specific activity of acetylcholinesterase (AChE), a marker for cholinergic neurons and their synaptic compartments, and butyrylcholinesterase (BuChE), a marker for glial cells and neurovascular cells. Specific activities of these two enzymes were measured in SC tissue of 21- and 90 day-old (P21, weaning age; P90, young adulthood) GH deficient spontaneous dwarf (SpDwf) mutant rats which lack anterior pituitary and circulating plasma GH, and were compared with SC tissue of normal age-matched control animals. Assays were carried out for AChE and BuChE activity in the presence of their specific chemical inhibitors, BW284C51 and iso-OMPA, respectively. Results revealed that mean AChE activity was markedly and significantly reduced [28% at P21, 49% at P90, (p<0.01)] in the SC of GH deficient rats compared to age-matched controls. GH deficiency had a higher and more significant effect on AChE activity of the older (P90) rats than the younger ones (P21) ones. In contrast, BuChE activity in SC showed no significant changes in GH deficient rats at either of the two ages studied. Results imply that, in the absence of pituitary GH, the postnatal proliferation of cholinergic synapses in the rat SC, a CNS structure, where AChE activity is abundant, is markedly reduced during both the pre- and postweaning periods; more so in the postweaning than preweaning ages. In contrast, the absence of any effects on BuChE activity implies that GH does not affect the development of non-neuronal elements, e.g., glia, as much as the neuronal and synaptic compartments of the developing rat SC. Copyright © 2012 ISDN. Published by Elsevier Ltd. All rights reserved.

PDGF-beta receptor expression and ventilatory acclimatization to hypoxia in the rat.

PubMed

Alea, O A; Czapla, M A; Lasky, J A; Simakajornboon, N; Gozal, E; Gozal, D

2000-11-01

Activation of platelet-derived growth factor-beta (PDGF-beta) receptors in the nucleus of the solitary tract (nTS) modulates the late phase of the acute hypoxic ventilatory response (HVR) in the rat. We hypothesized that temporal changes in PDGF-beta receptor expression could underlie the ventilatory acclimatization to hypoxia (VAH). Normoxic ventilation was examined in adult Sprague-Dawley rats chronically exposed to 10% O(2), and at 0, 1, 2, 7, and 14 days, Northern and Western blots of the dorsocaudal brain stem were performed for assessment of PDGF-beta receptor expression. Although no significant changes in PDGF-beta receptor mRNA occurred over time, marked attenuation of PDGF-beta receptor protein became apparent after day 7 of hypoxic exposure. Such changes were significantly correlated with concomitant increases in normoxic ventilation, i.e., with VAH (r: -0.56, P < 0.005). In addition, long-term administration of PDGF-BB in the nTS via osmotic pumps loaded with either PDGF-BB (n = 8) or vehicle (Veh; n = 8) showed that although no significant changes in the magnitude of acute HVR occurred in Veh over time, the typical attenuation of HVR by PDGF-BB decreased over time. Furthermore, PDGF-BB microinjections did not attenuate HVR in acclimatized rats at 7 and 14 days of hypoxia (n = 10). We conclude that decreased expression of PDGF-beta receptors in the dorsocaudal brain stem correlates with the magnitude of VAH. We speculate that the decreased expression of PDGF-beta receptors is mediated via internalization and degradation of the receptor rather than by transcriptional regulation.

Differential effects of centrally-active antihypertensives on 5-HT1A receptors in rat dorso-lateral septum, rat hippocampus and guinea-pig hippocampus.

PubMed

Leishman, D J; Boeijinga, P H; Galvan, M

1994-01-01

1. The electrophysiological responses elicited by 5-hydroxytryptamine1A-(5-HT1A) receptor agonists in rat and guinea-pig CA1 pyramidal neurones and rat dorso-lateral septal neurones were compared in vitro by use of conventional intracellular recording techniques. 2. In the presence of 1 microM tetrodotoxin (TTX), to prevent indirect effects, 5-HT, N,N-dipropyl-5-carboxamidotryptamine (DP-5-CT) and 8-hydroxy-2(di-n-propylamino) tetralin (8-OH-DPAT) hyperpolarized the neurones from rat and guinea-pig brain. 3. The hypotensive drug flesinoxan, a selective 5-HT1A receptor agonist, hyperpolarized neurones in all three areas tested; however, another hypotensive agent with high affinity at 5-HT1A-receptors, 5-methyl-urapidil, hyperpolarized only the neurones in rat hippocampus and septum. 4. In guinea-pig hippocampal neurones, 5-methyl-urapidil behaved as a 5-HT1A-receptor antagonist. 5. The relative efficacies (5-HT = 1) of DP-5-CT, 8-OH-DPAT, flesinoxan and 5-methyl-urapidil at the three sites were: rat hippocampus, 1.09, 0.7, 0.5 and 0.24; rat septum, 0.88, 0.69, 0.82 and 0.7; guinea-pig hippocampus, 1.0, 0.69, 0.89 and 0, respectively. 6. It is concluded that the hypotensive agents flesinoxan and 5-methyl-urapidil appear to have different efficacies at 5-HT1A receptors located in different regions of the rodent brain. Whether these regional and species differences arise from receptor plurality or variability in intracellular transduction mechanisms remains to be elucidated.

Specific neurokinin receptors mediate plasma extravasation in the rat knee joint.

PubMed Central

Lam, F. Y.; Ferrell, W. R.

1991-01-01

1 Plasma extravasation in the rat knee joint was induced by intra-articular injection of neurokinins and specific neurokinin receptor agonists. 2 Pronounced plasma extravasation was produced by substance P (SP, 4-185 microM) and to a lesser extent by neurokinin-B (NKB, 83-413 microM), whereas neurokinin-A (NKA, 88-440 microM) and calcitonin gene-related peptide (CGRP, 26-130 microM) had no significant effect. 3 The specific neurokinin1 receptor agonist [Sar9, Met(O2)11]-substance P (NK1 agonist) in doses of 0.4-70 microM appeared to be more potent than SP in eliciting plasma extravasation. The neurokinin2 receptor agonist [Nle10]-neurokinin A4-10 (NK2 agonist) was not effective at 70 microM but produced a small and significant effect at 330 microM, whereas the neurokinin3 receptor agonist [MePhe7]-neurokinin B (NK3 agonist) was without effect at 40 microM or 400 microM. 4 Injections of SP or NKA into the synovial cavity of the rat knee were equally effective in producing marked plasma extravasation in remote sites such as the forelimb and hindlimb paws. 5 Co-administration experiments showed that the effects of SP were synergistic with NKA or the NK1 receptor agonist, but not with CGRP or the NK2 receptor agonist. 6 The rank order of potency was NK1 agonist greater than or equal to SP greater than NKB greater than NK2 agonist suggesting that NK1 receptors mediate plasma extravasation in the rat knee joint. PMID:1715229

The islet estrogen receptor-α is induced by hyperglycemia and protects against oxidative stress-induced insulin-deficient diabetes.

PubMed

Kilic, Gamze; Alvarez-Mercado, Ana I; Zarrouki, Bader; Opland, Darren; Liew, Chong Wee; Alonso, Laura C; Myers, Martin G; Jonas, Jean-Christophe; Poitout, Vincent; Kulkarni, Rohit N; Mauvais-Jarvis, Franck

2014-01-01

The female steroid, 17β-estradiol (E2), is important for pancreatic β-cell function and acts via at least three estrogen receptors (ER), ERα, ERβ, and the G-protein coupled ER (GPER). Using a pancreas-specific ERα knockout mouse generated using the Cre-lox-P system and a Pdx1-Cre transgenic line (PERαKO ⁻/⁻), we previously reported that islet ERα suppresses islet glucolipotoxicity and prevents β-cell dysfunction induced by high fat feeding. We also showed that E2 acts via ERα to prevent β-cell apoptosis in vivo. However, the contribution of the islet ERα to β-cell survival in vivo, without the contribution of ERα in other tissues is still unclear. Using the PERαKO ⁻/⁻ mouse, we show that ERα mRNA expression is only decreased by 20% in the arcuate nucleus of the hypothalamus, without a parallel decrease in the VMH, making it a reliable model of pancreas-specific ERα elimination. Following exposure to alloxan-induced oxidative stress in vivo, female and male PERαKO ⁻/⁻ mice exhibited a predisposition to β-cell destruction and insulin deficient diabetes. In male PERαKO ⁻/⁻ mice, exposure to E2 partially prevented alloxan-induced β-cell destruction and diabetes. ERα mRNA expression was induced by hyperglycemia in vivo in islets from young mice as well as in cultured rat islets. The induction of ERα mRNA by hyperglycemia was retained in insulin receptor-deficient β-cells, demonstrating independence from direct insulin regulation. These findings suggest that induction of ERα expression acts to naturally protect β-cells against oxidative injury.

Muscarinic and alpha 1-adrenergic receptor binding characteristics of saw palmetto extract in rat lower urinary tract.

PubMed

Suzuki, Mayumi; Oki, Tomomi; Sugiyama, Tomomi; Umegaki, Keizo; Uchida, Shinya; Yamada, Shizuo

2007-06-01

To elucidate the in vitro and ex vivo effects of saw palmetto extract (SPE) on autonomic receptors in the rat lower urinary tract. The in vitro binding affinities for alpha 1-adrenergic, muscarinic, and purinergic receptors in the rat prostate and bladder were measured by radioligand binding assays. Rats received vehicle or SPE (0.6 to 60 mg/kg/day) orally for 4 weeks, and alpha 1-adrenergic and muscarinic receptor binding in tissues of these rats were measured. Saw palmetto extract inhibited specific binding of [3H]prazosin and [N-methyl-3H]scopolamine methyl chloride (NMS) but not alpha, beta-methylene adenosine triphosphate [2,8-(3)H]tetrasodium salt in the rat prostate and bladder. The binding activity of SPE for muscarinic receptors was four times greater than that for alpha 1-adrenergic receptors. Scatchard analysis revealed that SPE significantly reduced the maximal number of binding sites (Bmax) for each radioligand in the prostate and bladder under in vitro condition. Repeated oral administration of SPE to rats brought about significant alteration in Bmax for prostatic [3H]prazosin binding and for bladder [3H]NMS binding. Such alteration by SPE was selective to the receptors in the lower urinary tract. Saw palmetto extract exerts significant binding activity on autonomic receptors in the lower urinary tract under in vitro and in vivo conditions.

Delayed preconditioning with NMDA receptor antagonists in a rat model of perinatal asphyxia.

PubMed

Makarewicz, Dorota; Sulejczak, Dorota; Duszczyk, Małgorzata; Małek, Michał; Słomka, Marta; Lazarewicz, Jerzy W

2014-01-01

In vitro experiments have demonstrated that preconditioning primary neuronal cultures by temporary application of NMDA receptor antagonists induces long-term tolerance against lethal insults. In the present study we tested whether similar effects also occur in brain submitted to ischemia in vivo and whether the potential benefit outweighs the danger of enhancing the constitutive apoptosis in the developing brain. Memantine in pharmacologically relevant doses of 5 mg/kg or (+)MK-801 (3 mg/kg) was administered i.p. 24, 48, 72 and 96 h before 3-min global forebrain ischemia in adult Mongolian gerbils or prior to hypoxia/ischemia in 7-day-old rats. Neuronal loss in the hippocampal CA1 in gerbils or weight deficit of the ischemic hemispheres in the rat pups was evaluated after 14 days. Also, the number of apoptotic neurons in the immature rat brain was evaluated. In gerbils only the application of (+)MK-801 24 h before ischemia resulted in significant prevention of the loss of pyramidal neurons. In rat pups administration of (+)MK-801 at all studied times before hypoxia-ischemia, or pretreatment with memantine or with hypoxia taken as a positive control 48 to 92 h before the insult, significantly reduced brain damage. Both NMDA receptor antagonists equally reduced the number of apoptotic neurons after hypoxia-ischemia, while (+)MK-801-evoked potentiation of constitutive apoptosis greatly exceeded the effect of memantine. We ascribe neuroprotection induced in the immature rats by the pretreatment with both NMDA receptor antagonists 48 to 92 h before hypoxia-ischemia to tolerance evoked by preconditioning, while the neuroprotective effect of (+)MK-801 applied 24 h before the insults may be attributed to direct consequences of the inhibition of NMDA receptors. This is the first report demonstrating the phenomenon of inducing tolerance against hypoxia-ischemia in vivo in developing rat brain by preconditioning with NMDA receptor antagonists.

Comparative tissue distribution profiles of five major bio-active components in normal and blood deficiency rats after oral administration of Danggui Buxue Decoction by UPLC-TQ/MS.

PubMed

Shi, Xuqin; Tang, Yuping; Zhu, Huaxu; Li, Weixia; Li, Zhenhao; Li, Wei; Duan, Jin-ao

2014-01-01

Astragali Radix (AR) and Angelicae Sinensis Radix (ASR) were frequently combined and used in China as herbal pair called as Danggui Buxue Decoction (DBD) for treatment of blood deficiency syndrome, such as women's ailments. This study is to investigate the tissue distribution profiles of five major bio-active constituents (ferulic acid, caffeic acid, calycosin-7-O-β-glucoside, ononin and astragaloside IV) in DBD after oral administration of DBD in blood deficiency rats, and to compare the difference between normal and blood deficiency rats. The blood deficiency rats were induced by bleeding from orbit at the dosages of 5.0mLkg(-1) every day, and the experimental period was 12 days. At the finally day of experimental period, both normal and blood deficiency rats were orally administrated with DBD, and then the tissues samples were collected at different time points. Ferulic acid, caffeic acid, calycosin-7-O-β-glucoside, ononin and astragaloside IV in different tissues were detected simultaneously by UPLC-TQ/MS, and the histograms were drawn. The results showed that the overall trend was CLiver>CKidney>CHeart>CSpleen>CLung, CC-30min>CM-30min>CM-60min>CC-5min>CM-5min>CC-60min>CM-240min>CC-240min. The contents of the detected compounds in liver were more than that in other tissues no matter in normal or blood deficiency rats. Compared to normal rats, partial contents of the compounds in blood deficiency rats' tissues at different time points had significant difference (P<0.05). This study was the first report about tissue distribution investigation in blood deficiency animals which is conducted by bleeding. And the results demonstrated that the five DBD components in normal and blood deficiency rats had obvious differences in some organs and time points, suggesting that the blood flow and perfusion rate of the organ were altered in blood deficiency animals. Copyright © 2013 Elsevier B.V. All rights reserved.

