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Sample records for estrous cycle influences

  1. Influence of uterine inflammation on the estrous cycle in rats.

    PubMed

    Kaneko, Kazuyuki; Aoki, Hajime; Furuichi, Tomohiro; Hatori, Sachiko; Tanimoto, Hanako; Kawakami, Shizuo

    2004-06-01

    To investigate how uterine inflammation affects ovarian activity in rats, endometritis was induced and changes in the length of estrous cycle and serum concentrations of estradiol-17beta (E(2)) and progesterone (P(4)) were examined. A suspension of Staphylococcus aureus (bacterial solution) or iodine solution was infused into the uterine lumen at various estrous phases. When the bacterial solution was infused at estrus, metestrus, or the first day of diestrus, the following diestrus continued for 5 to 12 days. In the case of the iodine solution, regardless of the estrous phase of the infusion, the following diestrus continued for approximately 6 days. E(2) concentration after infusion of each solution did not fluctuate largely and remained at a low concentration (around 5 pg/ml). P(4) concentration was high (35-45 ng/ml) on the day following infusion, but decreased rapidly to base line values within a few days and remained thereafter at a low level (around 5 ng/ml). It is assumed that the endometritis caused by biological or chemical stimulation raises the concentration of P(4) to depress gonadotrophic hormone secretion, and hence this high P(4) concentration might inhibit the growth of ovarian follicles.

  2. Influence of estrous and circadian cycles on calcium intake of the rat.

    PubMed

    Voznesenskaya, Anna; Tordoff, Michael G

    2013-03-15

    The food, water and sodium intake of laboratory rats fluctuates over the circadian and estrous cycles. Blood calcium and calcium-regulating hormones also wax and wane in response to these cycles, raising the possibility that the same might be true of calcium intake. To investigate this, we monitored the fluid intakes of female Long-Evans rats given a choice between water and 10mM CaCl2 solution for two consecutive estrous cycles. We found that calcium solution intake changed over the circadian cycle in a similar manner to water intake; the preference scores for CaCl2 solution remained stable. We did not detect any changes in calcium solution intake or preference scores during the estrous cycle despite a decrease in fluid intake at estrus. Thus, fluctuations in intake of calcium solution during the circadian cycle appear to be nonspecific and probably the result of changes in fluid balance. Estrous changes either do not influence calcium intake or their effects are masked by other factors, resulting in stable levels of calcium intake.

  3. Influence of sex, estrous cycle and estrogen on intracranial dural mast cells

    PubMed Central

    Boes, Tanner; Levy, Dan

    2014-01-01

    Background The frequency of migraine headaches is higher in women than in men and in susceptible women attacks are related to changes in ovarian hormone levels. Intracranial mast cells (MCs) are likely to play a role in migraine headache genesis, and changes in the dural MC population might influence headache susceptibility. The present study thus tested the hypothesis that sex and ovarian hormones influence the density and phenotypic makeup of dural MCs. Methods Histochemistry combined with quantitative analyses was employed to investigate sex differences, estrous cycle and ovarian hormone influences on dural MCs density, phenotype and degranulation level in males and females rats. Results Our data show that in female rats, dural MC density fluctuates during the estrous cycle and is overall higher than in males. In ovariectomized rats, estradiol, but not progesterone, promoted an increase in dural MCs density. This effect was abolished by a splenectomy, suggesting estrogen-related recruitment of MCs from the spleen. Finally, our data suggest that the phenotypic make up of dural MCs, which represents the level of cellular maturity, is also governed by changes in estrogen levels. Conclusions Given the potential role of dural MCs in triggering headache, our data suggest that estrogen-related modulation of dural MC density and phenotypic makeup could play a role in mediating the higher frequency and severity of headaches, such as migraine, in women. PMID:22833613

  4. Influence of the estrous cycle on the behavior of rats in the elevated T-maze.

    PubMed

    Gouveia, Amauri; dos Santos, Ubirajara D; Felisbino, Fabrício E; de Afonseca, Taciana L; Antunes, Gabriela; Morato, Silvio

    2004-09-30

    The elevated T-maze is an animal anxiety model which can discriminate between anxiety-like and fear-like behaviors. The estrous cycle is an important variable of the response in animal anxiety tests and is known to affect other models. The aim of the present study was to investigate the influence of the estrous cycle on behavior displayed in the elevated T-maze test. Seventeen male and 60 female rats were submitted to one session in this test, with the females being screened for the estrous cycle and divided into groups according to the various phases. The elevated T-maze had three arms of equal dimensions ( 50 cm x 10 cm), one enclosed by 40-cm high walls and perpendicular to the others, the apparatus being elevated 50 cm above the floor. Each rat was placed in the end of the enclosed arm and the latency for it to leave this arm was recorded. These measurements were repeated three times separated by 30-s intervals (passive avoidance). After trial 3, each rat was placed at the distal end of the right open arm and the latency to exit this arm was recorded. Whenever latencies were greater than 300 s the trial was finished. The results demonstrated females in diestrus exhibited anxiety-like behaviors while females in metaestrus behaved in a similar way as the males. There were no differences between groups in fear-like behaviors. The results also indicate the elevated T-maze to be a sensitive test to measure anxiety.

  5. Gender and estrous cycle influences on behavioral and neurochemical alterations in adult rats neonatally administered ketamine.

    PubMed

    Célia Moreira Borella, Vládia; Seeman, Mary V; Carneiro Cordeiro, Rafaela; Vieira dos Santos, Júnia; Romário Matos de Souza, Marcos; Nunes de Sousa Fernandes, Ethel; Santos Monte, Aline; Maria Mendes Vasconcelos, Silvânia; Quinn, John P; de Lucena, David F; Carvalho, André F; Macêdo, Danielle

    2016-05-01

    Neonatal N-methyl-D-aspartate (NMDA) receptor blockade in rodents triggers schizophrenia (SCZ)-like alterations during adult life. SCZ is influenced by gender in age of onset, premorbid functioning, and course. Estrogen, the hormone potentially driving the gender differences in SCZ, is known to present neuroprotective effects such as regulate oxidative pathways and the expression of brain-derived neurotrophic factor (BDNF). Thus, the aim of this study was to verify if differences in gender and/or estrous cycle phase during adulthood would influence the development of behavioral and neurochemical alterations in animals neonatally administered ketamine. The results showed that ketamine-treated male (KT-male) and female-in-diestrus (KTF-diestrus, the low estrogen phase) presented significant deficits in prepulse inhibition of the startle reflex and spatial working memory, two behavioral SCZ endophenotypes. On the contrary, female ketamine-treated rats during proestrus (KTF-proestrus, the high estradiol phase) had no behavioral alterations. This correlated with an oxidative imbalance in the hippocampus (HC) of both male and KTF-diestrus female rats, that is, decreased levels of GSH and increased levels of lipid peroxidation and nitrite. Similarly, BDNF was decreased in the KTF-diestrus rats while no alterations were observed in KTF-proestrus and male animals. The changes in the HC were in contrast to those in the prefrontal cortex in which only increased levels of nitrite in all groups studied were observed. Thus, there is a gender difference in the adult rat HC in response to ketamine neonatal administration, which is based on the estrous cycle. This is discussed in relation to neuropsychiatric conditions and in particular SCZ. © 2015 Wiley Periodicals, Inc.

  6. Hormonal oscillations during the estrous cycle influence the morphophysiology of the gerbil (Meriones unguiculatus) female prostate (skene paraurethral glands).

    PubMed

    Fochi, Ricardo A; Perez, Ana P S; Bianchi, Carlos V; Rochel, Sabrina S; Góes, Rejane M; Vilamaior, Patrícia S L; Taboga, Sebastião R; Santos, Fernanda C A

    2008-12-01

    The hormonal oscillations that occur during the female reproductive cycle influence the morphophysiology of several organs of the reproductive system. The female prostate is a functional organ sensitive to the action of steroidal hormones, but it is not known whether the hormonal oscillations that occur during the reproductive cycle can alter the biology of this gland. Thus, the present work aims to evaluate the morphofunctional aspects of the female prostate during the gerbil estrous cycle. For this purpose, morphological, morphometric-stereological, serological, and immunocytochemical analyses were carried out. The results of the present study show that the hormonal oscillations that occurred during the estrous cycle altered both the structure and functionality of the gerbil female prostate. These alterations include increased prostatic growth and augmented secretory activity during the proestrus and estrus phases and a gradual decrease of the secretory activity and glandular development in the diestrus I and II phases. These cyclical oscillations appear to be determined by the hormonal peaks of estrogen in diestrus II and by the high levels of progesterone during estrus, since the androgen levels remained constant throughout the estrous cycle.

  7. Estrous cycle influences the expression of neuronal nitric oxide synthase in the hypothalamus and limbic system of female mice

    PubMed Central

    Sica, Monica; Martini, Mariangela; Viglietti-Panzica, Carla; Panzica, GianCarlo

    2009-01-01

    Background Nitric oxide plays an important role in the regulation of male and female sexual behavior in rodents, and the expression of the nitric oxide synthase (NOS) is influenced by testosterone in the male rat, and by estrogens in the female. We have here quantitatively investigated the distribution of nNOS immunoreactive (ir) neurons in the limbic hypothalamic region of intact female mice sacrificed during different phases of estrous cycle. Results Changes were observed in the medial preoptic area (MPA) (significantly higher number in estrus) and in the arcuate nucleus (Arc) (significantly higher number in proestrus). In the ventrolateral part of the ventromedial nucleus (VMHvl) and in the bed nucleus of the stria terminalis (BST) no significant changes have been observed. In addition, by comparing males and females, we observed a stable sex dimorphism (males have a higher number of nNOS-ir cells in comparison to almost all the different phases of the estrous cycle) in the VMHvl and in the BST (when considering only the less intensely stained elements). In the MPA and in the Arc sex differences were detected only comparing some phases of the cycle. Conclusion These data demonstrate that, in mice, the expression of nNOS in some hypothalamic regions involved in the control of reproduction and characterized by a large number of estrogen receptors is under the control of gonadal hormones and may vary according to the rapid variations of hormonal levels that take place during the estrous cycle. PMID:19604366

  8. Sex and estrous cycle influence diazepam effects on anxiety and memory: Possible role of progesterone.

    PubMed

    Silva, Anatildes Feitosa; Sousa, Diego Silveira; Medeiros, André Macêdo; Macêdo, Priscila Tavares; Leão, Anderson Henrique; Ribeiro, Alessandra Mussi; Izídio, Geison Souza; Silva, Regina Helena

    2016-10-03

    Studies with rodents and humans show the relationship between female sex hormones and cognitive/emotional tasks. However, despite the greater incidence of anxiety disorders in women, the data are still inconclusive regarding the mechanisms related to this phenomenon. We evaluated the effects of a classical anxiolytic/amnestic drug (diazepam; DZP) on female (at different estrous cycle phases) and male rats tested in the plus-maze discriminative avoidance task (PMDAT), that allows the concomitant evaluation of memory and anxiety-like behavior. Further, in order to investigate the role of progesterone and its metabolites in the effects of DZP in the PMDAT, female rats were pre-treated with the progesterone receptor antagonist mifepristone or the 5-alpha-reductase inhibitor finasteride. The main findings were: (1) DZP caused memory impairment and anxiolysis in both sexes, but only the highest dose induced the anxiolytic effect in females; (2) females in proestrus did not present the amnestic and anxiolytic effects of DZP (at 2.0 and 4.0mg/kg, respectively) and (3) the co-administration of mifepristone reestablished both amnestic and anxiolytic effects of DZP, while finasteride reinstated the amnestic effect in proestrus female rats. These results suggest that changes in the endogenous levels of progesterone and its metabolites are important in the modulation of emotional/cognitive behavior in female rats. Based on the influence on different aspects of DZP action, the mechanisms related to this modulation are probably linked to GABAergic transmission, but this point remains to be investigated. Further, the variation in therapeutic and adverse effects of DZP depending on sex and hormonal state is of great relevance considering the higher prevalence of anxiety disorders in women.

  9. Sex, strain, and estrous cycle influences on alcohol drinking in rats.

    PubMed

    Priddy, Brittany M; Carmack, Stephanie A; Thomas, Lisa C; Vendruscolo, Janaina C M; Koob, George F; Vendruscolo, Leandro F

    2017-01-01

    Although women appear to be more vulnerable to alcohol-induced pathophysiology than men, the neurobiological basis for sex differences is largely unknown, partially because most studies on alcohol drinking are conducted in male subjects only. The present study examined sex differences in alcohol consumption in two rat strains, Long Evans and Wistar, using multiple behavioral paradigms. The effects of the estrous cycle on alcohol consumption were monitored throughout the study. The results indicated that females drank more alcohol than males when given either continuous or intermittent access to alcohol (vs. water) in their home cages (voluntary drinking). Under operant conditions, no sex or strain differences were found in drinking prior to development of alcohol dependence. However, upon dependence induction by chronic, intermittent alcohol vapor exposure, Wistar rats of both sexes substantially escalated their alcohol intake compared with their nondependent drinking levels, whereas Long Evans rats only exhibited a moderate escalation of drinking. Under these conditions, the estrous cycle had no effect on alcohol drinking in any strain and drinking model. Thus, strain, sex, and drinking conditions interact to modulate nondependent and dependent alcohol drinking. The present results emphasize the importance of including sex and strain as biological variables in exploring individual differences in alcohol drinking and dependence. Published by Elsevier Inc.

  10. Estrous cycle influences excitatory amino acid transport and visceral pain sensitivity in the rat: effects of early-life stress.

    PubMed

    Moloney, Rachel D; Sajjad, Jahangir; Foley, Tara; Felice, Valeria D; Dinan, Timothy G; Cryan, John F; O'Mahony, Siobhain M

    2016-01-01

    Early-life stress (ELS) is a recognized risk factor for chronic pain disorders, and females appear to be more sensitive to the negative effects of stress. Moreover, estrous cycle-related fluctuations in estrogen levels have been linked with alternating pain sensitivity. Aberrant central circuitry involving both the anterior cingulate cortex (ACC) and the lumbosacral spinal cord has also been implicated in the modulation of visceral pain in clinical and preclinical studies. Here we further investigate changes in visceral pain sensitivity and central glutamatergic systems in rats with respect to estrous cycle and ELS. We investigated visceral sensitivity in adult female Sprague-Dawley rats, which had undergone maternal separation (MS) in early life or remained non-separated (NS), by performing colorectal distension (CRD). We also assessed excitatory amino acid uptake through excitatory amino acid transporters (EAATs) in the lumbosacral spinal cord and ACC. NS animals in proestrus and estrus exhibited reduced EAAT uptake and decreased threshold to CRD. Moreover, total pain behaviors were increased in these stages. MS rats exhibited lower pain thresholds and higher total pain behaviors to CRD across all stages of the estrous cycle. Interestingly, cortical EAAT function in MS rats was inhibited in the low estrogen state-an effect completely opposite to that seen in NS rats. This data confirms that estrous cycle and ELS are significant factors in visceral sensitivity and fluctuations in EAAT function may be a perpetuating factor mediating central sensitization.

  11. Influence of sex and estrous cycle on the effects of acute tryptophan depletion induced by a gelatin-based mixture in adult Wistar rats.

    PubMed

    Jans, L A W; Lieben, C K J; Blokland, A

    2007-06-29

    Women are more vulnerable to develop depression and anxiety disorders than men. This may be related to higher serotonergic vulnerability in women. Serotonergic vulnerability entails that differences between people in the regulation of serotonin (5-HT) determine the vulnerability of an individual to develop depression or other 5-HT-related disorders. The aim of the present experiment was to evaluate whether male and female Wistar rats differ in serotonergic vulnerability. Here, a stronger behavioral response to acute tryptophan (TRP) depletion was assumed to reflect serotonergic vulnerability. Twenty-four male and 48 female rats were repeatedly subjected to treatment with a gelatin-based protein-carbohydrate mixture, either with or without L-tryptophan. Female estrous cycle phase was determined by means of vaginal smears and the females were divided into two groups based on their estrous cycle phase: pro-estrus/estrus and met-estrus/di-estrus. Blood samples showed stronger TRP depletion in males than females. There was no effect of estrous cycle on plasma TRP concentrations. In contrast, treatment effects on some brain TRP concentrations were influenced by estrous cycle phase, females in pro-estrus/estrus showed the strongest response to TRP depletion. In the open field test and home cage emergence test, females in pro-estrus/estrus also showed the strongest behavioral response to acute TRP depletion. In general, females showed more activity than males in anxiety-related situations and this effect appeared to be enhanced by TRP depletion. In the social interaction test, passive body contact in males and females in pro-estrus/estrus was decreased after TRP depletion whereas it was increased in females in the met-estrus/di-estrus phase. Acute TRP depletion affected object recognition, but did not affect behavior in the forced swimming test and a reaction time task. It is concluded that sex and estrous cycle phase can influence the behavioral response to TRP depletion

  12. Regulation of the estrous cycle by neutrophils via opioid peptides.

    PubMed

    Sasaki, Soichiro; Tamaki, Yutaka; Nagata, Kisaburo; Kobayashi, Yoshiro

    2011-07-15

    We found previously that neutrophil-depleted mice exhibited significant blockading of both the regular estrous cycle and cyclic changes of steroid hormone levels. In this study, we aimed at elucidation of the underlying mechanism. To examine the possibility that an increase in bacteria in the vaginal vault of neutrophil-depleted mice causes blockading of the estrous cycle, we treated neutrophil-depleted mice with antibiotics but failed to restore the estrous cycle. We then examined another possibility that neutrophils regulate the estrous cycle via opioid peptides, because opioid peptides regulate steroidogenesis in theca and granulosa cells in the ovaries, and because neutrophils contain opioid peptides. In support of this possibility, naloxone, an opioid antagonist, blocked the estrous cycle and a μ opioid receptor agonist restored the estrous cycle in neutrophil-depleted mice. Pro-opiomelanocortin was immunohistochemically detected in peripheral blood neutrophils but not in ones that had infiltrated into the ovaries. i.v. injection of anti-MIP-2 polyclonal Ab caused blockading of the estrous cycle, whereas MIP-2 was detected in the ovaries, suggesting a role of MIP-2 in the regulation of the estrous cycle. Moreover, i.v. injection of MIP-2 decreased the pro-opiomelanocortin signal in peripheral blood neutrophils and caused blockading of the estrous cycle. Together, these results suggest that neutrophils maintain the estrous cycle via opioid peptides.

  13. Unusual and abnormal canine estrous cycles.

    PubMed

    Meyers-Wallen, V N

    2007-12-01

    Preovulatory serum progesterone concentrations are used to estimate the day of LH peak (day 0), not only to accurately time insemination and predict parturition, but to identify abnormal or unusual estrous cycles due to ovarian dysfunction. Early identification of these disorders is of therapeutic and economic importance. This review discusses anovulation, slow preovulatory progesterone rise, "split heat", insufficient luteal phase, and persistent estrus in the bitch. Some of these were temporary dysfunctions; with appropriate breeding management, pregnancy can be achieved. However, in other cases, these were signs of severe, permanent ovarian dysfunction associated with infertility, with potentially lethal sequelae.

  14. Effect of the estrous cycle on water maze acquisition depends on the temperature of the water.

    PubMed

    Rubinow, Marisa J; Arseneau, Linda M; Beverly, J Lee; Juraska, Janice M

    2004-08-01

    The literature on the effects of ovarian hormones on rodent learning and memory is mixed. In this study, the authors examined the role of task stressfulness. Female hooded rats were tested during proestrus or estrus on the hidden-platform water maze in warm (33 degrees C) or cold (19 degrees C) water. There were no effects of cycle or temperature, but estrous phase interacted with temperature such that proestrous rats performed better overall under the warm condition and estrous rats performed better under the cold condition. Plasma corticosterone, measured after 4 trials, varied significantly with estrous phase. Water temperature, perhaps through stress, influences the effect of estrous phase on water maze performance.

  15. The influence of male pheromones on the contractile reactivity of the isolated superficial veins of the nose and face during the estrous cycle in gilts.

    PubMed

    Grzegorzewski, W J

    2005-01-01

    This study was designed to determine whether steroid sex pheromones of the boar may affect the contractile activity of the superficial venous vessels of the nose and face in gilts, and in this way contribute to recently discovered humoral transfer of pheromones to the brain and hypophysis. The dependence between the reactivity of nasal and facial veins to male pheromones and the phase of the estrous cycle in gilts was also studied. The gilts were used in the luteal phase of the cycle and in the follicular phase of the cycle. The dorsal nasal, frontal and facial veins were isolated on an appropriate day of the estrous cycle. The isolated rings of veins were treated with androstenone (5alpha-androst-16-en-3-one), androstenol (5alpha-androst-16-en-3-ol) and testosterone (17beta-hydroxy-4-androsten-3-one) in concentrations of 1 or 10 microM. Changes in the contractile activity of the isolated vein segments were measured using isometric transducer and recorded on HSE-ACAD software for Windows. Androstenone--main signaling boar pheromone--induced much stronger reactions of the vessels than androstenol. Androstenone caused significant relaxation of the dorsal nasal and frontal veins, and significant increased tension of the facial vein in the follicular phase of the estrous cycle. The results obtained suggest a direct effect of male pheromones on the contractile reactivity of the superficial veins of the nose and face in the female, and in this way contribute to a humoral pathway for transfer of pheromones to the brain and hypophysis. Moreover, the present study revealed changes in the reactivity during the estrous cycle of the veins, transporting blood from the region of the nasal cavity, to male pheromones participating in the regulation of female reproductive processes.

  16. The influence of steroids on vascular tension of isolated superficial veins of the nose and face during the estrous cycle of gilts.

    PubMed

    Grzegorzewski, W J; Chłopek, J; Tabecka-Łonczyńska, A; Stefańczyk-Krzymowska, S

    2010-01-15

    The arrangement of the superficial facial veins enables blood flow from the nasal cavity into the peripheral circulation by two pathways: through the frontal vein into the cavernous sinus and through the facial vein into the external jugular vein. The current study was designed to determine whether estradiol and progesterone affect the vascular tone of the superficial veins of the nose and face in cycling gilts (Sus scrofa f. domestica) and to analyze the immunolocalization of progesterone receptors and estradiol receptors in these veins. The influence of hormones on vascular tension differed depending on the type of vessel and the phase of the estrous cycle. Estradiol decreased vascular tension in the nasal vein during the follicular phase (P<0.05) and increased tension in the frontal vein during the luteal phase (P<0.05). Progesterone increased the vascular tension of the frontal vein (P<0.05) and decreased the tension of the other veins (P<0.05) in both phases of the cycle. Expression of estradiol receptor beta but not of progesterone receptor was observed in the superficial veins of the nose and face. In conclusion, the effect of ovarian steroid hormones on the vascular tension of the superficial veins of the nose and face in female pigs as well as the reactivity of these veins to steroid boar pheromones can affect the blood supply from the nasal cavity to the venous cavernous sinus. We propose that the ovarian steroid hormones that modulate the vascular tension of the nasal and facial veins may also influence the action of boar pheromones absorbed into the nasal mucosa in gilts and may reach the brain via local destination transfer.

  17. Validation of a mathematical model of the bovine estrous cycle for cows with different estrous cycle characteristics.

    PubMed

    Boer, H M T; Butler, S T; Stötzel, C; Te Pas, M F W; Veerkamp, R F; Woelders, H

    2017-02-15

    A recently developed mechanistic mathematical model of the bovine estrous cycle was parameterized to fit empirical data sets collected during one estrous cycle of 31 individual cows, with the main objective to further validate the model. The a priori criteria for validation were (1) the resulting model can simulate the measured data correctly (i.e. goodness of fit), and (2) this is achieved without needing extreme, probably non-physiological parameter values. We used a least squares optimization procedure to identify parameter configurations for the mathematical model to fit the empirical in vivo measurements of follicle and corpus luteum sizes, and the plasma concentrations of progesterone, estradiol, FSH and LH for each cow. The model was capable of accommodating normal variation in estrous cycle characteristics of individual cows. With the parameter sets estimated for the individual cows, the model behavior changed for 21 cows, with improved fit of the simulated output curves for 18 of these 21 cows. Moreover, the number of follicular waves was predicted correctly for 18 of the 25 two-wave and three-wave cows, without extreme parameter value changes. Estimation of specific parameters confirmed results of previous model simulations indicating that parameters involved in luteolytic signaling are very important for regulation of general estrous cycle characteristics, and are likely responsible for differences in estrous cycle characteristics between cows.

  18. Sleep homeostasis in the female rat during the estrous cycle.

    PubMed

    Schwierin, B; Borbély, A A; Tobler, I

    1998-11-16

    To investigate whether sleep homeostasis in the female rat is modulated by the estrous cycle, the vigilance states, EEG power spectra and cortical temperature (TCRT) were assessed on the basis of 4-day continuous recordings. A regulatory response was elicited by 6-h sleep deprivation (SD) during the proestrous (PRO) and the estrous (EST) day and compared to the baseline recordings. The vigilance states varied across the estrous cycle. In the PRO dark period the amount of sleep was reduced. The decrease in rapid-eye-movement (REM) sleep was already evident towards the end of the preceding light period, and an increased fragmentation of sleep was present throughout PRO. Compared to the other days of the estrous cycle, slow-wave activity (SWA; EEG power density 0.75-4.75 Hz) in nonREM (NREM) sleep was lower in PRO at the end of the light period and in the beginning of the dark period. High-frequency activity (HFA; EEG power density 10.25-25.0 Hz) was increased in the dark period of PRO. The SD performed during the first 6 h of the light period of PRO and EST enhanced SWA in NREM sleep and reduced sleep fragmentation during the subsequent 6 h. The extent and time course of the response to SD did not differ between the two phases of the estrous cycle. It is concluded that despite the marked baseline variations of the vigilance states and the EEG, homeostatic regulation is little affected by the estrous cycle. Copyright 1998 Elsevier Science B.V.

  19. Glycosaminoglycan Distribution in the Rat Uterine Cervix During the Estrous Cycle

    PubMed Central

    Cubas, Jairo Jose Matozinho; Simões, Ricardo Santos; Oliveira-Filho, Ricardo Martins; Simões, Manuel Jesus; Baracat, Edmund C; Soares, José Maria

    2010-01-01

    OBJECTIVE: To analyze the amount of glycosaminoglycans in the uterine cervix during each phase of the rat estrous cycle. DESIGN: Based on vaginal smears, forty female, regularly cycling rats were divided into four groups (n = 10 for each group): GI – proestrous, GII – estrous, GIII – metaestrous and GIV – diestrous. Animals were sacrificed at each phase of the cycle, and the cervix was immediately removed and submitted to biochemical extraction and determination of sulfated glycosaminoglycans and hyaluronic acid. The results were analyzed by ANOVA followed by the Bonferroni post-hoc test. RESULTS: The uterine cervix had the highest amount of total sulfated glycosaminoglycans and dermatan sulfate during the estrous phase (8.90 ± 0.55 mg/g of cetonic extract, p<0.001; and 8.86 ± 0.57 mg/g of cetonic extract, p<0.001). In addition, there was more heparan sulfate at the cervix during the proestrous phase (0.185 ± 0.03 mg/g of cetonic extract) than during any other phase (p<0.001). There were no significant changes in the concentration of hyaluronic acid in the uterine cervix during the estrous cycle. CONCLUSION: Our data suggest that the amount of total sulfated glycosaminoglycans may be influenced by hormonal fluctuations related to the estrous cycle, with dermatan sulfate and heparan sulfate being the glycosaminoglycans most sensitive to hormonal change. PMID:20668628

  20. Estrous cycle and cold stress in iron-deficient rats

    SciTech Connect

    Smith, S.M.; Bucher, D.R.; Lukaski, H.C. )

    1991-03-11

    Female iron-deficient (ID) rats have plasma triiodothyronine (T{sub 3}) concentrations similar to iron sufficient controls (CN) at 24C. Whether the apparently euthyroid ID female can thermoregulate when exposed to cold was studied to assess the interactive effects of iron deficiency and the female reproductive cycle. Rats were assigned to either ID (n = 60) or CN (n = 60) diets for a period of five weeks. The two groups were then subdivided into five groups, four based on stage of the estrous cycle and the fifth group was ovariectomized one week prior to sacrifice. Animals were exposed to 4C for 6 h. Following sacrifice, tissues were collected for analysis of thyroid hormone and iron status indices. There was an interactive effect of iron status and the estrous cycle on core temperature response to the cold. Plasma thyrozine (T{sup 4}) concentrations were unaffected by iron status or the estrous cycle, and plasma T{sub 3} concentrations were significantly lower in ID than CN rats. Thyroxine 5{prime} - deiodinase activity in the liver was significantly lower in ID animals than CN; this conforms with the plasma T{sub 3} findings. Brown adipose tissue deiodinase was not affected by either iron status or the estrous cycle. In conclusion, iron deficiency impairs thermoregulation in rats, and this effect is related to the ovarian cycle. However, brown adipose tissue does not appear specifically involved in this defect.

  1. Fluctuations in selenium status during the female rat estrous cycle

    SciTech Connect

    Cha, C.; Smith, A.M.; Kimura, R.E. Ohio State Univ., Columbus )

    1991-03-11

    A suggested relationship between selenium (Se) status and sex hormones is based on sex-linked differences in Se status of the liver and dramatic changes in Se status during pregnancy. The effect of estrous cycle hormone fluctuation on Se status was studied in the chronically-catheterized rat model. Se status, measured as plasma and RBC Se and glutathione peroxidase activity (GPx), was assessed at each stage of the 4-day estrous cycle. Stages, determined by cytological exam of vaginal smears, were estrus (E), metestrus (ME), diestrus (DE), and proestrus (PE). Five rats fed a 0.1 ppm Se diet, were catheterized at the abdominal aorta, allowing serial blood draws under nonstressful conditions. At least three blood samples per rat were collected daily for two consecutive cycles. Plasma Se during PE was significantly greater than that at E, ME, or DE. Peak plasma Se occurred at 1,000 hr PE. Peak estrogen and progesterone levels have been reported to occur later in PE. Peak plasma occurred during ME and early PE. A significant decrease in plasma GPx during late PE corresponds with reported peaks in estrogen and progesterone. There were no significant differences in RBC Se or GPx during the estrous cycle. The results of this study suggest that changes in plasma Se and GPx during the estrous cycle may precede similar fluctuations in estrogen and progesterone.

  2. Estrous influence on surgical cure of a mouse breast cancer

    PubMed Central

    1988-01-01

    We have studied the effect of estrous stage, as reflected by vaginal cellularity, at the time of surgical resection of an estrogen receptor- bearing mammary adenocarcinoma upon the metastatic potential of that tumor in the C3HeB/FeJ mouse. Presence of the tumor prolonged the length of the estrous cycle by approximately 25% and removal of the tumor returned the cycle to its usual duration. Neither estrous stage at tumor implant nor size of tumor at resection (within a small range) had significant independent effects upon differences observed in the incidence of subsequent pulmonary metastases. However, estrous stage at time of surgical removal of the tumor, as reflected by cell types in vaginal smear, markedly affected whether or not metastases ultimately appeared. Because the estrous cycle in mice, comparable to the human menstrual cycle, reflects high-amplitude, rhythmic changes in hormone concentrations, it may be that the hormonal status of a women at the time of tumor resection is an important determinant of whether or not that breast cancer ultimately metastasizes. PMID:3397703

  3. Effects of diet and exposure to hindlimb suspension on estrous cycling in Sprague-Dawley rats

    NASA Technical Reports Server (NTRS)

    Tou, Janet C L.; Grindeland, Richard E.; Wade, Charles E.

    2004-01-01

    Various factors can disrupt the female reproductive cycle resulting in subfertility. The primary objective of this study was to determine whether physiological changes associated with exposure to hypogravity disrupt reproductive cycles. The hindlimb suspension (HLS) model was used to simulate the major physiological effects of hypogravity in female Sprague-Dawley rats. Also, to determine whether diet may influence reproductive results, rats were fed purified American Institute of Nutrition (AIN)-93G or chow diet. Rats (n = 9-11/group) subjected to HLS had lengthened estrous cycles due to prolonged diestrus, indicating hypoestrogenism. Interestingly, HLS rats fed AIN-93G but not chow diet had significantly reduced time spent in estrus and decreased plasma estradiol. Attenuation of hypoestrogenism in the chow-fed rats suggested that diet provided an exogenous source of estrogen. The mechanism involved in the disruption of estrous cycling remains to be determined. HLS increased urinary corticosterone (CORT) levels during the initial 4 days of HLS, suggesting that physiological responses to acute stress may be a potential mechanism in the disruption of estrous cycles. Higher basal urinary CORT was observed in rats fed chow vs. AIN-93G diet. HLS resulted in increased urinary CORT. However, two-way ANOVA indicated a significant HLS effect (P < 0.001) but no effect of HLS x diet effect on urinary CORT levels, suggesting that estrogenic activity associated with the chow diet did not enhance the stress response. The results of this study indicate that HLS, diet, and the combination of HLS and diet influence estrous cycling. This has important implications for future reproductive success in the hypogravity environment of space.

  4. Effects of diet and exposure to hindlimb suspension on estrous cycling in Sprague-Dawley rats

    NASA Technical Reports Server (NTRS)

    Tou, Janet C L.; Grindeland, Richard E.; Wade, Charles E.

    2004-01-01

    Various factors can disrupt the female reproductive cycle resulting in subfertility. The primary objective of this study was to determine whether physiological changes associated with exposure to hypogravity disrupt reproductive cycles. The hindlimb suspension (HLS) model was used to simulate the major physiological effects of hypogravity in female Sprague-Dawley rats. Also, to determine whether diet may influence reproductive results, rats were fed purified American Institute of Nutrition (AIN)-93G or chow diet. Rats (n = 9-11/group) subjected to HLS had lengthened estrous cycles due to prolonged diestrus, indicating hypoestrogenism. Interestingly, HLS rats fed AIN-93G but not chow diet had significantly reduced time spent in estrus and decreased plasma estradiol. Attenuation of hypoestrogenism in the chow-fed rats suggested that diet provided an exogenous source of estrogen. The mechanism involved in the disruption of estrous cycling remains to be determined. HLS increased urinary corticosterone (CORT) levels during the initial 4 days of HLS, suggesting that physiological responses to acute stress may be a potential mechanism in the disruption of estrous cycles. Higher basal urinary CORT was observed in rats fed chow vs. AIN-93G diet. HLS resulted in increased urinary CORT. However, two-way ANOVA indicated a significant HLS effect (P < 0.001) but no effect of HLS x diet effect on urinary CORT levels, suggesting that estrogenic activity associated with the chow diet did not enhance the stress response. The results of this study indicate that HLS, diet, and the combination of HLS and diet influence estrous cycling. This has important implications for future reproductive success in the hypogravity environment of space.

  5. Effects of diet and exposure to hindlimb suspension on estrous cycling in Sprague-Dawley rats.

    PubMed

    Tou, Janet C L; Grindeland, Richard E; Wade, Charles E

    2004-03-01

    Various factors can disrupt the female reproductive cycle resulting in subfertility. The primary objective of this study was to determine whether physiological changes associated with exposure to hypogravity disrupt reproductive cycles. The hindlimb suspension (HLS) model was used to simulate the major physiological effects of hypogravity in female Sprague-Dawley rats. Also, to determine whether diet may influence reproductive results, rats were fed purified American Institute of Nutrition (AIN)-93G or chow diet. Rats (n = 9-11/group) subjected to HLS had lengthened estrous cycles due to prolonged diestrus, indicating hypoestrogenism. Interestingly, HLS rats fed AIN-93G but not chow diet had significantly reduced time spent in estrus and decreased plasma estradiol. Attenuation of hypoestrogenism in the chow-fed rats suggested that diet provided an exogenous source of estrogen. The mechanism involved in the disruption of estrous cycling remains to be determined. HLS increased urinary corticosterone (CORT) levels during the initial 4 days of HLS, suggesting that physiological responses to acute stress may be a potential mechanism in the disruption of estrous cycles. Higher basal urinary CORT was observed in rats fed chow vs. AIN-93G diet. HLS resulted in increased urinary CORT. However, two-way ANOVA indicated a significant HLS effect (P < 0.001) but no effect of HLS x diet effect on urinary CORT levels, suggesting that estrogenic activity associated with the chow diet did not enhance the stress response. The results of this study indicate that HLS, diet, and the combination of HLS and diet influence estrous cycling. This has important implications for future reproductive success in the hypogravity environment of space.

  6. Effect of season on estrous cycle of Yankasa sheep.

    PubMed

    Igono, M O; Molokwu, E C; Aliu, Y O

    1982-09-01

    An investigation was conducted to establish the effects of harmattan and hot-dry season on estrous cycle length, onset, and duration of estrus in Yankasa sheep indigenous to the Nigerian guinea savanna zone. Mean cycle lengths were 16.8 +/- 0.58 and 16.4 +/- 0.53 days during harmattan and hot-dry seasons, respectively; short cycles, 5-13 days, and long cycles, 21 to 30 days, were observed during both seasons. During the harmattan season, 57.1% of estrus began at night while 70% started at night during the hot-dry season. The duration of normal estrus observed during the harmattan, 33.6 +/- 5.87h, significantly decreased (P0.05) during the hot-dry season (24.0 +/- 5.45h). It is suggested that twice daily observation at 12-hour intervals will suffice to detect estrus in this breed of sheep.

  7. Influence of the estrous cycle on the sensitivity to catecholamines in right atria from rats submitted to foot-shock stress.

    PubMed

    Vanderlei, L C; Marcondes, F K; Lanza, L L; Spadari-Bratfisch, R C

    1996-06-01

    We investigated the mechanisms of the alterations in sensitivity to catecholamines in right atria from female rats exhibiting regular 4-day estrous cycles after three foot-shock sessions at estrus, metestrus, and diestrus or at diestrus, proestrus, and estrus. Right atria from stressed rats sacrificed at diestrus showed subsensitivity to noradrenaline and adrenaline. After in vitro sympathetic denervation (38 microM 6-hydroxydopamine) plus inhibition of neuronal reuptake (0.1 microM desipramine) subsensitivity to noradrenaline was abolished, but it was again evident when extraneuronal uptake was also inhibited (10 microM phenoxybenzamine and 30 microM corticosterone). The same pretreatment abolished the subsensitivity to adrenaline. After addition of 1 microM butoxamine, a beta 2-adrenoceptor antagonist, the tissues from stressed rats were subsensitive to adrenaline. Right atria from stressed rats sacrificed at estrus did not show any alteration in sensitivity to catecholamines. We conclude that after foot-shock stress, right atria from female rats sacrificed at diestrus showed subsensitivity of the chronotropic response to catecholamines as a result of a conformational alteration of beta 1-adrenoceptors, simultaneously with an increase in beta 2-adrenoceptor-mediated response. The mechanisms seem to be similar to those which underlie stress-induced alterations in catecholamine sensitivity in right atria from male rats. However, during estrus there are some protective factors that prevent the effects of stress on right atria.

  8. Hormone-dependence of sarin lethality in rats: Sex differences and stage of the estrous cycle

    SciTech Connect

    Smith, Carl D. Wright, Linnzi K.M.; Garcia, Gregory E.; Lee, Robyn B.; Lumley, Lucille A.

    2015-09-15

    Chemical warfare nerve agents (CWNAs) are highly toxic compounds that cause a cascade of symptoms and death, if exposed casualties are left untreated. Numerous rodent models have investigated the toxicity and mechanisms of toxicity of CWNAs, but most are limited to male subjects. Given the profound physiological effects of circulating gonadal hormones in female rodents, it is possible that the daily cyclical fluctuations of these hormones affect females' sensitivity to the lethal effects of CWNAs, and previous reports that included female subjects did not control for the stage of the hormonal cycle. The aim of the current study was to determine the 24-hour median lethal dose (LD{sub 50}) of the CWNA sarin in male, ovariectomized (OVEX) female, and female rats during different stages of the estrous cycle (diestrus, proestrus, and estrus). Additionally, baseline activity levels of plasma acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were measured to determine differences among the groups. Results indicated that females in proestrus had a significantly higher LD{sub 50} of sarin compared to OVEX and estrous females. Although some sex differences were observed in the activity levels of plasma esterases, they were not consistent and likely not large enough to significantly affect the LD{sub 50}s. These results suggest that hormonal cyclicity can influence the outcome of CWNA-related studies using female rodents, and that this variability can be minimized by controlling for the stage of the cycle. Additional research is necessary to determine the precise mechanism of the observed differences because it is unlikely to be solely explained by plasma esterase activity. - Highlights: • The LD{sub 50} of sarin was determined in female rats throughout the stages of the estrous cycle. • Females in proestrus had a significantly higher LD{sub 50} compared to estrous or ovariectomized females. • No sex differences were observed between male and female rats

  9. Estrous cycle synchronization in the Persian onager (Equus hemionus onager).

    PubMed

    Ter Beest, Julia M; Schook, Mandi W

    2016-01-01

    The endangered Persian onager (Equus hemionus onager) has experienced significant population declines over the past century due to poaching, habitat destruction, and resource competition. Remaining animals in zoos and the wild are regionally isolated. Artificial insemination (AI) may be particularly useful as a means of aiding in global genetic management of these isolated populations. The first successful AI in onagers was performed in 2009 utilizing urinary hormone analyses and regular transrectal ultrasound examinations that required specialized handling devices. A method for estrous synchronization in this species would alleviate the need for daily handling and provide a more feasible approach to AI. This study tested long-acting controlled-release preparations of estradiol and progesterone, followed by a single injection of prostaglandin 10 days later, in six adult female Persian onagers to determine whether ovulation would occur within a narrow window of time. Serial transrectal ultrasound exams were performed to determine the day of ovulation following hormone treatment. Means and standard deviations were determined for the lengths of follicular and luteal phases, follicle sizes, and time to ovulation, and compared to historical data in this species. All six onagers ovulated between Days 18 and 22, with three females ovulating on Day 19, as determined by the presence of a corpus luteum. This is an apparently safe and effective method for the synchronization of estrous cycles in the Persian onager, and may be used to develop a timed AI protocol for use at institutions that do not have specialized handling facilities to enable regular transrectal ultrasound.

  10. The estrous cycle of the ewe is resistant to disruption by repeated, acute psychosocial stress.

    PubMed

    Wagenmaker, Elizabeth R; Breen, Kellie M; Oakley, Amy E; Tilbrook, Alan J; Karsch, Fred J

    2010-06-01

    Five experiments were conducted to test the hypothesis that psychosocial stress interferes with the estrous cycle of sheep. In experiment 1, ewes were repeatedly isolated during the follicular phase. Timing, amplitude, and duration of the preovulatory luteinizing hormone (LH) surge were not affected. In experiment 2, follicular-phase ewes were subjected twice to a "layered stress" paradigm consisting of sequential, hourly application of isolation, restraint, blindfold, and predator cues. This reduced the LH pulse amplitude but did not affect the LH surge. In experiment 3, different acute stressors were given sequentially within the follicular phase: food denial plus unfamiliar noises and forced exercise, layered stress, exercise around midnight, and transportation. This, too, did not affect the LH surge. In experiment 4, variable acute psychosocial stress was given every 1-2 days for two entire estrous cycles; this did not disrupt any parameter of the cycle monitored. Lastly, experiment 5 examined whether the psychosocial stress paradigms of experiment 4 would disrupt the cycle and estrous behavior if sheep were metabolically stressed by chronic food restriction. Thirty percent of the food-restricted ewes exhibited deterioration of estrous cycle parameters followed by cessation of cycles and failure to express estrous behavior. However, disruption was not more evident in ewes that also encountered psychosocial stress. Collectively, these findings indicate the estrous cycle of sheep is remarkably resistant to disruption by acute bouts of psychosocial stress applied intermittently during either a single follicular phase or repeatedly over two estrous cycles.

  11. Effect of the season on some aspects of the estrous cycle in Martina Franca donkey.

    PubMed

    Contri, A; Robbe, D; Gloria, A; De Amicis, I; Veronesi, M C; Carluccio, A

    2014-03-15

    The Martina Franca (MF) donkey breed, with 48 jackasses and 515 jennies, is considered an endangered breed according to the data from the Monitoring Institute for Rare Breeds and Seeds in Europe. The knowledge of the estrous cycle characteristics has a great impact for assisted reproduction, especially in endangered species. In this study, the estrous cycle characteristics were investigated in 12 MF jennies throughout the year. Estrous cycle, estrous and diestrous lengths, follicular growth and ovulation, and estradiol-17β (E2) and progesterone (P4) plasma concentrations were monitored in MF jennies and compared in different seasons. In all jennies (100%) estrous cycle was detected during the whole year, with no differences in the estrous cycle length among seasons. However, a significant increase of estrous length in spring and summer compared with autumn and winter was found. Diestrus was shorter in summer than in the other seasons. Estrous behavior was always shown and characterized by rhythmic eversion of the vulvar labia (winking) with exhibition of the clitoris, urination, male receptivity and clapping, with sialorrhoea, neck and head extension, and back ears. Estrus was characterized by the ovulation of a larger follicle in spring and summer than in autumn and winter. The pattern of E2 and P4 plasma concentrations during the estrous cycle were similar to that reported for the mare, but without differences among the four seasons, so that a negligible effect of environmental conditions on ovarian E2 and P4 secretion was hypothesized, despite the larger diameter of the ovulating follicle in spring and summer.

  12. The novel roles of neutrophils via opioid peptides: regulation of the estrous cycle and pain.

    PubMed

    Kobayashi, Yoshiro

    2013-06-01

    Neutrophils are excreted into the vaginal vault at metestrus during the estrous cycle, and this phenomenon has long been used to determine the phase of the estrous cycle. A much smaller number of neutrophils are also detected in the uterus and the ovary. Recently, we provided several lines of evidence supporting the notion that neutrophils infiltrate into the ovary to regulate the estrous cycle by opioid peptides. Upon inflammation, on the other hand, neutrophils infiltrate into the site of infection to suppress pain by opioid peptides. Thus, opioid peptides are key molecules by which neutrophils play a novel role in regulation of the pain and estrous cycle. In both cases, opioid peptides appear to be secreted by neutrophils stimulated with chemokines, such as MIP-2 and KC in mouse, corticotropin-releasing hormone and IL-1.

  13. Hormonal Fluctuations during the Estrous Cycle Modulate Heme Oxygenase-1 Expression in the Uterus

    PubMed Central

    Zenclussen, Maria Laura; Casalis, Pablo Ariel; Jensen, Federico; Woidacki, Katja; Zenclussen, Ana Claudia

    2014-01-01

    Deletion of the heme oxygenase-1 (HO-1) (Hmox1) locus in mice results in intrauterine lethality. The expression of the heme catabolizing enzyme encoded by this gene, namely HO-1, is required to successfully support reproductive events. We have previously observed that HO-1 acts at several key events in reproduction ensuring pregnancy. HO-1 defines ovulation, positively influences implantation and placentation, and ensures fetal growth and survival. Here, we embarked on a study aimed to determine whether hormonal changes during the estrous cycle in the mouse define HO-1 expression that may influence receptivity. We analyzed the serum levels of progesterone and estrogen by ELISA and HO-1 mRNA expression in uterus by real time RT-PCR at the metestrus, proestrus, estrus, and diestrus phases of the estrous cycle. Further, we studied the HO-1 protein expression by western blot upon hormone addition to cultured uterine AN3 cells. We observed that HO-1 variations in uterine tissue correlated to changes in hormonal levels at different phases of the estrus cycle. In vitro, HO-1 protein levels in AN3 cells augmented after the addition of physiological concentrations of progesterone and estradiol, which confirmed our in vivo observations. Our data suggest an important role for hormones in HO-1 regulation in uterus during receptivity, a process known to have a significant impact in receptivity and later on blastocyst implantation. PMID:24659985

  14. Ultrastructural changes of goat corpus luteum during the estrous cycle.

    PubMed

    Jiang, Yi-Fan; Hsu, Meng-Chieh; Cheng, Chiung-Hsiang; Tsui, Kuan-Hao; Chiu, Chih-Hsien

    2016-07-01

    The present study was designed to study the ultrastructure of goat corpora lutea (CL, n=10) and structural changes as related to steroidogenic functions during the estrous cycle. The reproduction status of goats was estimated by analyzing serum progesterone concentrations. The CL at various stages was surgically collected. To characterize ultrastructural features associated with steroidogenesis, tissue and cellular structures were studied. Blood supplies were examined based on features of the endothelial cells and capillary structures in the CL. Activated endothelial cells and developing vessels were observed in the early stage, whereas mature endothelial cells, accumulating extracellular matrix fibers, and stabilized vessels were observed in the middle and late stages of assessment. In the late stage of assessment, shrunken goat luteal cells scattered around the capillaries were detected and formed circular regression areas. Features of autophagy and luteal cell apoptosis were noted. In large luteal cells, steroidogenic organelles were present, including microvillar channels, endoplasmic reticulum, and mitochondria. Conformational changes in the endoplasmic reticulum and increased mitochondria with tubular cristae were observed in the early-middle CL transitions. In contrast, mitochondria swelled and the cristae transformed to the lamellar type in the late stage, suggesting that organelle plasticity could contribute to steroidogenesis in goat CL. In conclusion, results suggest angiogenesis occurs in early developing CL and programmed cell death occurred in the late stage of CL assessment in the present study. Structures and quantiles of steroidogenic organelles are correlated with the steroidogenic functions in goats. Copyright © 2016 Elsevier B.V. All rights reserved.

  15. Disrupted reproduction, estrous cycle, and circadian rhythms in female mice deficient in vasoactive intestinal peptide.

    PubMed

    Loh, D H; Kuljis, D A; Azuma, L; Wu, Y; Truong, D; Wang, H B; Colwell, C S

    2014-10-01

    The female reproductive cycle is gated by the circadian timing system and may be vulnerable to disruptions in the circadian system. Prior work suggests that vasoactive intestinal peptide (VIP)-expressing neurons in the suprachiasmatic nucleus (SCN) are one pathway by which the circadian clock can influence the estrous cycle, but the impact of the loss of this peptide on reproduction has not been assessed. In the present study, we first examine the impact of the genetic loss of the neuropeptide VIP on the reproductive success of female mice. Significantly, mutant females produce about half the offspring of their wild-type sisters even when mated to the same males. We also find that VIP-deficient females exhibit a disrupted estrous cycle; that is, ovulation occurs less frequently and results in the release of fewer oocytes compared with controls. Circadian rhythms of wheel-running activity are disrupted in the female mutant mice, as is the spontaneous electrical activity of dorsal SCN neurons. On a molecular level, the VIP-deficient SCN tissue exhibits lower amplitude oscillations with altered phase relationships between the SCN and peripheral oscillators as measured by PER2-driven bioluminescence. The simplest explanation of our data is that the loss of VIP results in a weakened SCN oscillator, which reduces the synchronization of the female circadian system. These results clarify one of the mechanisms by which disruption of the circadian system reduces female reproductive success. © 2014 The Author(s).

  16. Latent inhibition is affected by phase of estrous cycle in female rats.

    PubMed

    Quinlan, Matthew G; Duncan, Andrew; Loiselle, Catherine; Graffe, Nicole; Brake, Wayne G

    2010-12-01

    Estrogen has been shown to have a strong modulatory influence on several types of cognition in both women and female rodents. Latent inhibition is a task in which pre-exposure to a neutral stimulus, such as a tone, later impedes the association of that stimulus with a particular consequence, such as a shock. Previous work from our lab demonstrates that high levels of estradiol (E2) administered to ovariectomized (OVX) female rats abolishes latent inhibition when compared to female rats with low levels of E2 or male rats. To determine if this E2-induced impairment also occurs with the natural variations of ovarian hormones during the estrous cycle, this behavior was investigated in cycling female rats. In addition, pre-pubertal male and female rats were also tested in this paradigm to determine if the previously described sex differences are activational or organizational in nature. In a latent inhibition paradigm using a tone and a shock, adult rats were conditioned during different points of the estrous cycle. Rats conditioned during proestrus, a period of high E2 levels, exhibited attenuated latent inhibition when compared to rats conditioned during estrus or metestrus, periods associated with low levels of E2. Moreover, this effect is not seen until puberty indicating it is dependent on the surge of hormones at puberty. This study confirms recent findings that high E2 interferes with latent inhibition and is the first to show this is based in the activational actions of hormones.

  17. Estrous Cycle Induces Peripheral Sensitization in Trigeminal Ganglion Neurons: An Animal Model of Menstrual Migraine.

    PubMed

    Saleeon, Wachirapong; Jansri, Ukkrit; Srikiatkhachorn, Anan; Bongsebandhu-phubhakdi, Saknan

    2016-02-01

    Many women experience menstrual migraines that develop into recurrent migraine attacks during menstruation. In the human menstrual cycle, the estrogen level fluctuates according to changes in the follicular and luteal phases. The rat estrous cycle is used as an animal model to study the effects of estrogen fluctuation. To investigate whether the estrous cycle is involved in migraine development by comparing the neuronal excitability of trigeminal ganglion (TG) neurons in each stage of the estrous cycle. Female rats were divided into four experimental groups based on examinations of the cytologies of vaginal smears, and serum analyses of estrogen levels following each stage of the estrous cycle. The rats in each stage of the estrous cycle were anesthetized and their trigeminal ganglia were removed The collections of trigeminal ganglia were cultured for two to three hours, after which whole-cell patch clamp experiments were recorded to estimate the electrophysiological properties of the TG neurons. There were many vaginal epithelial cells and high estrogen levels in the proestrus and estrus stages of the estrous cycle. Electrophysiological studies revealed that the TG neurons in the proestrus and estrus stages exhibited significantly lower thresholds of stimulation, and significant increase in total spikes compared to the TG neurons that were collected in the diestrus stage. Our results revealed that high estrogen levels in the proestrus and estrus stages altered the thresholds, rheobases, and total spikes of the TG neurons. High estrogen levels in the estrous cycle induced an increase in neuronal excitability and the peripheral sensitization of TG neurons. These findings may provide an explanation for the correlation of estrogen fluctuations during the menstrual cycle with the pathogenesis of menstrual migraines.

  18. Comparative histopathology of the estrous or menstrual cycle in laboratory animals

    PubMed Central

    Sato, Junko; Nasu, Masahiro; Tsuchitani, Minoru

    2016-01-01

    Accurate analysis of female reproductive toxicity requires a thorough understanding the differences in and specifics of estrous or menstrual cycles between laboratory animals. There are some species differences such as the time of sex maturation, the length of the estrous or menstrual cycle, the length of the luteal phase, the number of dominant follicles or corpora lutea, the size of follicles, processes of luteinization, and hormonal changes during the estrous or menstrual cycle. Rodents have a short estrous cycle, and their ovarian cycling features are the same in both ovaries, which contain a large number of follicles and corpora lutea. The dog estrous cycle is much longer than those of other laboratory animals, and it includes a long anestrus phase. The duration of the menstrual cycle of monkeys is roughly 30 days, and their ovarian cycling features are different between the left and right ovaries. In both rodents and dogs, the theca cells invade the early luteum, mixing with granulosa cells during luteinization. However in monkeys, the theca layer dose not mix with the granulosa cells as it invaginates only slightly into the early luteum. In addition, we found that high progesterone levels after ovulation are sustained for a much shorter duration in rodents than in dogs and monkeys due to the comparatively rapid passage of the rodent luteal phase. Based on these species differences, animal species for use in ovarian toxicology studies need to be selected appropriately. PMID:27559240

  19. Influence of personality, age, sex, and estrous state on chimpanzee problem-solving success

    PubMed Central

    Hopper, Lydia M.; Price, Sara A.; Freeman, Hani D.; Lambeth, Susan P.; Schapiro, Steven J.

    2015-01-01

    Despite the importance of individual problem solvers for group- and individual-level fitness, the correlates of individual problem-solving success are still an open topic of investigation. In addition to demographic factors, such as age or sex, certain personality dimensions have also been revealed as reliable correlates of problem-solving by animals. Such correlates, however, have been little-studied in chimpanzees. To empirically test the influence of age, sex, estrous state, and different personality factors on chimpanzee problem-solving, we individually tested 36 captive chimpanzees with two novel foraging puzzles. We included both female (N = 24) and male (N = 12) adult chimpanzees (aged 14–47 years) in our sample. We also controlled for the females’ estrous state—a potential influence on cognitive reasoning—by testing cycling females both when their sexual swelling was maximally tumescent (associated with the luteinizing hormone surge of a female’s estrous cycle) and again when it was detumescent. Although we found no correlation between the chimpanzees’ success with either puzzle and their age or sex, the chimpanzees’ personality ratings did correlate with responses to the novel foraging puzzles. Specifically, male chimpanzees that were rated highly on the factors Methodical, Openness (to experience), and Dominance spent longer interacting with the puzzles. There was also a positive relationship between the latency of females to begin interacting with the two tasks and their rating on the factor Reactivity/Undependability. No other significant correlations were found, but we report tentative evidence for increased problem-solving success by the females when they had detumescent estrous swellings. PMID:24322874

  20. Morphometrical and neurochemical changes in the anteroventral subdivision of the rat medial amygdala during estrous cycle.

    PubMed

    Carrillo, Beatriz; Pinos, Helena; Guillamón, Antonio; Panzica, Giancarlo; Collado, Paloma

    2007-05-30

    The anteroventral subdivision of the medial amygdala (MeAV) is one of the vomeronasal structures involved in the control of hormonally dependent behaviors such as sexual and agonistic behaviors in rats. The present study investigates some anatomical and neurochemical parameters of this nucleus (volume, number of neurons, number of glial elements, and of NADPH-diaphorase-positive neurons) in females in two estrous cycle phases (diestrous and estrous) and in males. We also investigate the possible existence of adult neurogenesis in this nucleus in the females. Results showed that volume and estimated number of Nissl-stained neurons in the MeAV vary with the estrous cycle phase: estrous females have greater values than diestrous females. As a consequence of these variations, there is a transient sex difference between males and diestrous females. Two subpopulations of NADPH-diaphorase-positive neurons were detected: intensely stained and medium stained. The intensely stained neurons were more numerous in the estrous than the diestrous females. Neither BrdU nor GFAP inmunostaining revealed significant differences between the two groups, suggesting that adult cell generation, i.e., increases in the number of glial elements, has no significant role in the changes detected in the number of Nissl-stained sections. In conclusion, the MeAV shows functional diergism, due to plastic changes in the female rat brain probably linked to the increase of estradiol during estrous. Finally, these changes are probably functionally related to changes in the behaviors that are controlled through this nucleus.

  1. Signaling Role of Prokineticin 2 on the Estrous Cycle of Female Mice

    PubMed Central

    Xiao, Ling; Zhang, Chengkang; Li, Xiaohan; Gong, Shiaoching; Hu, Renming; Balasubramanian, Ravikumar; Crowley W. Jr., William F.; Hastings, Michael H.; Zhou, Qun-Yong

    2014-01-01

    The possible signaling role of prokineticin 2 (PK2) and its receptor, prokineticin receptor 2 (PKR2), on female reproduction was investigated. First, the expression of PKR2 and its co-localization with estrogen receptor (ERα) in the hypothalamus was examined. Sexually dimorphic expression of PKR2 in the preoptic area of the hypothalamus was observed. Compared to the male mice, there was more widespread PKR2 expression in the preoptic area of the hypothalamus in the female mice. The likely co-expression of PKR2 and ERα in the preoptic area of the hypothalamus was observed. The estrous cycles in female PK2-null, and PKR2-null heterozygous mice, as well as in PK2-null and PKR2-null compound heterozygous mice were examined. Loss of one copy of PK2 or PKR2 gene caused elongated and irregular estrous cycle in the female mice. The alterations in the estrous cycle were more pronounced in PK2-null and PKR2-null compound heterozygous mice. Consistent with these observations, administration of a small molecule PK2 receptor antagonist led to temporary blocking of estrous cycle at the proestrous phase in female mice. The administration of PKR2 antagonist was found to blunt the circulating LH levels. Taken together, these studies indicate PK2 signaling is required for the maintenance of normal female estrous cycles. PMID:24633064

  2. Luteolysis in Bos indicus cows on Days 5 and 7 of estrous cycle with varying doses of PGF2α.

    PubMed

    Ferraz Junior, Marcos Vinicius C; Pires, Alexandre V; Biehl, Marcos Vinicius; Santos, Marcelo Henrique; Polizel, Daniel M; Nepomuceno, Delci D; Sartori, Roberto; Barreto Filho, João Bosco; Gonçalves, José Renato S; Day, Michael L

    2016-09-15

    The aim of this study was to evaluate luteolysis using three doses of PGF2α on Day 5 or Day 7 of the estrous cycle in nonlactating Nellore (Bos indicus) cows. Cows (n = 323) were assigned within date of estrus (Day 0 of estrous cycle) to receive 12.5, 25.0, or 50.0 mg of PGF2α on either Day 5 or Day 7 of the estrous cycle in a 3 × 2 factorial arrangement. Blood samples for progesterone (P4) concentrations were collected at 0, 24, 48, and 72 hours after PGF2α to assess luteolysis (L). Luteolysis was defined on the basis of P4 concentrations at 72 hours using either less than 0.5 ng/mL (L0.5) or less than 1.0 ng/mL (L1.0) as the cut off. Luteolysis was considered "partial" when P4 concentration declined within 24 hours after PGF2α but failed to decline further or, in some cases, increased. Incidence of luteolysis was less (P < 0.01) on Day 5 than Day 7 of the estrous cycle (17.3 vs. 47.6% and 30.4 vs. 77.2%; for L0.5 and L1.0, respectively). Dose of PGF2α increased (P < 0.01) L1.0 (12.5 mg = 38.9%; 25.0 mg = 52.3%; and 50.0 mg = 70.4%). Incidence of partial luteolysis for cows on Day 5 (57.1%) was greater (P < 0.01) than that on Day 7 (19.1%) of the estrous cycle and was more prevalent (P < 0.01) with lower doses of PGF2α (12.5 mg = 49.1%; 25.0 mg = 37.4%; and 50.0 mg = 27.8%). In conclusion, both days of the estrous cycle and doses of PGF2α influenced the incidence of complete and partial luteolysis in Nellore cows and should be an important consideration when devising estrus synchronization programs in this species.

  3. The estrous cycle surpasses sex differences in regulating the transcriptome in the rat medial prefrontal cortex and reveals an underlying role of early growth response 1.

    PubMed

    Duclot, Florian; Kabbaj, Mohamed

    2015-12-02

    Males and females differ in cognitive functions and emotional processing, which in part have been associated with baseline sex differences in gene expression in the medial prefrontal cortex. Nevertheless, a growing body of evidence suggests that sex differences in medial prefrontal cortex-dependent cognitive functions are attenuated by hormonal fluctuations within the menstrual cycle. Despite known genomic effects of ovarian hormones, the interaction of the estrous cycle with sex differences in gene expression in the medial prefrontal cortex remains unclear and warrants further investigations. We undertake a large-scale characterization of sex differences and their interaction with the estrous cycle in the adult medial prefrontal cortex transcriptome and report that females with high and low ovarian hormone levels exhibited a partly opposed sexually biased transcriptome. The extent of regulation within females vastly exceeds sex differences, and supports a multi-level reorganization of synaptic function across the estrous cycle. Genome-wide analysis of the transcription factor early growth response 1 binding highlights its role in controlling the synapse-related genes varying within females. We uncover a critical influence of the estrous cycle on the adult rat medial prefrontal cortex transcriptome resulting in partly opposite sex differences in proestrus when compared to diestrus females, and we discovered a direct role for Early Growth Response 1 in this opposite regulation. In addition to illustrating the importance of accounting for the estrous cycle in females, our data set the ground for a better understanding of the female specificities in cognition and emotional processing.

  4. The rodent estrous cycle: Characterization of vaginal cytology and its utility in toxicological studies

    EPA Science Inventory

    An evaluation of the estrous cycle in laboratory rodents can be a useful measure of the integrity of the hypothalamic-pituitary-ovarian reproductive axis. It can also serve as a way of insuring that animals exhibiting abnormal cycling patterns are disincluded from a study prior t...

  5. The rodent estrous cycle: Characterization of vaginal cytology and its utility in toxicological studies

    EPA Science Inventory

    An evaluation of the estrous cycle in laboratory rodents can be a useful measure of the integrity of the hypothalamic-pituitary-ovarian reproductive axis. It can also serve as a way of insuring that animals exhibiting abnormal cycling patterns are disincluded from a study prior t...

  6. Comparative Study on the Estimation of Estrous Cycle in Mice by Visual and Vaginal Lavage Method

    PubMed Central

    Ekambaram, Gnanagurudasan; Joseph, Leena Dennis

    2017-01-01

    Introduction Evaluation of estrous cycle in laboratory animals can be a useful measure of the integrity of hypothalamic-pituitary-ovarian reproductive axis. Assessment of vaginal cytology is crucial to assess the milieu and compare the endocrine status of animals among the experimental groups. Aim The present study was attempted to compare the estimation of estrous cycle by visual method and non invasive vaginal lavage method. Materials and Methods Sixty healthy female swiss albino mice were used for the present study. The appearance of the vagina with respect to the opening of vagina, vaginal swellings were observed. Non-invasive method was used in vaginal lavage method in which nucleated epithelial cells, cornified squamous epithelial cells and leucocytes present in vaginal smears were used to identify the estrous stages. Results The estimation of estrous cycle by visual method coincides with the vaginal lavage method. In Vaginal lavage method, the accurate proportion of cells and the transition phases can be evaluated. Conclusion The non-invasive method reduces the risk of pseudo -pregnancy and mechanical trauma. Though, visual method is quick and reliable, for accurate estimation of the stage of the estrous, non-invasive vaginal lavage method is ideal. PMID:28273958

  7. Hormone-Dependence of Sarin Lethality in Rats: Sex Differences and Stage of the Estrous Cycle

    DTIC Science & Technology

    2015-06-12

    Literature 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Hormone-dependence of sarin lethality in rats: sex differences and stage of the...U01NS058183-07S1. 14. ABSTRACT See reprint. 15. SUBJECT TERMS Sarin, nerve agents, sex differences, estrous cycle, LD50 16. SECURITY...Prescribed by ANSI Std. Z39.18 Hormone-dependence of sarin lethality in rats: Sex differences and stage of the estrous cycle Carl D. Smith ⁎, Linnzi K.M

  8. The role of pheromones in the regulation of estrous cycle duration in the guinea pig.

    PubMed

    Jesel, L; Aron, C L

    1976-01-01

    A decrease in estrous cycle duration, due to shortening of the period of vaginal closure (VC), has been observed in female guinea pigs exposed to the odor of urine from males of the same species. VC shortening was also observed in females exposed to the odor of female urine collected during the period of vaginal opening (VO). No alteration in VC duration occurred, however, in females exposed to urine collected in the 1st 7 days of VC. Also VC shortening did not occur in bulbectomized females exposed to the odor of male urine. Therefore, it was concluded that guinea pig urine, when highly concentrated, contains pheromones capable of shortening estrous cycle VC.

  9. Hormone-dependence of sarin lethality in rats: sex differences and stage of the estrous cycle

    PubMed Central

    Smith, Carl D.; Wright, Linnzi K.M.; Garcia, Gregory E.; Lee, Robyn B.; Lumley, Lucille A.

    2015-01-01

    Chemical warfare nerve agents (CWNAs) are highly toxic compounds that cause a cascade of symptoms and death, if exposed casualties are left untreated. Numerous rodent models have investigated the toxicity and mechanisms of toxicity of CWNAs, but most are limited to male subjects. Given the profound physiological effects of circulating gonadal hormones in female rodents, it is possible that the daily cyclical fluctuations of these hormones affect females’ sensitivity to the lethal effects of CWNAs, and previous reports that included female subjects did not control for the stage of the hormonal cycle. The aim of the current study was to determine the 24-hour median lethal dose (LD50) of the CWNA sarin in male, ovariectomized (OVEX) female, and female rats during different stages of the estrous cycle (diestrus, proestrus, and estrus). Additionally, baseline activity levels of plasma acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were measured to determine differences among the groups. Results indicated that females in proestrus had a significantly higher LD50 of sarin compared to OVEX and estrous females. Although some sex differences were observed in the activity levels of plasma esterases, they were not consistent and likely not large enough to significantly affect the LD50s. These results suggest that hormonal cyclicity can influence the outcome of CWNA-related studies using female rodents, and that this variability can be minimized by controlling for the stage of the cycle. Additional research is necessary to determine the precise mechanism of the observed differences because it is unlikely to be solely explained by plasma esterase activity. PMID:26079828

  10. Hormone-dependence of sarin lethality in rats: Sex differences and stage of the estrous cycle.

    PubMed

    Smith, Carl D; Wright, Linnzi K M; Garcia, Gregory E; Lee, Robyn B; Lumley, Lucille A

    2015-09-15

    Chemical warfare nerve agents (CWNAs) are highly toxic compounds that cause a cascade of symptoms and death, if exposed casualties are left untreated. Numerous rodent models have investigated the toxicity and mechanisms of toxicity of CWNAs, but most are limited to male subjects. Given the profound physiological effects of circulating gonadal hormones in female rodents, it is possible that the daily cyclical fluctuations of these hormones affect females' sensitivity to the lethal effects of CWNAs, and previous reports that included female subjects did not control for the stage of the hormonal cycle. The aim of the current study was to determine the 24-hour median lethal dose (LD50) of the CWNA sarin in male, ovariectomized (OVEX) female, and female rats during different stages of the estrous cycle (diestrus, proestrus, and estrus). Additionally, baseline activity levels of plasma acetylcholinesterase, butyrylcholinesterase, and carboxylesterase were measured to determine differences among the groups. Results indicated that females in proestrus had a significantly higher LD50 of sarin compared to OVEX and estrous females. Although some sex differences were observed in the activity levels of plasma esterases, they were not consistent and likely not large enough to significantly affect the LD50s. These results suggest that hormonal cyclicity can influence the outcome of CWNA-related studies using female rodents, and that this variability can be minimized by controlling for the stage of the cycle. Additional research is necessary to determine the precise mechanism of the observed differences because it is unlikely to be solely explained by plasma esterase activity.

  11. The effect of western juniper on the estrous cycle in beef cattle.

    PubMed

    Welch, Kevin D; Stonecipher, Clint A; Gardner, Dale R; Panter, Kip E; Parsons, Cory; Deboodt, Tim; Johnson, Bryan

    2015-02-01

    Numerous evergreen trees and shrubs contain labdane acids, including isocupressic acid, which can cause late-term abortions in cattle. Recent research has shown that the bark from western juniper trees can also cause late-term abortions in cattle. Additionally, ranchers have observed that cattle in western juniper-infested rangelands tend to have decreased conception rates. The objective of this study was to determine if western juniper alters the estrous cycle of cattle. Fourteen heifers (10 treated and 4 control) were monitored for 74 days for signs of normal estrous behavior, with a 21 day feeding trial with western juniper bark from days 28-48, after which the cattle were bred naturally with a bull. The cattle were checked for pregnancy 30 days after all cattle had been bred. The data from this study indicate that exposure to western juniper bark does not affect normal estrus, estrous cycle or conception rates of cattle. Published by Elsevier Ltd.

  12. Centrifugation Effects on Estrous Cycling, Mating Success and Pregnancy Outcome in Rats

    NASA Technical Reports Server (NTRS)

    Ronca, April E.; Rushing, Linda S.; Tou, Janet; Wade, Charles E.; Baer, Lisa A.

    2005-01-01

    We analyzed the effects of 2-g centrifugation on estrous cycling, mating success and pregnancy outcome in rats. Sexually mature female and male rats were assigned to either 2-g centrifuge or non-centrifuge conditions, and to non-breeding or breeding conditions. In non-breeding females, estrous cycles were analyzed by examining vaginal cytology before and for 35 days during centrifugation. Breeding females were time-mated following 7 days of adaptation to centrifugation. Following adaptation to centrifugation, estrous cycle duration over a five-cycle period was similar in centrifuged and non-centrifuged females. Identical numbers of centrifuged and non-centrifuged females conceived, however centrifuged females took four-times longer than controls to achieve conception. Births occurred at the normal gestational length. Pup birth weight and postnatal survival were p<0.05 reduced in centrifuged as compared to non-centrifuged groups. In conclusion, 2-g centrifugation had no effect on estrous cycle length or the probably of becoming pregnant but delayed conception and diminished pregnancy outcome.

  13. Centrifugation Effects on Estrous Cycling, Mating Success and Pregnancy Outcome in Rats

    NASA Technical Reports Server (NTRS)

    Ronca, April E.; Rushing, Linda S.; Tou, Janet; Wade, Charles E.; Baer, Lisa A.

    2005-01-01

    We analyzed the effects of 2-g centrifugation on estrous cycling, mating success and pregnancy outcome in rats. Sexually mature female and male rats were assigned to either 2-g centrifuge or non-centrifuge conditions, and to non-breeding or breeding conditions. In non-breeding females, estrous cycles were analyzed by examining vaginal cytology before and for 35 days during centrifugation. Breeding females were time-mated following 7 days of adaptation to centrifugation. Following adaptation to centrifugation, estrous cycle duration over a five-cycle period was similar in centrifuged and non-centrifuged females. Identical numbers of centrifuged and non-centrifuged females conceived, however centrifuged females took four-times longer than controls to achieve conception. Births occurred at the normal gestational length. Pup birth weight and postnatal survival were p<0.05 reduced in centrifuged as compared to non-centrifuged groups. In conclusion, 2-g centrifugation had no effect on estrous cycle length or the probably of becoming pregnant but delayed conception and diminished pregnancy outcome.

  14. A simple mathematical model of the bovine estrous cycle: follicle development and endocrine interactions.

    PubMed

    Boer, H M T; Stötzel, C; Röblitz, S; Deuflhard, P; Veerkamp, R F; Woelders, H

    2011-06-07

    Bovine fertility is the subject of extensive research in animal sciences, especially because fertility of dairy cows has declined during the last decades. The regulation of estrus is controlled by the complex interplay of various organs and hormones. Mathematical modeling of the bovine estrous cycle could help in understanding the dynamics of this complex biological system. In this paper we present a mechanistic mathematical model of the bovine estrous cycle that includes the processes of follicle and corpus luteum development and the key hormones that interact to control these processes. The model generates successive estrous cycles of 21 days, with three waves of follicle growth per cycle. The model contains 12 differential equations and 54 parameters. Focus in this paper is on development of the model, but also some simulation results are presented, showing that a set of equations and parameters is obtained that describes the system consistent with empirical knowledge. Even though the majority of the mechanisms that are included in the model are based on relations that in the literature have only been described qualitatively (i.e. stimulation and inhibition), the output of the model is surprisingly well in line with empirical data. This model of the bovine estrous cycle could be used as a basis for more elaborate models with the ability to study effects of external manipulations and genetic differences.

  15. Effect of increasing levels of undegradable intake protein on metabolic and endocrine factors in estrous cycling beef heifers.

    PubMed

    Kane, K K; Hawkins, D E; Pulsipher, G D; Denniston, D J; Krehbiel, C R; Thomas, M G; Petersen, M K; Hallford, D M; Remmenga, M D; Roberts, A J; Keisler, D H

    2004-01-01

    To determine the influence of three levels of undegradable intake protein (UIP) supplementation on metabolic and endocrine factors that influence reproduction, 23 yearling crossbred heifers (body condition score = 4.5 +/- 0.5; initial BW = 362 +/- 12 kg) were stratified by BW and assigned randomly to one of three supplements: 1) low UIP (1,135 g x heifer(-1) x d(-1); 30% CP, 115 g UIP, n = 7); 2) mid UIP (1,135 g x heifer(-1) x d(-1); 38% CP, 216 g UIP, n = 8); or 3) high UIP (1,135 g x heifer(-1) x d(-1); 46% CP, 321 g UIP, n = 8). Heifers were estrually synchronized before initiation of supplementation. Supplement was individually fed daily for 30 to 32 d, at which time heifers were slaughtered (d 12 to 14 of the estrous cycle) and tissues collected. Heifers were fed a basal diet of sudan grass hay (6.0% CP) ad libitum. On d 28 of supplementation (d 10 of the estrous cycle), no differences were observed (P > 0.10) in serum insulin or IGF-I among treatments. At slaughter (d 10 to 12 of the estrous cycle), treatments did not influence corpus luteum weight, cerebral spinal fluid leptin, or IGFBP; serum estradiol-17beta, progesterone, leptin, IGF-I, and IGFBP; or anterior pituitary content of IGFBP (P > 0.10). Follicular fluid IGFBP-2 and IGFBP-4 were greater in high-UIP heifers than low- or mid-UIP heifers on d 12 to 14 of the estrous cycle (P < 0.05). Basal serum LH concentrations and LH area under the curve (every 15 min for 240 min) did not differ (P > 0.10) following 28 d of supplementation (d 10 of the estrous cycle); however, basal serum FSH concentrations were greater (P = 0.06) in low- and mid- vs. high-UIP heifers (5.2 and 5.2 vs. 4.6 ng/mL, respectively), and FSH area under the curve was greater (P = 0.03) in low- vs. high-UIP heifers. At slaughter (d 12 to 14 of the estrous cycle), anterior pituitary LH and FSH content and steady-state mRNA encoding alpha, LHbeta, and GnRH receptor did not differ (P > 0.10) among treatments. However, FSHbeta mRNA was

  16. Expression of pluripotent stem cell markers in mouse uterine tissue during estrous cycle

    PubMed Central

    Choobineh, Kolsum; Zavareh, Saeed; Salehnia, Mojdeh; Ghorbanian, Mohamad Taghi; paylakhi, Seyed Hassan

    2016-01-01

    It was assumed that uterine stem cells are responsible for the unique regenerative capacity of uterine. Therefore, the aim of the present study was to investigate the expression of the pluripotent stem cell markers in the mice uterine tissue during different stages of estrous cycles. Twelve virgin female NMRI mice (6 to 8 weeks old) were considered at proestrus, estrus, metestrus and diestrus according to the cell types observed in the vaginal smear and underwent hysterectomy operation. Quantitative real-time polymerase chain reaction (PCR) and immunohistochemical staining for pluripotent stem cell markers (SOX2, OCT4, KLF4, and NANOG) were performed. Immunofluorescence staining revealed that expression and localization of the pluripotency markers SOX2, OCT4, KLF4, and NANOG at the protein level were not different throughout estrous cycle. Also, mRNA of pluripotency markers was detected in all tested samples. However, there were no significant differences in their genes expression at each stage and during the estrous cycle. Different hormonal profile during the estrous cycle could not affect expression of pluripotent stem cell markers in uterine tissue. PMID:27872713

  17. Role of estrogens in anterior pituitary gland remodeling during the estrous cycle.

    PubMed

    Zárate, S; Zaldivar, V; Jaita, G; Magri, L; Radl, D; Pisera, D; Seilicovich, A

    2010-01-01

    In this review, we analyze the action of estrogens leading to the remodeling of the anterior pituitary gland, especially during the estrous cycle. Proliferation and death of anterior pituitary cells and especially lactotropes is regulated by estrogens, which act by sensitizing these cells to both mitotic and apoptotic stimuli such as TNF-alpha, FasL and dopamine. During the estrous cycle, the changing pattern of gonadal steroids is thought to modulate both cell proliferation and death in the anterior pituitary gland, estrogens being key players in cell turnover. The mechanisms involved in estrogen-modulated cell renewal in the anterior pituitary gland during the estrous cycle could include an increase in the expression of proapoptotic cytokines as well as the increase in the Bax/Bcl-2 ratio at proestrus, when estrogen levels are highest and a peak of apoptosis, in particular of lactotropes, is evident in this gland. Estrogens exert rapid antimitogenic and proapoptotic actions in the anterior pituitary through membrane-associated estrogen receptors, a mechanism that might also be involved in remodeling of this gland during the estrous cycle.

  18. Performing Vaginal Lavage, Crystal Violet Staining, and Vaginal Cytological Evaluation for Mouse Estrous Cycle Staging Identification

    PubMed Central

    McLean, Ashleigh C.; Valenzuela, Nicolas; Fai, Stephen; Bennett, Steffany A.L.

    2012-01-01

    A rapid means of assessing reproductive status in rodents is useful not only in the study of reproductive dysfunction but is also required for the production of new mouse models of disease and investigations into the hormonal regulation of tissue degeneration (or regeneration) following pathological challenge. The murine reproductive (or estrous) cycle is divided into 4 stages: proestrus, estrus, metestrus, and diestrus. Defined fluctuations in circulating levels of the ovarian steroids 17-β-estradiol and progesterone, the gonadotropins luteinizing and follicle stimulating hormones, and the luteotropic hormone prolactin signal transition through these reproductive stages. Changes in cell typology within the murine vaginal canal reflect these underlying endocrine events. Daily assessment of the relative ratio of nucleated epithelial cells, cornified squamous epithelial cells, and leukocytes present in vaginal smears can be used to identify murine estrous stages. The degree of invasiveness, however, employed in collecting these samples can alter reproductive status and elicit an inflammatory response that can confound cytological assessment of smears. Here, we describe a simple, non-invasive protocol that can be used to determine the stage of the estrous cycle of a female mouse without altering her reproductive cycle. We detail how to differentiate between the four stages of the estrous cycle by collection and analysis of predominant cell typology in vaginal smears and we show how these changes can be interpreted with respect to endocrine status. PMID:23007862

  19. Relationship between stages of the estrous cycle and bone cell activity in Thoroughbreds.

    PubMed

    Jackson, Brendan F; Dyson, Philip K; Hattersley, Rachael D; Kelly, Hannah R; Pfeiffer, Dirk U; Price, Joanna S

    2006-09-01

    To investigate the relationship between stage of estrous cycle and bone cell activity in Thoroughbreds. Blood samples collected from forty-seven 2-year-old Thoroughbred mares in training for racing. Blood samples were collected monthly (in April through September) from the mares. Stage of estrus was determined by assessing serum progesterone concentration. Bone cell activity was determined by measuring concentrations of 2 markers of bone formation (osteocalcin and the carboxy-terminal propeptide of type I collagen [PICP]) and a marker of bone resorption (the cross-linked carboxy-terminal telopeptide of type I collagen [ICTP]) in sera. When the relationship between stage of the estrous cycle and markers of bone cell activity was examined, serum concentrations of both osteocalcin and ICTP were significantly higher in mares that were in the luteal phase, compared with mares that were at other stages of the estrous cycle. Stage of estrus did not affect serum PICP concentration. Results indicate that bone cell activity in Thoroughbred mares fluctuates during the estrous cycle; serum concentrations of markers of bone formation and bone resorption are increased during the luteal phase. Further studies are required to determine whether these changes are of clinical importance and increase the risk of injury for mares in training during the breeding season. As in humans, stage of estrus must be considered as a source of uncontrollable variability in serum bone marker concentrations in horses.

  20. Taenia crassiceps infection disrupts estrous cycle and reproductive behavior in BALB/c female mice.

    PubMed

    Arteaga-Silva, Marcela; Vargas-Villavicencio, José Antonio; Vigueras-Villaseñor, Rosa María; Rodríguez-Dorantes, Mauricio; Morales-Montor, Jorge

    2009-02-01

    Previously, it has been shown that parasitic infections are able to alter the normal mammal physiology, at several extents. Thus, we investigated the effects on estrous cycle and sexual behavior induced by intraperitoneal infection with Taenia crassiceps in female host mice. Along the weeks of infection, parasites were collected from the peritoneal cavity of female mice, showing the maximum parasite load at 16 weeks. No parasites were found outside peritoneal cavity. Vaginal estrous cycle was monitored daily for 4, 8, 12 and 16 weeks of infection, and results compared against age-matched female mice. Female sexual behavior (FSB) tests were performed, one test per week. Immediately after the last behavioral test, blood was collected by cardiac puncture for steroid determinations. First of all, there was a strong tissular damage in the female reproductive tract in all infected females. The phases of the estrous cycle were interrupted at 12 and 16 weeks, with increased leukocytes and the presence of a few cornified epithelial cells and nucleated epithelial cells. The FSB decreased starting 6 weeks post infection. On the 16th week, all infected female mice ceased to exhibit sexual responses, and estradiol levels showed a significant decrease. Control mice continued showing FSB and the different phases of the estrous cycle throughout the observation period. Our results strength the notion that parasites may be considered as an evolutionary force in the reproductive ability of mammals.

  1. Brain histamine levels in the hamster during the estrous cycle and on selected days of pregnancy.

    PubMed

    Hine, R J; Orsini, M W; Hegstrand, L R

    1986-01-01

    Brain histamine levels were determined in golden hamster hypothalamus and 'brain minus hypothalamus' on each of the 4 days of the estrous cycle and on selected days of pregnancy. The highest histamine content of the hypothalamus was observed on day 3 of the estrous cycle. The highest histamine content of the hypothalamus was observed on day 3 of the estrous cycle, which is the day prior to recurrence of heat on day 4. Day 4 terminates in ovulation. The histamine level in the remainder of the brain peaked on day 2. During gestation the histamine content of the 'brain minus hypothalamus' was greatest on day 5, while the maximum content of histamine in the hypothalamus was not reached until day 8. After the 8th day of pregnancy, there was an overall decline in brain histamine that continued until parturition. The hypothalamic histamine level in nonpregnant females was not different from that of males. However, in the remainder of the brain, histamine levels in females on days 1 and 2 of the estrous cycle were higher than in males.

  2. The stability of the transcriptome during the estrous cycle in four regions of the mouse brain.

    PubMed

    DiCarlo, Lisa M; Vied, Cynthia; Nowakowski, Richard S

    2017-10-15

    We analyzed the transcriptome of the C57BL/6J mouse hypothalamus, hippocampus, neocortex, and cerebellum to determine estrous cycle-specific changes in these four brain regions. We found almost 16,000 genes are present in one or more of the brain areas but only 210 genes, ∼1.3%, are significantly changed as a result of the estrous cycle. The hippocampus has the largest number of differentially expressed genes (DEGs) (82), followed by the neocortex (76), hypothalamus (63), and cerebellum (26). Most of these DEGs (186/210) are differentially expressed in only one of the four brain regions. A key finding is the unique expression pattern of growth hormone (Gh) and prolactin (Prl). Gh and Prl are the only DEGs to be expressed during only one stage of the estrous cycle (metestrus). To gain insight into the function of the DEGs, we examined gene ontology and phenotype enrichment and found significant enrichment for genes associated with myelination, hormone stimulus, and abnormal hormone levels. Additionally, 61 of the 210 DEGs are known to change in response to estrogen in the brain. 50 of the 210 genes differentially expressed as a result of the estrous cycle are related to myelin and oligodendrocytes and 12 of the 63 DEGs in the hypothalamus are oligodendrocyte- and myelin-specific genes. This transcriptomic analysis reveals that gene expression in the female mouse brain is remarkably stable during the estrous cycle and demonstrates that the genes that do fluctuate are functionally related. © 2017 Wiley Periodicals, Inc.

  3. Progesterone, estradiol, arachidonic acid, oxytocin, forskolin and cAMP influence on aquaporin 1 and 5 expression in porcine uterine explants during the mid-luteal phase of the estrous cycle and luteolysis: an in vitro study.

    PubMed

    Skowronska, Agnieszka; Młotkowska, Patrycja; Wojciechowicz, Bartosz; Okrasa, Stanisław; Nielsen, Soren; Skowronski, Mariusz T

    2015-02-18

    The cell membrane water channel protein, aquaporins (AQPs), regulate cellular water transport and cell volume and play a key role in water homeostasis. Recently, AQPs are considered as important players in the field of reproduction. In previous studies, we have established the presence of AQP1 and 5 in porcine uterus. Their expression at protein level altered in distinct tissues of the female reproductive system depending on the phase of the estrous cycle. However, the regulation of aquaporin genes and proteins expression has not been examined in porcine uterine tissue. Therefore, we have designed an in vitro experiment to explain whether steroid hormones, progesterone (P4) and estradiol (E2), and other factors: oxytocine (OT), arachidonic acid (AA; substrate for prostaglandins synthesis) as well as forskolin (FSK; adenylate cyclase activator) and cAMP (second messenger, cyclic adenosine monophosphate) may impact AQPs expression. Uterine tissues were collected on Days 10-12 and 14-16 of the estrous cycle representing the mid-luteal phase and luteolysis. Real-time PCR and Western blot analysis were performed to examine the expression of porcine AQP1 and AQP5. Their expression in the uterine explants was also evaluated by immunohistochemistry. The results indicated that uterine expression of AQP1 and AQP5 potentially remains under control of steroid hormones and AA-derived compounds (e.g. prostaglandins). P4, E2, AA, FSK and cAMP cause translocation of AQP5 from apical to the basolateral plasma membrane of the epithelial cells, which might affect the transcellular water movement (through epithelial cells) between uterine lumen and blood vessels. The AC/cAMP pathway is involved in the intracellular signals transduction connected with the regulation of AQPs expression in the pig uterus. This study documented specific patterns of AQP1 and AQP5 expression in response to P4, E2, AA, FSK and cAMP, thereby providing new indirect evidence of their role in maintaining the

  4. An interferon signature identified by RNA-sequencing of mammary tissues varies across the estrous cycle and is predictive of metastasis-free survival

    PubMed Central

    Snijders, Antoine M.; Langley, Sasha; Mao, Jian-Hua; Bhatnagar, Sandhya; Bjornstad, Kathleen A.; Rosen, Chris J.; Lo, Alvin; Huang, Yurong; Blakely, Eleanor A.; Karpen, Gary H.; Bissell, Mina J.; Wyrobek, Andrew J.