Maternal micronutrient deficiency leads to alteration in the kidney proteome in rat pups.

PubMed

Ahmad, Shadab; Basak, Trayambak; Anand Kumar, K; Bhardwaj, Gourav; Lalitha, A; Yadav, Dilip K; Chandak, Giriraj Ratan; Raghunath, Manchala; Sengupta, Shantanu

2015-09-08

Maternal nutritional deficiency significantly perturbs the offspring's physiology predisposing them to metabolic diseases during adulthood. Vitamin B12 and folate are two such micronutrients, whose deficiency leads to elevated homocysteine levels. We earlier generated B12 and/or folate deficient rat models and using high-throughput proteomic approach, showed that maternal vitamin B12 deficiency modulates carbohydrate and lipid metabolism in the liver of pups through regulation of PPAR signaling pathway. In this study, using similar approach, we identified 26 differentially expressed proteins in the kidney of pups born to mothers fed with vitamin B12 deficient diet while only four proteins were identified in the folate deficient group. Importantly, proteins like calreticulin, cofilin 1 and nucleoside diphosphate kinase B that are involved in the functioning of the kidney were upregulated in B12 deficient group. Our results hint towards a larger effect of vitamin B12 deficiency compared to that of folate presumably due to greater elevation of homocysteine in vitamin B12 deficient group. In view of widespread vitamin B12 and folate deficiency and its association with several diseases like anemia, cardiovascular and renal diseases, our results may have large implications for kidney diseases in populations deficient in vitamin B12 especially in vegetarians and the elderly people.This article is part of a Special Issue entitled: Proteomics in India. Copyright © 2015 Elsevier B.V. All rights reserved.

Hypoglycemic potency of novel trivalent chromium in hyperglycemic insulin-deficient rats.

PubMed

Machaliński, Bogusław; Walczak, Mieczysław; Syrenicz, Anhelli; Machalińska, Anna; Grymuła, Katarzyna; Stecewicz, Iwona; Wiszniewska, Barbara; Dabkowska, Elzbieta

2006-01-01

Two sources of chromium III, "chromium 454" and "chromium picolinate," were tested in insulin-deficient Streptozocin-treated diabetic rats. This model was selected in order to evaluate the possibility of any hypoglycemic potency of chromium in a relative absence of blood insulin concentration. Three weeks of the treatment with CRC454 and CrP resulted in a 38% and 11% reduction of blood glucose levels, respectively. Body weight gains were equally improved by both treatments. Blood levels of CK, ALT and AST were significantly reduced by CRC454 and CrP. These results might suggest that any hypoglycemic effect of trivalent chromium under insulin-deficient conditions could be largely dependent upon the type of chromium agent and associated characteristics such as solubility and bioavalibility. In contrast, improvement of body weight gains and blood levels of CK, AST and ALT seems to be less dependent on the type of chromium compound under these experimental conditions. In conclusion, CRC454 showed significant reduction of hyperglycemia under insulin-deficient conditions.

Different Hypothalamic Nicotinic α7 Receptor Expression and Response to Low Nicotine Dose in Alcohol-Preferring and Alcohol-Avoiding Rats.

PubMed

Nuutinen, Saara; Panula, Pertti; Salminen, Outi

2016-02-01

The aim of this study was to examine possible differences in nicotinic acetylcholine receptors and responses in rats with genetic preference or avoidance for alcohol. This was done by using 2 rat lines with high alcohol preference (Alko Alcohol [AA]) or alcohol avoidance (Alko Non-Alcohol [ANA]). Locomotor activity was measured following nicotine and histamine H3 receptor (H3R) antagonist treatment. In situ hybridization and receptor ligand binding experiments were used in drug-naïve animals to examine the expression of different α nicotinic receptor subunits. The AA rats were found to be more sensitive to the stimulatory effect of a low dose of nicotine than ANA rats, which were not significantly activated. Combination of histamine H3R antagonist, JNJ-39220675, and nicotine resulted to similar locomotor activation as nicotine alone. To further understand the mechanism underlying the difference in nicotine response in AA and ANA rats, we studied the expression of α5, α6, and α7 nicotinic receptor subunits in specific brain areas of AA and ANA rats. We found no differences in the expression of α5 nicotinic receptor subunits in the medial habenula and hippocampus or in α6 subunit in the ventral tegmental area and substantia nigra. However, the level of α7 nicotinic receptor subunit mRNA was significantly lower in the tuberomamillary nucleus of posterior hypothalamus of alcohol-preferring AA rats than in alcohol-avoiding ANA rats. Also the hypothalamic [125I-α-bungarotoxin binding was lower in AA rats indicating lower levels of α7 nicotinic receptors. The lower expression and receptor binding of α7 nicotinic receptors in the tuberomamillary nucleus of AA rats suggest a difference in the regulation of brain histamine neurons between the rat lines since the α7 nicotinic receptors are located in histaminergic neurons. Stronger nicotine-induced locomotor response, mediated partially via α7 receptors, and previously described high alcohol consumption in AA

An unusual case of iron deficiency anemia is associated with extremely low level of transferrin receptor.

PubMed

Hao, Shuangying; Li, Huihui; Sun, Xiaoyan; Li, Juan; Li, Kuanyu

2015-01-01

A case study of a female patient, diagnosed with iron deficiency anemia, was unresponsive to oral iron treatment and only partially responsive to parenteral iron therapy, a clinical profile resembling the iron-refractory iron deficiency anemia (IRIDA) disorder. However, the patient failed to exhibit microcytic phenotype, one of the IRIDA hallmarks. Biochemical assays revealed that serum iron, hepcidin, interluekin 6, and transferrin saturation were within the normal range of references or were comparable to her non-anemic offspring. Iron contents in serum and red blood cells and hemoglobin levels were measured, which confirmed the partial improvement of anemia after parenteral iron therapy. Strikingly, serum transferrin receptor in patient was almost undetectable, reflecting the very low activity of bone-marrow erythropoiesis. Our data demonstrate that this is not a case of systemic iron deficiency, but rather cellular iron deficit due to the low level of transferrin receptor, particularly in erythroid tissue.

Oxytocin improves behavioral and electrophysiological deficits in a novel Shank3-deficient rat.

PubMed

Harony-Nicolas, Hala; Kay, Maya; Hoffmann, Johann du; Klein, Matthew E; Bozdagi-Gunal, Ozlem; Riad, Mohammed; Daskalakis, Nikolaos P; Sonar, Sankalp; Castillo, Pablo E; Hof, Patrick R; Shapiro, Matthew L; Baxter, Mark G; Wagner, Shlomo; Buxbaum, Joseph D

2017-01-31

Mutations in the synaptic gene SHANK3 lead to a neurodevelopmental disorder known as Phelan-McDermid syndrome (PMS). PMS is a relatively common monogenic and highly penetrant cause of autism spectrum disorder (ASD) and intellectual disability (ID), and frequently presents with attention deficits. The underlying neurobiology of PMS is not fully known and pharmacological treatments for core symptoms do not exist. Here, we report the production and characterization of a Shank3 -deficient rat model of PMS, with a genetic alteration similar to a human SHANK3 mutation. We show that Shank3 -deficient rats exhibit impaired long-term social recognition memory and attention, and reduced synaptic plasticity in the hippocampal-medial prefrontal cortex pathway. These deficits were attenuated with oxytocin treatment. The effect of oxytocin on reversing non-social attention deficits is a particularly novel finding, and the results implicate an oxytocinergic contribution in this genetically defined subtype of ASD and ID, suggesting an individualized therapeutic approach for PMS.

Adipocyte Glucocorticoid Receptor Deficiency Attenuates Aging- and HFD-Induced Obesity and Impairs the Feeding-Fasting Transition.

PubMed

Mueller, Kristina M; Hartmann, Kerstin; Kaltenecker, Doris; Vettorazzi, Sabine; Bauer, Mandy; Mauser, Lea; Amann, Sabine; Jall, Sigrid; Fischer, Katrin; Esterbauer, Harald; Müller, Timo D; Tschöp, Matthias H; Magnes, Christoph; Haybaeck, Johannes; Scherer, Thomas; Bordag, Natalie; Tuckermann, Jan P; Moriggl, Richard

2017-02-01

Glucocorticoids (GCs) are important regulators of systemic energy metabolism, and aberrant GC action is linked to metabolic dysfunctions. Yet, the extent to which normal and pathophysiological energy metabolism depend on the GC receptor (GR) in adipocytes remains unclear. Here, we demonstrate that adipocyte GR deficiency in mice significantly impacts systemic metabolism in different energetic states. Plasma metabolomics and biochemical analyses revealed a marked global effect of GR deficiency on systemic metabolite abundance and, thus, substrate partitioning in fed and fasted states. This correlated with a decreased lipolytic capacity of GR-deficient adipocytes under postabsorptive and fasting conditions, resulting from impaired signal transduction from β-adrenergic receptors to adenylate cyclase. Upon prolonged fasting, the impaired lipolytic response resulted in abnormal substrate utilization and lean mass wasting. Conversely, GR deficiency attenuated aging-/diet-associated obesity, adipocyte hypertrophy, and liver steatosis. Systemic glucose tolerance was improved in obese GR-deficient mice, which was associated with increased insulin signaling in muscle and adipose tissue. We conclude that the GR in adipocytes exerts central but diverging roles in the regulation of metabolic homeostasis depending on the energetic state. The adipocyte GR is indispensable for the feeding-fasting transition but also promotes adiposity and associated metabolic disorders in fat-fed and aged mice. © 2017 by the American Diabetes Association.

Effects of Alpha-Lipoic Acid on Oxidative Stress and Kinin Receptor Expression in Obese Zucker Diabetic Fatty Rats.

PubMed

Midaoui, Adil El; Talbot, Sébastien; Lahjouji, Karim; Dias, Jenny Pena; Fantus, I George; Couture, Réjean

2015-06-01

To investigate the impact of alpha-lipoic acid on superoxide anion production and NADPH oxidase activity as well as on the expression of kinin B1 and B2 receptors in key organs of obese Zucker Diabetic Fatty rats. Superoxide anion production was measured by lucigenin chemiluminescence. Kinin B1 and B2 receptors expression was measured at protein and mRNA levels by western blot and qRT-PCR in key organs of Zucker Diabetic Fatty and Zucker lean control rats treated for a period of 6 weeks with a standard diet or a diet containing the antioxidant α-lipoic acid (1 g/kg). Superoxide anion production and NADPH oxidase activity were significantly enhanced in aorta and adipose tissue of Zucker Diabetic Fatty rats. Kinin B1 and B2 receptors expression levels were also significantly increased in the liver and the gastrocnemius muscle of Zucker Diabetic Fatty rats. Expression of both receptors was not altered in the pancreas of Zucker Diabetic Fatty rats and was undetectable in white retroperitoneal adipose tissue. Alpha-lipoic acid prevented the rise in NADPH oxidase activity in aorta and epididymal adipose tissue of Zucker Diabetic Fatty rats and the upregulation of kinin B1 receptor in liver and gastrocnemius muscle and that of kinin B2 receptor in the liver. Alpha-lipoic acid treatment was found to prevent the final body weight increase without affecting significantly hyperglycemia, hyperinsulinemia and insulin resistance index in Zucker Diabetic Fatty rats. Findings support the hypothesis that oxidative stress is implicated in the induction of kinin B1 receptor in Zucker Diabetic Fatty rats. The ability of α-lipoic acid to blunt the body weight gain appears to be mediated in part by preventing NADPH oxidase activity rise in adipose tissue and reversing the hepatic upregulation of kinin B1 receptor in Zucker Diabetic Fatty rats.

Dopamine receptors play distinct roles in sexual behavior expression of rats with a different sexual motivational tone.

PubMed

Guadarrama-Bazante, Irma L; Canseco-Alba, Ana; Rodríguez-Manzo, Gabriela

2014-10-01

Dopamine (DA) plays a central role in the expression of male sexual behavior. The effects of DA-enhancing drugs on copulation seem to vary depending on the dose of the agonist used, the type of DA receptor activated, and the sexual condition of the animals. The aim of the present study was to carry out a systematic analysis of the effects of dopaminergic agonists on the expression of male sexual behavior by sexually competent rats in different sexual motivational states, that is when sexually active (sexually experienced) and when temporarily inhibited (sexually exhausted). To this end, the same doses of the nonselective DA receptor agonist apomorphine, the selective D2-like DA receptor agonist quinpirole, and the selective D1-like DA receptor agonist SKF38393 were injected intraperitoneally to sexually experienced or sexually exhausted male rats and their sexual behavior was recorded. Low apomorphine doses induced expression of sexual behavior in sexually satiated rats, but only reduced the intromission latency of sexually experienced rats. SKF38393 facilitated the expression of sexual behavior by sexually exhausted rats, but not that of sexually experienced males and quinpirole did not exert an effect in both types of animal. In line with these results, the apomorphine-induced reversal of sexual exhaustion was blocked by the D1-like receptor antagonist SCH23390. The data suggest that DA receptors play distinct roles in the expression of sexual behavior by male rats depending on their motivational state and that activation of D1-like receptors promotes the expression of sexual behavior in satiated rats.

Abalation of Ghrelin receptor in leptin-deficient mice has paradoxical effects on glucose homeostasis compared to Ghrelin-abalated Leptin-deficient mice

USDA-ARS?s Scientific Manuscript database

Ghrelin is produced predominantly in stomach and is known to be the endogenous ligand of the growth hormone secretagogue receptor (GHSR). Ghrelin is a GH stimulator and an orexigenic hormone. In contrast, leptin is an anorexic hormone, and leptin-deficient ob/ob mice are obese and diabetic. To study...

Early childhood BMI trajectories in monogenic obesity due to leptin, leptin receptor, and melanocortin 4 receptor deficiency.