    2014-01-01

    The concept that a breast cancer patient's menstrual stage at the time of tumor surgery influences risk of metastases remains controversial. The scarcity of comprehensive molecular studies of menstrual stage-dependent fluctuations in the breast provides little insight. To gain a deeper understanding of the biological changes in mammary tissue and blood during the menstrual cycle and to determine the influence of environmental exposures, such as low-dose ionizing radiation (LDIR), we used the mouse to characterize estrous-cycle variations in mammary gene transcripts by RNA-sequencing, peripheral white blood cell (WBC) counts and plasma cytokine levels. We identified an estrous-variable and hormone-dependent gene cluster enriched for Type-1 interferon genes. Cox regression identified a 117-gene signature of interferon-associated genes, which correlated with lower frequencies of metastasis in breast cancer patients. LDIR (10cGy) exposure had no detectable effect on mammary transcripts. However, peripheral WBC counts varied across the estrous cycle and LDIR exposure reduced lymphocyte counts and cytokine levels in tumor-susceptible mice. Our finding of variations in mammary Type-1 interferon and immune functions across the estrous cycle provides a mechanism by which timing of breast tumor surgery during the menstrual cycle may have clinical relevance to a patient's risk for distant metastases. PMID:24994117

  5. Centrifugation effects on estrous cycle, mating success and pregnancy outcome in rats

    NASA Astrophysics Data System (ADS)

    Ronca, April E.; Rushing, Linda; Tou, Janet; Wade, Charles E.; Baer, Lisa A.

    2005-08-01

    We analyzed the effects of 2-g centrifugation on estrous cycling, mating success and pregnancy outcome in rats. Sexually mature female and male rats were assigned to either 2-g centrifuge or non-centrifuge conditions, and to non-breeding or breeding conditions. In non-breeding females, estrous cycles were analyzed by examining vaginal cytology before and for 35 days during centrifugation. Breeding females were time-mated following 7 days of adaptation to centrifugation. Following adaptation to centrifugation, estrous cycle duration over a five-cycle period was similar in centrifuged and non-centrifuged females. Identical numbers of centrifuged and non-centrifuged females conceived, however centrifuged females took four-times longer than controls to achieve conception. Births occurred at the normal gestational length. Pup birth weight and postnatal survival were p<0.05 reduced in centrifuged as compared to non-centrifuged groups. In conclusion, 2-g centrifugation had no effect on estrus cycle length or the probably of becoming pregnant but delayed conception and diminished pregnancy outcome.

  6. Effects of Simulated Hypogravity and Diet on Estrous Cycling in Rats

    NASA Technical Reports Server (NTRS)

    Tou, Janet C.; Grindeland, Richard E.; Baer, Lisa A.; Wade, Charles E.

    2003-01-01

    Environmental factors can disrupt ovulatory cycles. The study objective was to determine the effect of diet and simulated hypogravity on rat estrous cycles. Age 50 d Sprague-Dawley rats were randomly assigned to he fed either a purified or chow diet. Only normal cycling rats were used. Experimental rats (n=9-10/group) were kept as ambulatory controls (AC) or subjected to 40 d simulated hypogravity using a disuse atrophy hindlimb suspension (HLS) model. There was no effect on estrous cycles of AC fed either diet. At day 18, HLS rats fed either diet, had lengthened estrous cycles due to prolonged diestrus. HLS rats fed purified diet also had reduced time in estrus. Plasma estradiol was reduced in HLS rats fed purified diet but there was no effect on progesterone. This may have occurred because blood was collected from rats in estrus. Urinary progesterone collected during initial HLS was elevated in rats fed purified diet. In AC, corticosterone was elevated in chow vs purified diet fed rats. Differences were particularly striking following the application of a stressor with HLS/chow-fed rats displaying an enhanced stress response. Results emphasize the importance of diet selection when measuring endocrine-sensitive endpoints. HLS is a useful model for investigating the effects of environment on reproduction and providing insight about the impact extreme environment such as spaceflight on female reproductive health.

  7. Effects of Simulated Hypogravity and Diet on Estrous Cycling in Rats

    NASA Technical Reports Server (NTRS)

    Tou, Janet C.; Grindeland, Richard E.; Baer, Lisa A.; Wade, Charles E.

    2003-01-01

    Environmental factors can disrupt ovulatory cycles. The study objective was to determine the effect of diet and simulated hypogravity on rat estrous cycles. Age 50 d Sprague-Dawley rats were randomly assigned to he fed either a purified or chow diet. Only normal cycling rats were used. Experimental rats (n=9-10/group) were kept as ambulatory controls (AC) or subjected to 40 d simulated hypogravity using a disuse atrophy hindlimb suspension (HLS) model. There was no effect on estrous cycles of AC fed either diet. At day 18, HLS rats fed either diet, had lengthened estrous cycles due to prolonged diestrus. HLS rats fed purified diet also had reduced time in estrus. Plasma estradiol was reduced in HLS rats fed purified diet but there was no effect on progesterone. This may have occurred because blood was collected from rats in estrus. Urinary progesterone collected during initial HLS was elevated in rats fed purified diet. In AC, corticosterone was elevated in chow vs purified diet fed rats. Differences were particularly striking following the application of a stressor with HLS/chow-fed rats displaying an enhanced stress response. Results emphasize the importance of diet selection when measuring endocrine-sensitive endpoints. HLS is a useful model for investigating the effects of environment on reproduction and providing insight about the impact extreme environment such as spaceflight on female reproductive health.

  8. Analysis of LH receptor in canine ovarian follicles throughout the estrous cycle.

    PubMed

    De Los Reyes, Monica; Palomino, Jaime; Parraguez, Victor H; Ramirez, Fernando

    2017-04-15

    The aim of this study was to determine the mRNA LHR and LHR protein expression pattern in the canine ovarian follicles at different stage of development throughout the estrous cycle. Dog ovaries were obtained from 1-6y bitches at proestrus/estrus, anestrus and diestrus stages following ovariohysterectomy. Follicular cells were mechanically recovered from follicles distributed into four types (preantral, small antral, medium antral and large antral). Total RNA extraction was performed and the evaluation of gene expression levels was achieved by relative quantification q-PCR analysis. Intrafollicular amounts of LHR were assessed by western blot method. All results were evaluated by ANOVA. The expression levels of mRNA LHR in follicular cells were observed in every stage of development, however this gene expression varied over the estrous cycle. LHR transcripts increased (P < 0.05) from preantral to antral stage. There were not differences in LHR gene expression among follicles at preantral stages; however, at antral stages the lowest (P < 0.05) LHR mRNA expression was found at anestrus and the highest (P < 0.05) at proestrus/estrus. The LHR protein was also detected in dog follicles in all reproductive phases with patterns varying with stage of follicular development over the reproductive cycle. The antibody against human LHR revealed two bands at ∼90 and ∼67 kDa, probably representing the matured protein and its precursor respectively. Both bands LHR appeared already at preantral follicles increasing (P < 0.05) with growth. A high proportion of LHR was presented as immature forms in all follicles stages during different phases of the estrous cycle. In conclusion, the gene and protein of LHR are differentially expressed in dog follicles over the estrous cycle, increasing with growth and the precursor protein is the most predominant LHR form present in canine follicles. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Characteristics of estrous cycles in gilts treated with gonadotropins after estrus or treatment with a progestogen.

    PubMed

    Estienne, Mark J; Crawford, Russell J

    2015-03-01

    A combination of eCG (400 IU) and hCG (200 IU) (P.G. 600; Merck Animal Health, Summit, NJ, USA) stimulates puberty in gilts, but variation in the estrual response exists among farms. We hypothesized that some of the variability is a consequence of gilts that have commenced cycling being inadvertently treated. The objective of experiment 1 was to determine the effect of intramuscular (im) P.G. 600 on estrous cycles in sexually mature gilts. Gilts in treatment 1 (n = 16) received P.G. 600 at the onset of daily boar exposure. Gilts in treatments 2 to 5 (n = 16 per treatment) were allowed to express a natural first estrus and were then treated with P.G. 600 during the first estrous cycle as follows: treatment 2 at Day 6, treatment 3 at Day 12, and treatment 4 at Day 18 of the estrous cycle. Treatment 5 gilts received no P.G. 600. The proportion of gilts displaying a normal estrous cycle (18-24 days) was greater (P < 0.05) for treatments 4 (100%) and 5 (100%) compared with treatments 1 (73.3%) and 3 (60%), with treatment 2 having a value (87.5%) that was not different from the other groups. For treatment 3, 33% of gilts displayed an increased interestrus interval that averaged 32.5 days. Concentrations of progesterone remained elevated 20 days after the onset of first estrus in treatment 3 gilts, which supports the concept that P.G. 600 administered at Day 12 of the estrous cycle induced follicular growth, ovulation, and formation of CL that functioned for approximately 15 days, increasing the length of the estrous cycle. It is common for swine producers to have groups of replacement gilts that include both cycling and prepubertal animals, or individuals, the cycling status of which is unknown. The objective of experiment 2 was to evaluate a system using a combination of a progestogen (Matrix; Merck Animal Health) and P.G. 600 to synchronize estrus in replacement gilts. Crossbred gilts, assumed to be a mix of cycling and prepubertal females, were allocated to

  10. LTP varies across the estrous cycle: enhanced synaptic plasticity in proestrus rats.

    PubMed

    Warren, S G; Humphreys, A G; Juraska, J M; Greenough, W T

    1995-12-12

    Previous studies have shown that the number of dendritic spines and synapses in hippocampal CA1 stratum radiatum decreases more than 30% between the proestrus (high estrogen) and estrus (low estrogen) phases of the rat estrous cycle [10,27]. In the present study, we investigated whether hippocampal synaptic plasticity, as measured by long-term potentiation (LTP), might also vary across the estrous cycle of the female rat. Male rats, and female rats at each phase of the estrous cycle were tested in either the morning or afternoon. There were no significant group differences in the pre-LTP I/O curves. However, females examined during the afternoon of proestrus, the phase during which prior studies indicate synapse number to be highest, demonstrated the greatest degree of potentiation. Diestrus, proestrus and estrus females tested in the morning demonstrated similar amounts of potentiation. There were also significant differences in post-LTP I/O curves between the afternoon proestrus females and males tested in the afternoon. These results suggest that gonadal hormones, interacting with the time of day, may regulate neural processes underlying learning and memory.

  11. Control of the estrous cycle in guinea-pig (Cavia porcellus).

    PubMed

    Grégoire, A; Allard, A; Huamán, E; León, S; Silva, R M; Buff, S; Berard, M; Joly, T

    2012-09-01

    The aim of this work was to look for a simple method to obtain synchronized ovulation in guinea pigs under farming conditions while respecting animal welfare. The luteolytic activity of three different prostaglandins F2alpha (PGF2α) analogs (D-cloprostenol, D,L-cloprostenol and luprostiol) and a daily treatment with oral progestagen (altrenogest) was tested successively at different stages of the estrous cycle on the same group of females during a period of 8 mo. The estrous cycle length was not modified by the administration of PGF2α analogs, whatever the stage of the estrous cycle when the treatment was initiated. Our results led us to reject the use of PGF2α analog to induce practical synchronization of the estrus in this species. In females (n = 29), given 15 days with altrenogest (0.1 mL po once a day), ovulation occurred 4.43 ± 0.13 days after the end of the treatment. Altrenogest treatment was followed by mating. No negative impacts of the treatment on the pregnancy rates, delivery rates and litter sizes were observed. This standard method of guinea-pig estrus synchronization is less stressful for the animals compared to techniques using progesterone tubing.

  12. Alterations in dopamine system function across the estrous cycle of the MAM rodent model of schizophrenia.

    PubMed

    Perez, Stephanie M; Chen, Li; Lodge, Daniel J

    2014-09-01

    Clinical studies have reported differences in the incidence and severity of schizophrenia symptoms between male and female schizophrenia patients. Unfortunately, the cause of these differences is not currently known due, in part, to the fact that preclinical studies largely focus on male subjects. Dopamine neuron activity has been previously demonstrated to change across the estrous cycle, and may therefore be of relevance, as aberrant dopamine signaling is thought to underlie the positive symptoms of schizophrenia. Here we examine dopamine neuron activity across the estrous cycle in the MAM rodent model of schizophrenia. We demonstrate that the elevation in dopamine neuron activity, consistently observed in male MAM-treated rats, is most prominent during estrus and attenuated in met-estrus. Furthermore, this appears to be mediated, in part, by progesterone in the ventral hippocampus, as increases in dopamine neuron population activity (observed in estrus) were normalized by the intra-hippocampal administration of the progesterone receptor antagonist, mifepristone (but not the estrogen receptor antagonists, fulvestrant). Taken together, these data suggest that changes in dopamine system function occur across the estrous cycle in MAM-treated rats and may contribute to the differences in symptomatology between male and female schizophrenia patients. Copyright © 2014 Elsevier Ltd. All rights reserved.

  13. Collagen and matrix metalloproteinase-2 and -9 in the ewe cervix during the estrous cycle.

    PubMed

    Rodríguez-Piñón, M; Tasende, C; Casuriaga, D; Bielli, A; Genovese, P; Garófalo, E G

    2015-09-15

    The cervical collagen remodeling during the estrous cycle of the ewe was examined. The collagen concentration determined by a hydroxyproline assay and the area occupied by collagen fibers (%C), determined by van Gieson staining, were assessed in the cranial and caudal cervix of Corriedale ewes on Days 1 (n = 6), 6 (n = 5), or 13 (n = 6) after estrous detection (defined as Day 0). In addition, the gelatinase activity by in situ and SDS-PAGE gelatin zymographies and matrix metalloproteinase-2 and -9 (MMP-2 and MMP-9, respectively) expression by immunohistochemistry were determined. The collagen concentration and %C were lowest on Day 1 of the estrous cycle (P < 0.04), when MMP-2 activity was highest (P < 0.006) and the ratio of activated to latent MMP-2 trend to be highest (P = 0.0819). The MMP-2 activity was detected in 73% of the homogenized cervical samples, and its expression was mainly detected in active fibroblasts. By contrast, the MMP-9 activity was detected in 9% of the samples, and its scarce expression was associated with plasmocytes, macrophages, and lymphocytes. Matrix metalloproteinase-2 expression was maximal on Day 1 in the cranial cervix and on Day 13 in the caudal cervix and was lower in the cranial than in the caudal cervix (P < 0.0001). This time-dependent increase in MMP-2 expression that differed between the cranial and caudal cervix may reflect their different physiological roles. The decrease in the collagen content and increase in fibroblast MMP-2 activity in sheep cervix on Day 1 of the estrous cycle suggests that cervical dilation at estrus is due to the occurrence of collagen fiber degradation modulated by changes in periovulatory hormone levels.

  14. Evaluation of salivary electrolytes during estrous cycle in Murrah buffaloes with reference to estrus detection

    PubMed Central

    Devi, Indu; Singh, Pawan; Lathwal, Surerder Singh; Kumaresan, A.; Dudi, Kuldeep

    2016-01-01

    Aim: Timely estrus detection is one of the critical factors for increasing reproductive efficiency in buffaloes. In recent decades, saliva has become a more popular as a noninvasive source for determining physiological status of animals by various biochemical electrolytes. This study was designed to assess and correlate changes in different salivary minerals concentration (calcium, inorganic phosphorus, magnesium, sodium, potassium, and chloride) during different stages of the estrous cycle in Murrah buffaloes. Materials and Methods: The saliva samples were collected during the different phases of the estrous cycle from 20 Murrah buffaloes in early morning hours and were assayed using respective minerals assay kits. Results: The concentrations of calcium (8.76±0.08-12.11±0.11 mg/dl), inorganic phosphorus (6.56±0.13-14.72±4.50 mg/dl), magnesium (2.27±0.14-5.79±0.15 mg/dl), sodium (139.47±0.31-159.62±1.22 mmol/L), potassium (12.40±0.22-26.85±1.22 mmol/L), and chloride (109.28±0.41-137.07±0.68 mmol/L) varied during the different phases of estrous cycle. The concentration of calcium, inorganic phosphorus, magnesium, sodium, potassium, and chloride in saliva were significantly (p<0.01) higher during estrus phase compared to other phases of the estrous cycle. All these minerals were positively and significantly (p<0.0001) related to estrogen concentration while salivary concentrations of calcium, magnesium, sodium, and chloride showed a significant (p<0.0001) negative correlation with progesterone level in blood plasma. Conclusion: These preliminary findings indicate that there are definite variations in salivary mineral and electrolyte concentrations during different phases of the estrous cycle. These results may be used as an aid for estrus detection/confirmation in buffaloes although validation of the results using a large number of animals is required. PMID:27847429

  15. Spontaneous failure of the estrous cycle induces anxiogenic-related behaviors in middle-aged female mice.

    PubMed

    Guimarães, Rebecca A M; Asth, Laila; Engelberth, Rovena C; Cavalcante, Jeferson de Souza; Soares-Rachetti, Vanessa de Paula; Gavioli, Elaine C

    2015-08-01

    Clinical studies have shown that women during perimenopause and menopause have a higher incidence in the diagnoses of psychiatric problems compared with men. However, little literature information about the influence of spontaneous perimenopause on anxiety- and mood-related behaviors in mice is available. To this aim, we compared the behavioral responses of middle-aged and young adult female mice both in the diestrus phase in the elevated plus-maze, open field and forced swimming tests. In middle-aged mice, the duration of the estrous cycle was significantly prolonged compared to young adults, thus indicating that our middle-aged mice are in the perimenopausal period. In the elevated plus-maze test, middle-aged mice explored less the open arms when compared to young adults, suggesting an anxiogenic-like phenotype. No significant differences were observed in the estrogen plasma levels and emotional behavior in the forced swim and open field tests. In conclusion, the spontaneous failure of the estrous cycle increased anxiety in middle-aged females. These data suggest that the perimenopausal period has a significant influence on anxiety-related behaviors in female mice.

  16. Characterization of the estrous cycle and assessment of reproductive status in Matschie's tree kangaroo (Dendrolagus matschiei) with fecal progestin profiles.

    PubMed

    North, Lindsay A; Harder, John D

    2008-03-01

    The population of Matschie's tree kangaroos (Dendrolagus matschiei) held in North American zoos has declined to critically low numbers, and information on the reproductive biology of tree kangaroos is limited. The objectives of this study were to (1) characterize the temporal features of the estrous cycle through the measurement of fecal progesterone metabolite (i.e., progestin) concentrations and (2) determine the reproductive status of female tree kangaroos in the captive population of North America through the identification of estrous cyclicity. Fecal pellets and observations of estrous behaviors were collected from 16 captive female tree kangaroos. Fecal pellets were sampled and extracted with methanol, and progestin concentrations were quantified using a radioimmunoassay (RIA) for progesterone and its metabolites. A progestin profile was obtained for each female by plotting fecal progestin concentrations for every third day over a 120-day period. Profiles for 12 of 16 females showed evidence of estrous cyclicity (P<0.01). The mean length of the estrous cycle was estimated at 58.9+/-2.4 days (n=11). Progestin concentrations were low during the first 15-20 days of the luteal phase and remained elevated above baseline only during the last 30.2+/-3.2 days of the luteal phase, which averaged 46.6+/-2.5 days in duration. The progestin profile observed in the estrous cycle of Matschie's tree kangaroos in this study is very similar to that seen in the non-pregnant cycle of several other species in the family Macropodidae.

  17. Copper and zinc concentrations in the uterine fluid and blood serum during the bovine estrous cycle.

    PubMed

    Alavi-Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Pak, Mozhgan; Alizadeh, Sajad; Abedizadeh, Roya; Khaki, Amir

    2012-01-01

    To investigate uterine and serum copper (Cu) and zinc (Zn) concentrations variation during the bovine estrus cycle , 232 blood and genital tract samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by the examination of the ovaries and the uterine tonicity. Of the 46 samples selected for use in the study, 13 were pro-estrus, 10 estrus, 8 metestrus, and 15 diestrus. The uterus was incised and uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. The total mean (± SEM) Cu concentrations in serum and uterine fluid samples, determined by spectrophotometry, were 66.1± 6.5 and 171.3 ± 33.2µg dL(-1) respectively, which were significantly different, while total mean serum and uterine fluid Zn concentrations were 91.9 ± 5.4 and 291.6 ± 23.4 µg dL(-1), which also showed a significant difference. The mean serum Cu values in different phases of the estrous cycle were not significantly different, while uterine fluid Cu content in pro-estrus and diestrus were significantly higher than those in estrus and metestrus, and were also significantly higher than those of the serum samples. The mean Zn value of serum samples at different stages of the cycle was not significantly different. The mean Zn value of the uterine fluid samples was also not significantly different in different stages, but in pro-estrus, metestrus, and in diestrus they were highly significantly different from those of the serum. These results showed that Cu concentrations in the uterine fluid vary at different stages of the cycle and are higher than those in the blood serum, but, the uterine Zn content does not vary during the estrous cycle and is much higher than those in the serum, that seems to be due to the secretory action of the uterine mucosa.

  18. The use of prostaglandins in controlling estrous cycle of the ewe: a review.

    PubMed

    Fierro, Sergio; Gil, Jorge; Viñoles, Carolina; Olivera-Muzante, Julio

    2013-02-01

    This review considers the use of prostaglandin F(2α) and its synthetic analogues (PG) for controlling the estrous cycle of the ewe. Aspects such as phase of the estrus cycle, PG analogues, PG doses, ovarian follicle development pattern, CL formation, progesterone synthesis, ovulation rate, sperm transport, embryo quality, and fertility rates after PG administration are reviewed. Furthermore, protocols for estrus synchronization and their success in timed AI programs are discussed. Based on available information, the ovine CL is refractory to PG treatment for up to 2 days after ovulation. All PG analogues are effective when an appropriate dose is given; in that regard, there is a positive association between the dose administered and the proportion of ewes detected in estrus. Follicular response after PG is dependent on the phase of the estrous cycle at treatment. Altered sperm transport and low pregnancy rates are generally reported. However, reports on alteration of the steroidogenic capacity of preovulatory follicles, ovulation rate, embryo quality, recovery rates, and prolificacy, are controversial. Although various PG-based protocols can be used for estrus synchronization, a second PG injection improves estrus response when the stage of the estrous cycle at the first injection is unknown. The estrus cycle after PG administration has a normal length. Prostaglandin-based protocols for timed AI achieved poor reproductive outcomes, but increasing the interval between PG injections might increase pregnancy rates. Attempts to improve reproductive outcomes have been directed to provide a synchronized LH surge: use of different routes of AI (cervical or intrauterine), different PG doses, and increased intervals between PG injections. Finally we present our point of view regarding future perspectives on the use of PG in programs of controlled sheep reproduction. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. VEGF, VEGFR-1 and VEGFR-2 immunoreactivity in the porcine arteries of vascular subovarian plexus (VSP) during the estrous cycle.

    PubMed

    Postek, A; Andronowska, A; Doboszyńska, T; Niewegłowski, H; Jankowska, K

    2006-01-01

    Abstract: Vascular endothelial growth factor (VEGF) is an important angiogenic factor in the female reproductive tract. It binds to cell surface through ligand-stimulatable tyrosine kinase receptors, the most important being VEGFR-1 (flt-1) and VEGFR-2 (flk-1). The broad ligament of the uterus is a dynamic organ consisting of specialized complexes of blood vessels connected functionally to the uterus, oviduct and ovary. Endothelial cells form an inner coating of the vessel walls and thus they stay under the influence of various modulators circulating in blood including ovarian steriods involved in developmental changes in the female reproductive system. The aim of the present study was to immunolocalize VEGF and its two receptors: VEGFR-1 and VEGFR-2 in the broad ligament of the uterus in the area of vascular subovarian plexus during different phases of the estrous cycle in pig and to determine the correlation between immunoreactivity of the investigated factors and phases of the estrous cycle. The study was performed on cryostat sections of vascular subovarian plexus stained immunohistochemically by ABC method. Specific polyclonal antibodies: anti-VEGF, anti-VEGFR-1 and anti-VEGFR-2 were used. Data were subjected to one-way analysis of variance. Our study revealed the presence of VEGF and its receptors in endothelial and smooth muscle cells of VSP arteries. All agents displayed phase-related differences in immunoreactivity suggesting the modulatory effect of VEGF, VEGFR-1 and VEGFR-2 on the arteries of the VSP in the porcine broad ligament of the uterus.

  20. Estrous cycle-dependent morphology in the reproductive organs of the female Göttingen minipig.

    PubMed

    de Rijk, Eveline; van den Brink, Hetty; Lensen, Joost; Lambregts, Ankie; Lorentsen, Helle; Peter, Birgit

    2014-12-01

    The present study describes the normal histology of female reproductive organs during the estrous cycle in the Göttingen minipig. For this purpose, sexually mature females were sacrificed at different phases of the cycle (follicular/proliferation, ovulation, and early-, mid-, and late-luteal/secretory phase). Ovaries, uterus, cervix, vagina, and mammary gland tissues were processed for microscopic evaluation. Sexual maturity was assured by selecting females in which at least 1 progesterone peak was measured. Stage-distinguishing features in ovaries were the Graafian follicles (disrupted vs. nondisrupted) and corpora lutea of recent and preceding cycles (size, cell morphology, and structural composition). In the uterus, stage-specific markers were epithelial morphology, secretory activity (using periodic acid-Schiff/hematoxylin staining), and epithelial mitosis and/or apoptosis. The other reproductive organs were not suitable to discriminate between the different phases of the cycle due to a high morphologic variability (mammary gland, and vagina) or absence of clear morphologic differences between the phases (cervix). The increased use of young minipigs (frequently immature/peripubertal) in preclinical testing requires more knowledge on the histologic cyclic changes. With the present morphologic description of the morphologic characteristics of the reproductive tract in recently ovulating minipigs, a guidance for staging the estrous cycle and determination of sexual immaturity is provided.

  1. Estrous cycle fluctuations in sex and ingestive behavior are accentuated by exercise or cold ambient temperatures.

    PubMed

    Abdulhay, Amir; Benton, Noah A; Klingerman, Candice M; Krishnamoorthy, Kaila; Brozek, Jeremy M; Schneider, Jill E

    2014-06-01

    This article is part of a Special Issue "Energy Balance". In female Syrian hamsters (Mesocricetus auratus), low circulating levels of ovarian steroids are associated with increased food hoarding and decreased sexual motivation, but these effects are exaggerated in food-restricted females. To determine whether cold ambient temperature has the same effects as food restriction, groups of hamsters were fed ad libitum while they were housed at either 5 °C or 22 °C, and then tested for behavior for 90 min on each day of the estrous cycle. In females housed at 22 °C, high levels of sexual motivation and low levels of food hoarding were seen every day of the estrous cycle. In females housed at 5 °C, high levels of sexual motivation were restricted to the periovulatory day. On the three nonestrous days, these females showed high levels of food hoarding, but not food intake. A separate cohort of females were provided with access to running wheels and housed at 22 °C. They showed high levels of sexual motivation restricted to the periovulatory day, similar to the pattern of sexual motivation seen in cold-housed females. Unlike cold-housed females, those with running wheels showed low levels of food hoarding and high levels of food intake. Food restriction, cold housing, and access to wheels had no significant effect on plasma estradiol or progesterone concentrations, but significantly decreased plasma leptin concentrations. All three energetic challenges unmask estrous cycle fluctuations in sexual motivation that are obscured in laboratory conditions, i.e., isolation in a small cage with an overabundance of food.

  2. Endocrine patterns of the estrous cycle and pregnancy of wildebeest in the Serengeti ecosystem.

    PubMed

    Clay, A Moss; Estes, R D; Thompson, K V; Wildt, D E; Monfort, S L

    2010-04-01

    Despite the importance of the western white-bearded wildebeest (Connochaetes taurinus mearnsi) to the Serengeti-Mara ecosystem, surprisingly little is known about the reproductive physiology of this keystone species. A longitudinal, non-invasive endocrine study was conducted on female wildebeest captured from the Serengeti-Mara migration and maintained for approximately 16 months in large fenced enclosures within the species' natural range. An intact bull was introduced to a female subgroup (n=5), while remaining females (n=10) were unexposed to a male. Fecal progestagen patterns reflected ovarian activity and pregnancy. In non-pregnant animals, luteal and inter-luteal baseline progestagen values differed (p<0.001) over time, thereby allowing identification of recurrent estrous cycles. The average durations of the luteal phase, estrous cycle, gestation, and post-partum anestrus were 14.3+/-0.5, 22.6+/-1.0, 240.8+/-11.7, and 104.1+/-15.6 d, respectively. Annual reproductive patterns indicated a distinctive period of ovarian activity that extended from 13 May through 3 December (203.5+/-29.9 d) with all unmated females displaying from one to 14 estrous cycles. Progestagens were higher (p <0.001) in pregnant (n=4) than non-pregnant (n=10) cows. These data (1) reveal the value of fecal hormone monitoring for establishing the first ever endocrine profiles of female wildebeest in semi-free-living conditions in their native range, and (2) indicate that the species is a seasonal breeder that is polyestrous and a spontaneous ovulator. (c) 2009 Elsevier Inc. All rights reserved.

  3. RHAMM Expression in the Rat Endometrium during the Estrous Cycle and following Implantation

    PubMed Central

    Ozbilgin, Kemal; Boz, Banu; Tuğyan, Kazım; Inan, Sevinç; Vatansever, Seda

    2012-01-01

    Background Receptor for hyaluronic acid mediated motility (RHAMM) has intracellular and extracellular functions. In this study, we focus on the expression of RHAMM in the rat uterus during estrous cycle and implantation period. Methods The female adult rats were divided into six groups following estrous cycle determination (n = 36). The utreri of rats were collected according to estrous cycle phases (menstruation group). For the implantation groups, uteri were obtained on D4, D5 and D6 (day of implantation) of pregnancy. The tissue samples were fixed and cut into 5 µm thick sections. RHAMM was investigated using immunohisto-chemical techniques and the intensity of RHAMM was evaluated by using the H-score technique. Comparisons between groups were performed using Kruskal-Wallis test. Results The RHAMM immunoreactivity of uterine antimesometrial epithelium (343.00±12.81), mesometrial subepithelium (285.00±27.26) and mesometrial stroma (270.00±36.00) were more prominent (p < 0.05) in the proestrus than estrus (275.00± 25.96; 220.00±14.48; 218.00±11.19) and diestrus (262.00±20.71; 192.50± 29.25; 216.00±12.97) groups, respectively. The most intense staining was seen in the epithelium on day four (275.50±30.06) and six (293.50±34.47) of pregnancy (p < 0.05). Strong RHAMM expressions were in both mature and predecidual cells on D5 (256.00±18.71), (247.50±22.14) and D6 (256.00±30.72), (265.00±14.87), respectively. RHAMM expression was prominent in the nondecidual region on D5 (270.00± 13.36). Conclusion Considering the role of RHAMM in cell proliferation, differentiation and angiogenesis, spatiotemporal expression of RHAMM in the uterus during estrous cycle and peri-implantation period is a means through which uterus becomes receptive for developing an embryo. PMID:23926537

  4. Melatonin in the control of the estrous cycle of the Indian desert gerbil (Meriones hurrianae: Jerdon).

    PubMed

    Joshi, B N; Manepalli, S K; Saibaba, P

    1994-01-01

    Daily administration of melatonin for 8 weeks, either in the morning (9 a.m.) or late in the afternoon (5 p.m.), resulted in significant prolongation of the estrous cycle in the Indian desert gerbil Meriones hurrianae. The gonadosomatic index increased significantly (p < 0.01) in the melatonin-treated gerbils compared to the control animals. Histological study of the ovaries revealed enlargement of follicles and corpora lutea with hypertrophied granulosa cells in the melatonin-treated gerbils in comparison to their controls. The data suggest that the mechanism involved in the gonadal response to melatonin may not be the same in the temperate and tropical species.

  5. C/EBPβ Isoforms Expression in the Rat Brain during the Estrous Cycle

    PubMed Central

    Hansberg-Pastor, Valeria; Piña-Medina, Ana Gabriela; González-Arenas, Aliesha; Camacho-Arroyo, Ignacio

    2015-01-01

    The CCAAT/enhancer-binding protein beta (C/EBPβ) is a transcription factor expressed in different areas of the brain that regulates the expression of several genes involved in cell differentiation and proliferation. This protein has three isoforms (LAP1, LAP2, and LIP) with different transcription activation potential. The role of female sex hormones in the expression pattern of C/EBPβ isoforms in the rat brain has not yet been described. In this study we demonstrate by western blot that the expression of the three C/EBPβ isoforms changes in different brain areas during the estrous cycle. In the cerebellum, LAP2 content diminished on diestrus and proestrus and LIP content diminished on proestrus and estrus days. In the prefrontal cortex, LIP content was higher on proestrus and estrus days. In the hippocampus, LAP isoforms presented a switch on diestrus day, since LAP1 content was the highest while that of LAP2 was the lowest. The LAP2 isoform was the most abundant one in all the three brain areas. The LAP/LIP ratio changed throughout the cycle and was tissue specific. These results suggest that C/EBPβ isoforms expression changes in a tissue-specific manner in the rat brain due to the changes in sex steroid hormone levels presented during the estrous cycle. PMID:26064112

  6. Changes in estrogen-alpha receptor immunoreactivity during the estrous cycle in lactating dairy cattle.

    PubMed

    van Eerdenburg, F J; Daemen, I A; van der Beek, E M; van Leeuwen, F W

    2000-10-13

    Estradiol is one of the most important hormones in the regulation of estrous behavior, which is at a very low level of expression in the modern dairy cow. In the present study the neuroanatomical distribution of estrogen receptors of the alpha-subtype (ER-alpha) in the bovine hypothalamic area is determined with immunocytochemical methods, at various stages of the estrous cycle. During the luteal phase of the cycle, ER-alpha immunoreactive cells were found in most of the nuclei that are known to express ER-alpha immunoreactivity in other species, like the Bed nucleus of the Stria terminalis, Medial preoptic area, Ventromedial hypothalamus and Arcuate nucleus. During estrus and metestrus, however, no ER-alpha immunoreactive cells could be detected in those areas, except for a few in the caudal Arcuate nucleus. The results from the present study indicate that there is a coherent regulation and timing of physiological and behavioral events around ovulation, in which estradiol and its receptor play a key role.

  7. [Adrenal function in different phases of the estrous cycle in the domesticated silver fox, Vulpes fulvus].

    PubMed

    Bazhan, N M; Lutsenko, N D

    1987-01-01

    Experiments were made on silver foxes from a population which had been selected for 10 to 15 generations for the domestic behaviour and on animals from a control, unselected population. In females from both populations, studies were made of the level of 11-OHCS in the blood serum, in vitro production of 11-OHCS, the size of fascicular zone in the adrenal cortex, the volume of cellular nuclei and nucleoli, as well as the reaction of the adrenals in vitro to 2 doses of ACTH (1 and 5 units/g of the adrenals) during anestrus, proestrus and estrus. In control females, all the characters investigated significantly increased from anestrus to proestrus. In domesticated females, no changes in the production of 11-OHCS in vitro or changes in morphological features of the fascicular zone were observed in the course of estrous cycle. During proestrus, the adrenals of the domesticated animals were not able to increase the production of 11-OHCS in vitro after application of ACTH. The decrease in the reactivity of the adrenals to the effect of ACTH is presumably the main cause why in unselected females the adrenal are not activated during proestrus. Therefore, in the course of selection for the domestication type of behaviour, species specific dynamics of activation of the adrenals during estrous cycle is lost.

  8. Serum hormone concentrations and ovarian follicular wave emergence in Jilin sika deer (Cervus nippon hortulorum) after synchronization of estrous cycles.

    PubMed

    Chen, X M; Wei, H J; Yang, Y F; Xue, H L; Zhao, W G; Zhao, M

    2015-02-01

    The study was conducted to investigate the serum hormone concentrations and follicular dynamics present after synchronous treatment (CIDR) in female Jilin sika deer (n = 15) of estrous cycles. Blood samples were collected to analyze the FSH, LH, estradiol and progesterone during the estrous cycles. Manual transrectal ultrasonography examination was conducted at least thrice weekly to monitor the follicular wave. Ultrasonography showed that follicle development occurred in waves, and most estrous cycles in Jilin sika deer consist of one, two, or three waves. The largest follicles of the interwaves of two- and three-wave cycles were different (P < 0.05). The mean interovulatory interval was 15.0 ± 4.6 d. There was a surge in circulating FSH in two- and three-wave cycles. The emergence of the largest follicle was related to the peak of serum concentration of estradiol. Serum progesterone concentrations were not different between one- and three-wave cycles (P < 0.05). We concluded that FSH and estradiol concentration may have an important role in controlling follicular development, that the estrous cycle in Jilin sika deer is characterized by one, two, or three waves of follicular development after synchronization. Copyright © 2015. Published by Elsevier B.V.

  9. Prolactin messenger ribonucleic acid concentrations throughout the ovine estrous cycle: Assessment relative to prolactin serum and pituitary amounts

    SciTech Connect

    Landefeld, T.; Roulia, V.; Bagnell, T.; Ballard, T.; Levitan, I. )

    1991-01-01

    Prolactin (PRL) mRNA concentrations were assessed by nucleic acid hybridization assays in pituitaries of ewes representing the defined stages of the ovine estrous cycle. Concomitantly, pituitary and serum PRL concentrations were measured in these ewes using radioimmunoassays. It was observed that PRL serum, pituitary and mRNA concentrations tended to increase near the time of the gonadotropin preovulatory surge, particularly between 24 hrs before behavioral estrus to 5 hours after estrus. However, the changes in PRL mRNA, serum and pituitary concentrations were shown not to be statistically significant. These data suggest that PRL production during the sheep estrous cycle is maintained without dramatic changes in synthesis or secretion.

  10. Stress and estrous cycle affect strategy but not performance of female C57BL/6J mice.

    PubMed

    ter Horst, J P; Kentrop, J; de Kloet, E R; Oitzl, M S

    2013-03-15

    Stress induces a switch in learning strategies of male C57BL/6J mice from predominantly spatial to more stimulus-response learning. To study generalization of these findings over sex, we investigated female C57BL/6J mice at three phases of the estrous cycle under non stress and acute (10 min) restraint stress conditions. On a circular hole board (CHB) task, about half of the naive female mice used spatial and stimulus-response strategies to solve the task. Under stress, female mice favored spatial over stimulus-response strategies, with 100% of female mice in the estrus phase. Performance expressed as latency to solve the task is only improved in stressed female mice in the estrus phase. We conclude that the use of learning strategies is influenced by sex and this difference between sexes is aggravated by acute stress.

  11. Sex differences and estrous cycle in female rats interact with the effects of fluoxetine treatment on fear extinction

    PubMed Central

    Lebrón-Milad, K.; Tsareva, A.; Ahmed, N.; Milad, M. R.

    2014-01-01

    A common treatment for anxiety disorders is chronic administration of selective serotonin reuptake inhibitors (SSRIs) such as fluoxetine. Recent data suggest that SSRIs modulate fear responses after conditioned fear extinction and that gonadal hormones influence fear extinction. In this study we investigated the influence of sex and the estrous cycle on the effects of acute (experiment 1) and chronic (experiment 2) fluoxetine treatment on fear extinction. In experiment 1, rats received tone-footshock pairings during day 1. On day 2, rats received either fluoxetine (10mg/kg in 0.5mL) or vehicle prior to extinction learning. On day 3, extinction memory was assessed during extinction recall. In experiment 2, rats were exposed to a similar behavioral protocol, except that fluoxetine and vehicle were administered for 14 consecutives days after conditioning (days 2–15). Extinction learning and extinction recall occurred on days 15 and 16, respectively. Acute administration of fluoxetine increased fear responses equally in males and females during extinction learning and extinction recall. Chronic administration of fluoxetine reduced fear responses during extinction learning and extinction recall in female but not in male rats and this effect seems to be modulated by the estrous cycle. The SSRI-induced reduction of freezing during extinction learning and recall suggest a general anxiolytic effect of the drug treatment rather than a specific effect on extinction learning per se. Our data show evidence of sex-specific anxiolytic effects of 14-day treatment of fluoxetine while the acute anxiogenic effect of SSRI seems independent of sex effects. PMID:23886596

  12. Using vaginal wall impedance to determine estrous cycle phase in Lewis rats.

    PubMed

    Jaramillo, Lorenza María; Balcazar, Ignacio Briceño; Duran, Camilo

    2012-05-01

    The use of Lewis rats in embryonic tissue transplantation experiments can present a challenge because of the fertility problems associated with this strain. The authors used estrous cycle phase determination to time pairings of reproductively active females and males in order to increase the likelihood that mating would occur. During a 24-month period, female rats in a production colony were evaluated for estrous phase by microscopic evaluation of vaginal smears and by vaginal impedance readings. Pairings that were arranged with females determined to be in the proestrous phase by vaginal smears resulted in a low rate of confirmed matings (14%). Serial vaginal smear sampling also produced a high incidence of pseudopregnancy. Pairings that were arranged with females determined to be in the proestrous phase by vaginal impedance readings resulted in a high rate of confirmed matings (48.1%) as well as a high rate of pregnancy (29.4%). An average of 7.2 embryos were produced per pregnancy. The vaginal impedance technique can be used to improve the breeding success rate of Lewis rats in order to maintain a stable production of embryos for experimentation.

  13. The effects of 17 alpha-methyltestosterone, methandrostenolone, and nandrolone decanoate on the rat estrous cycle.

    PubMed

    Blasberg, M E; Langan, C J; Clark, A S

    1997-02-01

    In a series of four separate experiments, the effects of anabolic-androgenic steroid (AAS) compounds on the estrous cycle of adult Long-Evans rats were examined. Sexual receptivity, vaginal cytology, and body weight were monitored throughout a 2-week baseline, AAS treatment, and recovery periods. In Experiments 1-3, subjects were administered 17 alpha-methyltestosterone, methandrostenolone, or nandrolone decanoate at doses selected to mimic the human abuse levels of each compound. In these studies, the highest doses of 17 alpha-methyltestosterone (7.5 mg/kg) and nandrolone decanoate (5.6 mg/kg) disrupted behavioral and vaginal cyclicity, whereas the highest dose of methandrostenolone (3.75 mg/kg) appeared to have slightly less robust effects. To compare effects on estrous cyclicity across AAS compounds, subjects in Experiment 4 received a single high dose (7.5 mg/kg) of each compound for 2 weeks. At this dose, all AAS compounds interfered with vaginal cyclicity, although effects on behavioral cyclicity and uterine weight were not uniform. Across all 4 experiments, AAS effects on body weight were minimal. The short-term administration of AAS compounds at levels commonly used by humans disrupts female neuroendocrine function in a dose-dependent manner.

  14. Stanozolol, oxymetholone, and testosterone cypionate effects on the rat estrous cycle.

    PubMed

    Clark, A S; Blasberg, M E; Brandling-Bennett, E M

    1998-01-01

    Anabolic-androgenic steroid (AAS) effects on the estrous cycle of adult Long-Evans rats were examined in four different experiments. Sexual receptivity, vaginal cytology, and body weight were monitored throughout two-week baseline, AAS treatment, and recovery periods. In Experiments 1-3, rats were administered stanozolol, oxymetholone, or testosterone cypionate within dose ranges selected to mimic the human abuse levels of each compound. In these studies, the highest doses of stanozolol (5 mg/kg), oxymetholone (12 mg/kg), or testosterone cypionate (7.5 mg/kg) disrupted the cyclical display of sexual receptivity and vaginal estrus. To compare effects on estrous cyclicity across AAS compounds, rats in Experiment 4 received a single dose (7.5 mg/kg) of each compound for 2 weeks. At the 7.5 mg/kg dose, all AAS compounds interfered with the cyclical display of vaginal estrus, although effects on sexual receptivity were not uniform. No striking AAS effects on body weight were seen in any experiment. The short-term administration of AAS compounds at high doses disrupts female neuroendocrine function in rats.