PubMed

Kohlsdorf, Katja; Nunziata, Adriana; Funcke, Jan-Bernd; Brandt, Stephanie; von Schnurbein, Julia; Vollbach, Heike; Lennerz, Belinda; Fritsch, Maria; Greber-Platzer, Susanne; Fröhlich-Reiterer, Elke; Luedeke, Manuel; Borck, Guntram; Debatin, Klaus-Michael; Fischer-Posovszky, Pamela; Wabitsch, Martin

2018-02-27

To evaluate whether early childhood body mass index (BMI) is an appropriate indicator for monogenic obesity. A cohort of n = 21 children living in Germany or Austria with monogenic obesity due to congenital leptin deficiency (group LEP, n = 6), leptin receptor deficiency (group LEPR, n = 6) and primarily heterozygous MC4 receptor deficiency (group MC4R, n = 9) was analyzed. A control group (CTRL) was defined that consisted of n = 22 obese adolescents with no mutation in the above mentioned genes. Early childhood (0-5 years) BMI trajectories were compared between the groups at selected time points. The LEP and LEPR group showed a tremendous increase in BMI during the first 2 years of life with all patients displaying a BMI >27 kg/m 2 (27.2-38.4 kg/m 2 ) and %BMI P95 (percentage of the 95th percentile BMI for age and sex) >140% (144.8-198.6%) at the age of 2 years and a BMI > 33 kg/m 2 (33.3-45.9 kg/m 2 ) and %BMI P95  > 184% (184.1-212.6%) at the age of 5 years. The MC4R and CTRL groups had a later onset of obesity with significantly lower BMI values at both time points (p < 0.01). As result of the investigation of early childhood BMI trajectories in this pediatric cohort with monogenic obesity we suggest that BMI values >27.0 kg/m 2 or %BMI P95  > 140% at the age of 2 years and BMI values >33.0 kg/m 2 or %BMI P95  > 184% at the age of 5 years may be useful cut points to identify children who should undergo genetic screening for monogenic obesity due to functionally relevant mutations in the leptin gene or leptin receptor gene.

High dose androgen therapy in male pseudohermaphroditism due to 5 alpha-reductase deficiency and disorders of the androgen receptor.

PubMed

Price, P; Wass, J A; Griffin, J E; Leshin, M; Savage, M O; Large, D M; Bu'Lock, D E; Anderson, D C; Wilson, J D; Besser, G M

1984-10-01

We describe the clinical and biochemical features of six men with male pseudohermaphroditism due to androgen resistance. Each of the subjects had male-gender behavior but incomplete virilization. The underlying defects in androgen metabolism were defined by studies of the 5 alpha-reductase enzyme and the androgen receptor in fibroblasts cultured from biopsies of genital skin. Four of the six have 5 alpha-reductase deficiency, and two have defects of the androgen receptor (the Reifenstein syndrome). The responses of these men to androgen treatment were assessed by monitoring nitrogen balance, plasma luteinizing hormone (LH) values, and clinical parameters of virilization including penile growth, potency and ejaculatory volume, muscle bulk, and growth of body and facial hair. In all of the subjects with 5 alpha-reductase deficiency and one man with the Reifenstein syndrome significant response occurred, as evidence by nitrogen retention, lowered plasma LH levels, and improved virilization, with doses of parenteral testosterone esters that raised plasma testosterone levels above the normal male range and brought plasma dihydrotestosterone levels into the normal male range. The subject who did not respond with clinical virilization nevertheless showed nitrogen retention in response to acute testosterone administration. This patient had a profound deficiency of the androgen receptor, whereas the man with a receptor defect who did respond clinically to therapy had normal amounts of a qualitatively abnormal receptor. We conclude that high dose androgen therapy may be of benefit in improving virilization, self-image, and sexual performance in subjects with 5 alpha-reductase deficiency who have male-gender behavior and in some subjects with defects of the androgen receptor.

Cytotoxicity of nitric oxide in Fu5 rat hepatoma cells: evidence for co-operative action with hydrogen peroxide.

PubMed Central

Ioannidis, I; de Groot, H

1993-01-01

The NO-releasing compounds 3-morpholinosydnonimine-N-ethylcarbamide (SIN-1), sodium nitroprusside (SNP) and S-nitroso-N-acetyl-DL-penicillamine (SNAP) mediated a rapid loss of viability of Fu5 rat hepatoma cells. SIN-1 in addition to NO also released the superoxide anion radical (O2-.). Its cytotoxicity, however, was not affected by superoxide dismutase. In contrast, the H2O2-converting enzyme catalase significantly, but not completely, diminished cell damage, indicating participation of H2O2 in the tumoricidal activity of SIN-1. Glucose oxidase (5 m-units/ml), producing similar amounts of H2O2 to 5 mM SIN-1, had no effect on cell viability. When 5 m-units/ml glucose oxidase was added to incubations with 5 mM SNP, which alone initiated cell injury of about 40%, cell damage was significantly increased up to 95%. Similar results were observed with 1 mM SNAP and 20 m-units/ml xanthine oxidase, which mediated cytotoxicity of about 90% when both compounds were added together, compared with 35% and 55% cell injury, respectively, induced by the single compounds. The results indicate that a co-operative action with H2O2 enhances the tumoricidal activity of NO in Fu5 cells. No evidence for an interplay of NO with O2-. in cytotoxicity, e.g. via the peroxynitrite anion (ONOO-), was found. PMID:8257422

Effect of zinc gluconate, sage oil on inflammatory patterns and hyperglycemia in zinc deficient diabetic rats.

PubMed

Elseweidy, Mohamed M; Ali, Abdel-Moniem A; Elabidine, Nabila Zein; Mursey, Nada M

2017-11-01

The relationship between zinc homeostasis and pancreatic function had been established. In this study we aimed firstly to configure the inflammatory pattern and hyperglycemia in zinc deficient diabetic rats. Secondly to illustrate the effect of two selected agents namely Zinc gluconate and sage oil (Salvia Officinalis, family Lamiaceae). Rats were fed on Zinc deficient diet, deionized water for 28days along with Zinc level check up at intervals to achieve zinc deficient state then rats were rendered diabetic through receiving one dose of alloxan monohydrate (120mg/kg) body weight, classified later into 5 subgroups. Treatment with sage oil (0.042mg/kg IP) and Zinc gluconate orally (150mg/kg) body weight daily for 8 weeks significantly reduced serum glucose, C-reactive protein (CRP), Tumor necrosis factor alpha (TNF- α), interleukins-6 1 β, inflammatory8 (IFN ȣ), pancreatic 1L1-β along with an increase in serum Zinc and pancreatic Zinc transporter 8 (ZNT8). Histopathological results of pancreatic tissues showed a good correlation with the biochemical findings. Both sage oil and zinc gluconate induced an improvement in the glycemic and inflammatory states. This may be of value like the therapeutic agent for diabetes. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Dopamine, Noradrenaline and Serotonin Receptor Densities in the Striatum of Hemiparkinsonian Rats following Botulinum Neurotoxin-A Injection.

PubMed

Mann, T; Zilles, K; Dikow, H; Hellfritsch, A; Cremer, M; Piel, M; Rösch, F; Hawlitschka, A; Schmitt, O; Wree, A

2018-03-15

Parkinson's disease (PD) is characterized by a degeneration of dopaminergic neurons in the substantia nigra pars compacta (SNpc) that causes a dopamine (DA) deficit in the caudate-putamen (CPu) accompanied by compensatory changes in other neurotransmitter systems. These changes result in severe motor and non-motor symptoms. To disclose the role of various receptor binding sites for DA, noradrenaline, and serotonin in the hemiparkinsonian (hemi-PD) rat model induced by unilateral 6-hydroxydopamine (6-OHDA) injection, the densities of D 1 , D 2 /D 3 , α 1 , α 2 , and 5HT 2A receptors were longitudinally visualized and measured in the CPu of hemi-PD rats by quantitative in vitro receptor autoradiography. We found a moderate increase in D 1 receptor density 3 weeks post lesion that decreased during longer survival times, a significant increase of D 2 /D 3 receptor density, and 50% reduction in 5HT 2A receptor density. α 1 receptor density remained unaltered in hemi-PD and α 2 receptors demonstrated a slight right-left difference increasing with post lesion survival. In a second step, the possible role of receptors on the known reduction of apomorphine-induced rotations in hemi-PD rats by intrastriatally injected Botulinum neurotoxin-A (BoNT-A) was analyzed by measuring the receptor densities after BoNT-A injection. The application of this neurotoxin reduced D 2 /D 3 receptor density, whereas the other receptors mainly remained unaltered. Our results provide novel data for an understanding of the postlesional plasticity of dopaminergic, noradrenergic and serotonergic receptors in the hemi-PD rat model. The results further suggest a therapeutic effect of BoNT-A on the impaired motor behavior of hemi-PD rats by reducing the interhemispheric imbalance in D 2 /D 3 receptor density. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.

Effects of riboflavin deficiency and clofibrate treatment on the five acyl-CoA dehydrogenases in rat liver mitochondria.

PubMed

Veitch, K; Draye, J P; Van Hoof, F; Sherratt, H S

1988-09-01

Rats were maintained on a riboflavin-deficient diet or on a diet containing clofibrate (0.5%, w/w). The activities of the mitochondrial FAD-dependent straight-chain acyl-CoA dehydrogenases (butyryl-CoA, octanoyl-CoA and palmitoyl-CoA) and the branched-chain acyl-CoA dehydrogenases (isovaleryl-CoA and isobutyryl-CoA) involved in the degradation of branched-chain acyl-CoA esters derived from branched-chain amino acids were assayed in liver mitochondrial extracts prepared in the absence and presence of exogenous FAD. These activities were low in livers from riboflavin-deficient rats (11, 28, 16, 6 and less than 2% of controls respectively) when prepared in the absence of exogenous FAD, and were not restored to control values when prepared in 25 microM-FAD (29, 47, 28, 7 and 17%). Clofibrate feeding increased the activities of butyryl-CoA, octanoyl-CoA and palmitoyl-CoA dehydrogenases (by 48, 116 and 98% of controls respectively), but not, by contrast, the activities of isovaleryl-CoA and isobutyryl-CoA dehydrogenases (62 and 102% of controls respectively). The mitochondrial fractions from riboflavin-deficient and from clofibrate-fed rats oxidized palmitoylcarnitine in State 3 at rates of 32 and 163% respectively of those from control rats.

Increase of dopamine D2(High) receptors in the striatum of rats sensitized to caffeine motor effects.

PubMed

Simola, Nicola; Morelli, Micaela; Seeman, Philip

2008-05-01

It has been previously demonstrated how rats can develop behavioral dopamine supersensitivity after long-term administration of caffeine. Since behavioral dopamine supersensitivity in rats is usually accompanied by an elevation in striatal dopamine D2(High) receptors, we examined whether alterations in D2(High) receptors occurred in the striatum of rats administered caffeine according to a regimen capable of eliciting behavioral dopamine supersensitivity (15 mg/kg i.p. every other day for 14 days). An increase of 126% in striatal D2(High) receptors was found in caffeine-sensitized rats. This marked elevation in D2(High) receptors may account for the caffeine-induced behavioral dopamine supersensitivity and may help elucidate the interactions between caffeine and dopamine neurotransmission. (c) 2008 Wiley-Liss, Inc.

Behavioral differences between selectively bred rats: D1 versus D2 receptors in yawning and grooming.

PubMed

Eguibar, José R; Romero-Carbente, José C; Moyaho, Alejandro

2003-03-01

We used SKF 38393 and quinpirole for determining whether activation of D(1) and D(2) receptors, respectively, is involved in behaviors of rats selectively bred for high or low rates of yawning. After injection of SKF 38393, yawning diminished more markedly in high-yawning (HY) than in low-yawning (LY) rats, whereas this drug increased the number and duration of grooming episodes similarly in both strains. After injection of quinpirole, yawning increased more markedly in HY than in LY rats, whereas this drug decreased the number and duration of grooming episodes similarly in both rat strains. After coadministration of SKF 38393 and quinpirole, yawning increased similarly in both rat strains, whereas the combination of drugs failed to reliably affect grooming behavior. We interpret our findings as indicating that D(2) receptors are more important than D(1) receptors for differences in yawning behavior between HY and LY rats.

Abnormalities in Osteoclastogenesis and Decreased Tumorigenesis in Mice Deficient for Ovarian Cancer G Protein-Coupled Receptor 1

PubMed Central

Li, Hui; Wang, Dongmei; Singh, Lisam Shanjukumar; Berk, Michael; Tan, Haiyan; Zhao, Zhenwen; Steinmetz, Rosemary; Kirmani, Kashif; Wei, Gang; Xu, Yan

2009-01-01

Ovarian cancer G protein-coupled receptor 1 (OGR1) has been shown to be a proton sensing receptor in vitro. We have shown that OGR1 functions as a tumor metastasis suppressor gene when it is over-expressed in human prostate cancer cells in vivo. To examine the physiological functions of OGR1, we generated conditional OGR1 deficient mice by homologous recombination. OGR1 deficient mice were viable and upon gross-inspection appeared normal. Consistent with in vitro studies showing that OGR1 is involved in osteoclastogenesis, reduced osteoclasts were detected in OGR1 deficient mice. A pH-dependent osteoclasts survival effect was also observed. However, overall abnormality in the bones of these animals was not observed. In addition, melanoma cell tumorigenesis was significantly inhibited in OGR1 deficient mice. OGR1 deficient mice in the mixed background produced significantly less peritoneal macrophages when stimulated with thioglycolate. These macrophages also showed altered extracellular signal-regulated kinases (ERK) activation and nitric oxide (NO) production in response to lipopolysaccharide. OGR1-dependent pH responses assessed by cAMP production and cell survival in macrophages or brown fat cells were not observed, presumably due to the presence of other proton sensing receptors in these cells. Our results indicate that OGR1's role in osteoclastogenesis is not strong enough to affect overall bone development and its role in tumorigenesis warrants further investigation. The mice generated can be potentially used for several disease models, including cancers or osteoclast-related diseases. PMID:19479052

Role of Leptin Deficiency, Inefficiency, and Leptin Receptors in Obesity.