  15. Characteristics of ovarian follicular dynamics throughout the estrous cycle of Egyptian buffaloes.

    PubMed

    Barkawi, A H; Hafez, Y M; Ibrahim, S A; Ashour, G; El-Asheeri, Amal K; Ghanem, N

    2009-02-01

    Data of 56 normal and 9 abnormal estrous cycles were collected from 9 Egyptian buffaloes (Bublus bublis) to describe the follicular growth wave pattern. Heat was checked twice daily while, ovaries were scanned daily to monitor the patterns of follicular waves. Day of ovulation was determined when the largest follicle was replaced by corpus haemorrhgicum (CH). Number of waves/cycle, day of emergence of the follicular wave, characteristics of the dominant follicle and corpus luteum (CL) growth features were monitored. Buffaloes displayed mainly two types of follicular waves; two (46.4%) and three (53.6%). In cycles of three wave pattern, time of emergence of the 1st wave post-heat was longer (P<0.05) and number of recruited follicles/wave were larger (P<0.05) compared to the corresponding values of the two wave pattern. Number of recruited follicles in early follicular waves (1st or the 2nd) had larger number (P<0.05) compared to the subsequent ones. Follicles that reached ovulation in both types of estrous cycle had shorter life-span (P<0.05) than the previous ones. Life-span of CH, growing and regressed CL were 3.6+/-0.6, 11.2+/-0.8 and 4.4+/-0.5 days, respectively with no difference in both types of follicular wave. Three types of ovarian disorders were observed. Follicular waves and CL growth features showed unique pattern for each individual. These results demonstrate that buffaloes display two main types of follicular waves with dominance of three wave type.

  16. The acute asymmetric effects of hemiovariectomy on testosterone secretion vary along the estrous cycle. The participation of the cholinergic system

    PubMed Central

    Flores, Angélica; Rodríguez, Jorge O; Palafox, María T; Meléndez, Griselda; Barco, Ana I; Chavira, Roberto; Esther Cruz, M; Domínguez, Roberto

    2006-01-01

    The presence of asymmetry in the capacity of the left and right ovaries to secrete testosterone was analyzed by studying the effects of hemiovariectomy along the estrus cycle one hour after surgery. The effects of ether anesthesia on hormone serum levels were also analyzed. Bilateral ovariectomy and the extirpation of the left ovary performed on the day of proestrus resulted in significantly lower testosterone levels. Compared to the anesthetized group, the effects of perforating the peritoneum unilaterally varied according to the day of the estrous cycle and the side of the peritoneum surgery was performed on. Injecting atropine sulfate (ATR) to control or anesthetized rats on D1 resulted in a significant increase of testosterone serum levels. The effects of perforating the peritoneum on testosterone levels depended on the cholinergic innervation and varied along the estrous cycle. Blocking the cholinergic system before performing unilateral or bilateral ovariectomy had different effects depending on the day of the estrous cycle. Testosterone plasma levels increased significantly when surgery was performed on the day of diestrus and dropped when surgery was performed on proestrus. Similar effects were observed when the left adrenal was extirpated from animals with the cholinergic system blocked. The results presented herein support the hypothesis of asymmetry in the ovaries' abilities to secrete steroid hormones, and that the capacity to secrete testosterone varies along the estrous cycle. PMID:16509991

  17. Estrous cycle characterisation and artificial insemination using frozen-thawed spermatozoa in the bottlenose dolphin (Tursiops truncatus).

    PubMed

    Robeck, T R; Steinman, K J; Yoshioka, M; Jensen, E; O'Brien, J K; Katsumata, E; Gili, C; McBain, J F; Sweeney, J; Monfort, S L

    2005-05-01

    The reproductive endocrinology of the bottlenose dolphin, Tursiops truncatus, was characterized to facilitate the development of artificial insemination using cryopreserved spermatozoa. Specific objectives were: (i) to determine the excretory dynamics of urinary luteinizing hormone (LH) and ovarian steroid metabolites during the estrous cycle; (ii) to evaluate the effect of an exogenously administered synthetic progesterone analog (altrenogest) on reproductive hormone excretion; (iii) to correlate follicular growth and ovulation (as determined by transabdominal ultrasound) to urinary LH and ovarian steroid metabolites; (iv) examine the in vivo fertilisation capacity of cryopreserved semen, and (v) to develop an intrauterine insemination technique. Based on urinary endocrine monitoring of natural estrous cycles (2 consecutive cycles) and nine post altrenogest cycles in ten females, estrous cycles were found to be 36 days long and comprised of an 8 day and 19 day follicular and luteal phase, respectively. Peak estrogen conjugates (EC; 5.4+/-3.8 ng/mg creatinine (Cr)) occurred 8 h prior to the LH surge (70.9+/-115.7 ng/mg Cr). The time of ovulation, as determined by ultrasonography, occurred 32.1+/-8.9 h and 24.3+/-7.0 h after the onset of the LH surge and LH peak, respectively. Mean preovulatory follicular diameter and circumference were 2.1+/-0.5 cm and 6.5+/-1.5 cm, respectively. Of the 27 estrous synchronisation attempts, 13 resulted in an ovulatory cycle, with ovulation occurring 21 days post-altrenogest treatment. Intrauterine (4 of 5) and intracornual (1 of 3) inseminations conducted across eight estrous cycles resulted in five pregnancies (63%), one pregnancy resulted from the use of liquid stored semen, whereas four were achieved using cryopreserved semen. These data provide new information on female bottlenose dolphin reproductive physiology, and demonstrate that the combination of endocrine monitoring and serial ultrasonography contributed to successful AI

  18. Impact of number of estrous cycles exhibited prior to start of breeding on reproductive performance in beef heifers

    USDA-ARS?s Scientific Manuscript database

    Objective of this research was to evaluate effect of number of estrous cycles exhibited prior to breeding on reproductive performance of replacement beef heifers. A total of 1,176 composite heifers (½ Red Angus, ¼ Charolais, ¼ Tarentaise) were evaluated over a 9-yr period. Circulating concentration...

  19. Association between Period 1 mRNA levels in leukocytes and initiation of estrous cycles in peripubertal beef heifers

    USDA-ARS?s Scientific Manuscript database

    Initiation of fertile estrous cycles is one of the largest reproductive obstacles that a beef cow must overcome. In beef cows, postpartum interval and age at puberty are moderately heritable reproductive traits that have been reported to have a positive genetic correlation (between 0.45 and 0.70). ...

  20. Estrogen-dependent expression of sine oculis homeobox 1 in the mouse uterus during the estrous cycle

    SciTech Connect

    Bae, Sijeong; Kwon, Hwang; Yoon, Hyemin; Park, Miseon; Kim, Hye-Ryun; Song, Haengseok; Hong, Kwonho; Choi, Youngsok

    2016-04-08

    The sine oculis homeobox 1 (SIX1) is a member of the Six gene family. SIX1 is involved in tissue development by regulating proliferation, apoptosis, and differentiation. However, function of SIX1 in the uterus remains unknown. Here, we found that Six1 expression is regulated along the estrous cycle in mouse uterus. Six1 expression was significantly increased at estrus stage and decreased at the rest of stages. SIX1 is detected in the luminal and glandular epithelium of uterine endometrium at the estrus stage. Estrogen injection increased Six1 expression in the ovariectomized mouse uterus, whereas progesterone had no effect on its expression. Estrogen receptor antagonist inhibited estrogen-induced Six1 expression. Our findings imply that SIX1 may play a role as an important regulator to orchestrate the dynamic of uterine endometrium in response to estrogen level during the estrous cycle. These results will give us a better understanding of uterine biology. - Highlights: • Six1 expression is regulated during the estrous cycle in mouse uterus. • Six1 is highly expressed at the estrus stage of estrous cycle. • SIX1 is detected in luminal/glandular epithelium of the uterus at the estrus stage. • Estrogen stimulates Six1 expression in an estrogen receptor-dependent manner.

  1. Expression of progesterone receptor membrane component (PGRMC) 1 and 2, serpine mRNA binding protein 1 (SERBP1) and nuclear progesterone receptor (PGR) in the bovine endometrium during the estrous cycle and the first trimester of pregnancy.

    PubMed

    Kowalik, Magdalena K; Slonina, Dominika; Rekawiecki, Robert; Kotwica, Jan

    2013-03-01

    Progesterone (P4) is involved in the regulation of essential reproductive functions affecting the target cells through both nuclear progesterone receptors (PGRs) and membrane progesterone receptors. The aim of this study was to determine the mRNA and protein expression for PGRMC1, PGRMC2, SERBP1 and PGR within the bovine endometrium during the estrous cycle and the first trimester of pregnancy. There were no changes in PGRMC1 and PGRMC2 mRNA and protein expression during the estrous cycle, however, mRNA levels of PGRMC1 and PGRMC2 were increased (P<0.001) in pregnant animals. SERBP1 mRNA expression was increased (P<0.05), while the level of this protein was decreased (P<0.05) on days 11-16 of the estrous cycle. The expression of PGR mRNA was higher (P<0.01) on days 17-20 compared to days 6-10 and 11-16 of the estrous cycle and pregnancy. PGR-A and PGR-B protein levels were elevated on days 1-5 and 17-20 of the estrous cycle as compared to other stages of the cycle and during pregnancy. In conclusion, our results indicate that P4 may influence endometrial cells through both genomic and nongenomic way. This mechanism may contribute to the regulation of the estrous cycle and provide protection during pregnancy. Copyright © 2013 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  2. Endometrial expression of leptin receptor and members of the growth hormone-Insulin-like growth factor system throughout the estrous cycle in heifers.

    PubMed

    Sosa, C; Carriquiry, M; Chalar, C; Crespi, D; Sanguinetti, C; Cavestany, D; Meikle, A

    2010-12-01

    The growth hormone (GH)-insulin-like growth factor (IGF) system is expressed in bovine uterus during the estrous cycle and early pregnancy and is acknowledged to play an important role in regulating the development of the embryo and uterus. The leptin receptor (LEPR) is also expressed in the bovine uterus although it is not known whether its expression varies during the estrous cycle. In this study, the expression of the IGF-I and -II, the type 1 IGF receptor (IGF-1R), GH receptor (GHR) and LEPR transcripts was determined on endometrial transcervical biopsies collected on days 0 (estrus), 5, 12 and 19 of the cow estrous cycle (n=8). The expression of mRNA was determined by RT real time PCR using ribosomal protein L19 as a housekeeping gene. It has been demonstrated for the first time that LEPR mRNA is expressed in the bovine uterus throughout the estrous cycle and that it presents a cycle-dependent variation, with higher levels observed during the luteal phase. The expression of IGF-I mRNA was greatest at estrus and day 5 (100%), and decreased on days 12 and 19 to 47% and 35% of the initial values. IGF-II mRNA increased on day 12 and decreased sharply thereafter (to one-third of day 12 values). Interestingly, IGF-1R showed the same pattern as IGF-II: increased 50% on day 12 compared to values at estrus and presented a sharp decrease on day 19. The expression of GHR transcript was greatest at estrus and on day 5 and progressively decreased thereafter. These results show that the GH-IGF system components are distinctively regulated during the estrous cycle suggesting that modulation of the IGF system may influence uterine activity during this period. The increase in the uterine sensitivity to IGFs during the late luteal phase - as demonstrated by the increased IGF-1R expression - concomitant with the increased IGF-II mRNA expression may reinforce the role of IGF-II during early pregnancy. Moreover, leptin is also likely to play roles during early embryo development.

  3. Transcriptomic analysis of the porcine endometrium during early pregnancy and the estrous cycle.

    PubMed

    Franczak, Anita; Wojciechowicz, Bartosz; Kotwica, Genowefa

    2013-09-01

    The goal of this study was to describe the alterations in the transcriptome of the endometrium in pigs during the beginning of implantation (days 15-16 of pregnancy) compared to cyclic pigs during the onset of luteolysis (days 15-16 of the estrous cycle). The global expression of genes in porcine gravid and non-gravid endometria was investigated using the Porcine (V2) Two-color gene expression microarray, 4 × 44 (Agilent, USA). Analysis of the microarray data showed that, of 589 accurately annotated genes, the expression of 266 genes was up-regulated and expression of 323 was down-regulated in the endometrium harvested during early pregnancy compared with the endometrium during the estrous cycle. In pregnant pigs, genes with the most significantly altered expression were involved in the following biological processes: the metabolic process, cellular process, cell communication, immune system process, developmental process, cell adhesion, antigen processing and presentation, antigen processing and presentation of peptide or polysaccharide antigen via major histocompatibility complex (MHC) class II, immune response, and the polysaccharide metabolic process. In the pregnant endometrium, cell adhesion molecules and steroid hormone biosynthesis pathways were the most significantly enriched biological pathways. Analysis of the interaction network among selected genes showed that androgen receptor (AR) encoding genes interact with genes involved in important processes occurring during early pregnancy. The bioinformatic analysis revealed information about the meaning of differentially expressed genes. The data provided new insight into the dynamic changes of the endometrial gene expression profile during days 15-16 of pregnancy.

  4. Lactoferrin expression in the canine uterus during the estrous cycle and with pyometra.

    PubMed

    Kida, K; Baba, E; Torii, R; Kawate, N; Hatoya, S; Wijewardana, V; Sugiura, K; Sawada, T; Tamada, H; Inaba, T

    2006-09-15

    The expression of lactoferrin, a non-specific antimicrobial defence, in the canine uterus during the normal estrous cycle and in bitches with pyometra was examined. Using polymerase chain reaction analysis, lactoferrin gene transcripts were detected in the endometrium at all stages of the estrous cycle, with the highest levels in estrus. In normal bitches, endometrial lactoferrin mRNA increased from proestrus to estrus (P<0.05). Thereafter, it dramatically decreased from estrus to Day 10 of diestrus (P<0.05), and stayed low at Day 35 of diestrus and anestrus; this was consistent with blood estrogen concentrations. Levels of lactoferrin mRNA were higher in bitches with pyometra than in normal diestrus (P<0.05). With immunohistochemistry, distinct staining of lactoferrin was detected in the luminal and glandular epithelial cells of the endometrium at proestrus and estrus, but little staining was detected at Day 10 of diestrus. At Day 35 of diestrus and anestrus, a partial and weak reaction was present in the same region. In bitches with pyometra, the glandular epithelial cells and many cells in the uterine stroma were strongly stained. Staining cells in the stroma were morphologically similar to neutrophils. No lactoferrin staining was seen in the uterine stromal cells or myometrium in any section. These results suggest that, in the canine uterus, lactoferrin expression is related to the blood concentration of estrogen, and that the dramatic reduction in lactoferrin observed at the early stage of diestrus may impair antimicrobial defense. Also, enhanced expression of lactoferrin mRNA in the endometrium with pyometra may be associated with neutrophil invasion into the uterus to combat the infection.

  5. The role of the muscarinic system in regulating estradiol secretion varies during the estrous cycle: the hemiovariectomized rat model

    PubMed Central

    Cruz, María E; Flores, Angélica; Palafox, María T; Meléndez, Griselda; Rodríguez, Jorge O; Chavira, Roberto; Domínguez, Roberto

    2006-01-01

    There is evidence that one gonad has functional predominance. The present study analyzed the acute effects of unilateral ovariectomy (ULO) and blocking the cholinergic system, by injecting atropine sulfate (ATR), on estradiol (E2) serum concentrations during the estrous cycle. The results indicate that ULO effects on E2 concentrations are asymmetric, vary during the estrous cycle, and partially depend on the cholinergic innervation. Perforation of the left peritoneum resulted in lower E2 serum concentrations in the three stages of the estrous cycle. At proestrus, unilateral or bilateral perforation of the peritoneum resulted in lower E2 serum concentrations. ULO of the right ovary (left ovary in situ) resulted in significantly higher E2 concentrations than animals with ULO of the left ovary (right ovary in situ). ATR treatment to ULO rats on D1 resulted in a significant drop of E2 serum concentrations. ULO rats treated with ATR on D2 or P, resulted in an asymmetrical E2 secretion response; when the right ovary remained in situ an increase in E2 was observed, and a decrease when the left ovary remained in situ. The results obtained in the present study suggest that each ovary's ability to compensate the secretion of E2 from the missing ovary is different and varies during the estrous cycle. The results also suggest that the cholinergic system participates in regulating ovarian E2 secretion. Such participation varies according to the ovary remaining in situ and the stage of the estrous cycle of the animal. The results agree with previously stated hypothesis of a neural pathway arising from the peritoneum that participates in regulating E2 secretion, and also supports the idea of cross-talk between the ovaries, via a neural communication, that modulates E2 secretion. PMID:16923184

  6. Expression and regulation of scavenger receptor class B type 1 in the rat ovary and uterus during the estrous cycle.

    PubMed

    Wang, Yalei; Meng, Chenling; Wei, Quanwei; Shi, Fangxiong; Mao, Dagan

    2015-04-01

    Scavenger receptor class B type 1 (SR-B1) preferentially mediates the selective uptake of high density lipoprotein-cholesterol ester and the delivery of cholesterol for steroidogenesis. Although multiple analyses have investigated the function of SR-B1 in the liver, adrenal and ovary, its expression in rat ovary and uterus during the estrous cycle is lacking. In the present study, real-time PCR, western blot and immunohistochemistry (IHC) were used to investigate SR-B1 expression in the rat ovary and uterus during the estrous cycle. The results demonstrated that ovarian SR-B1 expression was in a stage-dependent manner, continuously increased from proestrus and kept elevated during metoestrus, while uterine SR-B1 expression decreased from proestrus to diestrus. To determine whether ovarian and uterine SR-B1 expression were affected by sex steroid hormones, immature rats were treated with 17 β-estradiol (E2), progesterone (P4), or their antagonists from postnatal days 24-26. Results showed that the levels of SR-B1 mRNA and protein were significantly up-regulated by E2 in both the ovary and uterus. IHC results showed that SR-B1 was primarily localized in the oocytes, theca internal cells (T-I) of follicles, interstitial cells (IC) as well as corpus luteum (CL), but not granulosa cells (GC) in the ovary during the estrous cycle. Uterine SR-B1 was highly expressed in the endometrial luminal epithelial cells (LEC) and glandular epithelial cells (GEC) as well as in the circular muscle (CM) cells, and weak staining in stromal cells (SC) through estrous cycle. Taken together, SR-B1 expression in the ovary and uterus across the estrous cycle demonstrate that SR-B1 may be involved in uterine function, follicular development as well as luteal function. Copyright © 2015 Elsevier GmbH. All rights reserved.

  7. MMP-2 and MMP-9 localization and activity in the female prostate during estrous cycle.

    PubMed

    Santos, Fernanda C A; Rochel-Maia, Sabrina S; Fochi, Ricardo A; Justulin, Luis A; Santos, Sérgio A A; Vilamaior, Patrícia S L; Felisbino, Sérgio L; Góes, Rejane M; Taboga, Sebastião R

    2011-09-15

    The gerbil female prostate undergoes morphological and physiological changes resulting from hormonal fluctuations that occur during the reproductive cycle. These repetitive cycles of glandular growth and regression are followed by an extensive reconstruction and remodeling of prostate stroma throughout the reproductive life of the female gerbil. The objective of this study was to evaluate the effect that the hormonal fluctuations of the reproductive cycle have on the stromal remodeling and the expression and activity of matrix metalloproteinases MMP-2 and -9 in the adult female gerbil prostate. For this, serological, ultrastructural, immunohistochemical and biochemical methods were employed. The results showed that the major stromal alteration coincide with the peak of estradiol, which occurs in estrus, and with the peak of progesterone, occurring during diestrus II. MMP-2 and -9 presented a similar pattern of expression and activity during estrous cycle. The estrus was the phase of greater expression and activity of MMP-2 and -9. On the other hand, in DI and DII, the tissue expression and activity of MMP-2 and -9 was very weak. These results are important since they suggest the involvement of estradiol and progesterone in regulating the expression and activity of MMP-2 and -9 in adult gerbil female prostate. Copyright © 2011 Elsevier Inc. All rights reserved.

  8. The Syrian Golden Hamster Estrous Cycle: Unique Characteristics, Visual Guide to Staging, and Comparison with the Rat.

    PubMed

    Chanut, Franck J A; Williams, Ann M

    2016-01-01

    The Syrian hamster, Mesocricetus auratus, is a suitable rodent species for standard regulatory toxicity studies. However, little is published about the female Syrian hamster reproductive system. It has unique anatomic features that differ from the other rodent species. In the hamster, the upper cervix is composed of 2 canals and the vagina shows 2 lateral pouches where keratin debris accumulates. These pouches must be distinguished from the vagina in order to stage the estrous cycle properly. The microscopic changes occurring during all the estrous cycle stages show some differences with the other rodents, the lower cervix and upper vagina presenting the more dramatic changes. The aim of this work was to produce a practical guide to staging the cycle and to highlight some of the differences between the rat and hamster reproductive system.

  9. Calcium and magnesium concentrations in uterine fluid and blood serum during the estrous cycle in the bovine.

    PubMed

    Alavi-Shoushtari, Sayed Mortaza; Asri-Rezaie, Siamak; Abedizadeh, Roya; Khaki, Amir; Pak, Mozhgan; Alizadeh, Sajad

    2012-01-01

    To investigate uterine and serum Ca(++) and Mg(++) variations during the estrous cycle in the bovine, 66 genital tracts and blood samples were collected from Urmia abattoir, Urmia, Iran. The phase of the estrous cycle was determined by examination of the structures present on ovaries and uterine tonicity. Of the collected samples, 17 were pro-estrus, 12 estrus, 14 metestrus and 23 diestrus. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. The mean ± SEM concentration of serum Ca(++) in pro-estrus, estrus, metestrus and diestrus was 5.77 ± 0.69, 8.87 ± 1.83, 10.95 ± 1.52, 11.09 ± 1.08 mg dL(-1), and the mean concentration of uterine fluid Ca(++) was 4.40 ± 0.72, 3.15 ± 0.67, 5.89 ± 0.88, 8.63 ± 0.97 mg dL(-1), respectively. The mean concentration of serum Mg(++) in pro-estrus, estrus, metestrus and diestrus was 3.53 ± 0.30, 4.20 ± 0.52, 3.49 ± 0.38, 3.39 ± 0.29 mg dL(-1), and mean concentration of uterine fluid Mg(++) was 5.27 ± 0.42, 4.92 ± 0.60, 5.56 ± 0.30, 5.88 ± 0.36 mg dL(-1), respectively. The serum and uterine fluid Ca(++) in pro-estrus were significantly different from those of the metestrus and diestrus. In all stages of estrous cycle the mean concentration of serum Ca(++) was higher than that in the uterine fluid. The difference between serum and uterine fluid Ca(++) in estrus, metestrus and diestrus was significant. There was no significant difference between serum Mg(++) content nor was it different from uterine fluid Mg(++) content at any stages of estrous cycle. In all stages of estrous cycle the uterine fluid Mg(++) was higher than that of the serum. These results suggest that during the estrous cycle in the cow, Ca(++) is passively secreted in uterine fluids and is mostly dependent on blood serum Ca(++) variations but Mg(++) is secreted independently and does not follow variations in the serum concentrations.

  10. Multi-parameter flow cytometric analysis of uterine immune cell fluctuations over the murine estrous cycle.

    PubMed

    Diener, Kerrilyn R; Robertson, Sarah A; Hayball, John D; Lousberg, Erin L

    2016-02-01

    Investigating immune cell populations within various reproductive tissues commonly utilises flow cytometric methods. With advances in fluorophore technology and equipment capabilities, multiple cell types from a single tissue sample can be identified by using different combinations of cell surface markers to distinguish specific cell populations. Here a protocol optimized for mouse uterine tissue was used to show the proportional changes in dendritic cells, monocyte/macrophages, T and B cells, NK and NK T cells, and the granulocytes, neutrophils and eosinophils at each of the four stages of the estrous cycle. Importantly, we demonstrate that use of anti-SiglecF or assessment of FSC/SSC plots could be used to differentiate monocyte/macrophage and eosinophil populations that otherwise cannot be distinguished by use of the common combination of antibodies against F4/80 and CD11b. Our results clearly indicate that within the uterus a dynamic population of immune cells resides, with many cell types reaching peak abundance at estrus and metestrus phases of the cycle, consistent with their importance in the response to paternal antigens and/or pathogens encountered after insemination.

  11. A Golgi study of the plasticity of dendritic spines in the hypothalamic ventromedial nucleus during the estrous cycle of female rats.

    PubMed

    González-Burgos, I; Velázquez-Zamora, D A; González-Tapia, D; Cervantes, M

    2015-07-09

    Estradiol-induced plasticity involves changes in dendritic spine density and in the relative proportions of the different dendritic spine types that influence neurons and neural circuits. Such events affect brain structures that control the timing of neuroendocrine and behavioral processes, influencing both reproductive and cognitive functions during the estrous cycle. Accordingly, to investigate the dendritic spine-related plastic changes that may affect the neural processes involved in mating, estradiol-mediated dendritic spine plasticity was studied in type II cells situated in the ventrolateral portion of the ventromedial hypothalamic nucleus (VMN) of female, adult rats. The rats were assigned to four different groups (n=6) in function of their stage in the estrous cycle: proestrus, estrus, metaestrus, and diestrus. Dendritic spine density and the proportions of the different spine types on type II neurons were analyzed in the ventrolateral region of the VMN of these animals. Dendritic spine density on primary dendrites of VMN type II neurons was significantly lower in metaestrus than in diestrus, proestrus and estrus (with no differences between these latter stages). However, a significant variation in the proportional density of the different spine types was found, with a higher proportion of thin spines in diestrus, proestrus and estrus than in metaestrus. Likewise, a higher proportion of mushroom spines was seen in diestrus and proestrus than in metaestrus, and a higher proportion of stubby spines in estrus than in diestrus and metaestrus. Very few branched spines were found during proestrus and they were not detected during estrus or metaestrus. The different types of dendritic spines in non-projection neurons of the VMN could serve to maintain greater synaptic excitatory activity when receptivity and estradiol levels are maximal. However, they may also fulfill an additional functional role when receptivity and estradiol decline. To date specific roles of

  12. Manipulation of estrous cycle in dwarf goat (Capra hircus) using estrumate under different management conditions.

    PubMed

    Khanum, Shahnaz Adeeb; Hussain, Mujahid; Kausar, Rehana

    2006-03-01

    A study was conducted to elucidate the effectiveness of exogenous estrumate (prostaglandin F(2alpha)) treatment as a synchronizing agent for Dwarf goats and to establish the progesterone levels at different reproductive stages under two different environmental and nutritional conditions. Female Dwarf goats of various ages were raised, 10 each at two sites, viz. the Bio-Saline Research Substation (BSRS), Lahore and at the Nuclear Institute for Agriculture and Biology (NIAB), Faisalabad. The animals at the NIAB farm were reared on non-saline soil under normal grazing conditions, while the other animal lot was raised on salt-affected lands at the BSRS, Lahore and was fed on non-conventional fodders produced by salt-affected lands. The animals received two intramuscular doses (0.5 ml each) of estrumate (125 microg/ml) at 10 days interval. Nineteen of the 20 animals exhibited estrus after 56-72 h of the second injection of estrumate. The mean progesterone concentration in the NIAB and BSRS lots was 2.8 and 2.4 ng/ml, respectively, at the time of second injection and declined to the basal level (estrus) within 48 h. A gradual increase in the progesterone level occurred during the metestrus, reaching maximum during the luteal phase when it was 6.3 and 6.7 ng/ml in NIAB-lot and BSRS-lot, respectively. During the proestrous phase, the progesterone level decreased to the basal level (0.1 ng/ml) at the onset of the next estrus after 22 days. The length of the induced or natural estrous cycle (20+/-1 days) was not affected by the estrumate treatment, nor by the environmental and nutritional conditions. Breeding was allowed after the natural estrous cycle at the onset of third estrus and a high fertility rate (95%) was achieved. The progesterone concentrations remained at higher level (4.5-9.4 ng/ml) throughout the gestation period, declined gradually in the prepartum period, and dropped to the basal level at the completion of parturition. The results suggested that estrumate

  13. Sex-Specific and Estrous Cycle-Dependent Antidepressant-Like Effects and Hippocampal Akt Signaling of Leptin

    PubMed Central

    Carrier, Nicole; Wang, Xuezhen; Sun, Linshan

    2015-01-01

    Sex differences in the incidence of depression and antidepressant treatment responses are well documented. Depression is twice as common in women as in men. Recent studies indicate that low levels of leptin, an adipocyte-derived hormone, are associated with increased symptoms of depression in women. Leptin has been shown to produce antidepressant-like effects in male rodents. In the present study, we examined sex differences and estrous cycle variations in antidepressant-like responses to leptin. Leptin administration significantly reduced immobility, a putative measure of behavioral despair, in the forced swim test in intact female mice in the proestrus phase but not in the diestrus phase of the estrous cycle. Moreover, leptin administration stimulated Akt phosphorylation in the hippocampus of female mice in proestrus but not in diestrus, in correlation with its differential behavioral effects in these two phases of the cycle. Leptin-induced behavioral responses and stimulation of hippocampal Akt phosphorylation in female mice were abolished by ovariectomy. By contrast, the antidepressant-like effect of leptin in male mice was not affected by gonadectomy (castration). Pretreatment with 17β-estradiol restored sensitivity to the effects of leptin on behavior and hippocampal Akt phosphorylation in ovariectomized female mice. These results suggest leptin regulates depression-like behavior and hippocampal Akt signaling in a sex-specific and estrous cycle-dependent manner. PMID:26181103

  14. The interleukin-1β system in the corpora lutea of pigs during early pregnancy and the estrous cycle.

    PubMed

    Zmijewska, Agata; Franczak, Anita; Kotwica, Genowefa

    2013-06-01

    Expression of mRNAs encoding interleukin-1β (IL-1β), IL-1β receptor I (IL-1RI), IL-1 receptor accessory protein (IL-1RAcP) and IL-1 receptor antagonist (IL-1Ra), as well as synthesis of IL-1β and IL-1RI proteins, were examined in the corpus luteum (CL) during critical stages of CL activity on days 10-16 of pregnancy and 2-16 of the estrous cycle. Luteal cells were cultured in vitro with IL-1β, and the effect on release of steroid hormones was determined. Expression of the IL-1β system in the CL changed significantly during pregnancy and the estrous cycle. IL-1β, IL-1RI, and IL-1Ra mRNA levels were elevated on days 12-13, whereas IL-1RAcP mRNA was increased on days 15-16 of pregnancy. In cyclic CL, expression of IL-1β, IL-1RI, and IL-1RAcP mRNAs was increased on days 12-13. IL-1β and IL-1RI protein were highest in the CL on days 10-11 and 8-11 of pregnancy and the estrous cycle. Luteal cells harvested from gravid and cyclic CL produced IL-1β in vitro. IL-1β increased progesterone and estradiol-17β (E2) release by luteal cells on days 10-16 and 10-11 of pregnancy, respectively and on days 2-11 of the estrous cycle. IL-1β decreased the level of E2 produced by regressed CL (days 15-16). Expression of the IL-1β system in CL and IL-1β secretion from luteal cells changed depending on the status of the CL. These data show that IL-1β may be involved in intraluteal, luteotrophic regulation of CL functions in gravid and cyclic pigs.

  15. Effect of the juice of lime (Citrus aurantifolia) on estrous cycle and ovulation of Sprague-Dawley rats.

    PubMed

    Salawu, Adeola A; Osinubi, Abraham A A; Dosumu, Olufunke O; Kusemiju, Taiwo O; Noronha, Cressie C; Okanlawon, Abayomi O

    2010-01-01

    To determine the effect of lime juice on the estrous cycle and ovulation of cyclic female rats. Twenty-five adult female Sprague-Dawley rats were used. The study was divided into 2 experiments (I and II). In experiment I, 15 rats were randomly subclassified into 3 groups (Ia, Ib, and Ic) of 5 rats each. The estrous cycles of the rats were studied for the first 16 days to establish cyclicity, after which lime juice was administered by gastric gavage for the next 24 days. Rats in group Ia received 1 mL of undiluted lime juice, rats in group Ib received 1 mL of 50% diluted lime juice, and rats in group Ic (control animals) received only distilled water. In experiment II, 10 female rats were used and were categorized into 2 groups (IIa and IIb), with 5 rats in each group. Rats in group IIa received 1 mL of undiluted lime juice during the morning of proestrus, and those in group IIb received only distilled water on the day of proestrus. The rats were killed the next day with use of chloroform anesthesia. The upper parts of the oviducts were excised and examined under the light microscope for assessment of the number of ova shed. There was an irregular pattern in all phases of the estrous cycle of 100% of the rats given undiluted lime juice and in 80% of those given 50% diluted lime juice. There was a significant (P = .001) reduction in the number of ova shed in rats administered undiluted lime juice in comparison with the control animals. Ovulation was partially blocked, as shown by the reduced number of ova observed in the oviducts from the rats given undiluted lime juice (5.10 +/- 2.37) in comparison with the control rats (12.70 +/- 1.14). In rats, lime juice causes irregularity of the estrous cycle, partially blocks ovulation, and may possibly compromise fertility.

  16. High-Yield Superovulation in Adult Mice by Anti-Inhibin Serum Treatment Combined with Estrous Cycle Synchronization.

    PubMed

    Hasegawa, Ayumi; Mochida, Keiji; Inoue, Hiroki; Noda, Yoshihiro; Endo, Tamao; Watanabe, Gen; Ogura, Atsuo

    2016-01-01

    Producing many mature oocytes is of great importance for assisted reproductive technologies. In mice, superovulation by consecutive injections of equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) has been the gold standard for oocyte collection. However, the yield of mature oocytes by this regimen can fluctuate according to the stage of the estrous cycle, strain, and age. Therefore, our objective was to develop a high-yield superovulation protocol to collect higher numbers of oocytes from adult female mice of different strains and ages. First, we aimed to synchronize the estrous cycle using C57BL/6 (B6) female mice. Most (93%) were synchronized to metestrus after two daily injections of progesterone. Second, we found that with the injection of anti-inhibin serum (AIS) instead of eCG, the mean number of ovulated oocytes almost doubled (21 vs. 41 per mouse). Third, by combining estrous cycle synchronization with two AIS injections, we obtained 62 oocytes per mouse, about three times that with the eCG-hCG protocol. Importantly, this approach increased the proportion of mice that ovulated >25 oocytes from about 40% (eCG-hCG) to 90%. The same protocol was also effective in other inbred (BALB/cA), outbred (ICR), and hybrid (B6D2F1) strains. In addition, B6 female mice aged over 1 yr ovulated 1.8-fold more oocytes by this protocol. Thus, estrous cycle synchronization followed by AIS-hCG yielded a broadly applicable, highly efficient superovulation. This protocol should promote the effective use of invaluable female mouse strains and decrease the numbers of animals euthanized.

  17. Secretory pattern of inhibin during estrous cycle and pregnancy in African (Loxodonta africana) and Asian (Elephas maximus) elephants.

    PubMed

    Yamamoto, Yuki; Yuto, Natsuki; Yamamoto, Tatsuya; Kaewmanee, Saroch; Shiina, Osamu; Mouri, Yasushi; Narushima, Etsuo; Katayanagi, Masayuki; Sugimura, Keisuke; Nagaoka, Kentaro; Watanabe, Gen; Taya, Kazuyoshi

    2012-01-01

    The ovary of female elephants has multiple corpora lutea (CL) during the estrous cycle and gestation. The previous reports clearly demonstrated that inhibin was secreted from lutein cells as well as granulosa cells of antral follicles in cyclic Asian elephants. The aim of this study is to investigate the inhibin secretion during the pregnancy in African and Asian elephants. Two African elephants and two Asian elephants were subjected to this study. Circulating levels of immunoreactive (ir-) inhibin and progesterone were measured by radioimmunoassay. Four pregnant periods of an African elephant and three pregnant periods of an Asian elephant were analyzed in this study. Circulating levels of ir-inhibin started to increase at 1 or 2 week before the ovulation and reached the peak level 3 or 4 weeks earlier than progesterone during the estrous cycle in both African and Asian elephants. After last luteal phase, the serum levels of ir-inhibin remained low throughout pregnancy in both an African and an Asian elephant. The mean levels of ir-inhibin during the pregnancy were lower than the luteal phase in the estrous cycle despite high progesterone levels were maintained throughout the pregnancy. These results strongly suggest that CL secrete a large amount of progesterone but not inhibin during the pregnancy in elephants. © 2011 Wiley Periodicals, Inc.

  18. Is one-wave follicular growth during the estrous cycle a usual phenomenon in water buffaloes (Bubalus bubalis)?

    PubMed

    Awasthi, M K; Khare, Abhishek; Kavani, F S; Siddiquee, G M; Panchal, M T; Shah, R R

    2006-05-01

    The pattern of growth and regression of ovarian follicles was monitored once daily for one complete estrous cycle in eight individual water buffaloes by ultrasonographic scanning of the ovaries for an entire interovulatory interval of normal cycle length. One-wave follicular growth was observed in five animals and two-wave follicular growth in three buffaloes during the estrous cycle. The first follicular wave of a two-wave cycle emerged significantly earlier (P < 0.05) than the emergence of the solitary wave of a one-wave cycle. One- and two-wave cycles differed significantly (P < 0.05) with respect to the mean interovulatory interval (21.0 +/- 0.54 days versus 22.7 +/- 0.33 days) and the mean interestrus interval (20.8 +/- 0.58 days versus 22.3 +/- 0.66 days). The overall linear growth rate of the ovulatory follicle was significantly greater (P < 0.01) in a two-wave cycle compared to that of a one-wave cycle (1.17 +/- 0.33 mm/day versus 0.32 +/- 0.01 mm/day). In a one-wave pattern, the growth profile of the solitary dominant follicle was atypical, showing three distinct phases, i.e. growth phase, regression phase and regrowth phase culminating in ovulation. The level of plasma progesterone steadily increased from day 0 of estrous cycle, attained peak level on day 14 and declined thereafter. A slower growth rate of the dominant follicle was observed in the presence of higher plasma progesterone concentration. The present study shows that one-wave follicular growth is a normal phenomenon in suckled water buffaloes.

  19. VGF Changes during the Estrous Cycle: A Novel Endocrine Role for TLQP Peptides?

    PubMed Central

    Noli, Barbara; Brancia, Carla; D’Amato, Filomena; Ferri, Gian-Luca; Cocco, Cristina

    2014-01-01

    Although the VGF derived peptide TLQP-21 stimulates gonadotropin-releasing hormone (GnRH) and gonadotropin secretion, available data on VGF peptides and reproduction are limited. We used antibodies specific for the two ends of the VGF precursor, and for two VGF derived peptides namely TLQP and PGH, to be used in immunohistochemistry and enzyme-linked immunosorbent assay complemented with gel chromatography. In cycling female rats, VGF C-/N-terminus and PGH peptide antibodies selectively labelled neurones containing either GnRH, or kisspeptin (VGF N-terminus only), pituitary gonadotrophs and lactotrophs, or oocytes (PGH peptides only). Conversely, TLQP peptides were restricted to somatostatin neurones, gonadotrophs, and ovarian granulosa, interstitial and theca cells. TLQP levels were highest, especially in plasma and ovary, with several molecular forms shown in chromatography including one compatible with TLQP-21. Among the cycle phases, TLQP levels were higher during metestrus-diestrus in median eminence and pituitary, while increased in the ovary and decreased in plasma during proestrus. VGF N- and C-terminus peptides also showed modulations over the estrous cycle, in median eminence, pituitary and plasma, while PGH peptides did not. In ovariectomised rats, plasmatic TLQP peptide levels showed distinct reduction suggestive of a major origin from the ovary, while the estrogen-progesterone treatment modulated VGF C-terminus and TLQP peptides in the hypothalamus-pituitary complex. In in vitro hypothalamus, TLQP-21 stimulated release of growth hormone releasing hormone but not of somatostatin. In conclusion, various VGF peptides may regulate the hypothalamus-pituitary complex via specific neuroendocrine mechanisms while TLQP peptides may act at further, multiple levels via endocrine mechanisms involving the ovary. PMID:25280008

  20. A correlation of fecal volatiles and steroid hormone profiles with behavioral expression during estrous cycle of goat, Capra hircus.

    PubMed

    SankarGanesh, Devaraj; Ramachandran, Rajamanickam; Muniasamy, Samuthirapandi; Saravanakumar, Veluchamy Ramesh; Suriyakalaa, Udhayaraj; Kannan, Soundarapandian; Archunan, Govindaraju; Achiraman, Shanmugam

    2014-09-15

    Chemical signals (both volatile and non-volatile) form the major communication channels in animals. These signals are transferred mainly through excretory sources to facilitate inter-individual communication. In particular, the reproductive cycle of female mammals, including goats, exhibits significant changes in the constituents of their excretory products, and female mammals also express different behavioral patterns. We propose that feces is one of the important sources of chemo-signals in goats. However, the behavioral patterns and analysis of excretory sources based on chemical communication have not yet been studied in the Indian goat, Capra hircus. To validate our hypothesis, we analyzed the behavioral patterns and the volatiles and steroid hormone profiles in the feces samples of female goats during the estrous cycle. Here, we synchronized the estrous cycle in six female goats and obtained feces samples. The samples were extracted with dichloromethane and analyzed using gas chromatography-mass spectrometry. A portion of the sample was used for hormone assay to confirm the phases in the estrous cycle. Induction of she-goats into estrus was detected from the vaginal swelling, mucus discharge, restlessness, reduced milk secretion, bellowing, bleating, frequent urination, standing heat, allowing the male to mount, mounting on other females and teasing of males. The repeated male behaviors viz., flehmen, mounting, penile protrusion, body rubbing, dominance over other males and finally coitus with estrus female by male goats were observed. Analysis of volatiles revealed a total of twenty-four compounds combining all the phases in the estrous cycle. Among those, some of the volatile compounds and two antioxidants (ascorbic acid and vitamin E) were estrus-specific. Based on the fecal steroid analysis, higher level of estradiol during estrus and higher level of progesterone during post-estrus were observed. The behavioral patterns of female and male goats combined

  1. The effect of intramuscular injections of boar pheromone 5alpha-androstenol on the hormonal regulation of the estrous cycle in hypoosmatic gilts.

    PubMed

    Stefańczyk-Krzymowska, S; Wasowska, B; Skipor, J

    2005-01-01

    Until 1999 it was accepted that pheromones act exclusively by stimulating the dendritic receptors present in olfactory epithelium. Cycling gilts with an experimentally-disrupted neural olfactory pathway were used to test the hypothesis that boar pheromone 5alpha-androstenol may affect the secretion of hormones involved in the regulation of the estrous cycle by the humoral pathway. On day 12 of the estrous cycle the nasal cavity of gilts (n=15) was irrigated with zink sulfate solution. From day 16 to 20, the experimental group (n=10) was injected intramuscularly with 5alpha-androstenol (20 microg) twice a day. Blood samples were collected from the jugular vein at 4 h intervals on days 17-21 to estimate plasma concentration of LH, oxytocin, estradiol-17beta, testosterone and progesterone. The experimental group displayed a significantly lower mean concentration of LH than the control animals (P<0.0001). The decrease in concentration of LH was accompanied by the reduction of oxytocin (P<0.001), estradiol-17beta (P<0.001) and testosterone (P<0.01) secretion. These results demonstrated that 5alpha-androstenol influenced hormonal regulation by humoral pathway and might be considered to be the priming pheromone in gilts.

  2. The quantitative expression of peroxisome proliferator activated receptor (PPAR) genes in porcine endometrium through the estrous cycle and early pregnancy.

    PubMed

    Bogacka, I; Bogacki, M

    2011-10-01

    Peroxisome proliferator activated receptors (PPAR) are a family of the nuclear receptors which play an important role as transcriptional factors. The aim of the present study was to determine the expression of PPARs (α, β, γ) mRNA in the porcine endometrium during the estrous cycle and periimplantation period. Gilts were divided into two groups (cyclic and pregnant), synchronized and superovulated. The animals from the first group were slaughtered throughout the estrous cycle: 2-4, 5-8, 9-10, 11-12, 13-15, 16-17 and 18-21. Gilts from the second group were inseminated and slaughtered at different days of pregnancy to create subgroups: 5-8, 9-10, 11-12, 13-15, 16-17, 18-21, 21-30. PPAR mRNA expression in the endometrium was analyzed by real-time PCRs. During the estrous cycle the expression of PPARγ1 mRNA was significantly higher on days 13-15 than at the remaining stages. The expression of PPARα and β transcripts showed a similar pattern and the lowest levels were observed on days 2-4, 16-17 and 18-21 in comparison with the remaining stages (days 5-8, 9-10, 11-12). During pregnancy a significant increase in the expression of PPARγ1 mRNA was noted on days 16-17, 18-21 and 22-30 compared to earlier stages. The transcript level of PPARβ was significantly lower on days 11-12 and 22-30 than on days 5-8, 9-10, 13-15. mRNA expression of PPARα was high on days beginning from 5-8 until 18-21 and significantly dropped on days 22-30. The results indicate that the endometrial expression of PPARs genes fluctuates during the estrous cycle and pregnancy. PPARα and PPARβ transcript levels show similar profiles during the estrous cycle. The decrease of both transcripts concentration on days 10-12 and 22-30 days in pregnant gilts implicates their role in maternal recognition of pregnancy and the end of implantation, respectively.

  3. Nonluteal estrous cycles of 3-week duration are initiated by anovulatory luteinizing hormone peaks in African elephants.

    PubMed

    Kapustin, N; Critser, J K; Olson, D; Malven, P V

    1996-11-01

    Previous attempts to characterize the estrous cycle of elephants have yielded conflicting estimates of cycle length and LH profiles. In order to establish artificial breeding programs in this species, resolution of these issues is needed. Therefore, four female African elephants housed at the Indianapolis Zoo were studied for approximately 6 mo beginning in December 1994. Blood was collected weekly, and the serum was immediately analyzed for progesterone (P4). Whenever the weekly concentration of P4 was found to be low, blood was collected one or four times per day. All serum samples were assayed for LH, and the daily samples were assayed for P4 and estradiol. Transient increases of serum LH (designated as peaks) were observed four times in each of the four females. Of these 16 LH peaks, 8 were classified as ovulatory LH (ovLH) peaks and 8 were classified as anovulatory LH (anLH) peaks. Peaks designated ovLH averaged 3.60 +/- 0.67 ng/ml (mean +/- SEM); serum P4 measured during these peaks began to increase 2-3 days before each ovLH peak and continued to increase for several weeks thereafter, reaching a peak of 675 +/- 35 pg/ml. The eight other LH peaks, designated anLH peaks, were of similar (p > 0.05) magnitude averaging 3.07 +/- 0.72 ng/ml, but the serum concentration of P4 remained very low (< 80 pg/ml) during and for several weeks after these peaks. Six peaks designated anLH occurred an average of 12.2 +/- 1.4 days after serum P4 had declined below 80 pg/ml. In each elephant, there was a regular sequence in which each ovLH peak was followed by a luteal-active period lasting about 60 days and then about 12 days later by one anLH peak. Each anLH peak was followed 19-22 days later by one ovLH peak, but serum P4 remained at nonluteal levels throughout this interval between peaks. The authors propose to designate this interval after the anLH peak and before the next ovLH peak as a nonluteal (i.e., low P4) estrous cycle of only 3-wk duration. Following each short

  4. Effect of summer heat environment on body temperature, estrous cycles and blood antioxidant levels in Japanese Black cow.

    PubMed

    Sakatani, Miki; Balboula, Ahmed Z; Yamanaka, Kenichi; Takahashi, Masashi

    2012-05-01

    This study investigated the effect of summer heat environment on estrous cycles and blood antioxidant levels in Japanese Black cows. A total of 13 non-lactating Japanese Black cows (summer: 9, winter: 4) were examined. Body temperature was measured rectally and intravaginally using a thermometer and data logger, respectively. Estrous behavior was monitored using a radiotelemetric pedometer that recorded walking activity. Rectal temperatures were higher during summer than winter (P<0.001). There was an acute increase in vaginal temperature at the onset of estrus during winter but such an increase was not observed during summer. Walking activity during estrus decreased dramatically in the summer compared to the winter. Duration of estrous cycle was longer in summer (23.4 days, P<0.05) than winter (21.5 days), and the subsequent rise in progesterone concentrations following estrus tended to be delayed in summer. The level of thiobarbituric acid reactive substances (TBARS) in peripheral blood cells was higher during summer (P<0.05), while the levels of superoixde dismutase (SOD), glutathione peroxidase (GPx) and glutathione were lower (P<0.05). These results indicate that high ambient temperature during summer increases both body temperature and oxidative stress, and also reduces signs of estrus in Japanese Black cows. © 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

  5. Sex and estrous cycle differences in cocaine-induced approach-avoidance conflict.

    PubMed

    Kerstetter, Kerry A; Su, Zu-In; Ettenberg, Aaron; Kippin, Tod E

    2013-03-01

    Human and animal research indicates that females may have a higher biological propensity for cocaine abuse than do males. Furthermore, reproductive status modulates the subjective effects of cocaine in women and self-administration rates in rats. Despite the attention that has been given to the modulation of appetitive responses by reproductive status and the well-known mixed positive and negative subjective effects of cocaine, it is unknown if similar effects are observed on aversive responses to cocaine. The present study examines the impact of sex and estrous cycle on approach-avoidance behavior for cocaine as measured in the runway self-administration model. Male and freely cycling female Sprague Dawley rats were trained to traverse a straight alley for single daily injections of 1.0 mg/kg intravenous cocaine over 21 trials. Relative to males, females had significantly longer start latencies but significantly faster approach and shorter run times during the first week of training. Further, estrus females displayed significantly fewer approach-avoidance retreats across all sessions relative to non-estrus females. These results suggest that females initially exhibit greater motivation for cocaine (faster approach) than do males and that the drug's anxiogenic properties have a reduced impact on the motivation to seek cocaine (fewer retreats) in females during the estrus phase relative to other reproductive phases. These findings indicate that both sex and reproductive status contribute to the motivation for cocaine and that sex differences in addiction vulnerability may be attributable in part to differences in the motivational impact of both the appetitive and aversive properties of cocaine. © 2011 The Authors, Addiction Biology © 2011 Society for the Study of Addiction.

  6. Changes in the oviducal epithelium during the estrous cycle in the marsupial Monodelphis domestica

    PubMed Central

    Kress, Annetrudi; Morson, Gianni

    2007-01-01

    The Monodelphis oviduct can be divided into four anatomical segments: preampulla (comprising fimbriae and infundibulum), ampulla, isthmus with crypts and uterotubal junction. Ovaries are enclosed in a periovarial sac, the bursa, and in some specimens tubules of an epoophoron could be identified. In both structures non-ciliated cells develop small translucent vesicles, which accumulate in the cell apices and presumably produce fluid as often seen in the bursa and in the tubules of the epooophoron. These vesicles do not stain with Alcian blue or PAS. The same applies also to the non-ciliated cells of the fimbriae. The oviducal epithelium of ampulla and the surface epithelium of the isthmus consisting of ciliated and non-ciliated, secretory cells undergo considerable changes during the estrous cycle. Proestrus shows low numbers of ciliated cells, some are in the process of neo-ciliogenesis, non-ciliated cells carry solitary cilia and few remnant secretory granules from the previous cycle may be found. At estrus the amount of ciliated cells in ampulla and isthmus has increased, most non-cililated cells lost the solitary cilia, developed longer microvilli and formed numerous secretory granules in their cell apices. At postestrus secretory products, often surrounded by membranes, are extruded into the oviducal lumen and contribute towards egg coat formation. First signs of deciliation processes are apparent. Solitary cilia reappear. At metestrus only few secretory cells are left with some secretory material. The lumen is often filled with shed cilia and cell apices. Proliferation of basal bodies within non-secretory cells indicate the formation of new ciliated cells. The non-ciliated epithelial cells of the isthmic crypts form no secretory granules but accumulate a great number of translucent vesicles, which in contrast to the secretory granules do not stain with Alcian blue or PAS. PMID:17883438

  7. Non-invasive monitoring of the estrous cycle in captive crab-eating foxes (Cerdocyon thous).

    PubMed

    Souza, N Pinheiro; Furtado, P Viau; da Paz, R C Rodrigues

    2012-01-15

    In this study, four crab-eating fox females (Cerdocyon thous) maintained at the Federal University of Mato Grosso Zoo, Cuiabá, Brazil, were investigated for 16 mo, using transabdominal ultrasonography and measurement of estradiol and progesterone concentrations in blood plasma and feces. Blood collection and ultrasonography were performed once a month, whereas fecal collections were performed three times a week. During the experimental period, there was an annual estrous cycle in all females, with the reproductive season lasting from winter to spring, and three became pregnant. Transabdominal ultrasonography was inconclusive for characterization of estrus cycles phase, but was effective for early detection of pregnancy, pregnancy monitoring, and for evaluating postpartum uterine involution. There were similarities between C. thous female's reproductive aspect and bitches, with similar pregnancy data, although uterine involution was faster in C. thous. Peak serum concentrations of P4 and E2 were (mean ± SD) 14.58 ± 5.8 ng/ml and 31.62 ± 53.54 pg/ml, respectively, whereas mean fecal peaks of P4 and E2 were 2.37 ± 1.42 ng/g and 157.95 ± 82.63 pg/g, respectively. All pregnant females had serum and fecal P4 concentrations reaching maximum values (16.5 ± 4.0 ng/ml and 2.7 ± 0.4 ng/g, respectively) from 10 to 30 d of gestation; those values subsequently declined, reaching baseline at parturition (5.0 ± 4.0 and 0.7 ± 0.4 ng/g, respectively). Peaks of E2 occurred throughout the year, and were absent only during apparent lactational anestrus. Copyright © 2012 Elsevier Inc. All rights reserved.

  8. Apoptosis in the uterotubal junction and oviductal isthmus during the estrous cycle of the bitch.

    PubMed

    Urhausen, C; Beineke, A; Piechotta, M; Karre, I; Beyerbach, M; Günzel-Apel, A R

    2011-02-01

    Apoptotic cells were evaluated in the lamina epithelialis (LE) and lamina propria (LP) of the canine uterotubal junction and oviductal isthmus by means of the TUNEL assay and Caspase-3 detection regarding cyclic changes. Oviducts of bitches in anestrus, early and late follicular phase, 2 and 4 days after ovulation, mid-luteal phase, and endometrial reparation were available. The rate of apoptosis was generally low (min = 0; max = 33 apoptotic cells in 500 cells). Regardless of the stage of the estrous cycle, the number of apoptotic cells was significantly higher in the LE compared to the LP (P < 0.05). In anoestrus, early and late follicular phase as well as during endometrial reparation, the number of apoptotic cells was on a constantly low level. A significant increase was found 4 days after ovulation by caspase-3 detection coinciding with early luteal development and in mid-luteal phase. The results demonstrate that the number of apoptotic cells changes depending on the stage of the ovarian cycle. The coincidence of the increase in the number of apoptotic cells and the time of achievement of oocyte competence, which is known to occur in the bitch 3-4 days after ovulation, suggests a causal relationship between the postovulatory maturation stage of oocytes and the rate of apoptosis in the caudal oviduct. Furthermore, a specific relevance of apoptosis may exist in the process of fertilization regarding sperm storage and detachment of spermatozoa bound to the epithelium of the caudal oviduct, which has been identified as a functional sperm reservoir in other species.

  9. Changes in the oviducal epithelium during the estrous cycle in the marsupial Monodelphis domestica.

    PubMed

    Kress, Annetrudi; Morson, Gianni

    2007-10-01

    The Monodelphis oviduct can be divided into four anatomical segments: preampulla (comprising fimbriae and infundibulum), ampulla, isthmus with crypts and uterotubal junction. Ovaries are enclosed in a periovarial sac, the bursa, and in some specimens tubules of an epoophoron could be identified. In both structures non-ciliated cells develop small translucent vesicles, which accumulate in the cell apices and presumably produce fluid as often seen in the bursa and in the tubules of the epooophoron. These vesicles do not stain with Alcian blue or PAS. The same applies also to the non-ciliated cells of the fimbriae. The oviducal epithelium of ampulla and the surface epithelium of the isthmus consisting of ciliated and non-ciliated, secretory cells undergo considerable changes during the estrous cycle. Proestrus shows low numbers of ciliated cells, some are in the process of neo-ciliogenesis, non-ciliated cells carry solitary cilia and few remnant secretory granules from the previous cycle may be found. At estrus the amount of ciliated cells in ampulla and isthmus has increased, most non-cililated cells lost the solitary cilia, developed longer microvilli and formed numerous secretory granules in their cell apices. At postestrus secretory products, often surrounded by membranes, are extruded into the oviducal lumen and contribute towards egg coat formation. First signs of deciliation processes are apparent. Solitary cilia reappear. At metestrus only few secretory cells are left with some secretory material. The lumen is often filled with shed cilia and cell apices. Proliferation of basal bodies within non-secretory cells indicate the formation of new ciliated cells. The non-ciliated epithelial cells of the isthmic crypts form no secretory granules but accumulate a great number of translucent vesicles, which in contrast to the secretory granules do not stain with Alcian blue or PAS.

  10. Hippocampal excitability increases during the estrous cycle in the rat: a potential role for brain-derived neurotrophic factor.

    PubMed

    Scharfman, Helen E; Mercurio, Thomas C; Goodman, Jeffrey H; Wilson, Marlene A; MacLusky, Neil J

    2003-12-17

    To test the hypothesis that induction of BDNF may contribute to changes in hippocampal excitability occurring during the female reproductive cycle, we examined the distribution of BDNF immunoreactivity and changes in CA1 and CA3 electrophysiology across the estrous cycle in rats. Hippocampal BDNF immunoreactivity increased on the day of proestrus as well as on the following morning (estrus), relative to metestrus or ovariectomized animals. Changes in immunoreactivity were clearest in mossy fiber axons of dentate gyrus granule cells, which contain the highest concentration of BDNF. Increased immunoreactivity was also apparent in the neuropil-containing dendrites of CA1 and CA3 neurons. Electrophysiological recordings in hippocampal slices showed robust cycle-dependent differences. Evoked responses of CA1 neurons to Schaffer collateral stimulation changed over the cycle, with larger maximum responses at both proestrus and estrus relative to metestrus. In area CA3, repetitive hilar stimuli frequently evoked multiple population spikes at proestrus and estrus but only rarely at other cycle stages, and never in slices of ovariectomized rats. Hyperexcitability in area CA3 at proestrus was blocked by exposure to the high-affinity neurotrophin receptor antagonist K252a, or an antagonist of the alpha7 nicotinic cholinergic receptor, whereas it was induced at metestrus by the addition of BDNF to hippocampal slices. These studies suggest that hippocampal BDNF levels change across the estrous cycle, accompanied by neurophysiological responses that resemble the effects of BDNF treatment. An estrogen-induced interaction of BDNF and alpha7 nicotinic receptors on mossy fibers seems responsible for estrous cycle changes in area CA3. Periovulatory changes in hippocampal function may, thus, involve estrogen-induced increases in BDNF expression.

  11. Neonatal isolation alters the estrous cycle interactions on the acute behavioral effects of cocaine.

    PubMed

    Kosten, Therese A; Sanchez, Hayde; Jatlow, Peter I; Kehoe, Priscilla

    2005-09-01

    We demonstrated that neonatal isolation (ISO) increases acquisition of cocaine self-administration and alters psychostimulant-induced ventral striatal dopamine and serotonin levels in female rats. Both dopamine and serotonin modulate the behavioral effects of cocaine and these effects can vary across estrous stages. We now test whether ISO modifies the manner in which estrous stage affects the acute behavioral responses to cocaine. Litters were assigned to ISO (1 h/day isolation; post-natal days 2-9) or non-handled (NH) conditions. In Experiment 1, the ability of cocaine (0.3-30 mg/kg; IP) to disrupt schedule-controlled responding for food was assessed in proestrus, estrus, and diestrus stages. Diestrus and proestrus NH females showed increased response rates at low cocaine doses and decreased rates at higher doses relative to baseline. In contrast, estrus NH females showed decreased responding across all doses. ISO eliminated this estrous stage distinction; only decreased responding to high cocaine doses were seen. Yet, estrous cyclicity during food restriction (Experiment 2) did not differ by group. To confirm this ISO effect, proestrus or estrus rats were administered cocaine (0, 5, 10 mg/kg; IP) and activity monitored in Experiment 3. Locomotor activity differed by estrous stage in NH but not ISO rats. Cocaine plasma levels (Experiment 4) at the time of peak behavioral activity did not differ by group or estrous stage. Results extend prior studies to show estrous stage alters the behavioral effects of cocaine. Neonatal isolation eliminates these effects perhaps reflecting alterations in accumbens monoamine levels or the effects of estrogen on this system.

  12. Melatonin and exposure to constant light/darkness affects ovarian follicular kinetics and estrous cycle in Indian desert gerbil Meriones hurrianae.

    PubMed

    Sinhasane, S V; Joshi, B N

    1997-12-01

    Melatonin mediates photoperiodic influence on reproduction and constant light and darkness affect pineal biosynthesis of melatonin. The present study was undertaken to assess the effects of melatonin and drastic photoperiodic changes on reproduction in a tropical desert species with a fossorial lifestyle. Ovarian follicular kinetics and estrous cycle were studied in the Indian desert gerbil Meriones hurrianae, after treatment with melatonin and exposure to constant light (LL) and darkness (DD) regimes. Melatonin treatment increased (P < 0.001) ovarian weights without changing the uterine weights. While exposure to LL decreased (P < 0.001) both ovarian and uterine weights, exposure to DD had no effect on these weights. Follicular kinetics of growing and regressing follicles revealed that ovaries of melatonin-treated and DD-exposed animals had significantly more growing follicles. Melatonin treatment increased all types of growing follicles, especially antral and Graafian follicles. Exposure to DD increased all types of growing follicles, with the medium sized antral and Graafian follicles being significant (P < 0.01). In contrast to stimulation of follicular growth by melatonin and DD, LL caused regression of all stages of follicular growth and also reduced the number of small preantral follicles. Melatonin treatment increased (P < 0.001) the length of estrous cycle (5.08 to 7.29 days). Gerbils treated with melatonin, exposed to LL and DD, had a longer (P < 0.001) metestrus. Animals held in LL, had the least number (P < 0.001) of estrous smears (1 in 30 days). The results suggest that melatonin is involved in growth of ovarian follicles in the Indian desert gerbil.

  13. Estrogens Suppress Spinal Endomorphin 2 Release in Female Rats in Phase with the Estrous Cycle

    PubMed Central

    Kumar, Arjun; Storman, Emiliya M.; Liu, Nai-Jiang; Gintzler, Alan R.

    2015-01-01

    Background/Aims Male and female rats differ in their ability to utilize spinal endomorphin 2 (EM2; the predominant mu-opioid receptor ligand in spinal cord) and in the mechanisms that underlie spinal EM2 analgesic responsiveness. We investigated the relevance of spinal estrogen receptors (ERs) to the in vivo regulation of spinal EM2 release. Methods ER antagonists were administered directly to the lumbosacral spinal cord of male and female rats, intrathecal perfusate was collected, and resulting changes in EM2 release were quantified using a plate-based radioimmunoassay. Results Intrathecal application of an antagonist of either estrogen receptor-α (ERα) or the ER GPR30 failed to alter spinal EM2 release. Strikingly, however, the concomitant blockade of ERα and GPR30 enhanced spinal EM2 release. This effect was sexually dimorphic, being absent in males. Furthermore, the magnitude of the enhancement of spinal EM2 release in females was dependent upon estrous cycle stage, suggesting a relationship with circulating levels of 17β-estradiol. The rapid onset of enhanced EM2 release following intrathecal application of ERα/GPR30 antagonists (within 30–40 min) suggests mediation via ERs in the plasma membrane, not the nucleus. Notably, both ovarian and spinally synthesized estrogens are essential for membrane ER regulation of spinal EM2 release. Conclusion These findings underscore the importance of estrogens for the regulation of spinal EM2 activity and, by extension, endogenous spinal EM2 antinoci-ception in females. Components of the spinal estrogenic mechanism(s) that suppress EM2 release could represent novel drug targets for improving utilization of endogenous spinal EM2, and thereby pain management in women. PMID:25925013

  14. In vitro effect of peroxisome proliferator activated receptor (PPAR) ligands on prostaglandin E2 synthesis and secretion by porcine endometrium during the estrous cycle and early pregnancy.

    PubMed

    Bogacka, I; Bogacki, M; Gaglewska, M; Kurzynska, A; Wasielak, M

    2013-02-01

    Peroxisome proliferator activated receptors (PPARs) are ligand-dependent transcriptional factors which are expressed in distinct tissues of the female reproductive system, including the ovary, uterus and placenta. An important role of PPARs in the regulation of reproductive processes has been previously highlighted in rodents. In the present study we investigated the in vitro effect of PPAR ligands on prostaglandin E2 (PGE2) release and prostaglandin E synthase (PGES) gene expression in the endometrial explants collected from cyclic (days 10-12 and 14-16 of the estrous cycle) or pregnant (days 10-12 and 14-16) pigs. A stimulatory (p<0.05) effect of rosiglitazone (PPARγ agonist) on PGE2 accumulation was noted during both stages of the estrous cycle and both stages of pregnancy, whereas a higher (p<0.05) PGES mRNA level was observed on days 10-12 of the estrous cycle and on days 14-16 of gestation when compared to the controls. The activation of PPARβ by L-165,041 augmented (p<0.05) PGE2 release by the endometrium on days 14-16 of the estrous cycle and on days 14-16 of pregnancy, but the increase (p<0.05) in PGES mRNA abundance was noted on days 10-12 of the estrous cycle and during both stages of pregnancy. A stimulatory (p<0.05) effect of WY-14643 (agonist) and MK 886 (antagonist) on PGE2 release was noted on days 10-12 of the estrous cycle, and days 14-16 of pregnancy, respectively. There was a lack of change in PGES mRNA abundance in the endometrium exposed to PPARα ligands. We conclude that PPARs are mediators of prostaglandin E2 synthesis/accumulation in porcine endometrium during the luteal phase of the estrous cycle and the time of periimplantation.

  15. Female Flinders Sensitive Line rats show estrous cycle-independent depression-like behavior and altered tryptophan metabolism.

    PubMed

    Eskelund, Amanda; Budac, David P; Sanchez, Connie; Elfving, Betina; Wegener, Gregers

    2016-08-04

    Clinical studies suggest a link between depression and dysfunctional tryptophan (TRP) metabolism. Even though depression is twice as prevalent in women as men, the impact of the estrous cycle on TRP metabolism is not well-understood. Here we investigated 13 kynurenine and serotonin metabolites in female Flinders Sensitive Line (FSL) rats, a genetic rat model of depression. FSL rats and controls (Flinders Resistant Line rats), 12-20weeks old, were subject to the forced swim test (FST), a commonly used measure of depression-like behavior. Open field was used to evaluate locomotor ability and agoraphobia. Subsequently, plasma and hemispheres were collected and analyzed for their content of TRP metabolites using liquid chromatography-tandem mass spectrometry. Vaginal saline lavages were obtained daily for ⩾2 cycles. To estimate the effects of sex and FST we included plasma from unhandled, naïve male FSL and FRL rats. Female FSL rats showed a depression-like phenotype with increased immobility in the FST, not confounded by anxiety. In the brain, 3-hydroxykynurenine was increased whereas anthranilate and 5-hydroxytryptophan were decreased. In plasma, anthranilate and quinolinate levels were lower in FSL rats compared to the control line, independent of sex and FST. The estrous cycle neither impacted behavior nor TRP metabolite levels in the FSL rat. In conclusion, the female FSL rat is an interesting preclinical model of depression with altered TRP metabolism, independent of the estrous cycle. The status of the pathway in brain was not reflected in the plasma, which may indicate that an inherent local, cerebral regulation of TRP metabolism occurs.

  16. Effects of female bovine plasma collected at different days of the estrous cycle on epididymal spermatozoa motility.

    PubMed

    Nait Mouloud, M; Ouennoughi, F; Yaiche, L; Kaidi, R; Iguer-Ouada, M

    2017-03-15

    The aim of this study was to assess the effects of female bovine plasma collected at different days of the reproductive cycle on epididymal spermatozoa motility and to test hypothesis that the subpopulations pattern of motile spermatozoa is affected by this treatment. Blood plasma samples were collected from five Holstein Friesian cows at different stages of the estrous cycle (days 0, 5, 10, 12 and 18), one pregnant cow and one adult bull and were diluted 1:9 (V/V) with normal saline. Female charcoal-treated plasma, Bull plasma and saline were used as controls. Semen samples were obtained from cauda epididymidis through retrograde flushing and diluted in saline to approximately 60 × 106 sperm/ml. The extended semen was diluted 1:2 (V/V) with tested media and motility was evaluated at 15 min and then every hour for 6 h using a computer-assisted semen analysis. Multivariate clustering procedure was applied to identify and quantify specific subpopulations within the semen samples. The statistical analysis clustered all the motile spermatozoa into three separate subpopulations with defined patterns of movement: Subpopulation 1 poorly motile and non-progressive spermatozoa (39.3%), subpopulation 2 including the fastest and the most vigorous spermatozoa (46.4%) and subpopulation 3 represented by slow, non-vigorous but linear spermatozoa (14.3%). Initially, sperm samples supplemented with female, male or female charcoal-treated plasma stimulated equally total motility and spermatozoa belonging to subpopulation 2 regardless of the estrous cycle stage. After 1-h incubation, the motility of these both categories of spermatozoa (total motile and those assigned to subpopulation 2) is enhanced and maintained more in day 12, 18 and pregnant cow plasma than in female plasma from earlier stage of the estrous cycle (day 0, 5 and 10), male plasma and female-charcoal treated plasma. In conclusion, the overall results showed that female plasma stimulated significantly sperm

  17. A collaboration of aquaporins handles water transport in relation to the estrous cycle in the bitch uterus.

    PubMed

    Aralla, M; Borromeo, V; Groppetti, D; Secchi, C; Cremonesi, F; Arrighi, S

    2009-08-01

    Fluid movement through uterine cell membranes is crucial, as it can modulate the tissue imbibition pattern in the different phases of the estrous cycle. To gain insight into the mechanisms underlying steroid-controlled water handling, the presence and distribution of aquaporins (AQPs), integral membrane channel proteins permitting rapid passive water movement, was explored in bitch uterine tissues. Immunohistochemistry and Western immunoblot analysis were used to study the presence of AQP1, AQP2, and AQP5 in the layers of the bitch uterine wall during the different estrous phases. Presence of endothelial nitric oxide-generating enzyme NO synthase (NOS3) was also investigated, as it is known that the vasodilator NOS3 might be involved in the development of uterine edema. The results demonstrated the following: (1) AQP1, AQP2, and AQP5 were present in the uterus of cycling bitches. (2) AQP1 was localized within uterine mesometrial, myometrial, and endometrial blood vessels and in the circular and longitudinal layers of myometrium. AQP1 localization and expression were unaffected by the estrous cycle. (3) The estrogenic milieu was probably at the basis of AQP2 expression in the glandular and luminal epithelium of the endometrium. (4) AQP5 water channels were present in the apical plasma membrane of uterine epithelial cells in coincidence with plasma progesterone increase. (5) NOS3 was localized in the myometrial and epithelial tissues as well as in blood vessels indicating a contribution of this vasoactive peptide to the uterine imbibition processes. Thus, we can hypothesize that a functional and distinctive collaboration exists among diverse AQPs in water handling during the different functional uterine phases.

  18. Effects of the estrous cycle and ovarian hormones on central expression of interleukin-1 evoked by stress in female rats.

    PubMed

    Arakawa, Keiko; Arakawa, Hiroyuki; Hueston, Cara M; Deak, Terrence

    2014-01-01

    Exposure to stressors such as foot shock (FS) leads to increased expression of multiple inflammatory factors, including the proinflammatory cytokine interleukin-1 (IL-1) in the brain. Studies have indicated that there are sex differences in stress reactivity, suggesting that the fluctuations in gonadal steroid levels across the estrous cycle may play a regulatory role in the stress-induced cytokine expression. The present studies were designed to investigate the role of 17-β-estradiol (E2) and progesterone (Pg) in regulating the cytokine response within the paraventricular nucleus (PVN) of the hypothalamus through analysis of gene expression with real-time RT-PCR. Regularly cycling female rats showed a stress-induced increase in PVN IL-1 levels during the diestrous, proestrous, and estrous stages. During the metestrous stage, no change in IL-1 levels was seen following FS; however, estrogen receptor (ER)-β levels did increase. Ovariectomy resulted in an increase in PVN IL-1 levels, which was attenuated by treatment with estradiol benzoate (10 or 50 µg), indicating an E2-mediated anti-inflammatory effect. Ovariectomized rats treated with Pg (500 or 1,250 µg) showed no alteration in IL-1 levels, but Pg did up-regulate ER-β gene expression. The results from the current study implicate a potential mechanism through which high availability of endogenous Pg during the metestrous stage increases ER-β sensitivity, which in turn attenuates the PVN IL-1 response to stress. Thus, the interaction between gonadal steroid hormones and their central receptors may exert a powerful inhibitory effect on neuroimmune consequences of stress throughout the estrous cycle.

  19. Changes in the levels of progesterone receptor mRNA and protein in the bovine corpus luteum during the estrous cycle.

    PubMed

    Sakumoto, Ryosuke; Vermehren, Margarete; Kenngott, Rebecca A-M; Okuda, Kiyoshi; Sinowatz, Fred

    2010-04-01

    Progesterone (P4) is synthesized in the luteal cells of many species. The objective of the present study was to determine the expression pattern of P4 receptor (PR) mRNA and the distribution of PR protein in the bovine corpus luteum (CL) during the estrous cycle. The gene expression of PR in the bovine CL throughout the estrous cycle was determined by real-time PCR analysis, and the PR protein expression was evaluated by immunohistochemistry. Messenger RNA of PR was clearly expressed in the CL throughout the estrous cycle. The level of PR mRNA in the CL was highest at the early stage of the estrous cycle and was higher at the mid and late stages than at the regressed stage (P<0.01). In regard to the distribution of PR, the protein was expressed in both small and large luteal cells and in vascular endothelial cells throughout the estrous cycle. These results suggest that P4 has a role in regulating luteal and endothelial cell function in the bovine CL, especially at the early luteal stage as an autocrine/paracrine regulator.

  20. Expression of ODC1, SPD, SPM and AZIN1 in the hypothalamus, ovary and uterus during rat estrous cycle.

    PubMed

    Fernandes, Joseph R D; Jain, Sammit; Banerjee, Arnab

    2017-05-15

    The aim of the present study was to investigate variation in the expression pattern of ornithine decarboxylase (ODC1), spermine (SPM), spermidine (SPD) and antizyme inhibitor (AZIN1) in hypothalamus, ovary and uterus during the estrous cycle of rats. Further, to understand any correlation between polyamines and GnRH I expression in hypothalamus; effect of putrescine treatment on GnRH I expression in hypothalamus and progesterone and estradiol levels in serum were investigated. The study also aims in quantifying all the immunohistochemistry images obtained based on pixel counting algorithm to yield the relative pixel count. This algorithm uses a red green blue (RGB) colour thresholding approach to quantify the intensity of the chromogen present. The result of the present study demonstrates almost similar expression pattern of polyamine and polyamine related factors, ODC1, SPD, SPM and AZIN1, with that of hypothalamic GnRH I, all of which mainly localized in the medial preoptic area (MPA) of the hypothalamus, during the proestrus, estrus and diestrus. This suggest that hypothalamic GnRH I expression is under regulation of polyamines. The study showed significant increase in hypothalamic GnRH I expression for both the doses of putrescine treatment to adult female rats. Further, it was shown that in ovary expression pattern of ODC1, SPM, SPD and AZIN1 were similar with that of steroidogenic factor, StAR during the estrous cycle, and putrescine supplementation increased significantly estradiol and progesterone levels in serum, all suggesting ovarian polyamines are involved in regulation of ovarian steroidogenesis. Localization of these factors in the theca and granulosa cells suggest involvement of polyamines in the process of folliculogenesis and luteinization; and ODC1, SPD, SPM and AZIN1 in oocyte further suggests polyamine role in maintenance of oocyte physiology. Finally, in uterus SPM and AZIN1 were localized throughout the estrous cycle, being comparatively more

  1. Ovarian blood flow responses to electroacupuncture stimulation depend on estrous cycle and on site and frequency of stimulation in anesthetized rats.

    PubMed

    Stener-Victorin, Elisabet; Fujisawa, Shigeko; Kurosawa, Mieko

    2006-07-01

    Electroacupuncture (EA) applied to the abdomen and hindlimb modulates the ovarian blood flow (OBF) response. The present study aimed to further elucidate the role of the site and the frequency of short-term EA stimulation and the influence of the estrous cycle on the OBF response using anesthetized rats. EA stimulation was applied to the abdominal or the hindlimb muscles at three different frequencies (2, 10, and 80 Hz) during the estrus or diestrus phase. Involvement of spinal and supraspinal reflexes in OBF responses to EA stimulation was investigated by spinal cord transection. Abdominal EA stimulation at 10 Hz increased the OBF response, whereas hindlimb EA stimulation at 10 Hz and abdominal and hindlimb stimulation at 80 Hz decreased the OBF response; 2-Hz EA caused no OBF response. The OBF response to abdominal EA was more pronounced in the estrus than the diestrus phase. The OBF response to abdominal and hindlimb EA stimulation at both 10 and 80 Hz was almost abolished, both after severance of the sympathetic nerves and after spinal cord transection. In conclusion, the OBF response to both abdominal and hindlimb EA stimulation was mediated as a reflex response via the ovarian sympathetic nerves, and the response was controlled via supraspinal pathways. Furthermore, the OBF response to segmental abdominal EA stimulation was frequency dependent and amplified in the estrous phase.

  2. Prostaglandin F2 alpha stimulates progesterone secretion by porcine luteal cells in vitro throughout the estrous cycle.

    PubMed

    Gadsby, J E; Earnest, K L

    1994-08-01

    In this study we examined the stimulatory effects of PGF2 alpha on progesterone secretion by porcine luteal cells on different days of the estrous cycle, and the effects of PGF2 alpha, A23187 and PMA on progesterone secretion by isolated large and small luteal cells, in vitro. Corpora lutea were obtained from cycling pigs (days 6-16), collagenase dispersed and luteal cells incubated in medium 199 in the absence or presence of increasing doses of PGF2 alpha, A23187, and PMA. Progesterone concentrations in spent media were measured by RIA. PGF2 alpha stimulation of progesterone secretion by mixed luteal cells did not vary significantly throughout the estrous cycle. Progesterone secretion by large, but not small, luteal cells was increased (p < 0.05) in a dose-dependent fashion by PGF2 alpha. A23187 also caused a dose-dependent increase in progesterone secretion by large luteal cells but inhibited small luteal cells. Progesterone secretion by both large and small luteal cells was significantly increased by increasing doses of PMA. We conclude that the stimulatory response of luteal cells to PGF2 alpha in vitro did not correlate with PGF2 alpha receptor concentrations (not measured in this study), and we speculate that calcium/protein kinase C may be involved in mediating the stimulatory action of PGF2 alpha on luteal cell progesterone secretion.

  3. Estrous cycle based on blood progesterone profiles and changes in vulvar appearance of Malayan tapirs (Tapirus indicus).

    PubMed

    Kusuda, Satoshi; Ikoma, Masakazu; Morikaku, Koki; Koizumi, Jun-ichi; Kawaguchi, Yoshiya; Kobayashi, Kuniyasu; Matsui, Kirito; Nakamura, Akira; Hashikawa, Hisashi; Kobayashi, Kazuhiro; Ueda, Miya; Kaneko, Mikako; Akikawa, Takako; Shibagaki, Sachiko; Doi, Osamu

    2007-12-01

    The progesterone (P(4)) profiles and macroscopic vulvar changes of female Malayan tapirs were investigated in order to understand their fundamental reproductive physiology and to search for visual indicators of estrus. Blood was collected once or twice a week from seven female Malayan tapirs kept at four zoos. Serum or plasma P(4) concentrations were determined by radioimmunoassay. The P(4) concentrations changed cyclically throughout the years, and a total of 56 cycles was confirmed in the seven females. The length of the estrous cycle based on the P(4) profiles was 43.6+/-2.0 days; however, this mean includes great variation in length, from 21 to 84 days. Mucous discharge from the vulva and vulvar swelling were seen when the P(4) concentrations were low before the beginning of a rise in most cases. In conclusion, captive female Malayan tapirs have variations of approximately 1 to 3 months in estrous cycle length, and visual changes in the vulva are helpful in estimating estrus in female Malayan tapirs.

  4. Effect of water decoction of Langsat bark (Lansium domesticum Corr.) on estrous cycle and uterus weight in mice (Mus musculus L.)

    NASA Astrophysics Data System (ADS)

    Kurniati, Reni; Dewi, Herviana; Hendra, Medi

    2017-05-01

    The study aims to determine the effect of water decoction of Langsat's bark stew on estrous cycle and uterus weight in mice. Twenty adults, healthy, female mice were divided into four groups, each given 1 mL of Langsat's bark stew with water concentrations of 20%, 40%, and 60%, as well as a control group that was given water ad libitum for twelve days. Estrous phases were determined every day; on the thirteenth day, all mice were euthanized and the uteruses were weighed. The observation of estrous cycles showed that there was no significant difference in the frequency of the phases of the estrous cycle between the control group and the treatment group. Uterine weight treatment groups were higher than in the control group in line with increasing doses, but this was not statistically significantly different. We conclude that water decoction of Langsat's bark stew does not affect the estrous cycle and weight of the mice uterus, and its use as an anti-fertility treatment has not been proven.

  5. Peripubertal Vitamin D3 Deficiency Delays Puberty and Disrupts the Estrous Cycle in Adult Female Mice1

    PubMed Central

    Dicken, Cary L.; Israel, Davelene D.; Davis, Joe B.; Sun, Yan; Shu, Jun; Hardin, John; Neal-Perry, Genevieve

    2012-01-01

    ABSTRACT The mechanism(s) by which vitamin D3 regulates female reproduction is minimally understood. We tested the hypothesis that peripubertal vitamin D3 deficiency disrupts hypothalamic-pituitary-ovarian physiology. To test this hypothesis, we used wild-type mice and Cyp27b1 (the rate-limiting enzyme in the synthesis of 1,25-dihydroxyvitamin D3) null mice to study the effect of vitamin D3 deficiency on puberty and reproductive physiology. At the time of weaning, mice were randomized to a vitamin D3-replete or -deficient diet supplemented with calcium. We assessed the age of vaginal opening and first estrus (puberty markers), gonadotropin levels, ovarian histology, ovarian responsiveness to exogenous gonadotropins, and estrous cyclicity. Peripubertal vitamin D3 deficiency significantly delayed vaginal opening without affecting the number of GnRH-immunopositive neurons or estradiol-negative feedback on gonadotropin levels during diestrus. Young adult females maintained on a vitamin D3-deficient diet after puberty had arrested follicular development and prolonged estrous cycles characterized by extended periods of diestrus. Ovaries of vitamin D3-deficient Cyp27b1 null mice responded to exogenous gonadotropins and deposited significantly more oocytes into the oviducts than mice maintained on a vitamin D3-replete diet. Estrous cycles were restored when vitamin D3-deficient Cyp27b1 null young adult females were transferred to a vitamin D3-replete diet. This study is the first to demonstrate that peripubertal vitamin D3 sufficiency is important for an appropriately timed pubertal transition and maintenance of normal female reproductive physiology. These data suggest vitamin D3 is a key regulator of neuroendocrine and ovarian physiology. PMID:22572998

  6. Superovulation at a specific stage of the estrous cycle determines the reproductive performance in mice.

    PubMed

    Inyawilert, Wilasinee; Liao, Yu-Jing; Tang, Pin-Chi

    2016-12-01

    Inconsistent reproductive performance has been reported in superovulated mice. Hence, the aim of this study was to analyze the effect and possible mechanism of superovulation timing on mouse reproductive performance. The results showed that mice superovulated at the metestrous (23.08±6.08%) and diestrous stages (33.33±11.45%) presented significantly lower pregnancy rates compared with those superovulated at the estrous stage (66.67±9.20%). After superovulation at the proestrous and estrous stages, mucin 1 (MUC1) and let-7a/let-7b microRNA (miRNA) expression levels were significantly attenuated and enhanced on embryonic day 3.5 (E3.5), respectively, whereas no significant differences in the expression level were found in mice superovulated at the other two stages. A higher number of developing and Graafian follicles was observed in the ovarian sections 48h after the administration of pregnant mare serum gonadotropin (PMSG) at the proestrous and estrous stages. The sections from mice treated at the metestrous and diestrous stages, however, presented more corpora lutea. Therefore, mice superovulated at the proestrous and estrous stages exhibited the best pregnancy rates. Furthermore, the disordered expression of MUC1 and let-7a/let-7b miRNA in mice superovulated at the metestrous and diestrous stages may impair reproduction performance. Copyright © 2016 Society for Biology of Reproduction & the Institute of Animal Reproduction and Food Research of Polish Academy of Sciences in Olsztyn. Published by Elsevier Urban & Partner Sp. z o.o. All rights reserved.

  7. Characterization of the estrous cycle in female beluga (Delphinapterus leucas) using urinary endocrine monitoring and transabdominal ultrasound: Evidence of facultative induced ovulation.

    PubMed

    Steinman, K J; O'Brien, J K; Monfort, S L; Robeck, T R

    2012-02-01

    Recent, successful application of assisted reproductive technologies in captive beluga has resulted from the extensive study of male beluga reproductive biology. Optimization of assisted reproduction requires additional detailed knowledge of the female estrous cycle. Our specific objectives were to: (1) validate urinary immunoassays for use in this species; (2) elucidate annual ovarian cycle dynamics through the combined use of hormone excretion patterns and transabdominal ultrasound; and (3) establish whether ovulation in this species is spontaneous or induced by male factors. Ovulation was observed in four of 15 estrous cycles monitored in four adult female beluga maintained in a single-sex group. After introduction of a breeding male, ovulation was observed in six of seven estrous cycles. All estrous cycles occurred from March through June. For spontaneous ovulations (n=4), the inter-estrous interval was 34d (range 33-35d), with a follicular phase length (FPL) of 25±8d (mean±SD). For all ovulatory estrous cycles (with and without a breeding male), urinary estrogen conjugates (EC, 15.3±7.9ng/mg Cr) and ovulatory luteinizing hormone (ovLH, 17.1±6.6ng/mg Cr) concentrations both peaked on Day 0, and EC concentrations returned to baseline 8±7d later. For non-conceptive cycles, urinary progestagen (Pg) concentrations increased on Day 0 (3.5±1.7ng/mg Cr), peaked on Day+19 (19.7±17.1ng/mg Cr), and were elevated above baseline for 27±4d. Preovulatory follicular diameter and circumference on Day -2±2 (range: Day -4 to -1) from peak EC were 2.5±0.7 and 7.8±1.3cm, respectively. The FPL in non-ovulatory estrous cycles (n=11) lasted 24±10d and EC concentrations gradually declined to baseline over a 21±10d interval following the EC peak (27.8±28.8ng/mg Cr). Non-ovulatory estrous cycles were characterized by the absence of an ovLH surge and no concomitant increase in Pg concentrations above baseline excretion; the mean follicular diameter at or near peak EC was 3

  8. Endocrine correlates of reproduction in the wolf. I. Serum progesterone, estradiol and LH during the estrous cycle

    USGS Publications Warehouse

    Seal, U.S.; Plotka, E.D.; Packard, J.M.; Mech, L.D.