PubMed

Wasim, Muhammad; Awan, Fazli Rabbi; Najam, Syeda Sadia; Khan, Abdul Rehman; Khan, Haq Nawaz

2016-10-01

Leptin protein consists of 167 amino acids, which is mainly secreted from the white adipose tissue. This protein acts on the hypothalamic regions of the brain which control eating behavior, thus playing a significant role in maintaining body's metabolism. Leptin receptors belong to glycoprotein 130 (gp130) family of cytokine receptors and exist in six isoforms (LEPR a-f), and all the isoforms are encoded by LEPR gene; out of these isoforms, the LEPR-b receptor is the 'longest form,' and in most of the cases, mutations in this isoform cause severe obesity. Also, mutations in the leptin gene (LEP) or its receptors gene can lead to obesity. Some biochemical pathways affect the bioactivity of leptin and/or its receptors. To date, eleven pathogenic mutations have been reported in the LEP which are p.L72S, p.N103K, p.R105W, p.H118L, p.S141C, p.W121X c.104_106delTCA, c.135del3bp, c.398delG, c.481_482delCT, and c.163C>T. Different mutations in the LEPR have also been reported as c.2396-1 G>T, c.1675 G>A, p.P316T, etc. In some studies, where leptin was deficient, leptin replacement therapy has shown positive impact by preventing weight gain and obesity.

Follitropin receptors in rat testis. Characterization with enzymatically 125I-labeled human follitropin.

PubMed

Ketelslegers, J M; Catt, K J

1978-07-03

The interaction between enzymatically radioiodinated human follitropin and the follitropin receptors in testis homogenate was investigated in immature and adult rats. The 125I-labeled human follitropin exhibited high binding activity with specific binding of up to 17% in the presence of an excess of testis homogenate. Approx. 50% of the bound hormone could be eluted at pH 5, and the receptor purified tracer exhibited a 3.6-fold increase in binding activity when compared with the original tracer preparation. Quantitative analysis of equilibrium binding data was performed with corrections for the measured specific activity and maximum binding activity of the tracer hormone. The equilibrium association constants (Ka) determined 24 degrees C were not significantly different in immature and adult rat testis, and the mean value for Ka was 3.9 . 10(9) M-1. At 37 degrees C, the Ka value obtained using immature rat testis was 1.3 . 10(10) M-1. The association of 125I-labeled human follitropin with immature rat testis homogenate was time and temperature dependent. In the presence of an excess of unlabeled hormone, 30--60% of the preformed hormone . receptor complex was dissociated after 24 h incubation. A specific and sensitive radioligand-receptor assay for follitropin was developed using immature rat testis homogenate. The minimum detectable dose of purified human follitropin was 0.6 ng, and human urinary and pituitary follitropin, ovine follitropin and pregnant mare serum gonadotropin reacted in the assay with equivalent slopes. The potencies of highly purified pregnent mare serum gonadotropin and highly purified human follitropin were similar in the radioligand-receptor assay, consistent with the follitropin bioactivity of the equine gonadotropin.

Functional significance of muscarinic receptor expression within the proximal and distal rat vagina.

PubMed

Basha, Maureen; Labelle, Edward F; Northington, Gina M; Wang, Tanchun; Wein, Alan J; Chacko, Samuel

2009-11-01

Information regarding the role of cholinergic nerves in mediating vaginal smooth muscle contraction is sparse, and in vitro studies of the effects of muscarinic agonists on vaginal smooth muscle are discrepant. The goal of this study was to determine the expression of muscarinic receptors in the vaginal wall of the rat. In addition, we sought to determine the effect of the muscarinic receptor agonist carbachol on contractility and inositol phosphate production of the proximal and distal rat vaginal muscularis. RT-PCR analysis indicated that both M(2) and M(3) receptor transcripts were expressed within the proximal and distal rat vagina. Carbachol dose-dependently (10(-7)-10(-4) M) contracted the rat vaginal muscularis with a greater maximal contractile response in the proximal vagina (P < 0.01) compared with the distal vagina. The contractile responses of the rat vaginal muscularis to carbachol were dose dependently inhibited by the M(3) antagonist para-fluoro-hexahydrosiladefenidol, and a pK(B) of 7.78 and 7.95 was calculated for the proximal and distal vagina, respectively. Inositol phosphate production was significantly increased in both regions of the vagina following 20-min exposure to 50 muM carbachol with higher levels detected in the proximal vagina compared with the distal (P < 0.05). Preliminary experiments indicated the presence of M(2) and M(3) receptors in the human vaginal muscularis as well as contraction of human vaginal muscularis to carbachol, indicating that our animal studies are relevant to human tissue. Our results provide strong evidence for the functional significance of M(3) receptor expression in the vaginal muscularis.

Functional significance of muscarinic receptor expression within the proximal and distal rat vagina

PubMed Central

Basha, Maureen; LaBelle, Edward F.; Northington, Gina M.; Wang, Tanchun; Wein, Alan J.

2009-01-01

Information regarding the role of cholinergic nerves in mediating vaginal smooth muscle contraction is sparse, and in vitro studies of the effects of muscarinic agonists on vaginal smooth muscle are discrepant. The goal of this study was to determine the expression of muscarinic receptors in the vaginal wall of the rat. In addition, we sought to determine the effect of the muscarinic receptor agonist carbachol on contractility and inositol phosphate production of the proximal and distal rat vaginal muscularis. RT-PCR analysis indicated that both M2 and M3 receptor transcripts were expressed within the proximal and distal rat vagina. Carbachol dose-dependently (10−7–10−4 M) contracted the rat vaginal muscularis with a greater maximal contractile response in the proximal vagina (P < 0.01) compared with the distal vagina. The contractile responses of the rat vaginal muscularis to carbachol were dose dependently inhibited by the M3 antagonist para-fluoro-hexahydrosiladefenidol, and a pKB of 7.78 and 7.95 was calculated for the proximal and distal vagina, respectively. Inositol phosphate production was significantly increased in both regions of the vagina following 20-min exposure to 50 μM carbachol with higher levels detected in the proximal vagina compared with the distal (P < 0.05). Preliminary experiments indicated the presence of M2 and M3 receptors in the human vaginal muscularis as well as contraction of human vaginal muscularis to carbachol, indicating that our animal studies are relevant to human tissue. Our results provide strong evidence for the functional significance of M3 receptor expression in the vaginal muscularis. PMID:19741053

Bone matrix, cellularity, and structural changes in a rat model with high-turnover osteoporosis induced by combined ovariectomy and a multiple-deficient diet.

PubMed

Govindarajan, Parameswari; Böcker, Wolfgang; El Khassawna, Thaqif; Kampschulte, Marian; Schlewitz, Gudrun; Huerter, Britta; Sommer, Ursula; Dürselen, Lutz; Ignatius, Anita; Bauer, Natali; Szalay, Gabor; Wenisch, Sabine; Lips, Katrin S; Schnettler, Reinhard; Langheinrich, Alexander; Heiss, Christian

2014-03-01

In estrogen-deficient, postmenopausal women, vitamin D and calcium deficiency increase osteoporotic fracture risk. Therefore, a new rat model of combined ovariectomy and multiple-deficient diet was established to mimic human postmenopausal osteoporotic conditions under nutrient deficiency. Sprague-Dawley rats were untreated (control), laparatomized (sham), or ovariectomized and received a deficient diet (OVX-Diet). Multiple analyses involving structure (micro-computed tomography and biomechanics), cellularity (osteoblasts and osteoclasts), bone matrix (mRNA expression and IHC), and mineralization were investigated for a detailed characterization of osteoporosis. The study involved long-term observation up to 14 months (M14) after laparotomy or after OVX-Diet, with intermediate time points at M3 and M12. OVX-Diet rats showed enhanced osteoblastogenesis and osteoclastogenesis. Bone matrix markers (biglycan, COL1A1, tenascin C, and fibronectin) and low-density lipoprotein-5 (bone mass marker) were down-regulated at M12 in OVX-Diet rats. However, up-regulation of matrix markers and existence of unmineralized osteoid were seen at M3 and M14. Osteoclast markers (matrix metallopeptidase 9 and cathepsin K) were up-regulated at M14. Micro-computed tomography and biomechanics confirmed bone fragility of OVX-Diet rats, and quantitative RT-PCR revealed a higher turnover rate in the humerus than in lumbar vertebrae, suggesting enhanced bone formation and resorption in OVX-Diet rats. Such bone remodeling caused disturbed bone mineralization and severe bone loss, as reported in patients with high-turnover, postmenopausal osteoporosis. Therefore, this rat model may serve as a suitable tool to evaluate osteoporotic drugs and new biomaterials or fracture implants. Copyright © 2014 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

Dietary Deficiency of Essential Amino Acids Rapidly Induces Cessation of the Rat Estrous Cycle

PubMed Central

Bannai, Makoto; Ichimaru, Toru; Nakano, Sayako; Murata, Takuya; Higuchi, Takashi; Takahashi, Michio

2011-01-01

Reproductive functions are regulated by the sophisticated coordination between the neuronal and endocrine systems and are sustained by a proper nutritional environment. Female reproductive function is vulnerable to effects from dietary restrictions, suggesting a transient adaptation that prioritizes individual survival over reproduction until a possible future opportunity for satiation. This adaptation could also partially explain the existence of amenorrhea in women with anorexia nervosa. Because amino acid nutritional conditions other than caloric restriction uniquely alters amino acid metabolism and affect the hormonal levels of organisms, we hypothesized that the supply of essential amino acids in the diet plays a pivotal role in the maintenance of the female reproductive system. To test this hypothesis, we examined ovulatory cyclicity in female rats under diets that were deficient in threonine, lysine, tryptophan, methionine or valine. Ovulatory cyclicity was monitored by daily cytological evaluations of vaginal smears. After continuous feeding of the deficient diet, a persistent diestrus or anovulatory state was induced most quickly by the valine-deficient diet and most slowly by the lysine-deficient diet. A decline in the systemic insulin-like growth factor 1 level was associated with a dietary amino acid deficiency. Furthermore, a paired group of rats that were fed an isocaloric diet with balanced amino acids maintained normal estrous cyclicity. These disturbances of the estrous cycle by amino acid deficiency were quickly reversed by the consumption of a normal diet. The continuous anovulatory state in this study is not attributable to a decrease in caloric intake but to an imbalance in the dietary amino acid composition. With a shortage of well-balanced amino acid sources, reproduction becomes risky for both the mother and the fetus. It could be viewed as an adaptation to the diet, diverting resources away from reproduction and reallocating them to

Anxiolytic-like Effect of Testosterone in Male Rats: GABAC Receptors Are Not Involved

PubMed Central

Roohbakhsh, Ali; Moghaddam, Akbar Hajizadeh; Delfan, Karim Mahmoodi

2011-01-01

Objective(s) The effect of testosterone on anxiety-like behaviors has been the subject of some studies. There is evidence that testosterone modulates anxiety via GABA (gama aminobutyric acid) and GABAergic system. The involvement of GABAC receptors in those effects of testosterone on anxiety-like behaviors of the rats was investigated in the present study. Materials and Methods A group of rats received subcutaneous injections of testosterone (5, 10 and 20 mg/kg). Two groups of rats received intracerebroventricular injections of either CACA (GABAC agonist, 0.125 μg/rat) or TPMPA (GABAC antagonist, 3 microg/rat) following administration of testosterone (5, 10 and 20 mg/kg). After the injections, the rats were submitted to the elevated plus-maze test of anxiety. Results The rats received testosterone alone, showed a decreased in anxiety-like behaviors (P< 0.01). Administration of either CACA or TPMPA did not modify animals’ behavior compared to the rats received testosterone alone. Conclusion The results of the present study showed that administration of testosterone induces anxiolytic-like behaviors in the rats and GABAC receptors possibly are not involved in the anxiolytic effect of testosterone. PMID:23493519

Deficiency of leptin receptor in myeloid cells disrupts hypothalamic metabolic circuits and causes body weight increase.

PubMed

Gao, Yuanqing; Vidal-Itriago, Andrés; Milanova, Irina; Korpel, Nikita L; Kalsbeek, Martin J; Tom, Robby Zachariah; Kalsbeek, Andries; Hofmann, Susanna M; Yi, Chun-Xia

2018-01-01

Leptin is a cytokine produced by adipose tissue that acts mainly on the hypothalamus to regulate appetite and energy homeostasis. Previous studies revealed that the leptin receptor is expressed not only in neurons, but also in glial cells. Microglia are resident immune cells in the brain that play an essential role in immune defense and neural network development. Previously we reported that microglial morphology and cytokine production are changed in the leptin receptor deficient db/db mouse, suggesting that leptin's central effects on metabolic control might involve signaling through microglia. In the current study, we aimed to uncover the role of leptin signaling in microglia in systemic metabolic control. We generated a mouse model with leptin receptor deficiency, specifically in the myeloid cells, to determine the role of microglial leptin signaling in the development of metabolic disease and to investigate microglial functions. We discovered that these mice have increased body weight with hyperphagia. In the hypothalamus, pro-opiomelanocortin neuron numbers in the arcuate nucleus (ARC) and α-MSH projections from the ARC to the paraventricular nucleus (PVN) decreased, which was accompanied by the presence of less ramified microglia with impaired phagocytic capacity in the PVN. Myeloid cell leptin receptor deficient mice partially replicate the db/db phenotype. Leptin signaling in hypothalamic microglia is important for microglial function and a correct formation of the hypothalamic neuronal circuit regulating metabolism. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

Effect of sulfite treatment on total antioxidant capacity, total oxidant status, lipid hydroperoxide, and total free sulfydryl groups contents in normal and sulfite oxidase-deficient rat plasma.

PubMed

Herken, Emine Nur; Kocamaz, Erdogan; Erel, Ozcan; Celik, Hakim; Kucukatay, Vural

2009-08-01

Sulfites, which are commonly used as preservatives, are continuously formed in the body during the metabolism of sulfur-containing amino acids. Sulfite oxidase (SOX) is an essential enzyme in the pathway of the oxidative degradation of sulfite to sulfate protecting cells from sulfite toxicity. This article investigated the effect of sulfite on total antioxidant capacity (TAC), total oxidant status, lipid hydroperoxide (LOOH), and total free sulfydryl groups (-SH) levels in normal and SOX-deficient male albino rat plasma. For this purpose, rats were divided into four groups: control, sulfite-treated, SOX-deficient, and sulfite-treated SOX-deficient groups. SOX deficiency was established by feeding rats a low molybdenum diet and adding to their drinking water 200 ppm tungsten. Sulfite (70 mg/kg) was administered to the animals via their drinking water. SOX deficiency together with sulfite treatment caused a significant increase in the plasma LOOH and total oxidant status levels. -SH content of rat plasma significantly decreased by both sulfite treatment and SOX deficiency compared to the control. There was also a significant decrease in plasma TAC level by sulfite treatment. In conclusion, sulfite treatment affects the antioxidant/oxidant balance of the plasma cells of the rats toward oxidants in SOX-deficient groups.