    1979-01-01

    The estrous cycle of 10 intact female wolves, aged 8 months-8 years at the initiation of the study, was characterized in terms of vaginal smears, behavioral observations and serum concentrations of estradiol-17β, progesterone and luteinizing hormone (LH) from January through June. No estrous cycles occurred in these animals between June and December. All were housed with male wolves. Two pups and 1 adult remained anestrous during this interval. One pup and 2 adults produced litters between May 4-6. Four adults exhibited endocrine changes similar to those of the pregnant animals but no litters or signs of abortion were observed. The duration of proestrus was 15.7 ± 1.6 days (X ± SEM, n = 6), of estrus 9.0 ± 1.2 days (n = 4) and of the luteal phase 63 ± 2 days (n = 6). The duration of pregnancy was between 60-65 days. The anestrous females (86 blood samples) had 6 progesterone values between 1-2 ng/ml and the remainder below 1 ng/ml. Their estradiol-17β concentrations varied between 5-20 pg/ml. Values for LH varied between 0.1-2 ng/ml, except for 1 value above 15 ng/ml for each of the 2 anestrous pups on 12 January.The 7 estrous animals (260 samples) included 1 pup and 2 adults that delivered litters. Estradiol-17β varied between 10-20 pg/ml during proestrus, peaked at 30-70 pg/ml late in proestrus and fluctuated between 10-30 pg/ml during pregnancy or the duration of luteal activity in the nonpregnant animals. The preovulatory LH rise, 5-15 ng/ml, extended over 3 days during and immediately following the peak estradiol-17β values. An earlier elevation in LH was observed in 3 of the estrous animals. Progesterone began increasing during the LH surge and peaked 11-14 days later at 22-40 ng/ml. Progesterone concentrations greater than 3 ng/ml were maintained for 56-68 days in 6 of the 7 animals exhibiting estrus. Progesterone concentrations declined at parturition but continued to fluctuate between 0.2-3 ng/ml for 3-6 weeks.

  9. The vaginal microbiome is stable in prepubertal and sexually mature Ellegaard Göttingen Minipigs throughout an estrous cycle.

    PubMed

    Lorenzen, Emma; Kudirkiene, Egle; Gutman, Nicole; Grossi, Anette Blak; Agerholm, Jørgen Steen; Erneholm, Karin; Skytte, Christina; Dalgaard, Marlene Danner; Bojesen, Anders Miki

    2015-10-28

    Although the pig has been introduced as an advanced animal model of genital tract infections in women, almost no knowledge exists on the porcine vaginal microbiota, especially in barrier-raised Göttingen Minipigs. In women, the vaginal microbiota plays a crucial role for a healthy vaginal environment and the fate of sexually transmitted infections such as Chlamydia trachomatis infections. Therefore, knowledge on the vaginal microbiota is urgently needed for the minipig model. The aim of this study was to characterize the microbiota of the anterior vagina by 16 s rRNA gene sequencing in prepubertal and sexually mature Göttingen Minipigs during an estrous cycle. The dominating phyla in the vaginal microbiota consisted of Firmicutes, Proteobacteria, Actinobacteria, Bacteriodetes and Tenericutes. The most abundant bacterial families were Enterobacteriaceae, unclassified families from Gammaproteobacteria, Clostridiales Family XI Incertae Sedis, Paenibacillaceae, Lactobacillaceae, Ruminococcaceae and Syntrophaceae. We found a higher abundance of Lactobacillaceae in the prepubertal Göttingen Minipigs compared to sexually mature non-pregnant Göttingen Minipigs. However, correlation tests and diversity parameters revealed a very stable vaginal microbiota in the Göttingen Minipigs, both before and after sexual maturity and on different days throughout an estrous cycle. The vaginal microbiota in Göttingen Minipigs was not dominated by lactobacilli, as it is in women and according to our results the minipig vaginal microbiota is very stable, in opposite to women. These differences should be considered when using the minipig as a model of the genital tract in women.

  10. The effect of cooling management on blood flow to the dominant follicle and estrous cycle length at heat stress.

    PubMed

    Honig, Hen; Ofer, Lior; Kaim, Moshe; Jacobi, Shamay; Shinder, Dima; Gershon, Eran

    2016-07-15

    The use of ultrasound imaging for the examination of reproductive organs has contributed substantially to the fertility management of dairy cows around the world. This method has many advantages such as noninvasiveness and immediate availability of information. Adding Doppler index to the ultrasound imaging examination, improved the estimation of blood volume and flow rate to the ovaries in general and to the dominant follicle in particular. The aim of this study was to examine changes in the blood flow to the dominant follicle and compare them to the follicular development throughout the cycle. We further set out to examine the effects of different types of cooling management during the summer on the changes in blood flow to the dominant follicle. For this purpose, 24 Israeli-Holstein dairy cows, under heat stress, were randomly assigned one of two groups: one was exposed to five cooling sessions per day (5CS) and the other to eight cooling sessions per day (8CS). Blood flow to the dominant follicle was measured daily using Doppler index throughout the estrous cycle. No differences in the preovulatory dominant follicle diameter were detected between the two cooling management regimens during the cycle. However, the length of the first follicular wave was significantly longer, whereas the second follicular wave was nonsignificantly shorter in the 5CS group as compared to the 8CS group. In addition, no difference in blood flow was found during the first 18 days of the cycle between the two groups. However, from Day 20 until ovulation a higher rate of blood flow was measured in the ovaries of cows cooled 8 times per day as compared to the 5CS group. No differences in progesterone levels were noted. Finally, the estrous cycle length was shorter in the 8CS group as compared to the 5CS group. Our data suggest that blood flow to the dominant follicle and estrous cycle length is affected by heat stress. Using the appropriate cooling management during heat stress can

  11. Alternative programs to presynchronize estrous cycles in dairy cattle before a timed artificial insemination program.

    PubMed

    Stevenson, J S

    2011-01-01

    The objective was to test potential presynchronization programs applied to cows before a timed artificial insemination (TAI) program to increase the percentage of cows ovulating in response to both GnRH injections of a TAI program and having a functional corpus luteum before the first GnRH injection of the TAI program. At calving, cows were blocked by lactation (1 vs. 2+) and assigned randomly to receive 1 of 5 presynchronization treatments. Two variants of the standard Presynch program were tested in which 2 injections of PGF2α were administered 14 d apart with either 14 d (Pre14; n=122), 12 d (Pre12; n=123), or 10 d (Pre10; n=151) intervening before a TAI program was initiated. Two other presynchronization programs consisted of administering a progesterone-releasing controlled internal drug release (CIDR) insert for 7 d plus PGF2α administration at insert removal. Insert removal occurred either 10 d (CIDR10; n=157) or 3 d (CIDR3; n=117) before a TAI program was initiated. The TAI program was a standard Cosynch program [injection of GnRH 7 d before (GnRH-1) and 72 h after (GnRH-2) PGF2α with TAI administered 72 h after PGF2α]. Cosynch served as the control (n=157), and cows were assumed to be starting this program at random stages of the estrous cycle. From a subset of cows per treatment (ranging from 49 to 51 cows each), blood samples were collected from coccygeal vessels by using evacuated tubes at d -28, -14, 0 (onset of TAI program), 7, 9, 14, and 21. Ovarian scans were conducted on d 0, 7, 9, 14, and 21 by transrectal ultrasonography. Diameters of follicles and corpus luteum were measured at each exam, and ovulation was determined on d 7 (response to GnRH-1 on d 0) and d 14 (response to GnRH-2 on d 10). Ovulatory incidence after GnRH-1 (47.1 to 67.3%) and GnRH-2 (78 to 90.2%) varied but did not differ among treatments. Before GnRH-1, progesterone concentrations were less in the CIDR3 treatment than in all other treatments. Before GnRH-2, progesterone was

  12. Calcium and magnesium content of the uterine fluid and blood serum during the estrous cycle and pre-pubertal phase in water buffaloes.

    PubMed

    Alavi Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Khaki, Amir; Belbasi, Abulfazle; Tahmasebian, Hamid

    2014-01-01

    To investigate uterine fluid and serum calcium (Ca) and Magnesium (Mg) variations during the estrus cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by examining ovarian structures. 18 animals were pro-estrous, 15 estrous, 16 met-estrous and 22 diestrous. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of 71 pre-pubertal buffalo calves were also collected and treated in similar manners. The mean ± SEM total serum and uterine fluid Ca in cyclic buffaloes were 8.68 ± 0.28 mg dL(-1) and 8.10 ± 0.2 mg dL(-1) vs. 6.76 ± 0.65 mg dL(-1) and 7.90 ± 0.15 mg dL(-1) in pre-pubertal calves, respectively. Blood serum Mg was not different in cyclic and pre-pubertal animals but the uterine fluid Mg in cyclic cows was higher than those in pre-pubertal calves. Serum Ca in pro-estrus and estrus were higher than those in other stages and also higher than those in the uterine fluid. The lowest Mg content of serum was recorded in diestrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle except for estrus the uterine fluid Mg content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Ca was passively secreted in uterine lumen and mostly dependent on blood serum Ca concentrations but Mg was secreted independently. The values (except for serum total Mg) also increased after puberty.

  13. Calcium and magnesium content of the uterine fluid and blood serum during the estrous cycle and pre-pubertal phase in water buffaloes

    PubMed Central

    Alavi Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Khaki, Amir; Belbasi, Abulfazle; Tahmasebian, Hamid

    2014-01-01

    To investigate uterine fluid and serum calcium (Ca) and Magnesium (Mg) variations during the estrus cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia. The phase of the estrous cycle was determined by examining ovarian structures. 18 animals were pro-estrous, 15 estrous, 16 met-estrous and 22 diestrous. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of 71 pre-pubertal buffalo calves were also collected and treated in similar manners. The mean ± SEM total serum and uterine fluid Ca in cyclic buffaloes were 8.68 ± 0.28 mg dL-1 and 8.10 ± 0.2 mg dL-1 vs. 6.76 ± 0.65 mg dL-1 and 7.90 ± 0.15 mg dL-1 in pre-pubertal calves, respectively. Blood serum Mg was not different in cyclic and pre-pubertal animals but the uterine fluid Mg in cyclic cows was higher than those in pre-pubertal calves. Serum Ca in pro-estrus and estrus were higher than those in other stages and also higher than those in the uterine fluid. The lowest Mg content of serum was recorded in diestrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle except for estrus the uterine fluid Mg content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Ca was passively secreted in uterine lumen and mostly dependent on blood serum Ca concentrations but Mg was secreted independently. The values (except for serum total Mg) also increased after puberty. PMID:25610582

  14. Gender features and estrous cycle variations of nocturnal behavior of mice after a single exposure to light at night.

    PubMed

    Datta, Siddhartha; Samanta, Diptaman; Sinha, Priyobrata; Chakrabarti, Nilkanta

    2016-10-01

    Light at night alters behavior and cognitive performances in rodents, the variations of which in gender and stages of reproductive cycle in females are elusive. Young mice habituated in light:dark (12:12h) cycle were given a single exposure of light (100lx) at early night for one hour duration followed by experimentations in open field (closed wall with circular big arena), elevated plus maze and square habituated field for memory performance using novel object recognition task. Light effects were compared with results found during without light conditions. Proestrous females appeared to have greater locomotor activity, less anxiety and better memory performance compared to the diestrous females at night without light exposure. The status of locomotor activity, anxiety and memory performance of male mice at night without light exposure appeared to be comparable to females where the stage of estrous cycle is important to characterize the nocturnal behavior of male mice. Light maximally affected proestrous females with decrease in locomotor activity, increase in anxiety and failure of memory performance. Male and diestrous female mice performed memory performance without alteration of locomotor activity and anxiety after exposure to light where males performed better memory performance with greater locomotor activity and more anxiety compared to that of diestrous females. The present study characterizes the mice nocturnal behavior with and without a single exposure to light stimuli with its gender features and estrous cycle variation. In addition, the study indicates an association of memory performance with locomotor activity and anxiety in mice nocturnal behavior. Copyright © 2016 Elsevier Inc. All rights reserved.

  15. Long-Term High Fat Diet Has a Profound Effect on Body Weight, Hormone Levels, and Estrous Cycle in Mice.

    PubMed

    Chakraborty, Tandra R; Donthireddy, Laxminarasimha; Adhikary, Debasis; Chakraborty, Sanjoy

    2016-05-12

    BACKGROUND Obesity causes several health complications along with disruption of the reproductive system. The aim of the current study was to determine how long-term intake of very high fat diet (VHFD) changes the hormonal milieu, affecting the cellular morphology and reproductive cycle in female mice. MATERIAL AND METHODS Mice were fed on normal diet (ND) and VHFD for 2 weeks, 12 weeks, and 25-27 weeks. We assessed changes in body weight, food consumption, energy intake, cellular and tissue morphology, hormonal levels (leptin, insulin, and estradiol), and vaginal smears were performed at various time points to determine the length and cellularity at each stage of the estrous cycle. RESULTS Mice fed on VHFD showed a significant increase in weight gain, reduction in food intake, and increase in energy intake compared to animals fed on ND, indicating that the caloric density of the diet is responsible for the differences in weight gain. Hormonal analysis showed hyperleptinemia, hyperinsulinemia, and increases in estrogen levels, along with increases in size of the islet of Langerhans and adipocytes. After 25-27 weeks, all animals fed on VHFD showed complete acyclicity; elongation of phases (e.g., diestrous), skipping of phases (e.g., metestrous), or a combination of both, indicating disruption in the reproductive cycle. Quantitative analysis showed that in the diestrous phase there was a 70% increase in cell count in VHFD compared to animals fed on ND. CONCLUSIONS The above results show that morphological and hormonal changes caused by VHFD probably act via negative feedback to the hypothalamic-pituitary axis to shut down reproduction, which has a direct effect on the estrous cycle, causing acyclicity in mice.

  16. Comparison of visual and computerized estrous detection and evaluation of influencing factors.

    PubMed

    Gaude, Ina; Kempf, Andreas; Strüve, Klaas Dietrich; Hoedemaker, Martina

    2017-09-01

    The aim of this study was to compare the automatic estrous detection system (AED) Heatime(®) with visual estrous detection (VED). The study was conducted on 139 Holstein Friesian cows in one dairy herd in Northern Germany. The cows were fitted with activity collars from d 21 postpartum until d 40 of gestation and a 30-min visual estrous observation was conducted three times a day. In addition, as a separate part of the VED, estrous detection by exclusive consideration of standing estrus (SE) was investigated. Ovulation detected by regular trans-rectal ultrasonography and serum progesterone analyses served as gold standard to calculate estrous detection rate (EDR) and reliability rate (RR) for each of the three estrous detection systems (AED, VED and SE). Change in body condition antepartum and postpartum, lameness, milk yield and milk fat- milk protein- ratio (FPR) on the expression and detection of estrus were investigated. Estrus was more precisely detected by the AED (EDR: 85.1%) than by VED (EDR: 52.2%) and SE (EDR: 22.3%) (P<0.05). The RR when using the three methods did not differ (P>0.05). Changes in body condition, lameness, milk yield or the FPR were not associated with the estrous detection rate by the AED. The estrous detection rate by VED in lame animals (EDR: 24.2%) was, however, less than in cows without any lameness (EDR: 52.7%; P<0.05). In conclusion, the AED Heatime(®) system can be effectively used for estrous detection and can be used to more precisely detect estrus than with VED. Copyright © 2017 Elsevier B.V. All rights reserved.

  17. Influence of the drinking water disinfection by-product dibromoacetic acid on rat estrous cyclicity and ovarian follicular steroid release in vitro.

    PubMed

    Balchak, S K; Hedge, J M; Murr, A S; Mole, M L; Goldman, J M

    2000-01-01

    The drinking water disinfection by-product, dibromoacetic acid (DBA) has been reported to affect gonadal functions in the male rat. However, there is little information regarding the influence of DBA on female reproductive activity. Consequently, the present study investigated the effects of DBA on estrous cyclicity and the impact in vitro of DBA on ovarian follicular steroid secretion. Regularly cycling animals were dosed with DBA (0 to 270 mg/kg/day) for 14 days and estrous cyclicity was monitored during treatment and for an additional 2-week posttreatment interval. A dose-related alteration in cyclicity was observed at 90 and 270 mg/kg/day, which persisted through the posttreatment monitoring in the high dose group. An in vitro exposure of preovulatory follicles to DBA was then used to assess the influence of DBA on steroid release. To select a concentration for use, a single oral exposure to 270 mg/kg was administered, and the mean blood levels were determined over a 5-h interval. For this in vitro work, pairs of preovulatory follicles from PMSG-primed immature rats were exposed to 0 or 50 microg/mL DBA over a 24-h period and evaluated for estradiol and progesterone release under baseline and hCG-stimulated conditions. The influence of tumor necrosis factor (TNFalpha) exposures under these conditions was also determined. In the nonstimulated condition, DBA was found to increase the release of estradiol, but had no detectable effect in response to hCG. Progesterone, however, showed marked suppression under hCG stimulation following exposure to DBA, while nonstimulated secretion was unaffected. TNFalpha by itself also suppressed stimulated progesterone release, but had no additional effect in combination with DBA. The data suggest that one factor in the disruption in estrous cyclicity could be an alteration in steroid production, which was characterized by separate effects on both estradiol and progesterone secretion.

  18. In vitro mimicking of estrous cycle stages in porcine oviduct epithelium cells: estradiol and progesterone regulate differentiation, gene expression, and cellular function.

    PubMed

    Chen, Shuai; Einspanier, Ralf; Schoen, Jennifer

    2013-09-01

    Throughout the estrous cycle the oviduct epithelium undergoes dramatic morphological and functional changes. To elucidate cyclic cellular events and associated regulation mechanisms of 17beta estradiol (E2) and progesterone (P4), we mimicked estrous cycle stages in vitro using a culture system of primary porcine oviduct epithelium cells (POEC). Cells were polarized in an air/liquid interface and then treated with E2 and P4 for physiological time periods: In experiment 1, high concentration of P4 with low concentration of E2 for 10 days resembled diestrus; in experiment 2, following the previous diestrus, sequential high E2 with low P4 for 2.5 days represented estrus. Histomorphometry and electron microscopy showed cyclic changes in cellular height, cell population, and cilia density under the influence of hormone stimulation. Transepithelial electrical resistance was high in simulated diestrus but reduced in estrus. Thus, E2 and P4 affect cellular polarity, transformation of ciliated and secretory cells, as well as electrical conductivity of oviduct epithelium. Simulation of diestrus led to significant decrease in expression of hormone receptors (PGR and ESR1) and other epithelial markers (MUC16, OVGP1, and HSP90B1), while sequential simulated estrus caused an increase in these markers. The hormonal regulation of some marker genes was clearly time-dependent. Furthermore, POEC showed increased sperm-binding capacity in simulated estrus. In this study, we also present a novel approach based on the AndroVision software, which can be routinely utilized as a parameter for ciliary activity, and for the first time, we showed fluid movement patterns along the epithelium lining in vitro.

  19. Bovine luteal prolactin receptor expression: potential involvement in regulation of progesterone during the estrous cycle and pregnancy.

    PubMed

    Thompson, I M; Ozawa, M; Bubolz, J W; Yang, Q; Dahl, G E

    2011-05-01

    In the present study, we performed quantitative reverse-transcription PCR (qPCR) to examine changes in gene expression of prolactin receptor (long form: l-PRLR; short form: s-PRLR) and 20α-hydroxysteroid dehydrogenase (20α-HSD; EC 1.1.1.149) in the bovine corpus luteum (CL) throughout the estrous cycle and pregnancy. Western blotting was used to determine protein abundance. Bovine CL were collected and luteal stages (n = 6/stage) were classified by macroscopic observation as early (d 1 to 4 after ovulation), mid (d 5 to 10), late (d 11 to 17), and regressing (d 18 to 20). A CL of pregnancy (n = 6) was determined by the presence of conceptus (d 28 to term). The mRNA for both forms of PRLR were expressed at all the luteal stages. Expression of s-PRLR and l-PRLR mRNA was less (P < 0.01) during early and regressing luteal stages compared with mid and late stages. Expression of s-PRLR mRNA in CL of pregnancy was greater (P < 0.01) than early, mid, and regressing CL and did not differ from late luteal stage expression. A greater (P < 0.01) expression of l-PRLR mRNA was observed in pregnant vs. early and regressing CL. In addition, qPCR showed the presence of 20α-HSD mRNA during all luteal stages of the estrous cycle, with the greatest (P < 0.01) expression observed in the regressing luteal stage. Western blotting revealed protein abundance of both PRLR isoforms during all luteal stages and pregnancy, with a predominance of the s-PRLR protein. Densitometry analysis indicated that protein abundances of s-PRLR were greater (P < 0.05) than l-PRLR during early, mid, and late luteal stages and did not differ during the regressing luteal stage. Protein abundances of 20α-HSD were least (P < 0.05) during the early luteal stage. In conclusion, results of the current study suggest a possible involvement of PRLR, especially s-PRLR, in the regulation of progesterone secretion and metabolism during the bovine estrous cycle and pregnancy.

  20. Seasonality, estrous cycle characterization, estrus synchronization, semen cryopreservation, and artificial insemination in the Pacific white-sided dolphin (Lagenorhynchus obliquidens).

    PubMed

    Robeck, T R; Steinman, K J; Greenwell, M; Ramirez, K; Van Bonn, W; Yoshioka, M; Katsumata, E; Dalton, L; Osborn, S; O'Brien, J K

    2009-08-01

    The reproductive physiology of the Pacific white-sided dolphin, Lagenorhynchus obliquidens, was characterized to facilitate the development of artificial insemination (AI) using cryopreserved spermatozoa. Specific objectives were to: 1) describe reproductive seasonality of the Pacific white sided dolphins; 2) describe urinary LH and ovarian steroid metabolites during the estrous cycle; 3) correlate LH and ovarian steroidal metabolite patterns to ultrasound-monitored follicular growth and ovulation; and 4) assess the efficacy of synchronizing estrus, sperm collection/cryopreservation, and intrauterine insemination. Ovulations (64%, n=37) and conceptions (83%, n=18) occurred from August to October. Peak mean serum testosterone (24 ng/ml), cross-sectional testicular area (41.6 cm(2)), and sperm concentration (144.3 x 10(7) sperm/ml) occurred in July, August, and September respectively. Spermatozoa were only found in ejaculates from July to October. Estrous cycles (n=22) were 31 d long and were comprised of a 10 d follicular and 21 d luteal phase. Ovulation occurred 31.2 h after the onset of the LH surge and 19.3 h after the LH peak. Follicular diameter and circumference within 12 h of ovulation were 1.52 and 4.66 cm respectively. Estrus synchronization attempts with altrenogest resulted in 17 (22%) ovulatory cycles with ovulation occurring 21 d post-altrenogest. Ten AI attempts using cryopreserved semen resulted in five pregnancies (50%). The mean gestation length was 356 days (range 348-367). These data provide new information on the Pacific white-sided dolphin's reproductive physiology and collectively enabled the first application of AI in this species.

  1. Estrous cycle regulatory mechanisms of the uterus are altered in cows that do not demonstrate behavioral estrus during an ovulation induction protocol

    USDA-ARS?s Scientific Manuscript database

    Estrus is the start of an estrous cycle in cows, and triggers several precisely timed events including receptivity to the bull, ovulation, conception, formation of the corpus luteum, and recognition of pregnancy. In the absence of a pregnancy signal, the corpus luteum (CL) must regress in response ...

  2. Variability in tumor necrosis factor-alpha, nitric oxide, and xanthine oxidase responses to endotoxin challenge in heifers: Effect of estrous cycle stage

    USDA-ARS?s Scientific Manuscript database

    The severity of host response to some disease agents differs between sexes and this dimorphism has been attributed to the immunomodulating effects of steroid hormones. Our objective was to determine in heifers whether the phase of estrous cycle affected immune response mediators after endotoxin cha...

  3. Distribution and quantitative changes in amounts of aquaporin 1, 5 and 9 in the pig uterus during the estrous cycle and early pregnancy

    PubMed Central

    2010-01-01

    Background Aquaporins (AQPs) are a family of membrane channel proteins that facilitate bulk water transport. To date, 11 isoforms of AQPs have been reported to be expressed in the female and male reproductive systems. The purpose of our study was to determine the localization and quantitative changes in the expression of AQP1, 5 and 9 within the pig uterus during different stages of the estrous cycle and early pregnancy. Methods Immunoperoxidase and semi-quantitative immunoblotting techniques were used to examine the distribution and changes in amounts of AQP1, AQP5 and AQP9 in uteral cells of pigs at the early (Days 2-4), middle (10-12), late (14-16) stage of the luteal phase and late (18-20) stage of the follicular phase of the estrous cycle as well as on Days 14-16 and 30-32 of gestation (the onset and the end of implantation process). Results The results demonstrated that AQP1, 5, and 9 were clearly detected in all studied stages of the estrous cycle and pregnancy. AQP1 was localized within uterine blood vessels. In cyclic gilts, endometrial and myometrial expression of AQP1 protein did not change significantly but increased during gestation. AQP5 was localized in smooth muscle cells and uterine epithelial cells. Endometrial expression of AQP5 protein did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Myometrial expression of AQP5 did not differ significantly during the estrous cycle but increased in the pregnancy. The anti-AQP9 antibody labeled uterine epithelial cells of uterus. Endometrial expression of AQP9 did not change significantly between Days 2-4 and 10-12 of the estrous cycle but increased on Days 14-16 and 18-20 as well as during early pregnancy. Conclusions The results suggest that a functional and distinctive collaboration exists among diverse AQPs in water handling during the different uterine phases in the estrous cycle and early pregnancy. PMID

  4. Substance P and neurokinin A variations throughout the rat estrous cycle; comparison with ovariectomized and male rats: I. Plasma, hypothalamus, anterior and posterior pituitary.

    PubMed

    Duval, P; Lenoir, V; Moussaoui, S; Garret, C; Kerdelhué, B

    1996-09-01

    The concentrations of Substance P and Neurokinin A were measured in plasma, and the hypothalamo-pituitary complex of 4-day-cycling female, ovariectomized and male rats. Estrous cycle-related fluctuations were recorded for these two neurokinins. The patterns of plasma concentrations of Substance P and Neurokinin A, however, were not similar throughout the rat estrous cycle. The plasma concentration of Substance P increased on proestrus at 19.00 hr, while Neurokinin A decreased. The plasma concentration of Substance P was positively correlated with plasma 17 beta-estradiol levels. In the ovariectomized rat, the absence of ovarian steroids led to low levels of plasma Neurokinin A, but the plasma concentration of Substance P did not show any change as compared to the estrous cycle. In the male rat, a similar observation was made in the presence of a testosterone environment. The largest variations in tissue concentration of both peptides were observed in the anterior pituitary. Substance P and Neurokinin A contents were higher throughout the proestrous day than the 3 other days. However, the level fell at 18.00 hr on proestrus, and there were similar falls in the hypothalamic contents of Substance P and Neurokinin A at 19.00 hr. In the ovariectomized rat, with no gonadal steroids, the hypothalamic and/or anterior pituitary levels of Substance P were in the same range as during the estrous cycle. However, the hypothalamic levels of Neurokinin A were lower and Neurokinin A was undetectable in the anterior pituitary. Substance P and Neurokinin A concentrations in the posterior pituitary were stable throughout the estrous cycle, with the exception of rises for both peptides on estrous day. Substance P levels were much lower in ovariectomized and male rats. These results describe large fluctuations in hypothalamic and pituitary Substance P and Neurokinin A contents through the estrous cycle in the female rat. They also strongly suggest the involvement of gonadal steroids in

  5. Investigation of individual and group variability in estrous cycle characteristics in female Asian elephants (Elephas maximus) at the Oregon Zoo.

    PubMed

    Glaeser, S S; Hunt, K E; Martin, M S; Finnegan, M; Brown, J L

    2012-07-15

    Evaluating ovarian cycle activity through longitudinal progestagen monitoring is important for optimizing breeding management of captive elephants and understanding impact of life events (births, deaths, and transfers) on reproductive function. This study summarized serum progestagen profiles for eight Asian mainland elephants (Elephas maximus indicus) and one Bornean elephant (E. maximus borneensis) at the Oregon Zoo over a 20-yr interval, and represents the longest longitudinal dataset evaluated to date. Estrous cycle characteristics were more varied than previously reported for this species, with an overall duration of 12 to 19 wk, luteal phase duration of 4 to 15 wk, and follicular phase duration of 2 to 12 wk. In general, there was more cycle variability across than within individual elephants. Compared with other elephants in the group, the Borneo female exhibited consistently longer cycle lengths, higher progestagen concentrations, and greater cycle variability; however, it is not known if this represents a subspecies or an individual difference. Cycle durations did not appear to change over time or with age, and the first pubertal cycle was similar to subsequent cycles. Variability in duration of the follicular phase was greater than that of the luteal phase. In addition, there was a significant negative relationship between luteal and follicular phase durations, suggesting a possible regulatory role of the follicular phase in maintaining a relatively consistent cycle duration within individuals. Overall, we found these elephants to be highly resilient in that major life events (births, deaths, and changes in herd structure) had minimal effect on cycle dynamics over time. In conclusion, the higher range in cycle phase characteristics is likely because of the larger number of elephants studied and longer duration of longitudinal monitoring, and may be more representative of the captive population as a whole. Furthermore, identification of significant

  6. The estrous cycle and the olivo-cerebellar circuit. I. Contrast enhancement of sensorimotor-correlated cerebellar discharge.

    PubMed

    Smith, S S; Chapin, J K

    1996-10-01

    Neuromodulation of Purkinje (Pnj) cell responses by monoamines and estrous hormones is well characterized in the cerebellum at the cellular level, but not at the level of neuronal circuits in the awake behaving animal. In the present study, simultaneous recordings of up to 16 single neurons from within the olivo-cerebellar circuit were obtained through chronically implanted microwire electrode bundles: arrays of Pnj cell like neurons (Pnj cln) in the paravermal cerebellum and neurons within the afferent source of its climbing fiber input, the rostral dorsal accessory olive (rDAO), were recorded simultaneously across 3-20 consecutive estrous cycles during constant or variable speed treadmill locomotion performance tasks. Over 90% of Pnj cln recorded during treadmill locomotion exhibited significant increases (80%) or decreases (10%) in activity correlated with the stance phase of locomotion. In contrast, cells from the rDAO increased activity during speed changes or when the rat failed to maintain the treadmill speed (position slip). On the night of behavioral estrus, which is triggered by elevations in circulating levels of 17 beta-estradiol and progesterone, the magnitude of both increases and decreases in stance-correlated Pnj cln activity increased by 85-115%. These results are consistent with our previous findings that 17 beta-estradiol and progesterone enhance excitatory and inhibitory responses of single Pnj cells to locally applied glutamate and GABA, respectively. This dual enhancement of both excitatory and inhibitory effects, apparently paradoxical at the cellular level, produced a marked heightening of the contrast of the neural population "signal" at the neuronal ensemble level. Furthermore, the stance-correlated discharge of Pnj cln during estrus preceded that during diestrus by approximately 120 ms. Frame-by-frame video analysis also suggested that the swing phase of the step cycle was shortened on estrus compared with diestrus (low hormone state). In

  7. Changes in the endometrial transcriptome during the bovine estrous cycle: effect of low circulating progesterone and consequences for conceptus elongation.

    PubMed

    Forde, N; Beltman, M E; Duffy, G B; Duffy, P; Mehta, J P; O'Gaora, P; Roche, J F; Lonergan, P; Crowe, M A

    2011-02-01

    In cattle, elevated concentrations of circulating progesterone (P4) in the immediate postconception period are associated with advanced conceptus development, while low P4 is implicated as a causative factor in low pregnancy rates observed in dairy cows. This study aimed to: 1) describe the transcriptional changes that occur in the bovine endometrium during the estrous cycle, 2) determine how elevated P4 affects these changes, 3) identify if low P4 alters the expression of these genes, and 4) assess the impact that low P4 has on conceptus development. Relatively few differences occurred in endometrial gene expression during the early luteal phase of the estrous cycle (Day 5 vs. 7), but comparison of endometria from more distant stages of the luteal phase (Day 7 vs. 13) revealed large transcriptional changes, which were significantly altered by exogenous supplementation of P4. Induction of low circulating P4 altered the normal temporal changes in gene expression, and these changes were coordinate with a delay in the down-regulation of the PGR from the LE and GE. Altered endometrial gene expression induced by low P4 was associated with a reduced capacity of the uterus to support conceptus development after embryo transfer on Day 7. In conclusion, the present study provides clear evidence that the temporal changes in the transcriptome of the endometrium of cyclic heifers are sensitive to circulating P4 concentrations in the first few days after estrus. Under low P4 conditions, a suboptimal uterine environment with reduced ability to support conceptus elongation is observed.

  8. Fibronectin From Oviductal Cells Fluctuates During the Estrous Cycle and Contributes to Sperm-Oviduct Interaction in Cattle.

    PubMed

    Osycka-Salut, Claudia E; Castellano, Luciana; Fornes, Daiana; Beltrame, Jimena S; Alonso, Carlos A I; Jawerbaum, Alicia; Franchi, Ana; Díaz, Emilce S; Perez Martinez, Silvina

    2017-11-01

    During the passage of sperm through the oviduct, spermatozoa bind to the oviductal epithelium and form the oviductal reservoir. This interaction keeps the fertilizing capacity of sperm until ovulation-associated signals induce sperm release from the oviductal epithelium, allowing the transit of spermatozoa to the fertilization site. Fibronectin is a glycoprotein from the extracellular matrix that binds to α5β1 receptors. Fibronectin has been found to be expressed in the oviduct, whereas α5β1 has been found to be expressed in the sperm of different species. Fibronectin is involved through α5β1 in sperm functions. The aim of this work was to study the participation of oviductal fibronectin in the regulation of the sperm-oviduct interaction in cattle. We found that oviductal epithelial cells differentially expressed all mRNA splice variants of fibronectin during the estrous cycle. Fibronectin was localized in the apical region of oviductal epithelial cells and fibronectin levels in the oviductal fluid fluctuated during the estrous cycle. Also, bovine spermatozoa expressed α5β1. Using in vitro sperm-oviduct co-cultures, we found that spermatozoa were attached to the oviductal epithelium through α5β1. The incubation of co-cultures with fibronectin induced sperm release from the oviductal cells through α5β1. The sperm population released from oviductal cells by fibronectin was enriched in motile and capacitated spermatozoa. Based on our in vitro culture system results, we propose that fibronectin and α5β1 are involved in the sperm-oviduct interaction. Also, an increase in fibronectin levels in the oviductal fluid during the pre-ovulatory period may promote sperm release from the oviductal epithelium in cattle. J. Cell. Biochem. 118: 4095-4108, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  9. Transcriptome studies of bovine endometrium reveal molecular profiles characteristic for specific stages of estrous cycle and early pregnancy.

    PubMed

    Bauersachs, S; Mitko, K; Ulbrich, S E; Blum, H; Wolf, E

    2008-07-01

    The endometrium undergoes marked functional changes during estrous cycle and pregnancy. As the adjacent environment of the conceptus, it represents the maternal interface for embryo-maternal communication, which is essential to maintain pregnancy. Transcriptome studies provide the unique opportunity to assess molecular profiles changing in response to endocrine or metabolic stimuli or to embryonic pregnancy recognition signals. Here we review the current state of transcriptome profiling techniques and the results of a series of transciptome studies comparing bovine endometrium samples during the estrous cycle or endometrium samples from pregnant vs. non-pregnant animals. These studies revealed specific mRNA profiles which are characteristic for the functional status of the endometrium. Transcriptome studies of endometrial samples recovered during the pre-attachment period identified many interferon-stimulated genes, genes that are possibly involved in embryo-maternal immune modulation ( C1S, C1R, C4, SERPING1, UTMP, CD81, IFITM1, BST2), as well as genes affecting cell adhesion ( AGRN, CD81, LGALS3BP, LGALS9, GPLD1, MFGE8, and TGM2) and remodeling of the endometrium ( CLDN4, MEP1B, LGMN, MMP19, TIMP2, TGM2, MET, and EPSTI1). The results of these transcriptome studies were compared to those of similar microarray analyses in human, mouse and Rhesus monkey to identify similarities in endometrial biology between mammalian species and species-specific differences. Future studies will cover dynamic transcriptome changes between different stages of early pregnancy, the relationship between metabolic problems in dairy cows and the functionality of reproductive tissues as well as endometrium transcriptome profiles in recipients of somatic cell nuclear transfer embryos.

  10. Ovarian and PGF2α responses to stimulation of endogenous PRL pulses during the estrous cycle in mares.

    PubMed

    Pinaffi, F L V; Khan, F A; Silva, L A; Beg, M A; Ginther, O J

    2012-10-01

    The effects of a PRL-stimulating substance (sulpiride) on PRL and PGF2α secretion and on luteal and ovarian follicular dynamics were studied during the estrous cycle in mares. A control group (n = 9) and a sulpiride group (Sp; n = 10) were used. Sulpiride (25 mg) was given every 8 h from Day 13 postovulation to the next ovulation. Repeated sulpiride treatment did not appear to maintain PRL concentrations at 12-h intervals beyond Day 14. Therefore, the hypothesis that a long-term increase in PRL altered luteal and follicular end points was not testable. Hourly samples were collected from the hour of a treatment (Hour 0) to Hour 8 on Day 14. Concentrations of PRL increased to maximum at Hour 4 in the Sp group. The PRL pulses were more prominent (P < 0.008) in the sulpiride group (peak, 19.4 ± 1.9 ng/mL; mean ± SEM) than in the controls (11.5 ± 1.8 ng/mL). Concentrations of a metabolite of PGF2α (PGFM), number, and characteristics of PGFM pulses, and concentrations of progesterone during Hours 0 to 8 were not affected by the increased PRL. A novel observation was that the peak of a PRL pulse occurred at the same hour or 1 h later than the peak of a PGFM pulse in 8 of 8 PGFM pulses in the controls and in 6 of 10 pulses in the Sp group (P < 0.04), indicating that sulpiride interfered with the synchrony between PGFM and PRL pulses. The hypothesis that sulpiride treatment during the equine estrous cycle increases concentrations of PRL and the prominence of PRL pulses was supported.

  11. Plasma progesterone levels during the estrous cycle of Holstein and Brahman cows, Carora type and cross-bred heifers.

    PubMed

    Díaz, T; Manzo, M; Trocóniz, J; Benacchio, N; Verde, O

    1986-10-01

    Daily plasma progesterone (P(4)) was determined during one estrous cycle of 19 cows and 18 heifers of four different breeds: Holstein (H), Brahman (B), Carora-type (C) and crossbred (CB) females. Estrus detection was made by visual observation and using a teaser bull with a chin-ball marker. The P(4) profiles showed no differences among groups. In Group 1 (H), P(4) levels ranged from 0.5 ng/ml plasma on the day of estrus (Day 0) to 5.1 ng/ml at the luteal phase peak (Day 13). In Group 2 (B), P(4) levels ranged from 0.5 ng/ml on Day 0 to 9.2 ng/ml on Day 13. In Groups 3 (C) and 4 (CB), P(4) levels ranged from 0.5 ng/ml, on Day 0, to 13.7 ng/ml on Day 12 and 8.8 ng/ml on Day 13. These last two groups were moved to the same location and then compared. It was found that P(4) concentrations were significantly higher (P < 0.025) in Group 3 between Days 7 and 14 of the estrous cycle. In all groups, P(4) levels were lower than 1 ng/ml one day before the next estrus, and levels of 0.4, 0.5, 0.4 and 0.4 ng/ml were obtained the day of estrus in Groups 1 to 4, respectively. Results indicated that the pattern of P(4) for each one of the groups was similar to those reported by other investigators.

  12. Copper and zinc concentrations in uterine fluid and blood serum during the estrous cycle and pre-pubertal phase in water buffaloes.

    PubMed

    Alavi Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Khaki, Amir; Belbasi, Abulfazl; Tahmasebian, Hamid

    2015-01-01

    To investigate uterine fluid and serum copper (Cu) and zinc (Zn) variations during the estrous cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia, Iran. The phase of the estrous cycle was determined by examining ovarian structures; 18, 15, 16 and 22 were pro-estrous, estrous, met-estrous and diestrous, respectively. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of 71 pre-pubertal buffalo calves were also collected and treated in similar manners. The mean (± SEM) total serum (77.10 ± 1.50 µg dL(-1)) and uterine fluid (296.40 ± 9.40 μg dL(-1)) Cu in cyclic cows was higher than the values of 54.00 ± 1.10 μg dL(-1) and 133.40 ± 5.70 μg dL(-1) in pre-pubertal calves, respectively. Blood serum (114.60 ± 3.20 μg dL(-1)) and the uterine fluid (349.90 ± 8.90 μg dL(-1)) Zn content in cyclic cows were also higher than those (98.80 ± 1.50 μg dL(-1) and 246.6 ± 4.50 μg dL(-1) respectively) in pre-pubertal calves. Serum Cu in pro-estrus and estrus were lower than those in other stages and also lower than those in the uterine fluid. The lowest serum Zn content was recorded in pro- and met-estrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle the uterine fluid Zn content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Cu and Zn were actively secreted in uterine lumen and were not dependent on blood serum. The values also increased after puberty.

  13. Copper and zinc concentrations in uterine fluid and blood serum during the estrous cycle and pre-pubertal phase in water buffaloes

    PubMed Central

    Alavi Shoushtari, Sayed Mortaza; Asri Rezaie, Siamak; Khaki, Amir; Belbasi, Abulfazl; Tahmasebian, Hamid

    2015-01-01

    To investigate uterine fluid and serum copper (Cu) and zinc (Zn) variations during the estrous cycle in water buffaloes, 71 genital tracts and blood samples were collected from the abattoir in Urmia, Iran. The phase of the estrous cycle was determined by examining ovarian structures; 18, 15, 16 and 22 were pro-estrous, estrous, met-estrous and diestrous, respectively. The uterine fluid was collected by gentle scraping of the uterine mucosa with a curette. Blood serum and uterine fluid samples of 71 pre-pubertal buffalo calves were also collected and treated in similar manners. The mean (± SEM) total serum (77.10 ± 1.50 µg dL-1) and uterine fluid (296.40 ± 9.40 μg dL-1) Cu in cyclic cows was higher than the values of 54.00 ± 1.10 μg dL-1 and 133.40 ± 5.70 μg dL-1 in pre-pubertal calves, respectively. Blood serum (114.60 ± 3.20 μg dL-1) and the uterine fluid (349.90 ± 8.90 μg dL-1) Zn content in cyclic cows were also higher than those (98.80 ± 1.50 μg dL-1 and 246.6 ± 4.50 μg dL-1 respectively) in pre-pubertal calves. Serum Cu in pro-estrus and estrus were lower than those in other stages and also lower than those in the uterine fluid. The lowest serum Zn content was recorded in pro- and met-estrus, while in the uterine fluid it was observed in estrus. In all stages of estrous cycle the uterine fluid Zn content was significantly higher than those of the serum. These results suggested that during the estrous cycle in the buffalo cows, Cu and Zn were actively secreted in uterine lumen and were not dependent on blood serum. The values also increased after puberty. PMID:26893810

  14. Relationship between concentrations of progesterone, oxytocin, noradrenaline, gene expression and protein level for their receptors in corpus luteum during estrous cycle in the cow.

    PubMed

    Rekawiecki, R; Nowocin, A; Kotwica, J

    2010-06-01

    The aim of these studies was to evaluate of the relationship between luteal concentrations of oxytocin (OT), noradrenaline (NA), progesterone (P4), oxytocin receptors (OT-R) and beta(2)-adrenoreceptors (beta(2)-R) gene expression and their protein level throughout the estrous cycle in cattle. Corpora lutea (CL) collected during days 1-5, 6-10, 11-16 and 17-21 of the estrous cycle were used in these studies. Concentrations of P4, OT and NA were determined in tissue extracts. Gene expression and protein level for OT-R and beta(2)-R were investigated by RT-PCR and Western blot, respectively. Luteal concentration of P4 was higher (P<0.01) on days 6-10 and 11-16 than during days 1-5 and 17-20 of the estrous cycle. Concentration of OT was the highest on days 1-5 and 6-10 of the estrous cycle. This concentration decreased (P<0.01) during days 11-16 reaching the lowest level (P<0.001) on days 17-20 as opposed to days 1-10 of the estrous cycle. Expression of OT-R mRNA was lower on days 6-16 (P<0.05) followed by its increase on days 17-20 as opposed to the expression observed on days 1-5. Expression of OT-R mRNA was negatively correlated (P<0.05) with the profile of OT-R protein level. This latter parameter was the lowest on days 17-20 and 1-5, and the highest on days 6-10 and 11-16. Oxytocin concentration was negatively correlated (P<0.05) with expression of OT-R mRNA and positively correlated (P<0.001) with OT-R protein level. This protein level was only correlated with P4 (r=0.59; P<0.05). Concentration of OT was positively correlated with level of P4 (P<0.001). Concentration of NA was the highest on days 1-5 of the estrous cycle, whereas it was similar or lower (P<0.05) on days 6-21. Expression of mRNA for beta(2)-R was the lowest on days 1-5 and was highly increased (P<0.05) on days 6-16. The expression was the highest (P<0.001) on days 17-21 compared to all others group of the estrous cycle. Protein level for beta(2)-R was the highest on days 1-5 and decreased (P<0

  15. Serum leptin concentrations, leptin mRNA expression, and food intake during the estrous cycle in rats.

    PubMed

    Fungfuang, Wirasak; Nakada, Tomoaki; Nakao, Nobuhiro; Terada, Misao; Yokosuka, Makoto; Gizurarson, Sveinbjorn; Hau, Jann; Moon, Changjong; Saito, Toru R

    2013-03-01

    The aim of this study was to investigate food intake, serum leptin levels, and leptin mRNA expression during the sexual cycle in rats. Female Wistar-Imamichi rats aged 8-10 weeks were used in this experiment. Food intake was measured during the light and dark phases (light on at 07:00 and off at 19:00) of the 4-day estrous cycle in female rats. Serum leptin levels were measured by ELISA, and leptin mRNA expression levels were analyzed using real-time PCR on diestrous- and proestrous-stage rats. Our results revealed that during the sexual cycle, food intake was significantly higher in the dark phase compared with the light phase. Food intake in proestrous females was significantly lower in the light and dark phases compared with the other groups. Serum leptin concentrations were significantly higher in both phases in proestrous rats compared with diestrous rats. There was a significant increase in leptin mRNA expression in adipose tissue during the proestrous period compared with the diestrous period. These findings suggest that increased leptin mRNA expression and serum leptin levels, which are induced by estrogen during the proestrous stage, may play a role in regulating appetitive behavior.