Dopamine receptor D5 deficiency results in a selective reduction of hippocampal NMDA receptor subunit NR2B expression and impaired memory.

PubMed

Moraga-Amaro, Rodrigo; González, Hugo; Ugalde, Valentina; Donoso-Ramos, Juan Pablo; Quintana-Donoso, Daisy; Lara, Marcelo; Morales, Bernardo; Rojas, Patricio; Pacheco, Rodrigo; Stehberg, Jimmy

2016-04-01

Pharmacological evidence associates type I dopamine receptors, including subtypes D1 and D5, with learning and memory. Analyses using genetic approaches have determined the relative contribution of dopamine receptor D1 (D1R) in cognitive tasks. However, the lack of drugs that can discriminate between D1R and D5R has made the pharmacological distinction between the two receptors difficult. Here, we aimed to determine the role of D5R in learning and memory. In this study we tested D5R knockout mice and wild-type littermates in a battery of behavioral tests, including memory, attention, locomotion, anxiety and motivational evaluations. Our results show that genetic deficiency of D5R significantly impairs performance in the Morris water maze paradigm, object location and object recognition memory, indicating a relevant role for D5R in spatial memory and recognition memory. Moreover, the lack of D5R resulted in decreased exploration and locomotion. In contrast, D5R deficiency had no impact on working memory, anxiety and depressive-like behavior, measured using the spontaneous alternation, open-field, tail suspension test, and forced swimming test. Electrophysiological analyses performed on hippocampal slices showed impairment in long-term-potentiation in mice lacking D5R. Further analyses at the molecular level showed that genetic deficiency of D5R results in a strong and selective reduction in the expression of the NMDA receptor subunit NR2B in the hippocampus. These findings demonstrate the relevant contribution of D5R in memory and suggest a functional interaction of D5R with hippocampal glutamatergic pathways. Copyright © 2015 Elsevier Ltd. All rights reserved.

Accumbal μ-Opioid Receptors Modulate Ethanol Intake in Alcohol-Preferring Alko Alcohol Rats.

PubMed

Uhari-Väänänen, Johanna; Raasmaja, Atso; Bäckström, Pia; Oinio, Ville; Airavaara, Mikko; Piepponen, Petteri; Kiianmaa, Kalervo

2016-10-01

The nucleus accumbens shell is a key brain area mediating the reinforcing effects of ethanol (EtOH). Previously, it has been shown that the density of μ-opioid receptors in the nucleus accumbens shell is higher in alcohol-preferring Alko Alcohol (AA) rats than in alcohol-avoiding Alko Non-Alcohol rats. In addition, EtOH releases opioid peptides in the nucleus accumbens and opioid receptor antagonists are able to modify EtOH intake, all suggesting an opioidergic mechanism in the control of EtOH consumption. As the exact mechanisms of opioidergic involvement remains to be elucidated, the aim of this study was to clarify the role of accumbal μ- and κ-opioid receptors in controlling EtOH intake in alcohol-preferring AA rats. Microinfusions of the μ-opioid receptor antagonist CTOP (0.3 and 1 μg/site), μ-opioid receptor agonist DAMGO (0.03 and 0.1 μg/site), nonselective opioid receptor agonist morphine (30 μg/site), and κ-opioid receptor agonist U50488H (0.3 and 1 μg/site) were administered via bilateral guide cannulas into the nucleus accumbens shell of AA rats that voluntarily consumed 10% EtOH solution in an intermittent, time-restricted (90-minute) 2-bottle choice access paradigm. CTOP (1 μg/site) significantly increased EtOH intake. Conversely, DAMGO resulted in a decreasing trend in EtOH intake. Neither morphine nor U50488H had any effect on EtOH intake in the used paradigm. The results provide further evidence for the role of accumbens shell μ-opioid receptors but not κ-opioid receptors in mediating reinforcing effects of EtOH and in regulating EtOH consumption. The results also provide support for views suggesting that the nucleus accumbens shell has a major role in mediating EtOH reward. Copyright © 2016 by the Research Society on Alcoholism.

Change in pharmacological effect of endothelin receptor antagonists in rats with pulmonary hypertension: Role of ETB-receptor expression levels

PubMed Central

Sauvageau, Stéphanie; Thorin, Eric; Villeneuve, Louis; Dupuis, Jocelyn

2013-01-01

Background and purpose The endothelin (ET) system is activated in pulmonary arterial hypertension (PAH). The therapeutic value of pharmacological blockade of ET receptors has been demonstrated in various animal models and led to the current approval and continued development of these drugs for the therapy of human PAH. However, we currently incompletely comprehend what local modifications of this system occur as a consequence of PAH, particularly in small resistance arteries, and how this could affect the pharmacological response to ET receptor antagonists with various selectivities for the receptor subtypes. Therefore, the purposes of this study were to evaluate potential modifications of the pharmacology of the ET system in rat pulmonary resistance arteries from monocrotaline (MCT)-induced pulmonary arterial hypertension. Experimental approach ET-1 levels were quantified by ELISA. PreproET-1, ETA and ETB receptor mRNA expressions were quantified in pulmonary resistance arteries using Q-PCR, while protein expression was evaluated by Western blots. Reactivity to ET-1 of isolated pulmonary resistance arteries was measured in the presence of ETA (A-147627), ETB (A-192621) and dual ETA/B (bosentan) receptor antagonists. Key results In rats with PAH, plasma ET-1 increased (p < 0.001) while pulmonary levels were reduced (p < 0.05). In PAH arteries, preproET-1 (p < 0.05) and ETB receptor (p < 0.001) gene expressions were reduced, as were ETB receptor protein levels (p < 0.05). ET-1 induced similar vasoconstrictions in both groups. In arteries from sham animals, neither bosentan nor the ETA or the ETB receptor antagonists modified the response. In arteries from PAH rats, however, bosentan and the ETA receptor antagonist potently reduced the maximal contraction, while bosentan also reduced sensitivity (p < 0.01). Conclusions and implications The effectiveness of both selective ETA and dual ETA/B receptor antagonists is markedly increased in PAH. Down-regulation of

High-Iron Consumption Impairs Growth and Causes Copper-Deficiency Anemia in Weanling Sprague-Dawley Rats

PubMed Central

Ha, Jung-Heun; Doguer, Caglar; Wang, Xiaoyu; Flores, Shireen R.; Collins, James F.

2016-01-01

Iron-copper interactions were described decades ago; however, molecular mechanisms linking the two essential minerals remain largely undefined. Investigations in humans and other mammals noted that copper levels increase in the intestinal mucosa, liver and blood during iron deficiency, tissues all important for iron homeostasis. The current study was undertaken to test the hypothesis that dietary copper influences iron homeostasis during iron deficiency and iron overload. We thus fed weanling, male Sprague-Dawley rats (n = 6-11/group) AIN-93G-based diets containing high (~8800 ppm), adequate (~80) or low (~11) iron in combination with high (~183), adequate (~8) or low (~0.9) copper for 5 weeks. Subsequently, the iron- and copper-related phenotype of the rats was assessed. Rats fed the low-iron diets grew slower than controls, with changes in dietary copper not further influencing growth. Unexpectedly, however, high-iron (HFe) feeding also impaired growth. Furthermore, consumption of the HFe diet caused cardiac hypertrophy, anemia, low serum and tissue copper levels and decreased circulating ceruloplasmin activity. Intriguingly, these physiologic perturbations were prevented by adding extra copper to the HFe diet. Furthermore, higher copper levels in the HFe diet increased serum nonheme iron concentration and transferrin saturation, exacerbated hepatic nonheme iron loading and attenuated splenic nonheme iron accumulation. Moreover, serum erythropoietin levels, and splenic erythroferrone and hepatic hepcidin mRNA levels were altered by the dietary treatments in unanticipated ways, providing insight into how iron and copper influence expression of these hormones. We conclude that high-iron feeding of weanling rats causes systemic copper deficiency, and further, that copper influences the iron-overload phenotype. PMID:27537180

Baicalein inhibits the migration and invasive properties of human hepatoma cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chiu, Yung-Wei; Institute of Medicine, Chung Shan Medical University, Taiwan; Lin, Tseng-Hsi

Flavonoids have been demonstrated to exert health benefits in humans. We investigated whether the flavonoid baicalein would inhibit the adhesion, migration, invasion, and growth of human hepatoma cell lines, and we also investigated its mechanism of action. The separate effects of baicalein and baicalin on the viability of HA22T/VGH and SK-Hep1 cells were investigated for 24 h. To evaluate their invasive properties, cells were incubated on matrigel-coated transwell membranes in the presence or absence of baicalein. We examined the effect of baicalein on the adhesion of cells, on the activation of matrix metalloproteinases (MMPs), protein kinase C (PKC), and p38more » mitogen-activated protein kinase (MAPK), and on tumor growth in vivo. We observed that baicalein suppresses hepatoma cell growth by 55%, baicalein-treated cells showed lower levels of migration than untreated cells, and cell invasion was significantly reduced to 28%. Incubation of hepatoma cells with baicalein also significantly inhibited cell adhesion to matrigel, collagen I, and gelatin-coated substrate. Baicalein also decreased the gelatinolytic activities of the matrix metalloproteinases MMP-2, MMP-9, and uPA, decreased p50 and p65 nuclear translocation, and decreased phosphorylated I-kappa-B (IKB)-{beta}. In addition, baicalein reduced the phosphorylation levels of PKC{alpha} and p38 proteins, which regulate invasion in poorly differentiated hepatoma cells. Finally, when SK-Hep1 cells were grown as xenografts in nude mice, intraperitoneal (i.p.) injection of baicalein induced a significant dose-dependent decrease in tumor growth. These results demonstrate the anticancer properties of baicalein, which include the inhibition of adhesion, invasion, migration, and proliferation of human hepatoma cells in vivo. - Highlight: > Baicalein inhibits several essential steps in the onset of metastasis.« less

Metallochaperone for Cu,Zn-superoxide dismutase (CCS) protein but not mRNA is higher in organs from copper-deficient mice and rats.

PubMed

Prohaska, Joseph R; Broderius, Margaret; Brokate, Bruce

2003-09-15

Cu,Zn-superoxide dismutase (SOD1) is an abundant metalloenzyme important in scavenging superoxide ions. Cu-deficient rats and mice have lower SOD1 activity and protein, possibly because apo-SOD1 is degraded faster than holo-SOD1. SOD1 interacts with and requires its metallochaperone CCS for donating copper. We produced dietary Cu deficiency in rodents to determine if the reduction in SOD1 was related to the level of its specific metallochaperone CCS. CCS levels determined by immunoblot were 2- to 3-fold higher in liver, heart, kidney, and brain from male Cu-deficient rats and mice under a variety of conditions. CCS was also higher in livers of Cu-deficient dams. Interestingly, CCS levels in brain of Cu-deficient mice were also higher even though SOD1 activity and protein were not altered, suggesting that the rise in CCS is correlated with altered Cu status rather than a direct result of lower SOD1. A DNA probe specific for rat CCS detected a single transcript by Northern blot hybridization with liver RNA. CCS mRNA levels in mouse and rat liver were not altered by dietary treatment. These results suggest a posttranscriptional mechanism for higher CCS protein when Cu is limiting in the cell, perhaps due to slower protein turnover. Elevation in CCS level is one of the most dramatic alterations in Cu binding proteins accompanying Cu deficiency and may be useful to assess Cu status.

Mild zinc deficiency in male and female rats: early postnatal alterations in renal nitric oxide system and morphology.

PubMed

Tomat, Analia Lorena; Veiras, Luciana Cecilia; Aguirre, Sofía; Fasoli, Héctor; Elesgaray, Rosana; Caniffi, Carolina; Costa, María Ángeles; Arranz, Cristina Teresa

2013-03-01

Fetal and postnatal zinc deficiencies induce an increase in arterial blood pressure and impair renal function in male adult rats. We therefore hypothesized that these renal alterations are present in early stages of life and that there are sexual differences in the adaptations to this nutritional injury. The aim was to study the effects of moderate zinc deficiency during fetal life and lactation on renal morphology, oxidative stress, apoptosis, and the nitric oxide system in male and female rats at 21 d of life. Female Wistar rats received low (8 ppm) or control (30 ppm) zinc diets from the beginning of pregnancy to weaning. Glomerulus number, morphology, oxidative stress, apoptotic cells, nitric oxide synthase activity, and protein expression were evaluated in the kidneys of offspring at 21 d. Zinc deficiency decreased the nephron number, induced glomerular hypertrophy, increased oxidative damage, and decreased nitric oxide synthase activity in the male and female rat kidneys. Nitric oxide synthase activity was not affected by inhibitors of the neuronal or inducible isoforms, so nitric oxide was mainly generated by the endothelial isoenzyme. Gender differences were observed in glomerular areas and antioxidant enzyme activities. Zinc deficiency during fetal life and lactation induces an early decrease in renal functional units, associated with a decrease in nitric oxide activity and an increase in oxidative stress, which would contribute to increased arterial blood pressure and renal dysfunction in adulthood. The sexual differences observed in this model may explain the dissimilar development of hypertension and renal diseases in adult life. Copyright © 2013 Elsevier Inc. All rights reserved.

Hexachlorobenzene induces cell proliferation, and aryl hydrocarbon receptor expression (AhR) in rat liver preneoplastic foci, and in the human hepatoma cell line HepG2. AhR is a mediator of ERK1/2 signaling, and cell cycle regulation in HCB-treated HepG2 cells.

PubMed

de Tomaso Portaz, Ana Clara; Caimi, Giselle Romero; Sánchez, Marcela; Chiappini, Florencia; Randi, Andrea S; Kleiman de Pisarev, Diana L; Alvarez, Laura

2015-10-02

Hexachlorobenzene (HCB) is a widespread environmental pollutant, and a liver tumor promoter in rodents. Depending on the particular cell lines studied, exposure to these compounds may lead to cell proliferation, terminal differentiation, or apoptosis. The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor that is involved in drug and xenobiotic metabolism. AhR can also modulate a variety of cellular and physiological processes that can affect cell proliferation and cell fate determination. The mechanisms by which AhR ligands, both exogenous and endogenous, affect these processes involve multiple interactions between AhR and other signaling pathways. In the present study, we examined the effect of HCB on cell proliferation and AhR expression, using an initiation-promotion hepatocarcinogenesis protocol in rat liver and in the human-derived hepatoma cell line, HepG2. Female Wistar rats were initiated with a single dose of 100 mg/kg of diethylnitrosamine (DEN) at the start of the experiment. Two weeks later, daily dosing of 100 mg/kg HCB was maintained for 10 weeks. Partial hepatectomy was performed 3 weeks after initiation. The number and area of glutathione S-transferase-P (GST-P)-positive foci, in the rat liver were used as biomarkers of liver precancerous lesions. Immunohistochemical staining showed an increase in proliferating cell nuclear antigen (PCNA)-positive cells, along with enhanced AhR protein expression in hepatocytes within GST-P-positive foci of (DEN HCB) group, when compared to DEN. In a similar manner, Western blot analysis demonstrated that HCB induced PCNA and AhR protein expression in HepG2 cells. Flow cytometry assay indicated that the cells were accumulated at S and G2/M phases of the cell cycle. HCB increased cyclin D1 protein levels and ERK1/2 phosphorylation in a dose-dependent manner. Treatment of cells with a selective MEK1 inhibitor, prevented HCB-stimulatory effect on PCNA and cyclinD1, indicating that these effects

CRF2 Receptor Deficiency Eliminates the Long-Lasting Vulnerability of Motivational States Induced by Opiate Withdrawal

PubMed Central

Morisot, Nadège; Rouibi, Khalil; Contarino, Angelo

2015-01-01

Vulnerability to stressful life events is a hallmark of drug dependence that may persist long after cessation of drug intake and dramatically fuel key clinical features, such as deregulated up-shifted motivational states and craving. However, to date, no effective therapy is available for reducing vulnerability to stressful events in former drug users and drug-dependent patients, mostly because of poor knowledge of the mechanisms underlying it. In this study, we report that genetic inactivation of the stress-responsive corticotropin-releasing factor receptor-2 (CRF2−/−) completely eliminates the reemergence of increased nonrewarded nose-pokes, reflecting up-shifted motivational states, triggered by ethological environmental stressors long after cessation of morphine administration in mice. Accordingly, CRF2 receptor deficiency completely abolishes the increase in biomarkers of synthesis of major brain motivational substrates, such as ventral tegmental area (VTA) dopamine (DA) and amygdala γ-aminobutyric acid (GABA) systems, associated with the stress-induced reemergence of up-shifted motivational states long after opiate withdrawal. Nevertheless, neither CRF2 receptor deficiency nor long-term opiate withdrawal affects amygdala CRF or hypothalamus CRF expression, indicating preserved brain stress-coping systems. Moreover, CRF2 receptor deficiency does not influence the locomotor or the anxiety-like effect of long-term opiate withdrawal. Thus, the present results reveal an essential and specific role for the CRF2 receptor in the stress-induced reemergence of up-shifted motivational states and related alterations in brain motivational systems long after opiate withdrawal. These findings suggest new strategies for the treatment of the severe and long-lasting vulnerability that inexorably follows drug withdrawal and hinder drug abstinence. PMID:25672976

Norepinephrine Activates Dopamine D4 Receptors in the Rat Lateral Habenula

PubMed Central

Root, David H.; Hoffman, Alexander F.; Good, Cameron H.; Zhang, Shiliang; Gigante, Eduardo

2015-01-01

The lateral habenula (LHb) is involved in reward and aversion and is reciprocally connected with dopamine (DA)-containing brain regions, including the ventral tegmental area (VTA). We used a multidisciplinary approach to examine the properties of DA afferents to the LHb in the rat. We find that >90% of VTA tyrosine hydroxylase (TH) neurons projecting to the LHb lack vesicular monoamine transporter 2 (VMAT2) mRNA, and there is little coexpression of TH and VMAT2 protein in this mesohabenular pathway. Consistent with this, electrical stimulation of LHb did not evoke DA-like signals, assessed with fast-scan cyclic voltammetry. However, electrophysiological currents that were inhibited by L741,742, a DA-D4-receptor antagonist, were observed in LHb neurons when DA uptake or degradation was blocked. To prevent DA activation of D4 receptors, we repeated this experiment in LHb slices from DA-depleted rats. However, this did not disrupt D4 receptor activation initiated by the dopamine transporter inhibitor, GBR12935. As the LHb is also targeted by noradrenergic afferents, we examined whether GBR12935 activation of DA-D4 receptors occurred in slices depleted of norepinephrine (NE). Unlike DA, NE depletion prevented the activation of DA-D4 receptors. Moreover, direct application of NE elicited currents in LHb neurons that were blocked by L741,742, and GBR12935 was found to be a more effective blocker of NE uptake than the NE-selective transport inhibitor nisoxetine. These findings demonstrate that NE is released in the rat LHb under basal conditions and that it activates DA-D4 receptors. Therefore, NE may be an important regulator of LHb function. PMID:25716845

Effect of diet-induced vitamin D deficiency on rotator cuff healing in a rat model.

PubMed

Angeline, Michael E; Ma, Richard; Pascual-Garrido, Cecilia; Voigt, Clifford; Deng, Xiang Hua; Warren, Russell F; Rodeo, Scott A

2014-01-01

Few studies have considered hormonal influences, particularly vitamin D, on healing. Vitamin D deficiency would have a negative effect on the structure of the healing tendon-bone interface in a rat model and would result in decreased tendon attachment strength. Controlled laboratory study. Vitamin D deficiency was induced in 28 male Sprague-Dawley rats using a specialized vitamin D-deficient diet and ultraviolet light restriction. Serum levels of vitamin D were measured after 6 weeks. These vitamin D-deficient animals (experimental group) plus 32 rats with normal vitamin D levels (controls) underwent unilateral detachment of the right supraspinatus tendon from the greater tuberosity of the humerus, followed by immediate repair using bone tunnel suture fixation. The animals were sacrificed at 2- and 4-week intervals after surgery for biomechanical analysis. A paired t test was used to compare serum vitamin D levels at day 0 and at 6 weeks. A nonparametric Mann-Whitney U test was used to compare load-to-failure and stiffness values between the experimental group and controls. Bone density and new bone formation at the tendon insertion site on the greater tuberosity were assessed with micro-computed tomography (CT). The organization of collagen tissue, new bone formation, vascularity at the tendon-bone interface, fibrocartilage at the tendon-bone interface, and collagen fiber continuity between the tendon and bone tissue were evaluated with safranin O and picrosirius red staining. Blood draws confirmed vitamin D deficiency at 6 weeks compared with time zero/baseline for rats in the experimental group (10.9 ng/mL vs 6.5 ng/mL, respectively; P < .001). Biomechanical testing demonstrated a significant decrease in load to failure in the experimental group compared with controls at 2 weeks (5.8 ± 2.0 N vs 10.5 ± 4.4 N, respectively; P < .006). There was no difference in stiffness at 2 weeks between the control and experimental groups. At 4 weeks, there was no significant

Perinatal iron deficiency predisposes the developing rat hippocampus to greater injury from mild to moderate hypoxia–ischemia

PubMed Central

Rao, Raghavendra; Tkac, Ivan; Townsend, Elise L; Ennis, Kathleen; Gruetter, Rolf; Georgieff, Michael K

2008-01-01

The hippocampus is injured in both hypoxia–ischemia (HI) and perinatal iron deficiency that are comorbidities in infants of diabetic mothers and intrauterine growth restricted infants. We hypothesized that preexisting perinatal iron deficiency predisposes the hippocampus to greater injury when exposed to a relatively mild HI injury. Iron-sufficient and iron-deficient rats (hematocrit 40% lower and brain iron concentration 55% lower) were subjected to unilateral HI injury of 15, 30, or 45 mins (n = 12 to 13/HI duration) on postnatal day 14. Sixteen metabolite concentrations were measured from an 11 μL volume on the ipsilateral (HI) and contralateral (control) hippocampi 1 week later using in vivo 1H NMR spectroscopy. The concentrations of creatine, glutamate, myo-inositol, and N-acetylaspartate were lower on the control side in the iron-deficient group (P < 0.02, each). Magnetic resonance imaging showed hippocampal injury in the majority of the iron-deficient rats (58% versus 11%, P < 0.0001) with worsening severity with increasing durations of HI (P = 0.0001). Glucose, glutamate, N-acetylaspartate, and taurine concentrations were decreased and glutamine, lactate and myo-inositol concentrations, and glutamate/glutamine ratio were increased on the HI side in the iron-deficient group (P < 0.01, each), mainly in the 30 and 45 mins HI subgroups (P < 0.02, each). These neurochemical changes likely reflect the histochemically detected neuronal injury and reactive astrocytosis in the iron-deficient group and suggest that perinatal iron deficiency predisposes the hippocampus to greater injury from exposure to a relatively mild HI insult. PMID:16868555

Beneficial effects of gradual intense exercise in tissues of rats fed with a diet deficient in vitamins and minerals: a pilot study.

PubMed

Teixeira, Angélica; Müller, Liz; dos Santos, Alessandra A; Reckziegel, Patrícia; Emanuelli, Tatiana; Rocha, João Batista T; Bürger, Marilise E

2009-05-01

This study evaluated the preliminary effects of intense physical training (swimming) on oxidative stress in rats with nutritional deficiencies. Rats were fed with a standard diet or a diet deficient in vitamins and minerals for 4 months. The deficient diet contained one-fourth of the recommended vitamin and mineral levels for rats. From the second month, half of the animals were subjected to a swimming exercise in a plastic container with water maintained at 34 +/- 1 degrees C for 1 h/d, five times per week, for 11 wk. The rats were subjected to swimming exercise with loads attached to the dorsal region, which were progressively increased according to their body weight (1% to 7%). Sedentary rats were transported to the experimental room and handled as often in a similar way as the exercise group, except that they were not put in water. In the exercised group, blood lactate levels were significantly lower and the heart weight/body weight ratio was significantly higher than in the sedentary group (P < 0.05). Increased lipid peroxidation was observed in the liver, heart, and skeletal muscle of rats fed with the deficient diet, but it was completely reversed by exercise. Exercise also decreased lipid peroxidation levels in the heart and skeletal muscle of rats fed with the standard diet (P < 0.05). This pilot study leads to the continuity of the studies, because the partial results observed suggest that inadequate nutrition may enhance oxidative stress, and that intense chronic physical training may activate antioxidant defenses, possibly by hormesis.

Delta receptor antagonism, ethanol taste reactivity, and ethanol consumption in outbred male rats.

PubMed

Higley, Amanda E; Kiefer, Stephen W

2006-11-01

Naltrexone, a nonspecific opioid antagonist, produces significant changes in ethanol responsivity in rats by rendering the taste of ethanol aversive as well as producing a decrease in voluntary ethanol consumption. The present study investigated the effect of naltrindole, a specific antagonist of delta opioid receptors, on ethanol taste reactivity and ethanol consumption in outbred rats. In the first experiment, rats received acute treatment of naltrexone, naltrindole, or saline followed by the measurement of ethanol consumption in a short-term access period. The second experiment involved the same treatments and investigated ethanol palatability (using the taste-reactivity test) as well as ethanol consumption. Results indicated that treatment with 3 mg/kg naltrexone significantly affected palatability (rendered ethanol more aversive, Experiment 2) and decreased voluntary ethanol consumption (Experiments 1 and 2). The effects of naltrindole were inconsistent. In Experiment 1, 8 mg/kg naltrindole significantly decreased voluntary ethanol consumption but this was not replicated in Experiment 2. The 8 mg/kg dose produced a significant increase in aversive responding (Experiment 2) but did not affect ingestive responding. Lower doses of naltrindole (2 and 4 mg/kg) were ineffective in altering rats' taste-reactivity response to and consumption of ethanol. While these data suggest that delta receptors are involved in rats' taste-reactivity response to ethanol and rats' ethanol consumption, it is likely that multiple opioid receptors mediate both behavioral responses.

Deficiency of the NR4A Orphan Nuclear Receptor NOR1 attenuates Neointima Formation Following Vascular Injury

PubMed Central

Nomiyama, Takashi; Zhao, Yue; Gizard, Florence; Findeisen, Hannes M.; Heywood, Elizabeth B.; Jones, Karrie L.; Conneely, Orla M.; Bruemmer, Dennis

2009-01-01

Background The neuron-derived orphan receptor-1 (NOR1) belongs to the evolutionary highly conserved and most ancient NR4A subfamily of the nuclear hormone receptor superfamily. Members of this subfamily function as early response genes regulating key cellular processes including proliferation, differentiation, and survival. Although NOR1 has previously been demonstrated to be required for smooth muscle cell (SMC) proliferation in vitro, the role of this nuclear receptor for the proliferative response underlying neointima formation and target genes trans-activated by NOR1 remain to be defined. Methods and Results Using a model of guide wire-induced arterial injury, we demonstrate decreased neointima formation in NOR1-/- mice compared to wildtype mice. In vitro, NOR1-deficient SMC exhibit decreased proliferation due to a G1→S phase arrest of the cell cycle and increased apoptosis in response to serum deprivation. NOR1-deficiency alters phosphorylation of the retinoblastoma protein by preventing mitogen-induced cyclin D1 and D2 expression. Conversely, overexpression of NOR1 induces cyclin D1 expression and the transcriptional activity of the cyclin D1 promoter in transient reporter assays. Gel shift and chromatin immunoprecipitation assays identified a putative response element for NR4A receptors in the cyclin D1 promoter, to which NOR1 is recruited in response to mitogenic stimulation. Finally, we provide evidence that these observations are applicable in vivo by demonstrating decreased cyclin D1 expression during neointima formation in NOR1-deficient mice. Conclusions These experiments characterize cyclin D1 as a NOR1-regulated target gene in SMC and demonstrate that NOR1 deficiency decreases neointima formation in response to vascular injury. PMID:19153266

Lipopolysaccharide stimulates HepG2 human hepatoma cells in the presence of lipopolysaccharide-binding protein via CD14.