  16. Control of the estrous cycle to improve fertility for fixed-time artificial insemination in beef cattle: a review.

    PubMed

    Lamb, G C; Dahlen, C R; Larson, J E; Marquezini, G; Stevenson, J S

    2010-04-01

    Early estrus-synchronization protocols focused on regressing the corpus luteum (CL) with an injection of PGF(2alpha) followed by detection of estrus or involved the use of exogenous progestins that prevent estrus from occurring. Later, protocols combining the use of PGF(2alpha) and exogenous progestins were developed. Gonadotropin-releasing hormone was utilized to control follicular waves, synchronize ovulation, or to luteinize large dominant follicles. Our research aimed to develop reliable protocols that 1) relied solely on fixed-timed AI (TAI); 2) required a maximum of 3 animal handlings, and 3) were successful in estrous-cycling and noncycling females. In cows, insertion of an intravaginal progesterone insert during the 7-d interval between the initial GnRH and PGF(2alpha) injections enhanced pregnancy rates by 9 to 10%. In a multi-location study, a TAI protocol yielded pregnancy rates similar to a protocol involving detection of estrus plus a fixed-time clean-up AI for females not detected in estrus (54 vs. 58%, respectively, for cows and 53 vs. 57%, respectively, for heifers). Initiation of estrous cycles in noncycling cows is likely the primary manner in which beef producers may improve fertility in response to estrus synchronization and TAI protocols. Treatment of noncycling females with progesterone and GnRH increases the percentage of cycling females and improves fertility to a TAI, but inducing cyclicity with hCG failed to enhance fertility in TAI protocols. Supplementing progesterone after TAI failed to increase pregnancy rates in beef cattle. In contrast, administration of hCG 7 d after TAI induced an accessory CL, increased progesterone, and tended to enhance pregnancy rates. Development of TAI protocols that reduce the hassle factors associated with ovulation synchronization and AI provide cattle producers efficient and effective tools for capturing selective genetic traits of economic consequences. Location variables, however, which may include

  17. Effect of the estrous cycle and surgical ovariectomy on energy balance, fuel utilization, and physical activity in lean and obese female rats

    PubMed Central

    Giles, Erin D.; Jackman, Matthew R.; Johnson, Ginger C.; Schedin, Pepper J.; Houser, Jordan L.

    2010-01-01

    This study presents an in-depth analysis of the effects of obesity on energy balance (EB) and fuel utilization in adult female rats, over the estrous cycle and immediately after surgical ovariectomy (OVX), to model pre- and postmenopausal states, respectively. Female Wistar rats were fed a high-fat (46%) diet for 16 wk to produce mature lean and obese animals. Stage of estrous was identified by daily vaginal lavage, while energy intake (EI), total energy expenditure (TEE), and fuel utilization were monitored in a multichamber indirect calorimeter and activity was monitored by infrared beam breaks. Metabolic monitoring studies were repeated during the 3-wk period of rapid OVX-induced weight gain. Component analysis of TEE was performed to determine the nonresting and resting portions of energy expenditure. Obesity was associated with a greater fluctuation in EB across the estrous cycle. Cycling obese rats were less active, expended more energy per movement, and oxidized more carbohydrate than lean rats. The changes in EB over the cycle in lean and obese rats were driven by changes in EI. Finally, OVX induced a large positive energy imbalance in obese and lean rats. This resulted primarily from an increase in EI in both groups, with little change in TEE following OVX. These observations reveal a dominant effect of obesity on EB, fuel utilization, and activity levels in cycling rats, which has implications for studies focused on obesity and EB in female rodents. PMID:20926768

  18. Estrous cycle affects the neurochemical and neurobehavioral profile of carvacrol-treated female rats

    SciTech Connect

    Trabace, L.; Zotti, M.; Morgese, M.G.; Tucci, P.; Colaianna, M.; Schiavone, S.; Avato, P.; Cuomo, V.

    2011-09-01

    Carvacrol is the major constituent of essential oils from aromatic plants. It showed antimicrobial, anticancer and antioxidant properties. Although it was approved for food use and included in the chemical flavorings list, no indication on its safety has been estimated. Since the use of plant extracts is relatively high among women, aim of this study was to evaluate carvacrol effects on female physiology and endocrine profiles by using female rats in proestrus and diestrus phases. Serotonin and metabolite tissue content in prefrontal cortex and nucleus accumbens, after carvacrol administration (0.15 and 0.45 g/kg p.o.), was measured. Drug effects in behavioral tests for alterations in motor activity, depression, anxiety-related behaviors and endocrine alterations were also investigated. While in proestrus carvacrol reduced serotonin and metabolite levels in both brain areas, no effects were observed in diestrus phase. Only in proestrus phase, carvacrol induced a depressive-like behavior in forced swimming test, without accompanying changes in ambulation. The improvement of performance in FST after subchronic treatment with fluoxetine (20 mg/kg) suggested a specific involvement of serotonergic system. No differences were found across the groups with regard to self-grooming behavior. Moreover, in proestrus phase, carvacrol reduced only estradiol levels without binding hypothalamic estradiol receptors. Our study showed an estrous-stage specific effect of carvacrol on depressive behaviors and endocrine parameters, involving serotonergic system. Given the wide carvacrol use not only as feed additive, but also as cosmetic essence and herbal remedy, our results suggest that an accurate investigation on the effects of its chronic exposure is warranted. - Highlights: > Carvacrol induced a depressive-like phenotype in rats, depending on ovarian cyclicity. > Carvacrol selectively reduced serotonin content in female rats in proestrus phase. > Carvacrol reduced serotonin levels

  19. Participation of vasoactive intestinal polypeptide in ovarian steroids production during the rat estrous cycle and in the development of estradiol valerate-induced polycystic ovary.

    PubMed

    Parra, Claudio; Fiedler, Jenny L; Luna, S Leticia; Greiner, Monika; Padmanabhan, Vasantha; Lara, Hernán E

    2007-01-01

    Vasoactive intestinal polypeptide (VIP) stimulates estradiol and progesterone release from ovarian granulosa cells in vitro. Very little information is available as to the role VIP plays in the control of steroid secretion during reproductive cyclicity and in ovarian pathologies involving altered steroid secretion. In this study, we determined the involvement of VIP in regulating ovarian androgen and estradiol release during estrous cyclicity and estradiol valerate (EV)-induced polycystic ovarian development in rats. Our findings show that androgen and estradiol release from ovaries obtained during different stages of rat estrous cycle mimic cyclic changes in steroid release observed in vivo with maximal release occurring during late proestrus. VIP increased androgen release from ovaries of all cycle stages except late proestrus and estradiol release from all cycle stages. Increases in VIP-induced androgen and estradiol release were maximal at early proestrus. Inclusion of saturating concentrations of androstenedione increased magnitude of VIP-induced estradiol release at diestrus and estrus but not proestrus. Magnitude of VIP-induced androgen and estradiol release tended to be greater in the ovaries from EV-treated rats with polycystic ovary compared with estrous controls. At the tissue level, ovarian VIP concentration was cycle stage dependent with highest level seen in diestrus. Maximum concentration of VIP was found in EV-treated rats. Changes in VIP were inversely related to changes in ovarian nerve growth factor, a neuropeptide involved in ovarian androgen secretion. These results strongly suggest that intraovarian VIP participates in the control of estradiol secretion during the rat estrous cycle and possibly in the maintenance of increased ovarian estradiol secretory activity of EV-treated rats.

  20. Estrous cycle variations in GABAA receptor phosphorylation enable rapid modulation by anabolic androgenic steroids in the medial preoptic area

    PubMed Central

    Oberlander, JG; Porter, DM; Onakomaiya, MM; Penatti, CAA; Vithlani, M; Moss, SJ; Clark, AS; Henderson, LP

    2012-01-01

    Anabolic androgenic steroids (AAS), synthetic testosterone derivatives that are used for ergogenic purposes, alter neurotransmission and behaviors mediated by GABAA receptors. Some of these effects may reflect direct and rapid action of these synthetic steroids at the receptor. The ability of other natural allosteric steroid modulators to alter GABAA receptor-mediated currents is dependent upon the phosphorylation state of the receptor complex. Here we show that phosphorylation of the GABAA receptor complex immunoprecipitated by β2/β3 subunit-specific antibodies from the medial preoptic area (mPOA) of the mouse varies across the estrous cycle; with levels being significantly lower in estrus. Acute exposure to the AAS, 17α-testosterone (17α-MeT), had no effect on the amplitude or kinetics of inhibitory postsynaptic currents in the mPOA of estrous mice when phosphorylation was low, but increased the amplitude of these currents from mice in diestrus, when it was high. Inclusion of the protein kinase C (PKC) inhibitor, calphostin, in the recording pipette eliminated the ability of 17α-MeT to enhance currents from diestrous animals, suggesting that PKC-receptor phosphorylation is critical for the allosteric modulation elicited by AAS during this phase. In addition, a single injection of 17α-MeT was found to impair an mPOA-mediated behavior (nest-building) in diestrus, but not in estrus. PKC is known to target specific serine residues in the β3 subunit of the GABAA receptor. Although phosphorylation of these β3 serine residues showed a similar profile across the cycle, as did phosphoserine in mPOA lysates immunoprecipitated with β2/β3 antibody (lower in estrus than in diestrus or proestrus), the differences were not significant. These data suggest that the phosphorylation state of the receptor complex regulates both the ability of AAS to modulate receptor function in the mPOA and the expression of a simple mPOA-dependent behavior through PKC-dependent mechanism

  1. Substance P and neurokinin A variations throughout the rat estrous cycle; comparison with ovariectomized and male rats: II. Trigeminal nucleus and cervical spinal cord.

    PubMed

    Duval, P; Lenoir, V; Moussaoui, S; Garret, C; Kerdelhué, B

    1996-09-01

    Substance P and neurokinin A were assayed in the trigeminal nucleus and cervical spinal cord of 4-day cycling female, ovariectomized, and male rats. During the estrous cycle, levels were largely stable in the trigeminal nucleus. In ovariectomized rats, the levels differed from those on any day of the estrous cycle suggesting a weak effect of ovarian steroids. In males, the variations in the substance P and neurokinin A contents in the trigeminal nucleus were not similar to those in either cyclic or ovariectomized rats. The levels fluctuated substantially in the cervical spinal cord. During the first 3 days of the estrous cycle, the substance P and neurokinin A contents fell concomitant with the 17 beta-estradiol surge, suggesting a downregulation of substance P and neurokinin A contents by 17 beta-estradiol. Furthermore, on estrus, progesterone seemed to inhibit the accumulation of both neurokinins. Testosterone may stimulate accumulation of substance P and neurokinin A in the cervical spinal cord, with a marked circadian rhythm. These results are in favor of the neurokinin content of the spinal cord being regulated by the gonadal steroids. In the trigeminal nucleus, only testosterone has an effect.

  2. Immunolocalization of NGF and its receptors trkA and p75 in the oviducts of golden hamsters during the estrous cycle.

    PubMed

    Weng, Qiang; Shi, ZhanQuan; Watanabe, Gen; Taya, Kazuyoshi

    2009-10-01

    To investigate the physiological roles of nerve growth factor (NGF) in the oviduct of golden hamsters during the estrous cycle, the localization of NGF and its receptors, trkA and p75, were determined by immunohistochemistry. Positive staining of NGF, trkA, and p75 was present in epithelial cells and muscle cells of the infundibulum, ampulla, and isthmus in the oviduct. The intensities of the immunohistochemical signals for NGF, trkA, and p75 did not markedly change in any segment of the oviduct during the estrous cycle. These results suggest that NGF may play autocrine/paracrine roles in oviductal transport, fertilization, capacitation of spermatozoa and early embryonic development in the oviduct of golden hamsters.

  3. Differential expression of secretogranin II and chromogranin A genes in the female rat pituitary through sexual maturation and estrous cycle

    SciTech Connect

    Anouar, Y.; Duval, J. )

    1991-03-01

    Secretogranin II (SgII) is a protein of pituitary secretory granules released by LHRH-stimulated gonadotrope cells. Estrogens and androgens are modulators of SgII release. Experiments were performed to determine the regulation of expression of the SgII gene in the female rat pituitary, during sexual maturation and according to the estrous cycle. Age- and cycle-related changes in SgII mRNA content were estimated through cytoplasmic slot blot; SgII content was determined by western blotting; maturation of the protein was controlled through (35S)sulfate labeling. Variations in chromogranin A (CgA), another protein of secretory granules, were analyzed in the same experimental conditions to assess the specificity of SgII regulation. The pituitary SgII concentration increased between days 7 and 21 (2.2-fold) and then declined to the initial 7-day-old value. Simultaneously, the CgA concentration went through a maximum between days 14 and 21 and then strongly dropped to barely detectable levels in the adult pituitary. The SgII mRNA concentration followed roughly the same pattern as the protein. Moreover, the sulfation level remained constant between days 14 and 60. These results demonstrated a regulatory mechanism operating, during sexual maturation, on the SgII gene and not on the protein processing or on storage/release steps. In the 4-day cycling females, the pituitary SgII mRNA and protein contents were the lowest during estrus. They then increased to their highest values in diestrus II. Moreover, the sulfation level of SgII was significantly higher during estrus than during any other stage. Due to its low content level, variations in pituitary CgA could not be demonstrated during the cycle.

  4. Changes in Knee Laxity and Relaxin Receptor Isoforms Expression (RXFP1/RXFP2) in the Knee throughout Estrous Cycle Phases in Rodents.

    PubMed

    Dehghan, Firouzeh; Soori, Rahman; Dehghan, Parvin; Gholami, Khadijeh; Muniandy, Sekaran; Azarbayjani, Mohammad Ali; Yusof, Ashril

    2016-01-01

    The changes in knee laxity and relaxin receptor expression at different phases of rodent estrous cycle are not known. Here, changes in the parameter were investigated in rats at different phases of the estrous cycle. Estrous cycle phases of intact female rats were determined by cytological examination of the vaginal smear. Following phase identification, blood was collected for serum hormone analyses. Knee passive range of motion (ROM) was determined by using a digital miniature goniometer. The animals were then sacrificed and patellar tendon, collateral ligaments and hamstring muscles were harvested for relaxin/insulin-like family peptide receptor 1 and 2 (RXFP1/RXFP2) analyses. Knee passive ROM was the highest at proestrus followed by diestrus and the lowest at estrus. Estrogen level was the highest at proestrus while progesterone and relaxin levels were the highest at diestrus. A strong correlation was observed between relaxin and progesterone levels. At proestrus, expression of RXFP1 and RXFP2 proteins and mRNAs were the highest at proestrus followed by diestrus and estrus. The finding shows that higher level of progesterone and relaxin in diestrus might be responsible for higher laxity of knee joint in rats.

  5. Changes in Knee Laxity and Relaxin Receptor Isoforms Expression (RXFP1/RXFP2) in the Knee throughout Estrous Cycle Phases in Rodents

    PubMed Central

    Dehghan, Firouzeh; Soori, Rahman; Dehghan, Parvin; Gholami, Khadijeh; Muniandy, Sekaran; Azarbayjani, Mohammad Ali; Yusof, Ashril

    2016-01-01

    The changes in knee laxity and relaxin receptor expression at different phases of rodent estrous cycle are not known. Here, changes in the parameter were investigated in rats at different phases of the estrous cycle. Estrous cycle phases of intact female rats were determined by cytological examination of the vaginal smear. Following phase identification, blood was collected for serum hormone analyses. Knee passive range of motion (ROM) was determined by using a digital miniature goniometer. The animals were then sacrificed and patellar tendon, collateral ligaments and hamstring muscles were harvested for relaxin/insulin-like family peptide receptor 1 and 2 (RXFP1/RXFP2) analyses. Knee passive ROM was the highest at proestrus followed by diestrus and the lowest at estrus. Estrogen level was the highest at proestrus while progesterone and relaxin levels were the highest at diestrus. A strong correlation was observed between relaxin and progesterone levels. At proestrus, expression of RXFP1 and RXFP2 proteins and mRNAs were the highest at proestrus followed by diestrus and estrus. The finding shows that higher level of progesterone and relaxin in diestrus might be responsible for higher laxity of knee joint in rats. PMID:27513858

  6. Progesterone receptor membrane component 1 (PGRMC1) gene expression in corpus luteum during the estrous cycle in cows.

    PubMed

    Kowalik, Magdalena K; Kotwica, Jan

    2008-11-01

    The aim of the study was to investigate progesterone receptor membrane component 1 (PGRMC1) mRNA expression in bovine corpus luteum (CL) obtained from heifers or non-pregnant cows on the following days of the estrous cycle: 1-5, 6-10, 11-16 and 17-21 (n=4/each time period). The expression of PGRMC1 mRNA, analyzed by semiquantitative RT-PCR, was the highest on days 6-10 (p<0.01) and then it declined (p<0.05). The lowest expression was found on days 1-5 (p<0.05). A significant correlation (p<0.05) was also observed between luteal progesterone (P(4)) concentration and PGRMC1 mRNA expression. These data indicate that PGRMC1 mRNA is expressed in bovine CL and this expression varies throughout the luteal phase. It is assumed that PGRMC1 may be involved in a non-genomic effect of P(4) on luteal cells.

  7. Activation of the transcription factor, nuclear factor kappa-B, during the estrous cycle and early pregnancy in the pig

    PubMed Central

    2010-01-01

    Establishment and maintenance of pregnancy in the pig involves intricate communication between the developing conceptuses and the maternal endometrium. This process occurs during trophoblast elongation which is spaciotemporally associated with conceptus synthesis and release of IL1B concomitant with pregnancy-specific endometrial up-regulation of IL-1 receptors, providing the potential for activation of the transcription factor, NFKB. The objective of the current investigation was to determine changes in expression and cellular localization of NFKB and associated factors during the estrous cycle and early pregnancy in the pig. In situ hybridization was used to localize changes in PGR, ESR1, and TNFRSF11A during the peri-implantation period. Quantitative RT-PCR was utilized to demonstrate gene expression changes for NFKB1, RELA, TNFRSF11A, TLR4, NFKBIA and NFKBIB. Transcription factor ELISA demonstrated an overall increase in RELA during the peri-implantation period in both cyclic and pregnant gilts. While the presence of TNFSF11A and TLR4 were both detected, TLR4 expression changes were temporally associated with NFKB expression and activation. Collectively, these data demonstrate that NFKB activation may occur during the period of uterine receptivity in both the cyclic and pregnant endometrium. PMID:20426870

  8. Difference in expression between AQP1 and AQP5 in porcine endometrium and myometrium in response to steroid hormones, oxytocin, arachidonic acid, forskolin and cAMP during the mid-luteal phase of the estrous cycle and luteolysis.

    PubMed

    Skowronska, Agnieszka; Mlotkowska, Patrycja; Nielsen, Soren; Skowronski, Mariusz T

    2015-12-01

    Recently, we demonstrated in vitro that AQP1 and AQP5 in the porcine uterus are regulated by steroid hormones (P4, E2), arachidonic acid (AA), forskolin (FSK) and cAMP during the estrous cycle. However, the potential of the porcine separated uterine tissues, the endometrium and myometrium, to express these AQPs remains unknown. Thus, in this study, the responses of AQP1 and AQP5 to P4, E2 oxytocin (OT), AA, FSK and cAMP in the porcine endometrium and myometrium were examined during the mid-luteal phase of the estrous cycle and luteolysis. Real-time PCR and western blot analysis. Progesterone up-regulated the expression of AQP1/AQP5 mRNAs and proteins in the endometrium and myometrium, especially during luteolysis. Similarly, E2 also stimulated the expression of both AQPs, but only in the endometrium. AA led to the upregulation of AQP1/AQP5 in the endometrium during luteolysis. In turn, OT increased the expression of AQP1/AQP5 mRNAs and proteins in the myometrium during mid-luteal phase. Moreover, a stimulatory effect of forskolin and cAMP on the expression of AQP1/AQP5 mRNAs and proteins in the endometrium and myometrium dominated during luteolysis, but during the mid-luteal phase their influence on the expression of these AQPs was differentiated depending on the type of tissue and the incubation duration. These results seem to indicate that uterine tissues; endometrium and myometrium, exhibit their own AQP expression profiles in response to examined factors. Moreover, the responses of AQP1/AQP5 at mRNA and protein levels to the studied factors in the endometrium and myometrium are more pronounced during luteolysis. This suggests that the above effects of the studied factors are connected with morphological and physiological changes taking place in the pig uterus during the estrous cycle.

  9. Prolactin messenger ribonucleic acid levels, prolactin synthesis, and radioimmunoassayable prolactin during the estrous cycle in the Golden Syrian hamster

    SciTech Connect

    Massa, J.S. ); Blask, D.E. )

    1990-01-01

    The purpose of this study was to observe the molecular dynamics of pituitary prolactin (PRL) gene expression during the estrous cycle of the Golden Syrian hamster. PRL messenger ribonucleic acid (mRNA) levels, PRL synthesis were measured in the morning on each day of the cycle. We observed that all of these PRL indices declined or did not change from Day 2 to Day 3 of the cycle. From Day 3 to Day 4 however, PRL mRNA levels increased 33-38% and media {sup 3}H-PRL increased 32-42%, while there were no significant changes in pituitary {sup 3}H-PRL, or RIA-PRL in the media or pituitary. From Day 4 to Day 1 (estrus) there was reciprocal change in the levels of {sup 3}H-PRL in the pituitary vs. the media, with the former increasing 37-50% and the latter decreasing 25-32%. Pituitary RIA-PRL did also increased 45-64% from Day 4 to Day 1 while media RIA-PRL did not change. These data are consistent with the following hypothesis: On the morning of proestrus(Day 4) in the hamster, PRL mRNA levels are elevated compared to those on Day 3, signaling an increase in PRL synthesis. This newly synthesized PRL is shunted into a readily releasable pool on the morning of Day 4 (contributing to the afternoon surge of serum PRL), and into a preferentially stored pool by the morning of Day 1.

  10. Effect of plastoquinone derivative 10-(6'-plastoquinonyl) decyltriphenylphosphonium (SkQ1) on estrous cycle and 17β-estradiol level in rats.

    PubMed

    Chistyakov, V A; Dem'yanenko, S V; Alexandrova, A A; Gutnikova, L V; Prokof'ev, V N; Kosheleva, O N

    2012-12-01

    Administration of the plastoquinone derivative 10-(6'-plastoquinonyl)decyltriphenylphosphonium (SkQ1) to female Wistar rats with regular estrous cycle once a day for two weeks at doses of 25 nmol/kg (but not 250 nmol/kg) leads to increase in proestrus duration by reducing the phase of diestrus and metestrus. Neither dose caused significant changes in serum 17β-estradiol level for any stage of the cycle. However, relative elongation of the proestrus stage leads to an increase in average per cycle estradiol levels by 20%.

  11. Response to GnRH on day 6 of the estrous cycle is diminished as the percentage of Bos indicus breeding increases in Angus, Brangus, and Brahman x Angus heifers.

    PubMed

    Portillo, Germán E; Bridges, G Allen; de Araujo, Jennifer W; Shaw, Mary-Karen V; Schrick, F Neal; Thatcher, William W; Yelich, Joel V

    2008-01-15

    Angus (n=6), Brangus (5/8 Angus x 3/8 Brahman, n=6), and Brahman x Angus (3/8 Angus x 5/8 Brahman, n=6) heifers exhibiting estrous cycles at regular intervals were used to determine if the percentage of Bos indicus breeding influenced the secretory patterns of LH in response to a GnRH treatment on Day 6 of the estrous cycle. Heifers were pre-synchronized with a two-injection PGF(2 alpha) protocol (25 mg i.m. Day -14 and 12.5 mg i.m. Day -3 and -2 of experiment). Heifers received 100 microg GnRH i.m. on Day 6 of the subsequent estrous cycle. Blood samples were collected at -60, -30, and -1 min before GnRH and 15, 30, 60, 90, 120, 150, 180, 240, 300, 360, 420, and 480 min after GnRH to determine concentrations of serum LH. Estradiol concentrations were determined at -60, -30, and -1 min before GnRH. On Day 6 and 8, ovaries were examined by ultrasonography to determine if ovulation occurred. On Day 13, heifers received 25 mg PGF(2 alpha) i.m. and blood samples were collected daily until either the expression of estrus or Day 20 for heifers not exhibiting estrus to determine progesterone concentrations. There was no effect (P>0.10) of breed on ovulation rate to GnRH as well as size of the largest follicle, mean estradiol, and mean corpus luteum volume at GnRH. Mean LH was greater (P<0.05) for Angus (7.0+/-0.8 ng/mL) compared to Brangus (4.6+/-0.8 ng/mL) and Brahman x Angus (2.9+/-0.8 ng/mL), which were similar (P>0.10). Mean LH peak-height was similar (P>0.10) for Brangus (13.9+/-3.4 ng/mL) compared to Angus (21.9+/-3.4 ng/mL) and Brahman x Angus (8.0+/-3.4 ng/mL), but was greater (P<0.05) for Angus compared to Brahman x Angus. Interval from GnRH to LH peak was similar (P>0.10) between breeds. As the percentage of Bos indicus breeding increased the amount of LH released in response to GnRH on Day 6 of the estrous cycle decreased.

  12. Relationship between serum gonadotropins and pituitary immunoreactive gonadotropins and steroid receptors during the first FSH increase of the estrous cycle and following steroid treatment in heifers.

    PubMed

    Lane, Elizabeth A; Sweeney, Torres; Ryan, Marion; Roche, James F; Crowe, Mark A

    2009-05-01

    The objectives were to determine the effects of (i) time during the first FSH increase of the estrous cycle (time-course study) and (ii) exogenous steroid treatment (steroid feedback study) on the relationship between circulating serum gonadotropins, and the proportions of pituitary cells immunoreactive for gonadotropins and steroid receptors during the estrous cycle in heifers. Pituitaries were collected from heifers (n=40) slaughtered at 13h (n=8), 30h (n=24) and 66h (n=8) after estrous onset, corresponding to before, during and after the first FSH increase of the estrous cycle. Heifers slaughtered during the FSH increase (at 30h) either received no treatment (n=8), or were treated (n=16) with estradiol benzoate and/or progesterone before slaughter. During the time-course study, the proportion of pituitary cells immunoreactive for FSH increased (P<0.05) during the first transient FSH increase reflecting serum concentrations. The proportion of pituitary cells immunoreactive for LH was unaltered, a reflection of serum LH concentrations. The proportion of estrogen receptors (ER)-alpha, but not ER-beta, was decreased (P<0.05) at 30h compared with at either 13 or 66h. During the steroid feedback study, exogenous progesterone with or without estradiol suppressed (P<0.05) the proportions of pituitary cells immunoreactive for gonadotropins, serum FSH concentrations and LH pulse frequency. Steroid treatment did not alter the proportion of pituitary cells positive for estrogen receptors (alpha and beta). While progesterone receptors (PR) were not detected in the anterior pituitary by immunohistochemistry during the early estrous cycle or in response to steroid treatment, quantitative real-time PCR revealed that mRNA for progesterone receptors was expressed at very low levels. The expression of pituitary PR mRNA was decreased (P<0.05) at 30 and 66h compared with 13h, and was suppressed (P<0.05) following steroid treatments. Alterations in pituitary steroid receptors are

  13. Effects of combination birth control on estrous behavior in captive western lowland gorillas, Gorilla gorilla gorilla.

    PubMed

    Sarfaty, Anna; Margulis, Susan W; Atsalis, Sylvia

    2012-01-01

    Combination birth control pills (CBC) are one of the most common birth control methods used for western lowland gorillas (Gorilla gorilla gorilla) housed in zoos. Since zoos are interested in maintaining as many natural behaviors as possible, it is important to know how contraception may affect social and sexual interactions among group members. Although some data are available regarding the influence of the pill on sexual behavior in human females, no data are available on its effects on gorilla estrous behavior. We examined temporal trends of estrous, aggressive, affiliative, and activity budget data in four females on CBC at the Lincoln Park Zoo in Chicago, IL. Behavioral data were collected using point sampling, all-occurrence records, and one-zero sampling. Estrous behavior occurred in less than 1% of observations. Using all-occurrence and one-zero sampling, estrous behavior occurred more frequently in week one of the cycle than any other week. The focal females exhibited affiliative, aggressive, and activity budget data evenly across their cycles. There were also no temporal trends in proximity to the silverback. Females varied by the types of estrous behavior they exhibited. We give a hormonal explanation for the prevalence of estrous behaviors in week one, and recommendations for effective behavioral sampling of gorilla estrous behavior. © 2011 Wiley Periodicals, Inc.

  14. Uterine Contractility in the Nonpregnant Mouse: Changes During the Estrous Cycle and Effects of Chloride Channel Blockade.

    PubMed

    Dodds, Kelsi N; Staikopoulos, Vasiliki; Beckett, Elizabeth A H

    2015-06-01

    Mechanisms involved in the generation of spontaneous uterine contractions are not fully understood. Kit-expressing interstitial cells of Cajal are pacemakers of contractile rhythm in other visceral organs, and recent studies describe a role for Ca(2+)-activated Cl(-) currents as the initiating conductance in these cells. The existence and role of similar specialized pacemaker cells in the nonpregnant uterus remains undetermined. Spontaneous contractility patterns were characterized throughout the estrous cycle in isolated, nonpregnant mouse uteri using spatiotemporal mapping and tension recordings. During proestrus, estrus, and diestrus, contraction origin predominated in the oviduct end of the uterus, suggesting the existence of a dominant pacemaker site. Propagation speed of contractions during estrus and diestrus were significantly slower than in proestrus and metestrus. Five major patterns of activity were predominantly exhibited in particular stages: quiescent (diestrus), high-frequency phasic (proestrus), low-frequency phasic (estrus), multivariant (metestrus), and complex. Kit-immunopositive cells reminiscent of pacemaking ICCs were not consistently observed within the uterus. Niflumic acid (10 μM), anthracene-9-carboxylic acid (0.1-1 mM), and 5-nitro-2-(3-phenylpropylamino)benzoic acid (10 μM) each reduced the frequency of spontaneous contractions, suggesting involvement of Cl(-) channels in generating spontaneous uterine motor activity. It is unlikely that this conductance is generated by the Ca(2+)-activated Cl(-) channels, anoctamin-1 and CLCA4, as immunohistochemical labeling did not reveal protein expression within muscle or pacemaker cell networks. In summary, these results suggest that spontaneous uterine contractions may be generated by a Kit-negative pacemaker cell type or uterine myocytes, likely involving the activity of a yet-unidentified Cl(-) channel.

  15. QRFP in Female Rats: Effects on High Fat Food Intake and Hypothalamic Gene Expression across the Estrous Cycle

    PubMed Central

    Primeaux, Stefany D.

    2011-01-01

    Pyroglutamylated arginine-phenylalanineamide peptide (QRFP) is a neuropeptide involved in feeding behavior. Central administration of QRFP selectively increases the intake of a high fat diet in male rats. QRFP administration also stimulates the hypothalamic-pituitary-gonadal axis via gonadotrophin-releasing hormone in male and female rats. Prepro-QRFP mRNA is expressed in localized regions of the mediobasal hypothalamus which are abundant in neurotransmitters, neuropeptides and receptor systems important for food intake regulation and reproductive behaviors. The current experiments were conducted to investigate the effects of centrally administered QRFP-26 on the intake of a high fat diet (HFD, 60% kcal from fat) in female rats and to investigate alterations in hypothalamic prepro-QRFP and its receptors, GPR130a and GPR103b, mRNA levels over the estrous cycle. In Experiment 1, female rats were administered QRFP-26 (intracerebroventricular; 0.3nmol, 0.5nmol, 1.0nmol) in rats consuming either a HFD or a low fat diet. All doses of QRFP-26 selectively increased the intake of the HFD in female rats. These data suggest that QRFP-26 regulates the intake of energy dense foods in female rats, which is similar to previous findings in male rats. In Experiment 2, hypothalamic levels of prepro-QRFP mRNA and its receptors were assessed during diestrus, proestrus, or estrus. The level of prepro-QRFP mRNA in the ventromedial/arcuate nucleus (VMH/ARC) of the hypothalamus was increased during proestrus, which suggests that endogenous estrogen levels regulate QRFP expression in the VMH/ARC. These data suggest that QRFP may play a role in coordinating feeding behaviors with reproductive function when energy demand is increased. PMID:21473894

  16. Feedback actions of estradiol on GnRH secretion during the follicular phase of the estrous cycle.

    PubMed

    Karsch, F J; Evans, N P

    1996-01-01

    The pattern of GnRH secretion during the follicular phase of the estrous cycle of sheep is characterized by an initial marked change in episodic secretion (increased frequency and decreased amplitude) followed by a massive and sustained discharge-the preovulatory GnRH surge. Studies employing a physiological model for the follicular phase have revealed that estradiol has profound and complex feedback effects on GnRH release during the preovulatory period. These include both quantitative effects on pulses (stimulation of frequency, inhibition of amplitude) and qualitative effects (altering pulse shape, stimulating interpulse secretion), in addition to inducing a preovulatory GnRH surge. In stimulating the surge, estradiol causes a highly characteristic change in the minute-to-minute pattern of GnRH in hypophyseal portal blood. Initially, a strictly episodic pattern gives way to one in which GnRH is consistently elevated between pulses. Then, following enhancement of both pulsatile and interpulse components, GnRh becomes extremely high and variable for the majority of the surge. From this point, a regular and well organized pulse pattern is not apparent. The characteristic time course of GnRH at surge onset provides insight into possible mechanistic changes in the GnRH neurosecretory system. Such changes include quantitative and qualitative alterations in the pulse generating mechanism, recruitment of a surge specific population of GnRH neurones, morphologic alterations in GnRH neurones and neighboring cells, and changes in efficiency or route of delivery of GnRH from its site of release to the portal vasculature. These possibilities, while untested and speculative, provide a conceptual framework for future research.

  17. Ovarian dynamics and estrous cycle length in the donkey (Equus asinus).

    PubMed

    Díaz-Duran, Maricruz; Zarco, Luis; Boeta, Ana Myriam

    2017-11-01

    Nine jennies were monitored daily by ultrasonography during three complete ovarian cycles in order to evaluate if the timing of luteolysis and the growth pattern of the ovulatory follicle (OVF) before, during and after luteolysis are related to the length of the interovulatory interval (IOI). Blood samples for progesterone determination were obtained daily during one of the cycles of each jenny. The cycles were classified according to the length of the IOI into three groups: Short IOI (21.2 ± 0.3 d, n = 10), medium IOI (23.9 ± 0.4 d, n = 7), and long IOI (26.2 ± 0.3 d, n = 10). Neither the time of luteolysis onset nor the time of luteolysis completion were significantly different between groups. The length of the IOI was mainly determined by the duration of the follicular phase, as the intervals from luteolysis onset to ovulation and from luteolysis completion to ovulation were directly correlated with the length of the IOI (p < 0.001 and p < 0.01 respectively). Multiple regression analysis revealed that the length of the IOI was negatively correlated with the size of the OVF at day 13 (p < 0.01), with its growth rate from day 13 to day 15 (p < 0.05) and with its growth rate from day 15 to day 18 (p < 0.01), and positively correlated with the final diameter of the OVF (p < 0.01). The correlation between the observed IOIs and those predicted by the multiple regression equation was highly significant (r = 0.91, p < 0.001), but the predictive ability of a simplified equation using only the diameter of the OVF at day 18 was almost as good (r = 0.89, p < 0.001). Estrus signs lasted longer and were more intense as the length of the IOI increased, and this was associated with a longer period of low progesterone concentrations during the follicular phase of jennies with longer cycles. It is concluded that the length of the luteal phase in jennies is relatively constant, and that most of the variation in the length of the IOI is

  18. Latent Inhibition Is Affected by Phase of Estrous Cycle in Female Rats

    ERIC Educational Resources Information Center

    Quinlan, Matthew G.; Duncan, Andrew; Loiselle, Catherine; Graffe, Nicole; Brake, Wayne G.

    2010-01-01

    Estrogen has been shown to have a strong modulatory influence on several types of cognition in both women and female rodents. Latent inhibition is a task in which pre-exposure to a neutral stimulus, such as a tone, later impedes the association of that stimulus with a particular consequence, such as a shock. Previous work from our lab demonstrates…

  19. Latent Inhibition Is Affected by Phase of Estrous Cycle in Female Rats

    ERIC Educational Resources Information Center

    Quinlan, Matthew G.; Duncan, Andrew; Loiselle, Catherine; Graffe, Nicole; Brake, Wayne G.

    2010-01-01

    Estrogen has been shown to have a strong modulatory influence on several types of cognition in both women and female rodents. Latent inhibition is a task in which pre-exposure to a neutral stimulus, such as a tone, later impedes the association of that stimulus with a particular consequence, such as a shock. Previous work from our lab demonstrates…

  20. Changes in the epithelium of the vaginal complex during the estrous cycle of the marsupial Monodelphis domestica. 2. Scanning electron microscopy study.

    PubMed

    Kress, Annetrudi; Regli, Christian; Spornitz, Udo M; Morson, Gianni

    2004-01-01

    The four stages of the estrous cycle in Monodelphis domestica, namely proestrus, estrus, postestrus and the transitional metestrus, were analyzed with the scanning electron microscope and compared with the results of the previously published transmission electron-microscopic paper [Cells Tissues Organs 2002;172:276-296]. During the estrous cycle the vaginal epithelium undergoes dramatic changes from a nonkeratinized to a highly keratinized epithelium. The predominant feature of proestrus with the beginning of keratinization is the presence of polygonal flat cells with pavement-like appearance, bordered by raised ridges and covered with microvilli. The epithelium is fully keratinized in estrus, and the superficial layers overlap like shingles. Many cells are still densely covered by microvilli, whereas others develop a complex pattern of microridges. In postestrus different epithelial structures are revealed depending on the actual stage of desquamation. In early postestrus surface cells resemble those present during estrus. In late postestrus, when only few keratinized cells are left, the nonkeratinized cells become exposed to the lumen through desquamation. These cells border the lumen during metestrus, a cycle stage during which numerous leukocytes migrate into the vaginal canal. A number of these uppermost cells is probably not yet prepared to function as metestrus cells and are therefore sloughed off as well. During metestrus compact cell masses stick in the vaginal furrows. Epithelial surface cells are highly irregular and bulging with their microvilli covered surfaces in the vaginal lumen. This study represents the first comprehensive description of alterations on the surface ultrastructure of a marsupial vagina during the estrous cycle, demonstrating considerable differences in comparison to many eutherians.

  1. Intermedin in rat uterus: changes in gene expression and peptide levels across the estrous cycle and its effects on uterine contraction

    PubMed Central

    2013-01-01

    Background The present study demonstrates the expression of intermedin (IMD) and its receptor components in the uterus of the female rat during the estrous cycle and its effect on uterine contraction. Methods The gene expression level of intermedin and its receptor components and the peptide level of intermedin were studied by real-time RT-PCR and enzyme immunoassay (EIA) respectively. The separation of precursor and mature IMD was studied by gel filtration chromatography and EIA. The localization of IMD in the uterus was investigated by immunohistochemistry. The effect of IMD on in vitro uterine contraction was studied by organ bath technique. Results Uterine mRNAs of Imd and its receptor components and IMD levels displayed cyclic changes across the estrous cycle. Imd mRNA level was the highest at proestrus while the IMD level was the highest at diestrus. IMD was found in the luminal and glandular epithelia and IMD treatment significantly reduced the amplitude and frequency of uterine contraction but not the basal tone. Both calcitonin gene-related peptide (CGRP) receptor antagonist hCGRP8-37 and adrenomedullin (ADM) receptor antagonist hADM22-52 partially abolished the inhibitory effect of IMD on uterine contraction while the specific IMD receptor antagonist hIMD17-47 completely blocked the actions. The enzyme inhibitors of NO (L-NAME) and PI3K (Wortmannin) pathways diminished the IMD effects on uterine contraction while the cAMP/PKA blocker, KT5720, had no effect, indicating an involvement of NO and PI3K/Akt but not PKA. Conclusions IMD and the gene expression of its receptor components are differentially regulated in the uterus during the estrous cycle and IMD inhibits uterine contraction by decreasing the amplitude and frequency. PMID:23442365

  2. Interleukin 1β-induced synthesis and secretion of prostaglandin E₂ in the porcine uterus during various periods of pregnancy and the estrous cycle.

    PubMed

    Franczak, A; Zmijewska, A; Kurowicka, B; Wojciechowicz, B; Kotwica, G

    2010-12-01

    Peri-implantation porcine embryos express interleukin-1β (IL-1β), which could affect uterine activity during early pregnancy. In vitro studies were conducted to determine if IL-1β stimulates secretion of PGE₂ and expression of cyclooxygenase-2 (COX-2) mRNA and microsomal PGE synthase-1 (mPGES-1) mRNA in uterine tissues harvested from pigs on days 10 to 11, 12 to 13 and 15 to 16 of pregnancy and the estrous cycle. IL-1β (10 ng/ml) increased PGE₂ secretion and mPGES-1 mRNA expression in uterine tissues isolated from pigs between days 10 to 13 of pregnancy and the estrous cycle. IL-1β stimulated PGE₂ and mPGES-1 mRNA expression only in cyclic uterine tissues on days 15 to 16. Interleukin-1β increased COX-2 mRNA expression in the endometrial tissues of pregnant and cyclic pigs harvested on days 10 to 13. It stimulated COX-2 expression in pregnant pigs' myometrial tissues on days 10 to 11, and on days 15 to 16 in tissues from both pregnant and cyclic pigs. The uterine secretion of PGE₂ in response to IL-1β was determined by local intrauterine concentrations of P₄ and E₂. This study demonstrates that IL-1β activates expression of mPGES-1 mRNA in uterine tissues to stimulate synthesis and secretion of PGE₂ on days 10 to 13 of both pregnancy and the estrous cycle. The profile of COX-2 mRNA expression in the myometrium differs from its profile in the endometrium. This work provides new insight on the role of IL-1β in PGE₂ production to overcome luteolysis in pregnant pigs.

  3. Presence of a temperature gradient among genital tract portions and the thermal changes within these portions over the estrous cycle in beef cows.

    PubMed

    El-Sheikh Ali, Hossam; Kitahara, Go; Tamura, Youji; Kobayashi, Ikuo; Hemmi, Koichiro; Torisu, Shidow; Sameshima, Hiroshi; Horii, Yoichiro; Zaabel, Samy; Kamimura, Shunichi

    2013-01-01

    The aim of the present study was to describe the temperature of the different portions of the female genital tract and their relation to rectal temperature and to investigate the effect of steroid hormones profiles on these variables over the estrous cycle in cattle. Four nonpregnant Japanese Black cows were investigated daily over two successive estrous cycles using a digital thermometer with a long probe and rounded-end sensor to record the temperature of the rectum (RT), vagina (VT), cervix (CT), uterine body (UBT) and uterine horns (UHT). Blood samples were collected immediately before temperature recording to assay peripheral levels of progesterone (P(4)) and estradiol-17β (E(2)). Moreover, transrectal ultrasonography was carried out after temperature recording to monitor the ovulatory follicle and track ovulation. During the experiment, the ambient temperature and relative humidity were recorded for further calculation of the temperature humidity index (THI). The temperature within the genital tracts in these cows progressively increased towards the uterine horns from the vagina. The VT, CT, UBT and UHTs were significantly higher in association with peripheral P(4) concentrations greater than 4 ng/ml (mid-luteal phase) when compared with lower peripheral P(4) concentrations. The VT was more significantly (P<0.01) correlated to the CT, UBT and UHTs than RT. In conclusion, a temperature gradient was present among the vagina, cervix and uterus over the estrous cycle, and changes in peripheral P(4) concentrations were associated with the thermal variations within these portions. The VT could be more beneficial than RT in monitoring temperature of deeper portions of the female genital tract in bovine.