PubMed

Nanbo, A; Nishimura, H; Muta, T; Nagasawa, S

1999-02-01

Lipopolysaccharide (LPS)-binding protein (LBP), an opsonin for activation of macrophages by bacterial LPS, is synthesized in hepatocytes and is known to be an acute phase protein. Recently, cytokine-induced production of LBP was reported to increase 10-fold in hepatocytes isolated from LPS-treated rats, compared with those from normal rats. However, the mechanism by which the LPS treatment enhances the effect of cytokines remains to be clarified. In the present study, we examined whether LPS alone or an LPS/LBP complex directly stimulates the hepatocytes, leading to acceleration of the cytokine-induced LBP production. HepG2 cells (a human hepatoma cell line) were shown to express CD14, a glycosylphosphatidylinositol-anchored LPS receptor, by both RT/PCR and flow cytometric analyses. An LPS/LBP complex was an effective stimulator for LBP and CD14 production in HepG2 cells, but stimulation of the cells with either LPS or LBP alone did not significantly accelerate the production of these proteins. The findings were confirmed by semiquantitative RT/PCR analysis of mRNA levels of LBP and CD14 in HepG2 cells after stimulation with LPS alone and an LPS/LBP complex. In addition, two monoclonal antibodies (mAbs) to CD14 (3C10 and MEM-18) inhibited LPS/LBP-induced cellular responses of HepG2 cells. Furthermore, prestimulation of HepG2 cells with LPS/LBP augmented cytokine-induced production and gene expression of LBP and CD14. All these findings suggest that an LPS/LBP complex, but not free LPS, stimulates HepG2 cells via CD14 leading to increased basal and cytokine-induced LBP and CD14 production.

Divergent effects of estradiol and the estrogen receptor-alpha agonist PPT on eating and activation of PVN CRH neurons in ovariectomized rats and mice.

PubMed

Thammacharoen, Sumpun; Geary, Nori; Lutz, Thomas A; Ogawa, Sonoko; Asarian, Lori

2009-05-01

Eating is modulated by estradiol in females of many species and in women. To further investigate the estrogen receptor mechanism mediating this effect, ovariectomized rats and mice were treated with estradiol benzoate or the estrogen receptor-alpha (ER-alpha)-selective agonist PPT. PPT inhibited eating in rats much more rapidly than estradiol (approximately 2-6 h versus >24 h). In contrast, the latencies to vaginal estrus after PPT and estradiol were similar (>24 h). PPT also inhibited eating within a few hours in wild-type mice, but failed to inhibit eating in transgenic mice deficient in ER-alpha (ERalphaKO mice). PPT, but not estradiol, induced the expression of c-Fos in corticotrophin-releasing hormone (CRH)-expressing cells of the paraventricular nucleus (PVN) of the hypothalamus within 90-180 min in rats. Both PPT and estradiol reduced c-Fos expression in an ER-alpha-containing area of the nucleus of the solitary tract. The anomalously rapid eating-inhibitory effect of PPT suggests that PPT's neuropharmacological effect differs from estradiol's, perhaps because PPT differentially activates membrane versus nuclear ER-alpha or because PPT activates non-ER-alpha membrane estrogen receptors in addition to ER-alpha. The failure of PPT to inhibit eating in ERalphaKO mice, however, indicates that ER-alpha is necessary for PPT's eating-inhibitory action and that any PPT-induced activation of non-ER-alpha estrogen receptors is not sufficient to inhibit eating. Finally, the rapid induction of c-Fos in CRH-expressing cells in the PVN by PPT suggests that PPT elicits a neural response that is similar to that elicited by stress or aversive emotional stimuli.

Changes in androgen receptor, estrogen receptor alpha, and sexual behavior with aging and testosterone in male rats.

PubMed

Wu, Di; Gore, Andrea C

2010-07-01

Reproductive aging in males is characterized by a diminution in sexual behavior beginning in middle age. We investigated the relationships among testosterone, androgen receptor (AR) and estrogen receptor alpha (ERalpha) cell numbers in the hypothalamus, and their relationship to sexual performance in male rats. Young (3months) and middle-aged (12months) rats were given sexual behavior tests, then castrated and implanted with vehicle or testosterone capsules. Rats were tested again for sexual behavior. Numbers of AR and ERalpha immunoreactive cells were counted in the anteroventral periventricular nucleus and the medial preoptic nucleus, and serum hormones were measured. Middle-aged intact rats had significant impairments of all sexual behavior measures compared to young males. After castration and testosterone implantation, sexual behaviors in middle-aged males were largely comparable to those in the young males. In the hypothalamus, AR cell density was significantly (5-fold) higher, and ERalpha cell density significantly (6-fold) lower, in testosterone- than vehicle-treated males, with no age differences. Thus, restoration of serum testosterone to comparable levels in young and middle-aged rats resulted in similar preoptic AR and ERalpha cell density concomitant with a reinstatement of most behaviors. These data suggest that age-related differences in sexual behavior cannot be due to absolute levels of testosterone, and further, the middle-aged brain retains the capacity to respond to exogenous testosterone with changes in hypothalamic AR and ERalpha expression. Our finding that testosterone replacement in aging males has profound effects on hypothalamic receptors and behavior has potential medical implications for the treatment of age-related hypogonadism in men. Copyright 2010 Elsevier Inc. All rights reserved.

A Critical Evaluation of Liver Pathology in Humans with Danon Disease and Experimental Correlates in a Rat Model of LAMP-2 Deficiency.

PubMed

Wang, Lu; Wang, Jingbo; Cai, Weile; Shi, Yongquan; Zhou, Xinmin; Guo, Guanya; Guo, Changcun; Huang, Xiaofeng; Han, Zheyi; Zhang, Shuai; Ma, Shuoyi; Zhou, Xia; Fan, Daiming; Gershwin, M Eric; Han, Ying

2017-08-01

Danon disease is a genetic deficiency in lysosome-associated membrane protein 2 (LAMP-2), a highly glycosylated constituent of the lysosomal membrane and characterized by a cardiomyopathy, skeletal muscle myopathy, and cognitive impairment. Patients, however, often manifest hepatic abnormalities, but liver function has not been well evaluated and the syndrome is relatively uncommon. Hence, we have taken advantage of a rat that has been deleted of LAMP-2 to study the relative role of LAMP-2 on liver function. Interestingly, rats deficient in LAMP-2 develop a striking increase in serum alkaline phosphatase (ALP) and a decrease in bile flow compared with wild-type littermates. Importantly and by ultrastructural analysis, deficient rats manifest dilated canaliculi that lack microvilli with evidence of bile-containing bodies. Moreover, following bile duct ligation, LAMP-2-deficient rats develop rapid and severe evidence of advanced cholestasis, with an increase in serum bilirubin, as early as 6 h later. In wild-type control rats, multidrug resistance-associated protein 2 (Mrp2) normally concentrates at the bile canalicular membranes to secrete conjugated bilirubin into bile. However, in LAMP-2 y/- rats, Mrp2 was detected in hepatocytes compared with other canalicular proteins including P-glycoproteins, dipeptidyl peptidase IV (CD26), and aminopeptidase (CD13). Our data further suggest that LAMP-2 interacts with the membrane cytoskeletal proteins radixin and F-actin in determining the localization of integral membrane proteins.

Nutritional status alters saccharin intake and sweet receptor mRNA expression in rat taste buds.

PubMed

Chen, Ke; Yan, Jianqun; Suo, Yi; Li, Jinrong; Wang, Qian; Lv, Bo

2010-04-14

Sweet taste usually signifies the presence of caloric food. It is commonly accepted that a close association exists among sweet taste perception, preference, and nutritional status. However, the mechanisms involved remain unknown. To investigate whether nutritional status affects the preference for palatable solutions and alters sweet taste receptor gene expression in rats, we measured saccharin intake and preference using a two-bottle preference test, and changes in body weight, plasma leptin levels, and gene expression for the sweet taste receptor in taste buds in high-fat diet-induced obese rats and chronically diet-restricted rats. We found that the consumption and preference ratios for 0.01 and 0.04 M saccharin were significantly lower in the high-fat diet-induced obese rats than in the normal diet rats, while the serum leptin levels were markedly increased in obese rats. Consistent with the changes in saccharin intake, the gene expression level of the sweet taste receptor T1R3 was significantly decreased in the high-fat diet-induced obese rats compared with the control rats. By contrast, the chronically diet-restricted rats showed remarkably enhanced consumption and preference for 0.04 M saccharin. The serum leptin concentration was decreased, and the gene expression of the leptin receptor was markedly increased in the taste buds. In conclusion, our results suggest that nutritional status alters saccharin preference and the expression of T1R3 in taste buds. These processes may be involved in the mechanisms underlying the modulation of peripheral sweet taste sensitivity, in which leptin plays a role. Copyright 2010 Elsevier B.V. All rights reserved.

Characterization and distribution of natriuretic peptide receptors in the rat uterus.

PubMed

Dos Reis, A M; Fujio, N; Dam, T V; Mukaddam-Daher, S; Jankowski, M; Tremblay, J; Gutkowska, J

1995-10-01

Atrial natriuretic peptide (ANP) receptors were characterized in rat uterus. The binding of [125I]ANP to uterine membranes was completely competed for by increasing concentrations of unlabeled ANP (Kd = 0.39 nM) and brain natriuretic peptide (Kd = 1.24 nM) and partially by C-type natriuretic peptide (CNP; Kd = 80.4 nM), but not by C-ANF. Also, [125I]Tyr-CNP bound to uterine membranes was completely competed by unlabeled CNP (Kd = 1.12 nM). Cross-linking of [125I]ANP to uterine membranes revealed the presence of one band of 130 kilodaltons, corresponding to the guanylyl cyclase (GC-A and/or GC-B) subtypes of natriuretic peptide receptors. The presence of messenger RNA coding for genes of both GC-A and GC-B receptors was shown by quantitative reverse transcriptase polymerase chain reaction. Furthermore, ANP and, to a lesser degree, CNP stimulated the production of cGMP in rat uterus. Autoradiographic studies localized the highest binding of [125I]ANP in the endometrium, whereas [125I]Tyr-CNP binding was distributed in the endometrium as well as in the myometrium. These results demonstrate that rat uterine ANP receptors are of the guanylyl cyclase-coupled subtypes. The uterus is a target of natriuretic peptides where ANP induces its biological effects through the production of cGMP.

Adrenocorticotropin receptors: Functional expression from rat adrenal mRNA in Xenopus laevis oocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mertz, L.M.; Catt, K.J.

1991-10-01

The adrenocorticotropin (ACTH) receptor, which binds corticotropin and stimulates adenylate cyclase and steroidogenesis in adrenocortical cells, was expressed in Xenopus laevis oocytes microinjected with rat adrenal poly(A){sup +} RNA. Expression of the ACTH receptor in individual stage 5 and 6 oocytes was monitored by radioimmunoassay of ligand-stimulated cAMP production. Injection of 5-40 ng of adrenal mRNA caused dose-dependent increases in ACTH-responsive cAMP production. Size fractionation of rat adrenal poly(A){sup +}RNA by sucrose density-gradient centrifugation revealed that mRNA encoding the ACTH receptor was present in the 1.1-to 2.0-kilobase fraction. These data indicate that ACTH receptors can be expressed from adrenal mRNAmore » in Xenopus oocytes and are fully functional in terms of ligand specificity and signal generation. The extracellular cAMP response to ACTH is a sensitive and convenient index of receptor expression. This system should permit more complete characterization and expression cloning of the ACTH receptor.« less

TEMPORAL PATTERNS OF LIPOPEROXIDATION AND ANTIOXIDANT ENZYMES ARE MODIFIED IN THE HIPPOCAMPUS OF VITAMIN A-DEFICIENT RATS

PubMed Central

Navigatore Fonzo, Lorena S.; Golini, Rebeca S.; Delgado, Silvia M.; Ponce, Ivana T.; Bonomi, Myrta R.; Rezza, Irma G.; Gimenez, María S.; Anzulovich, Ana C.

2011-01-01

Animals can adapt their behavior to predictable temporal fluctuations in the environment through both, memory-and-learning processes and an endogenous time-keeping mechanism. Hippocampus plays a key role in memory and learning and is especially susceptible to oxidative stress. In compensation, antioxidant enzymes activity, such as Catalase (CAT) and Glutathione peroxidase (GPx), has been detected in this brain region. Daily rhythms of antioxidant enzymes activitiy, as well as of glutathione and lipid peroxides levels, have been described in brain. Here, we investigate day/night variations in lipoperoxidation, CAT and GPx expression and activity, as well as the temporal fluctuations of two key components of the endogenous clock, BMAL1 and PER1, in the rat hippocampus and evaluate to which extent vitamin A deficiency may affect their amplitude or phase. Holtzman male rats from control, vitamin A-deficient and vitamin A-refed groups were sacrificed throughout a 24-h period. Daily levels of clock proteins, lipoperoxidation, CAT and GPx mRNA, protein, and activity, were determined in the rat hippocampus obtained every 4 or 5 h. Gene expression of RARα and RXRβ was also quantified in the hippocampus of the three groups of rats. Our results show significant daily variations of BMAL1 and PER1 protein expression. Rhythmic lipoperoxidation, CAT, and GPx, expression and activity, were also observed in the rat hippocampus. Vitamin A deficiency reduced RXRβ mRNA level, as well as the amplitude of BMAL1 and PER1 daily oscillation, phase-shifted the daily peak of lipoperoxidation, and had a differential effect on the oscillating CAT and GPx mRNA, protein, and activity. Learning how vitamin A deficiency affects the circadian gene expression in the hippocampus may have an impact on the neurobiology, nutritional and chronobiology fields, emphasizing for the first time the importance of nutritional factors, such as dietary micronutrients, in the regulation of circadian parameters

Perinatal intermittent hypoxia alters γ-aminobutyric acid: a receptor levels in rat cerebellum.

PubMed

Pae, Eung-Kwon; Yoon, Audrey J; Ahuja, Bhoomika; Lau, Gary W; Nguyen, Daniel D; Kim, Yong; Harper, Ronald M

2011-12-01

Perinatal hypoxia commonly causes brain injury in infants, but the time course and mechanisms underlying the preferential male injury are unclear. Intermittent hypoxia disturbs cerebellar γ-aminobutyric (GABA)-A receptor profiles during the perinatal period, possibly responding to transient excitatory processes associated with GABA(A) receptors. We examined whether hypoxic insults were particularly damaging to the male rodent cerebellum during a specific developmental time window. We evaluated cerebellar injury and GABA(A) receptor profiles following 5-h intermittent hypoxia (IH: 20.8% and 10.3% ambient oxygen, switched every 240s) or room-air control in groups of male and female rat pups on postnatal d 1-2, wk 1, or wk 3. The cerebella were harvested and compared between groups. The mRNA levels of GABA(A) receptors α6, normalized to a house-keeping gene GAPDH, and assessed using real-time reverse-transcriptase PCR assays were up-regulated by IH at wk 1, more extensively in male rats, with sex influencing the regulatory time-course. In contrast, GABA(A) α6 receptor protein expression levels, assessed using Western blot assays, reached a nadir at wk 1 in both male and female rats, possibly indicating involvement of a post-transcriptional mechanism. The extent of cerebellar damage and level of apoptosis, assessed by DNA fragmentation, were greatest in the wk 3 IH-exposed group. The findings suggest partial protection for female rats against early hypoxic insult in the cerebellum, and that down-regulation of GABA(A) receptors, rather than direct neural injury assessed by DNA fragmentation may modify cerebellar function, with potential later motor and other deficits. Copyright © 2011 ISDN. Published by Elsevier Ltd. All rights reserved.

Blonanserin extensively occupies rat dopamine D3 receptors at antipsychotic dose range.

PubMed

Baba, Satoko; Enomoto, Takeshi; Horisawa, Tomoko; Hashimoto, Takashi; Ono, Michiko

2015-03-01

Antagonism of the dopamine D3 receptor has been hypothesized to be beneficial for schizophrenia cognitive deficits, negative symptoms and extrapyramidal symptoms. However, recent animal and human studies have shown that most antipsychotics do not occupy D3 receptors in vivo, despite their considerable binding affinity for this receptor in vitro. In the present study, we investigated the D3 receptor binding of blonanserin, a dopamine D2/D3 and serotonin 5-HT2A receptors antagonist, in vitro and in vivo. Blonanserin showed the most potent binding affinity for human D3 receptors among the tested atypical antipsychotics (risperidone, olanzapine and aripiprazole). Our GTPγS-binding assay demonstrated that blonanserin acts as a potent full antagonist for human D3 receptors. All test-drugs exhibited antipsychotic-like efficacy in methamphetamine-induced hyperactivity in rats. Treatment with blonanserin at its effective dose blocked the binding of [(3)H]-(+)-PHNO, a D2/D3 receptor radiotracer, both in the D2 receptor-rich region (striatum) and the D3 receptor-rich region (cerebellum lobes 9 and 10). On the other hand, the occupancies of other test-drugs for D3 receptors were relatively low. In conclusion, we have shown that blonanserin, but not other tested antipsychotics, extensively occupies D3 receptors in vivo in rats. Copyright © 2015 Japanese Pharmacological Society. Production and hosting by Elsevier B.V. All rights reserved.

A Milk-Free Diet Downregulates Folate Receptor Autoimmunity in Cerebral Folate Deficiency Syndrome

ERIC Educational Resources Information Center

Ramaekers, Vincent T.; Sequeira, Jeffrey M.; Blau, Nenad; Quadros, Edward V.

2008-01-01

In cerebral folate deficiency syndrome, the presence of autoantibodies against the folate receptor (FR) explains decreased folate transport to the central nervous system and the clinical response to folinic acid. Autoantibody crossreactivity with milk FR from different species prompted us to test the effect of a milk-free diet. Intervention with a…

In Vivo Kinetics of Formate Metabolism in Folate-deficient and Folate-replete Rats*

PubMed Central

Morrow, Gregory P.; MacMillan, Luke; Lamarre, Simon G.; Young, Sara K.; MacFarlane, Amanda J.; Brosnan, Margaret E.; Brosnan, John T.

2015-01-01

It is now established that the mitochondrial production of formate is a major process in the endogenous generation of folate-linked one-carbon groups. We have developed an in vivo approach involving the constant infusion of [13C]formate until isotopic steady state is attained to measure the rate of endogenous formate production in rats fed on either a folate-replete or folate-deficient diet. Formate was produced at a rate of 76 μmol·h−1·100 g of body weight−1 in the folate-replete rats, and this was decreased by 44% in folate-deficient rats. This decreased formate production was confirmed in isolated rat liver mitochondria where formate production from serine, the principal precursor of one-carbon groups, was decreased by 85%, although formate production from sarcosine and dimethylglycine (choline metabolites) was significantly increased. We attribute this unexpected result to the demonstrated production of formaldehyde by sarcosine dehydrogenase and dimethylglycine dehydrogenase from their respective substrates in the absence of tetrahydrofolate and subsequent formation of formate by formaldehyde dehydrogenase. Comparison of formate production with the ingestion of dietary formate precursors (serine, glycine, tryptophan, histidine, methionine, and choline) showed that ∼75% of these precursors were converted to formate, indicating that formate is a significant, although underappreciated end product of choline and amino acid oxidation. Ingestion of a high protein diet did not result in increased production of formate, suggesting a regulation of the conversion of these precursors at the mitochondrial level to formate. PMID:25480787

Site-specific effects of the nonsteroidal anti-inflammatory drug lysine clonixinate on rat brain opioid receptors.

PubMed

Ortí, E; Coirini, H; Pico, J C

1999-04-01

In addition to effects in the periphery through inhibition of prostaglandin synthesis, several lines of evidence suggest that nonsteroidal anti-inflammatory drugs (NSAIDs) act in the central nervous system. The possibility that the central action of NSAIDs involves regulation of opioid receptors was investigated by quantitative autoradiography of mu, delta, and kappa sites in rat brain slices. Increased (p < 0.05) labeling of mu receptors was observed in thalamic nuclei, gyrus dentate, and layers of the parietal cortex of rats treated for 10 days with lysine clonixinate. Labeling of delta receptors was lower in the lateral septum, and kappa sites decreased in thalamic nuclei. These effects were not mediated through direct interaction with opioid-binding sites, since receptor-binding assays using rat brain membranes confirmed that clonixinate up to 1 x 10(-4) mol/l does not inhibit mu, delta, and kappa receptor specific binding. Central effects of NSAIDs might, therefore, involve interaction with the opioid receptor system through indirect mechanisms.

Systemic blockade of nicotinic and purinergic receptors inhibits ventilation and increases apnoea frequency in newborn rats.

PubMed

Niane, Lalah M; Joseph, Vincent; Bairam, Aida

2012-08-01

We hypothesized that the combined blockade of peripheral cholinergic and purinergic receptors alters the baseline breathing pattern and respiratory responses to carotid body stimuli (hypoxia, hyperoxia and hypercapnia). Rat pups at 4 (P4) and 12 days of postnatal age (P12) received an intraperitoneal injection of either saline vehicle or hexamethonium + suramin (Hex, 1 mg kg(-1), nicotinic receptor antagonist; Sur, 40 mg kg(-1), P2X receptor antagonist; both of which act mainly on peripheral receptors). Compared with the control animals (saline-injected rats), the Hex + Sur-treated rats demonstrated the following features: (1) decreased baseline ventilation and increased frequency of apnoea and breath-by-breath irregularities, with a larger effect in the P4 than in the P12 rats; (2) a decreased peak minute ventilation and respiratory frequency response to hypoxia (fractional inspired oxygen 12%), with a greater effect in the P12 than in the P4 rats; (3) an attenuated decline of the respiratory frequency during hyperoxia (fractional inspired oxygen 50%) to a similar magnitude in rats of both ages; and (4) a decreased hypercapnic ventilatory response (fractional inspired carbon dioxide 5%) to a similar magnitude in rats of both ages. We conclude that the cholinergic nicotinic and purinergic P2X receptors are essential to maintain an adequate baseline pattern in normoxia. They also contribute, albeit not exclusively, to the hypoxic ventilatory response, with an age-specific effect, most probably linked to the cholinergic component, which might partly underlie the postnatal maturation of peripheral chemoreceptors.

Behavioral responses and fluid regulation in male rats after combined dietary sodium deficiency and water deprivation.

PubMed

Lucia, Kimberly J; Curtis, Kathleen S

2018-02-01

Most investigators use a single treatment such as water deprivation or dietary sodium deficiency to evaluate thirst or sodium appetite, which underlie behavioral responses to body fluid challenges. The goal of the present experiments was to assess the effects of combined treatments in driving behaviors. Therefore, we evaluated the effect of combined overnight water deprivation and dietary sodium deficiency on water intake and salt intake by adult male rats in 2-bottle (0.5M NaCl and water) tests. Overnight water deprivation alone increased water intake, and 10days of dietary sodium deficiency increased 0.5M NaCl intake, with a secondary increase in water intake. During combined water deprivation and dietary sodium deficiency, water intake was enhanced and 0.5M NaCl was reduced, but not eliminated, suggesting that physiologically relevant behavioral responses persist. Nonetheless, the pattern of fluid intake was altered by the combined treatments. We also assessed the effect of these behaviors on induced deficits in body sodium and fluid volume during combined treatments and found that, regardless of treatment, fluid ingestion partially repleted the induced deficits. Finally, we examined urine volume and sodium excretion during dietary sodium deficiency with or without overnight water deprivation and found that, whether or not rats were water deprived, and regardless of water consumption, sodium excretion was minimal. Thus, the combination of water deprivation and dietary sodium deficiency appears to arouse drives that stimulate compensatory behavioral responses. These behaviors, in conjunction with physiological adaptations to the treatments, underlie body sodium and volume repletion in the face of combined water deprivation and dietary sodium deficiency. Copyright © 2017 Elsevier Inc. All rights reserved.

Muscarinic receptor-mediated excitation of rat intracardiac ganglion neurons.

PubMed

Hirayama, Michiko; Ogata, Masanori; Kawamata, Tomoyuki; Ishibashi, Hitoshi

2015-08-01

Modulation of the membrane excitability of rat parasympathetic intracardiac ganglion neurons by muscarinic receptors was studied using an amphotericin B-perforated patch-clamp recording configuration. Activation of muscarinic receptors by oxotremorine-M (OxoM) depolarized the membrane, accompanied by repetitive action potentials. OxoM evoked inward currents under voltage-clamp conditions at a holding potential of -60 mV. Removal of extracellular Ca(2+) markedly increased the OxoM-induced current (IOxoM). The inward IOxoM in the absence of extracellular Ca(2+) was fully inhibited by removal of extracellular Na(+), indicating the involvement of non-selective cation channels. The IOxoM was inhibited by organic cation channel antagonists including SKF-96365 and ML-204. The IOxoM was antagonized by muscarinic receptor antagonists with the following potency: 4-DAMP > pirenzepine = darifenacin > methoctramine. Muscarinic toxin 7 (MT-7), a highly selective inhibitor for M1 receptor, produced partial inhibition of the IOxoM. In the presence of MT-7, concentration-inhibition curve of the M3-preferring antagonist darifenacin was shifted to the left. These results suggest the contribution of M1 and M3 receptors to the OxoM response. The IOxoM was inhibited by U-73122, a phospholipase C inhibitor. The membrane-permeable IP3 receptor blocker xestospongin C also inhibited the IOxoM. Furthermore, pretreatment with thapsigargin and BAPTA-AM inhibited the IOxoM, while KN-62, a blocker of Ca(2+)/calmodulin-dependent protein kinase II, had no effect. These results suggest that the activation mechanism involves a PLC pathway, release of Ca(2+) from intracellular Ca(2+) stores and calmodulin. The cation channels activated by muscarinic receptors may play an important role in neuronal membrane depolarization in rat intracardiac ganglion neurons. Copyright © 2015 Elsevier Ltd. All rights reserved.

A dopamine D2 receptor mutant capable of G protein-mediated signaling but deficient in arrestin binding.

PubMed

Lan, Hongxiang; Liu, Yong; Bell, Michal I; Gurevich, Vsevolod V; Neve, Kim A

2009-01-01

Arrestins mediate G protein-coupled receptor desensitization, internalization, and signaling. Dopamine D(2) and D(3) receptors have similar structures but distinct characteristics of interaction with arrestins. The goals of this study were to compare arrestin-binding determinants in D(2) and D(3) receptors other than phosphorylation sites and to create a D(2) receptor that is deficient in arrestin binding. We first assessed the ability of purified arrestins to bind to glutathione transferase (GST) fusion proteins containing the receptor third intracellular loops (IC3). Arrestin3 bound to IC3 of both D(2) and D(3) receptors, with the affinity and localization of the binding site indistinguishable between the receptor subtypes. Mutagenesis of the GST-IC3 fusion proteins identified an important determinant of the binding of arrestin3 in the N-terminal region of IC3. Alanine mutations of this determinant (IYIV212-215) in the full-length D(2) receptor generated a signaling-biased receptor with intact ligand binding and G-protein coupling and activation, but deficient in receptor-mediated arrestin3 translocation to the membrane, agonist-induced receptor internalization, and agonist-induced desensitization in human embryonic kidney 293 cells. This mutation also decreased arrestin-dependent activation of extracellular signal-regulated kinases. The finding that nonphosphorylated D(2)-IC3 and D(3)-IC3 have similar affinity for arrestin is consistent with previous suggestions that the differential effects of D(2) and D(3) receptor activation on membrane translocation of arrestin and receptor internalization are due, at least in part, to differential phosphorylation of the receptors. In addition, these results imply that the sequence IYIV212-215 at the N terminus of IC3 of the D(2) receptor is a key element of the arrestin binding site.