  4. Impact of phase of the estrous cycle and season on LH surge profile and fertility in dairy cows treated with different GnRH analogs (gonadorelin vs. buserelin).

    PubMed

    Armengol-Gelonch, R; Mallo, J M; Ponté, D; Jimenez, A; Valenza, A; Souza, A H

    2017-03-15

    protocol, with no detectable interactions between GnRH type and season. In conclusion, phase of the estrous cycle had a great impact on the GnRH-induced LH surge profile and cows during warm season had reduced AUC. Additionally, type of GnRH did not influence LH surge profile and P/AI in synchronized cows. Regardless of GnRH type, strategies to avoid heat stress and excessively high levels of circulating P4 near the time of GnRH treatment might help improve LH release profile in dairy cows, and ultimately increase P/AI. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Starting Ovsynch protocol on day 6 of first postpartum estrous cycle increased fertility in dairy cows by affecting ovarian response during heat stress.

    PubMed

    Dirandeh, E

    2014-10-01

    The objective was to compare fertility in cows using an Ovsynch protocol starting on day 6 of first postpartum estrous cycle with an Ovsynch protocol initiated at random stages of the estrous cycle during heat stress (temperature-humidity index (THI)=77-83). Cows (n=459) at the beginning of the lactation period were randomly assigned to time-of-ovulation synchronization treatments: (1) control, Ovsynch (first GnRH treatment, PGF2α treatment 7 days later, second GnRH treatment 56 h later, and TAI 16 h later), initiated at random stages of the estrous cycle (40 ± 2 days postpartum, n=224) and (2) Ovsynch initiated on day 6 of first postpartum estrous cycle (estrus=day 0) based on detection of the first estrus after day 30 postpartum (O6, 35 ± 2 postpartum, n=235). Statistical analyses were conducted using SAS. The percentage of cows responding to the initial GnRH injection using the Ovsynch protocol was greater with the O6 treatment compared to the control treatment (60.4% compared with 52.6%). The percentage of cows having a corpus luteum (CL) on the day of the PGF2α injection was not different among treatments (control=87.0% and O6=90.2%, respectively). Also more cows in the O6 treatment group responded to the second GnRH injection of the Ovsynch protocol compared with control treatments (82.5% compared with 75.8%). Treatment affected the percentage of cows diagnosed pregnant at 32 ± 0.7 days and 60 ± 3 days after the resynchronized timing of AI but pregnancy losses (5.3% compared with 6.8%) did not differ between treatment groups. It is concluded that initiating the Ovsynch protocol 6 days after estrus during the first 40 days postpartum resulted in a greater pregnancy rate at the synchronized estrus and increased fertility compared with control cows during heat stress. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. The expression of ERα, OTR, cPLA(2), COX-2, and PPARγ in the cervix of the ewe during the estrous cycle.

    PubMed

    Falchi, L; Scaramuzzi, R J

    2013-01-01

    The ovine cervix relaxes at estrus allowing easier entry of spermatozoa into the uterus. The mechanism responsible for this relaxation is not fully elucidated and we hypothesized that cervical relaxation at estrus is induced by ovarian and pituitary hormones stimulating the local production of prostaglandin E(2) via a biosynthetic pathway involving a number of mediators including oxytocin, phospholipase A(2) (cPLA(2)), cyclooxygenase-2 (COX-2), and peroxisome proliferator-activated receptor gamma (PPARγ). The aim of this study was to investigate the cervical expression of estradiol receptor alpha (ERα), oxytocin receptor (OTR), cPLA(2), COX-2, and PPARγ at three stages of the estrous cycle (the luteal phase and two times during the follicular phase, just before and just after the LH surge). An experiment was conducted during the breeding season, in 25 ewes to test this hypothesis. Samples of cervical tissue were collected from groups of ewes at three stages of the estrous cycle: the luteal (N = 8), "pre-LH surge" (N = 8), and "post-LH surge" (N = 9) stages. Cervical tissue from uterine, mid, and vaginal regions of the cervix were analyzed by Western immunoblot analysis for ERα, OTR, cPLA(2,) COX-2, and PPARγ. The results showed that the levels of all five proteins were lowest during the luteal phase of the estrous cycle in all regions of the cervix. The levels of all except cPLA(2), increased significantly during the "pre-LH surge" stage. The levels of cPLA(2) and ERα increased in the "post-LH surge" stage and those for OTR and PPARγ were unchanged and those for COX-2 were lower. These data show that the cervical levels of all five of the intermediates in the synthesis of prostaglandin E(2) that were examined in this study were higher in the "pre-" and "post-LH surge" stages compared with the luteal phase of the estrous cycle and these findings are consistent with our hypothesis.

  7. Spatiotemporal expression of the serine protease inhibitor, SERPINE2, in the mouse placenta and uterus during the estrous cycle, pregnancy, and lactation

    PubMed Central

    2010-01-01

    Background SERPINE2, also known as glia-derived nexin or protease nexin-1, belongs to the serine protease inhibitor (SERPIN) superfamily. It is one of the potent serpins that modulates the activity of the plasminogen activator (PA) and was implicated in tissue remodeling. In this study, we investigated the expression patterns of SERPINE2 in the mouse placenta and uterus during the estrous cycle, pregnancy, and lactation. Methods SERPINE2 was purified from mouse seminal vesicle secretion using liquid chromatography (LC) and identified by LC/tandem mass spectrometry. The antiserum against the SERPINE2 protein was raised in rabbits. To reveal the uterine and placental expression of SERPINE2, tissues at various stages were collected for real-time PCR quantification, Western blotting, and immunohistochemical staining. Results Serpine2 mRNA was the major PA inhibitor in the placenta and uterus during the estrous cycle, pregnancy, and lactation, although Serpine1 mRNA had higher expression levels than Serpine2 mRNA in the placenta. Plat seemed to be the major PA in the mouse uterus and placenta. Antiserum against the SERPINE2 protein specifically recognized two forms of SERPINE2 and an extra 75-kDa protein, which was probably a complex of SERPINE2 with a certain protease, from among thousands of protein components in the tissue extract as demonstrated by Western blotting. In the uterus, SERPINE2 was primarily localized in luminal and glandular epithelial cells but it also was detected in circular and longitudinal smooth muscle cells during the estrous cycle and lactation. It was prominently expressed in decidual stroma cells, the metrial gland, and endometrial epithelium of the pregnant uterus. In the placenta, SERPINE2 was expressed in trophoblasts of the labyrinth and spongiotrophoblasts. However, its expression was remarkably reduced in giant cells which existed in the giant cell-decidual junction zone. In contrast, prominent expression of SERPINE2 seemed to be

  8. Ovarian follicle diameter at timed insemination and estrous response influence likelihood of ovulation and pregnancy after estrous synchronization with progesterone or progestin-based protocols in suckled Bos indicus cows.

    PubMed

    Sá Filho, M F; Crespilho, A M; Santos, J E P; Perry, G A; Baruselli, P S

    2010-07-01

    after FTAI. Pregnancy was influenced (P=0.001) by follicle diameter [LF1=27.5% (81/295), LF2=46.6% (328/705), LF3=57.9% (647/1118), LF4=63.3% (171/270)] and the occurrence of estrus [estrus=67.7% (174/257) and no estrus=36.2% (68/188)]. Follicle diameter at FTAI influenced ovulation rate [LF1=42.5% (34/80), LF2=73.9% (161/218), LF3=95.8% (407/425), LF4=97.8% (88/90)], the occurrence of estrus [LF1=54.8% (51/93), LF2=33.6% (43/128), LF3=68.9% (126/183), LF4=90.2% (37/41)] and P/AI among cows that had ovulations [LF1=32.4% (11/34), LF2=50.3% (81/161), LF3=60.0% (244/407), LF4=68.2% (60/88)]. Improving estrous responses between progesterone device withdrawal and FTAI and increasing the diameter of the LF at FTAI may be important aspects to achieve improved estrous synchronization responses and P/AI following progesterone/progestin and estradiol based FTAI protocols in suckled Bos indicus cows.

  9. The Activity and Localization of 3β-hydroxysteroid Dehydrogenase/Δ5-Δ4 Isomerase and Release of Androstenedione and Progesterone by Uterine Tissues During Early Pregnancy and the Estrous Cycle in Pigs

    PubMed Central

    WOJCIECHOWICZ, Bartosz; KOTWICA, Genowefa; KOLAKOWSKA, Justyna; FRANCZAK, Anita

    2012-01-01

    Abstract Steroid hormones are produced by the porcine uterus. We hypothesized that the uterus in pigs possesses active 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (3β-HSD) responsible for progesterone and androstenedione production, that uterine steroids may supplement the amount of steroid hormones produced by embryos and corpus luteum and that these steroids are necessary for maintenance of pregnancy. In this study, we examined 1) endometrial and myometrial expression of 3β-HSD mRNA, 2) uterine 3β-HSD protein activity and 3) in vitro production of A4 and P4 by uterine slices harvested from pigs on days 10 to 11, 12 to 13 and 15 to 16 of pregnancy and the estrous cycle. The expression of 3β-HSD and the presence and activity of 3β-HSD protein were different in the endometrium and the myometrium during the examined periods of pregnancy and the estrous cycle. Production of A4 by the endometrium and myometrium was highest on days 12 to 13 of pregnancy and the estrous cycle. Endometrial secretion of P4 did not differ in the course of early pregnancy and on the respective days of the estrous cycle. The gravid myometrium was the highest source of P4 in pregnant pigs on days 12 to 13. The release of P4 by the cyclic myometrium rose during the examined days of the estrous cycle. The steroidogenic activity of the uterus, as described in this study, may support early pregnancy or the luteal phase of the estrous cycle in pigs. PMID:23095516

  10. The activity and localization of 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4) isomerase and release of androstenedione and progesterone by uterine tissues during early pregnancy and the estrous cycle in pigs.

    PubMed

    Wojciechowicz, Bartosz; Kotwica, Genowefa; Kolakowska, Justyna; Franczak, Anita

    2013-01-01

    Steroid hormones are produced by the porcine uterus. We hypothesized that the uterus in pigs possesses active 3β-hydroxysteroid dehydrogenase/Δ(5)-Δ(4) isomerase (3β-HSD) responsible for progesterone and androstenedione production, that uterine steroids may supplement the amount of steroid hormones produced by embryos and corpus luteum and that these steroids are necessary for maintenance of pregnancy. In this study, we examined 1) endometrial and myometrial expression of 3β-HSD mRNA, 2) uterine 3β-HSD protein activity and 3) in vitro production of A(4) and P(4) by uterine slices harvested from pigs on days 10 to 11, 12 to 13 and 15 to 16 of pregnancy and the estrous cycle. The expression of 3β-HSD and the presence and activity of 3β-HSD protein were different in the endometrium and the myometrium during the examined periods of pregnancy and the estrous cycle. Production of A(4) by the endometrium and myometrium was highest on days 12 to 13 of pregnancy and the estrous cycle. Endometrial secretion of P(4) did not differ in the course of early pregnancy and on the respective days of the estrous cycle. The gravid myometrium was the highest source of P(4) in pregnant pigs on days 12 to 13. The release of P(4) by the cyclic myometrium rose during the examined days of the estrous cycle. The steroidogenic activity of the uterus, as described in this study, may support early pregnancy or the luteal phase of the estrous cycle in pigs.

  11. Expression of progesterone receptor membrane component 1, serpine mRNA binding protein 1 and nuclear progesterone receptor isoforms A and B in the bovine myometrium during the estrous cycle and early pregnancy.

    PubMed

    Slonina, Dominika; Kowalik, Magdalena K; Kotwica, Jan

    2012-01-01

    The aim of this study was to investigate the (1) expression of progesterone membrane component 1 (PGRMC1), serpine mRNA binding protein 1 (SERBP1) and progesterone receptor (PR) mRNA and (2) protein expression levels of PGRMC1, SERBP1 and PR isoforms A and B in the bovine myometrium during the estrous cycle and early pregnancy. Uteri from cows on days 1-5, 6-10, 11-16 and 17-21 of the estrous cycle and weeks 3-5, 6-8 and 9-12 of pregnancy were used (n=5-6 per period). There were no changes (P>0.05) in PGRMC1 mRNA expression during the estrous cycle, while expression of SERBP1 and PR mRNA was the lowest (P<0.05) on days 11-16 relative to other days of the cycle. The highest mRNA expression of PGRMC1, SERBP1 and PR was found during pregnancy. There were no changes (P>0.05) in SERBP1 protein expression in cycling and pregnant cows, while the highest (P<0.05) PGRMC1 protein expression was found during weeks 3-5 of pregnancy. Similar protein expression profiles for PRA and PRB were found, and protein levels were highest on days 1-5 of the estrous cycle. From day 6 of the cycle, PRA and PRB protein expression decreased and were maintained at this lower level during pregnancy. In conclusion, our study assessed mRNA and protein expression levels of PGRMC1, SERBP1 and PR in the bovine myometrium during the estrous cycle and the first trimester of pregnancy. It is possible that progesterone (P4) affects myometrial function in a genomic and nongenomic manner.

  12. Estrous cycle staging before mating led to increased efficiency in the production of pseudopregnant recipients without negatively affecting embryo transfer in mice.

    PubMed

    Heykants, Malte; Mahabir, Esther

    2016-03-15

    The goal was to increase pseudopregnant mice production by estrous cycle staging by visual examination before pairing and to determine the effect of such pseudopregnant recipients on embryo transfer. To compare methods of estrous cycle staging over 14 days, groups consisted of 10 females in proestrus-estrus and 10 vasectomized males; group 1: only daily visual observation; group 2: daily visual observation and cytological examination on day 1; group 3: daily visual observation and daily cytological examination. The average time to first vaginal plug was 1.8 days in group 1, 2.7 days in group 2, and 3.2 days in group 3, whereas the average time between consecutive vaginal plugs was 9.2 days (group 1), 10 days (group 2), and 9.25 days (group 3). The average time between consecutive estrous cycles was 9.7 days (group 1), 11.8 days (group 2), and 9.4 days (group 3). The congruence between visual and cytological examination in determining proestrus-estrus in group 2 was 100% and that for the four stages in group 3 was 79% with a range of 44% to 100%. From 162 plug-positive females originally selected in proestrus-estrus, 49%, 30%, 19%, and 2% were plug-positive on Day 1, Day 2, Day 3, and Day 4, respectively, showing that pseudopregnant mice production was significantly increased on the first 2 days. From 192 plug-positive females originally selected randomly, these values were 31%, 21%, 35%, 10%, and 3% on d1, d2, d3, d4, and d5, respectively. No significant differences were observed between groups with respect to embryo transfers with fresh or cryopreserved embryos although the number of pups born per litter was higher in group A with fresh (7.57 vs. 6.39) and cryopreserved-thawed embryos (5.0 vs. 4.38). Furthermore, the sex ratio and the genotype of the pups were not significantly affected.

  13. The effect of strategic supplementation with trans-10,cis-12 conjugated linoleic acid on the milk production, estrous cycle characteristics, and reproductive performance of lactating dairy cattle.

    PubMed

    Hutchinson, I A; Hennessy, A A; Dewhurst, R J; Evans, A C O; Lonergan, P; Butler, S T

    2012-05-01

    The objective was to determine the effects of a protected (lipid-encapsulated) conjugated linoleic acid (LE-CLA) supplement on milk production, estrous cycle characteristics, and reproductive performance in lactating dairy cows on a pasture-based diet. Spring calving dairy cows (n=409) on a single pasture-based commercial dairy farm were used in a completely randomized block design. Cows were assigned to 1 of 2 dietary supplements [LE-CLA (n=203) or no supplement (control, n=206)]. The LE-CLA cows received 51 g/d of a lipid supplement containing 5 g of both trans-10,cis-12 and cis-9,trans-11 CLA from 0 to 60 d in milk. Milk samples were collected 3 times weekly, and each sample was analyzed for progesterone to determine the interval to first ovulation and estrous cycle characteristics. Milk yield and concentrations of fat, protein, and lactose were measured every 2 wk. Cows were inseminated following visual observation of estrus. The breeding season commenced on April 8, 2009 and continued for 16 wk. Transrectal ultrasonography was carried out at 30 to 36 d and 60 to 66 d post-AI to diagnose pregnancy. The LE-CLA treatment resulted in a decrease in milk fat concentration (36.9±0.06 g/kg vs. 30.7±0.06 g/kg for control and LE-CLA, respectively) and yield (0.91±0.02 kg/d vs. 0.84±0.02 kg/d for control and LE-CLA, respectively); however, milk yield was increased by LE-CLA supplementation (24.7±0.7 kg/d vs. 27.2±0.7 kg/d for control and LE-CLA, respectively), resulting in no overall difference in milk energy output. No effect of LE-CLA was observed on any estrous cycle characteristics or measures of reproductive performance. These results support that in pasture-based systems of dairy production, where energy intake limits milk production, energy spared by CLA-induced milk fat depression is partitioned toward increasing milk yield rather than toward body reserves. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

  14. Expression and localization of progesterone receptor membrane component 1 and 2 and serpine mRNA binding protein 1 in the bovine corpus luteum during the estrous cycle and the first trimester of pregnancy.

    PubMed

    Kowalik, Magdalena K; Rekawiecki, Robert; Kotwica, Jan

    2014-11-01

    The aim of this study was to evaluate the mRNA and protein expression and the localization of progesterone receptor membrane component 1 (PGRMC1), PGRMC2, and the PGRMC1 partner serpine mRNA binding protein 1 (SERBP1) in the bovine CL on Days 2 to 5, 6 to 10, 11 to 16, and 17 to 20 of the estrous cycle as well as during Weeks 3 to 5, 6 to 8, and 9 to 12 of pregnancy (n = 5-6 per each period). The highest levels of PGRMC1 and PGRMC2 mRNA expression were found on Days 6 to 16 (P < 0.05) and 11 to 16, respectively, of the estrous cycle and during pregnancy (P < 0.001). The level of PGRMC1 protein was the highest (P < 0.05) on Days 11 to 16 of the estrous cycle compared with the other stages of the estrous cycle and pregnancy, whereas PGRMC2 protein expression (P < 0.001) was the highest on Days 17 to 20 and also during pregnancy. The mRNA expression of SERBP1 was increased (P < 0.05) on Days 11 to 16, whereas the level of its protein product was decreased (P < 0.05) on Days 6 to 10 of the estrous cycle and was at its lowest (P < 0.001) on Days 17 to 20. In pregnant cows, the patterns of SERBP1 mRNA and protein expression remained constant and were comparable with those observed during the estrous cycle. Progesterone receptor membrane component 1 and PGRMC2 localized to both large and small luteal cells, whereas SERBP1 was observed mainly in small luteal cells and much less frequently in large luteal cells. All proteins were also localized in the endothelial cells of blood vessels. The data obtained indicate the variable expression of PGRMC1, PGRMC2, and SERBP1 mRNA and protein in the bovine CL and suggest that progesterone may regulate CL function via its membrane receptors during both the estrous cycle and pregnancy. Copyright © 2014 Elsevier Inc. All rights reserved.

  15. Collagen and glycosaminoglycan profiles in the canine cervix during different stages of the estrous cycle and in open- and closed-cervix pyometra.

    PubMed

    Linharattanaruksa, Pichanun; Srisuwatanasagul, Sayamon; Ponglowhapan, Suppawiwat; Khalid, Muhammad; Chatdarong, Kaywalee

    2014-03-01

    The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyometra. Cervices were collected after ovariohysterectomy. The proportion of collagen to smooth muscle was determined using Masson's trichrome staining. Alcian blue staining was used to evaluate the relative distribution of cervical GAGs. The proportion of cervical collagen relative to smooth muscle was higher at estrus compared to anestrus (P≤0.05). It was also higher (P≤0.05) in bitches with open- compared to those with closed-cervix pyometra. Overall, hyaluronan (HA) was the predominant GAG in the canine cervix. In the luminal epithelium, the staining intensity for HA was stronger in estrus than in anestrus (P≤0.05), but not in diestrus (P>0.05). On the contrary, the intensity for the combined keratan sulfate (KS) and heparan sulfate (HS) was stronger in anestrus than in estrus and diestrus (P≤0.05). In bitches with pyometra, the staining intensity of the stroma for KS and HS was weaker in open- compared to closed-cervix pyometra (P≤0.05). Collectively, the different profiles of collagen and GAG suggest that the metabolism of both collagen and GAGs in the canine cervix is associated with hormonal statuses during the estrous cycle and cervical patency of bitches with pathological uterine conditions, such as pyometra.

  16. Collagen and Glycosaminoglycan Profiles in the Canine Cervix during Different Stages of the Estrous Cycle and in Open- and Closed-Cervix Pyometra

    PubMed Central

    LINHARATTANARUKSA, Pichanun; SRISUWATANASAGUL, Sayamon; PONGLOWHAPAN, Suppawiwat; KHALID, Muhammad; CHATDARONG, Kaywalee

    2013-01-01

    ABSTRACT The extracellular matrix of the cervix that comprises collagen, elastin, proteoglycans and glycosaminoglycans (GAGs) is thought to have an essential role in cervical relaxation. This study investigated the proportion of collagen and smooth muscle as well as the GAGs in cervices obtained from healthy bitches at different stages of the estrous cycle and bitches with open- and closed-cervix pyometra. Cervices were collected after ovariohysterectomy. The proportion of collagen to smooth muscle was determined using Masson’s trichrome staining. Alcian blue staining was used to evaluate the relative distribution of cervical GAGs. The proportion of cervical collagen relative to smooth muscle was higher at estrus compared to anestrus (P≤0.05). It was also higher (P≤0.05) in bitches with open- compared to those with closed-cervix pyometra. Overall, hyaluronan (HA) was the predominant GAG in the canine cervix. In the luminal epithelium, the staining intensity for HA was stronger in estrus than in anestrus (P≤0.05), but not in diestrus (P>0.05). On the contrary, the intensity for the combined keratan sulfate (KS) and heparan sulfate (HS) was stronger in anestrus than in estrus and diestrus (P≤0.05). In bitches with pyometra, the staining intensity of the stroma for KS and HS was weaker in open- compared to closed-cervix pyometra (P≤0.05). Collectively, the different profiles of collagen and GAG suggest that the metabolism of both collagen and GAGs in the canine cervix is associated with hormonal statuses during the estrous cycle and cervical patency of bitches with pathological uterine conditions, such as pyometra. PMID:24152876

  17. Characterization of [11C]vorozole binding in ovarian tissue in rats throughout estrous cycle in association with conversion of androgens to estrogens in vivo and in vitro.

    PubMed

    Kirilovas, Dmitrijus; Naessen, Tord; Bergström, Mats; Bergström-Petterman, Elizabeth; Carlström, Kjell; Långström, Bengt

    2003-12-01

    Estrogen levels vary in a cyclic fashion during the rat estrous cycle, reaching peak concentrations during proestrus. Previously, it was suggested that the preovulatory peak in estrogen production in rats in vivo is regulated by other control mechanisms than concentration of precursor and amount of aromatase enzyme, changing the specific activity of the enzyme. To explore this hypothesis, ovarian binding of [11C]vorozole in vivo and in vitro, representing the amount of active aromatase, and conversion activity of ovarian homogenate were assayed together with serum androstenedione (A4) and estradiol-17beta (E2) levels during the estrous cycle in rats. The reducing ovarian [11C]vorozole binding in vivo from proestrus +4 up to +8h might indicate that the ovarian aromatase is blocked, probably to prevent premature increase of E2 levels. Thereafter (between proestrus +9 and +13h), the binding dramatically increases (aromatase enzyme is unblocked), to enable increased E2 synthesis. In addition, during the latter period, serum E2 levels were strongly correlated with serum A4 levels after adjustment for amount of ovarian aromatase (P=0.03), but not with amount of aromatase adjusted for levels of A4 (P=0.13), which might indicate changes in specific activity of the aromatase enzyme. Significant correlation between Kd and serum E2 levels during the same period indicated that aromatase-precursor affinity might be involved in the regulation of the enzyme-specific activity. This conclusion is done assuming that [11C]vorozole binding mimics that of the substrate (A4). The [11C]vorozole in vivo technique keeps auto- and paracrine mechanisms intact, and might therefore yield additional information about biological processes compared with traditional in vitro techniques.

  18. LacZ Expression in Fut2-LacZ Reporter Mice Reveals Estrogen Regulated Endocervical Glandular Expression During Estrous Cycle, Hormone Replacement, and Pregnancy

    PubMed Central

    DOMINO, STEVEN E.; HURD, ELIZABETH A.

    2006-01-01

    The “Secretor” gene (FUT2) encodes an α(1,2)fucosyltransferase (E.C. 2.4.1.69) that elaborates α(1,2)fucose residues on mucosal epithelium and secreted mucins. While uterine α(1,2)fucosylated glycans have proposed to be involved in embryo adhesion, mice with a homozygous null mutation of Fut2 displayed normal fertility. To help develop alternative hypotheses for function, the cell type and regulation of Fut2 expression during the estrous cycle, hormone replacement, and pregnancy was examined in Fut2-LacZ reporter mice containing targeted replacement of Fut2 with bacterial lacZ. LacZ expression in the reproductive tract of Fut2-LacZ mice is most prominent in the glandular epithelium of the endocervix during estrus and pregnancy. Nuclear LacZ expression identifies cell specific expression of Fut2 in mucus secreting cells of the endocervix, uterine glands, foveolar pit and chief cells of the stomach, and goblet cells of the colon. In ovariectomized Fut2-LacZ mice, estradiol treatment stimulates X-gal staining in endocervix and uterus, but does not affect expression in stomach and colon. Northern blot analysis in wild type mice shows 15-fold elevations of Fut2 steady-state mRNA with estradiol treatment, while Fut1 varies little. Fut2 levels in the glandular stomach and distal colon remain constant while uterine Fut2 levels vary 8-fold during the estrous cycle. These data represent the first demonstration of a glycosyltransferase gene under tissue-specific hormonal regulation in a LacZ reporter mouse model. Endocervical expression of Fut2 in estrus and pregnancy may modify cervical mucus barrier properties from microbial infection analogous to the potential role of mucosal glycans in humans. PMID:14576173

  19. Evaluation of serum concentrations of tumor necrosis factor (TNF)-α, interleukin (IL)-2, IL-10, and nitric oxide (NO) during the estrous cycle, early pregnancy and abortion in goats.

    PubMed

    Chen, Youwang; Lv, Wenting; Jia, Jingliang; Wang, Jiantao; Yang, Jianhui

    2016-11-01

    The aim of this study was to establish the serum concentrations, ranges, and trends of Th1 type cytokine (tumor necrosis factor (TNF)-α and interleukin (IL)-2), Th2 type cytokine (IL-10), and nitric oxide (NO) during the estrous cycle, early pregnancy and abortion in goats. Boer goats (n=25) having symptoms of normal estrous cycles were selected, 20 were mated and 15 conceived a pregnancy, and the remaining five were not mated and served as estrous controls. On the Day 60 of pregnancy, all 15 pregnant goats were induced to abort the pregnancy by intramuscular injection of prostaglandin (PG). Serum samples were collected on Days 1, 7, 14, and 19 of the estrous cycle, at Days 0, 10, 20, 30, 40, 50, and 60 of pregnancy, and at Days 1, 3, 8, 10 over the period when abortion were occurring. Results of the present study indicated that during the estrous cycle the balance between Th1 and Th2 cytokines slightly shifted toward Th1 cytokine production (TNF-α and IL-2). The NO may have a direct positive role in inducing a Th1 response. During early pregnancy, TNF-α and IL-2 serum concentrations markedly increased from Days 0 to 10, and gradually decreased from Days 10 to 60, while IL-10 and NO serum concentrations remained elevated from Days 0 to 60. The increased concentrations of IL-10 and decreased concentrations of TNF-α and IL-2 are characteristic of a Th2-enhanced response, which may be related to increased concentrations of NO. These changes may be essential to maintain a normal pregnancy. In addition, the serum concentrations of TNF-α, IL-2 and NO at Days 1, 3, 8 and 10 of the period of induced abortion were markedly greater than that on Day 60 of pregnancy. Conversely, IL-10 concentrations at these four time points of abortion were markedly less than that on Day 60 of pregnancy. After abortion, the Th2 response shifted to a Th1-enhanced response. Thus, NO concentrations increase and the Th1-enhanced response may function synergistically to be involved in

  20. Estrous Cycle and Gestational Age-Dependent Expression of Members of the Interleukin-36 Subfamily in a Semi-Allogeneic Model of Infected and Non-Infected Murine Pregnancy

    PubMed Central

    Murrieta-Coxca, José Martin; Gómez-Chávez, Fernando; Baeza-Martínez, Damariz Adriana; Cancino-Diaz, Mario Eugenio; Cancino-Diaz, Juan Carlos; Pérez-Tapia, Sonia Mayra; Reyes-Maldonado, Elba; Rodríguez-Martínez, Sandra

    2016-01-01

    The IL-36 subfamily is a recently described group of cytokines with pro-inflammatory behavior, comprising three agonists (α, β, and γ), its receptor (R), and one antagonist (Ra). The expression and function of IL-36 subfamily members in the estrous cycle in healthy and infected pregnancy has not been described. We evaluated mRNA and protein expression of IL-36 family members during the estrous cycle, implantation, fetal development, and post-labor periods in a model of allogenic pregnancy in mice. We also explored the ability of Listeria monocytogenes to modulate the expression of IL-36 subfamily members during pregnancy. Expression of IL-36 subfamily members showed different expression during the estrous cycle and pregnancy but was induced at estrous, 16.5 days post coitum (dpc), 18.5 dpc, and labor. IL-36 subfamily members showed a characteristic distribution in the glandular epithelium, perimetrium, myometrium, and stratum vasculare. Infection with L. monocytogenes during pregnancy induced strong production of IL-36 subfamily members, an observation that correlated with an increasing prevalence of fetal loss. In conclusion, IL-36 agonists showed specific patterns of mRNA and protein expression that might suggest functional specialization or specific target cells. Infection with L. monocytogenes during pregnancy induced strong production of IL-36 subfamily members. PMID:27713746

  1. Estrous Cycle and Gestational Age-Dependent Expression of Members of the Interleukin-36 Subfamily in a Semi-Allogeneic Model of Infected and Non-Infected Murine Pregnancy.

    PubMed

    Murrieta-Coxca, José Martin; Gómez-Chávez, Fernando; Baeza-Martínez, Damariz Adriana; Cancino-Diaz, Mario Eugenio; Cancino-Diaz, Juan Carlos; Pérez-Tapia, Sonia Mayra; Reyes-Maldonado, Elba; Rodríguez-Martínez, Sandra

    2016-01-01

    The IL-36 subfamily is a recently described group of cytokines with pro-inflammatory behavior, comprising three agonists (α, β, and γ), its receptor (R), and one antagonist (Ra). The expression and function of IL-36 subfamily members in the estrous cycle in healthy and infected pregnancy has not been described. We evaluated mRNA and protein expression of IL-36 family members during the estrous cycle, implantation, fetal development, and post-labor periods in a model of allogenic pregnancy in mice. We also explored the ability of Listeria monocytogenes to modulate the expression of IL-36 subfamily members during pregnancy. Expression of IL-36 subfamily members showed different expression during the estrous cycle and pregnancy but was induced at estrous, 16.5 days post coitum (dpc), 18.5 dpc, and labor. IL-36 subfamily members showed a characteristic distribution in the glandular epithelium, perimetrium, myometrium, and stratum vasculare. Infection with L. monocytogenes during pregnancy induced strong production of IL-36 subfamily members, an observation that correlated with an increasing prevalence of fetal loss. In conclusion, IL-36 agonists showed specific patterns of mRNA and protein expression that might suggest functional specialization or specific target cells. Infection with L. monocytogenes during pregnancy induced strong production of IL-36 subfamily members.

  2. Measuring virgin female aggression in the female intruder test (FIT): effects of oxytocin, estrous cycle, and anxiety.

    PubMed

    de Jong, Trynke R; Beiderbeck, Daniela I; Neumann, Inga D

    2014-01-01

    The costs of violence and aggression in our society have stimulated the scientific search for the predictors and causes of aggression. The majority of studies have focused on males, which are considered to be more aggressive than females in most species. However, rates of offensive behavior in girls and young women are considerable and are currently rising in Western society. The extrapolation of scientific results from males to young, non-maternal females is a priori limited, based on the profound sex differences in brain areas and functioning of neurotransmitters involved in aggression. Therefore, we established a paradigm to assess aggressive behavior in young virgin female rats, i.e. the female intruder test (FIT). We found that approximately 40% of un-manipulated adult (10-11 weeks old) female Wistar rats attack an intruder female during the FIT, independent of their estrous phase or that of their intruder. In addition, adolescent (7-8 weeks old) female rats selected for high anxiety behavior (HABs) displayed significantly more aggression than non-selected (NAB) or low-anxiety (LAB) rats. Intracerebroventricular infusion of oxytocin (OXT, 0.1 µg/5 µl) inhibited aggressive behavior in adult NAB and LAB, but not HAB females. Adolescent NAB rats that had been aggressive towards their intruder showed increased pERK immunoreactivity (IR) in the hypothalamic attack area and reduced pERK-IR in OXT neurons in the paraventricular hypothalamic nucleus compared to non-aggressive NAB rats. Taken together, aggressive behavior in young virgin female rats is partly dependent on trait anxiety, and appears to be under considerable OXT control.

  3. The effect of interleukin 1β and interleukin 6 on estradiol-17β secretion in the endometrium of pig during early pregnancy and the estrous cycle.

    PubMed

    Franczak, A; Wojciechowicz, B; Zmijewska, A; Kolakowska, J; Kotwica, G

    2013-07-15

    Estrogens are produced by porcine embryos during early pregnancy. It was found that the uterus of pigs might be a source of steroid hormones, including estrogens. However, the factors involved in the regulation of endometrial steroidogenesis remain unknown. We hypothesize that interleukin (IL) 1β and IL6, which are cytokines produced by porcine embryos and uterine cells, might be involved in the regulation of endometrial estrogen synthesis. Porcine endometrial explants were harvested from gravid (N = 15) and cyclic (N = 15) pigs on days 10 to 11, 12 to 13, and 15 to 16. Samples were analyzed to determine: (1) the expression of CYP19 mRNA and the presence of aromatase cytochrome P450 protein in the tissue; and (2) the release of endometrial estradiol-17β (E2) in response to IL1β and IL6 after 6 and 12 hours of in vitro incubation. The effects observed in pregnant gilts were compared with the effects in nonpregnant gilts on corresponding days of the estrous cycle. On days 15 to 16 of pregnancy the expression of CYP19 in the endometrium was markedly decreased when compared with other periods, and the quantity of endometrial P450 aromatase protein was higher on these days than on days 12 to 13. In nongravid pigs, the expression of CYP19 was lower on days 15 to 16 when compared with days 12 to 13 and the quantity of P450 aromatase protein did not differ during the studied days of the estrous cycle. Basal endometrial E2 release was higher in pregnant gilts when compared with cyclic gilts only on days 15 to 16. In gravid pigs IL1β and IL6 did not affect endometrial E2 release on days 10 to 11 and 12 to 13 of pregnancy (P > 0.05); however, increased E2 release was observed on days 15 to 16 (P < 0.05). In cyclic pigs neither IL1β, nor IL6 affected endometrial E2 release (P > 0.05). These results provide evidence that: (1) the endometrium possesses a potential for steroidogenesis and produces E2in vitro in gravid and nongravid pigs between days 10 to 16; and (2) IL1

  4. Morphometric study of ovarian follicular growth during the estrous cycle of the laboratory-maintained Indian desert gerbil, Meriones hurrianae (Jerdon).

    PubMed

    Saidapur, S K; Kamath, S R

    1993-01-01

    The pattern of changes in the population of healthy and regressing follicles in relation to the estrous cycle, was studied in the recently domesticated desert gerbil, Meriones hurrianae, which exhibits a longer cycle (proestrus: 1.5 days; estrus: 1 day; metestrus: 1.5 days; diestrus: 3 days). As the granulosa cell layers were not distinct, the follicles were classified on the basis of their morphology and size (group I: small preantral follicles; group II: large preantral follicles; group III: small antral follicles; group IV: medium-sized antral follicles; group V: large-sized follicles; group VI: Graafian follicles). Regressing follicles were classified likewise. Five animals were used for each stage of the cycle. One ovary from each gerbil was serially cut and stained with hematoxylin-eosin. Healthy and regressing follicles were found throughout the cycle. The follicular development occurred typically in a biphasic manner. In phase A, in which follicles reach the antral stage, the growth of oocytes and follicles is linearly correlated, whereas, in phase B, oocyte size remains stationary while follicle size increases due to accumulation of antral fluid. However, oocyte growth and nucleus growth are positively and linearly correlated (r = 0.74). The healthy follicles under 260 microns (groups I, II) do not fluctuate in the ovary of cyclic gerbils, whereas follicles in group III (261-350 microns) increase significantly (p < 0.05) at estrus and those of group IV in diestrus. Further, healthy group III follicles are reduced in diestrus while regressing follicles in group III increase. These findings thus suggest that the antral follicles are rescued from atresia at estrus.(ABSTRACT TRUNCATED AT 250 WORDS)

  5. A study on the effects of the estrous cycle on uterine fluid and blood serum immunoglobulin G (IgG) content in the cow.

    PubMed

    Alavi-Shoushtari, Sayed Mortaza; Abedizadeh, Roya; Khaki, Amir; Mokarizadeh, Aram; Dorostkar, Kamran

    2014-01-01

    To investigate the IgG content and its variations in uterine fluid (UF) during the estrous cycle of the cow and to compare them with those of the blood serum (S), six pairs of serum and UF samples for each phase of the cycle selected out of 240 bovine genital tracts and blood samples were collected from Urmia abattoir. The UF samples were collected by gentle scraping of the endometrium using a curette after uterine incision and their IgG content and those of the serum were measured by single radial immuno-diffusion (SRID) assay. Serum IgG values (Mean ± SEM) were generally higher than the UF values throughout the cycle except for di-estrus (S: 38.50 ± 0.90, UF: 51.60 ± 2.10 mg mL(-1)), in which the highest values were observed in UF samples. In met-estrus the difference was not significant (S: 34.80 ± 1.80 mg mL(-1), UF: 30.80 ± 5.20 mg mL(-1)), however, in estrus the mean UF IgG value (12.50 ± 1.10 mg mL(-1)) was lower than that of the serum (31.30 ± 1.20 mg mL(-1)). In pro-estrus, the lowest values (S: 27.80 ± 1.30 mg mL(-1), UF: 9.10 ± 1.50 mg mL(-1)) were obtained. The results showed a lower IgG values in the bovine UF than those of the serum in the follicular phase of the cycle, while in di-estrus the UF IgG content was the highest, suggesting some IgG production in the uterus at this phase.

  6. A study on the effects of the estrous cycle on uterine fluid and blood serum immunoglobulin G (IgG) content in the cow

    PubMed Central

    Alavi-Shoushtari, Sayed Mortaza; Abedizadeh, Roya; Khaki, Amir; Mokarizadeh, Aram; Dorostkar, Kamran

    2014-01-01

    To investigate the IgG content and its variations in uterine fluid (UF) during the estrous cycle of the cow and to compare them with those of the blood serum (S), six pairs of serum and UF samples for each phase of the cycle selected out of 240 bovine genital tracts and blood samples were collected from Urmia abattoir. The UF samples were collected by gentle scraping of the endometrium using a curette after uterine incision and their IgG content and those of the serum were measured by single radial immuno-diffusion (SRID) assay. Serum IgG values (Mean ± SEM) were generally higher than the UF values throughout the cycle except for di-estrus (S: 38.50 ± 0.90, UF: 51.60 ± 2.10 mg mL-1), in which the highest values were observed in UF samples. In met-estrus the difference was not significant (S: 34.80 ± 1.80 mg mL-1, UF: 30.80 ± 5.20 mg mL-1), however, in estrus the mean UF IgG value (12.50 ± 1.10 mg mL-1) was lower than that of the serum (31.30 ± 1.20 mg mL-1). In pro-estrus, the lowest values (S: 27.80 ± 1.30 mg mL-1, UF: 9.10 ± 1.50 mg mL-1) were obtained. The results showed a lower IgG values in the bovine UF than those of the serum in the follicular phase of the cycle, while in di-estrus the UF IgG content was the highest, suggesting some IgG production in the uterus at this phase. PMID:25568704

  7. Effects of the Female Estrous Cycle on the Sexual Behaviors and Ultrasonic Vocalizations of Male C57BL/6 and Autistic BTBR T+ tf/J Mice

    PubMed Central

    Kim, Hyopil; Son, Junehee; Yoo, Hyoungseob; Kim, Hakyoo; Oh, Jihae; Han, DaeHee; Hwang, Yoon

    2016-01-01

    A primary characteristic of autism, which is a neurodevelopmental disorder, is impaired social interaction and communication. Furthermore, patients with autism frequently show abnormal social recognition. In mouse models of autism, social recognition is usually assessed by examining same-sex social behavior using various tests, such as the three-chamber test. However, no studies have examined the ability of male mice with autism to recognize the estrous cycle of female partners. In this study, we investigated the sexual behaviors, especially mounting and ultrasonic vocal communication (USV), of BTBR T+ tf/J (BTBR) mice, which are used as a well-known mouse model of autism, when they encountered estrus or diestrus female mice. As expected, C57BL/6 mice mounted more female mice in the estrus stage compared with the diestrus stage. We found that BTBR mice also mounted more female mice in the estrus stage than female mice in the diestrus stage. Although the USV emission of male mice was not different between estrus and diestrus female mice in both strains, the mounting result implies that BTBR mice distinguish sexual receptivity of females. PMID:27574482

  8. Peripheral Inhibitor of AChE, Neostigmine, Prevents the Inflammatory Dependent Suppression of GnRH/LH Secretion during the Follicular Phase of the Estrous Cycle

    PubMed Central

    Skipor, Janina; Krawczyńska, Agata; Bochenek, Joanna; Wojtulewicz, Karolina; Antushevich, Hanna; Paczesna, Kamila; Romanowicz, Katarzyna

    2017-01-01

    The study was designed to test the hypothesis that the inhibition of acetylcholinesterase (AChE) activity at the periphery by Neostigmine (0.5 mg/animal) will be sufficient to prevent inflammatory dependent suppression of the gonadotropin-releasing hormone (GnRH)/luteinising hormone (LH) secretion in ewes in the follicular phase of the estrous cycle, and this effect will be comparable with the systemic AChE inhibitor, Donepezil (2.5 mg/animal). An immune/inflammatory challenge was induced by peripheral administration of lipopolysaccharide (LPS; 400 ng/kg). Peripheral treatment with Donepezil and Neostigmine prevented the LPS-induced decrease (P < 0.05) in LHβ gene expression in the anterior pituitary gland (AP) and in LH release. Moreover, Donepezil completely abolished (P < 0.05) the suppressory effect of inflammation on GnRH synthesis in the preoptic area, when pretreatment with Neostigmine reduced (P < 0.05) the decrease in GnRH content in this hypothalamic structure. Moreover, administration of both AChE inhibitors diminished (P < 0.05) the inhibitory effect of LPS treatment on the expression of GnRH receptor in the AP. Our study shows that inflammatory dependent changes in the GnRH/LH secretion may be eliminated or reduced by AChE inhibitors suppressing inflammatory reaction only at the periphery such as Neostigmine, without the need for interfering in the central nervous system. PMID:28894751

  9. Biochemical and steroid concentrations in follicular fluid and blood plasma in different follicular waves of the estrous cycle from normal and superovulated beef cows.

    PubMed

    Aller, J F; Callejas, S S; Alberio, R H

    2013-11-30

    The objectives of the current study were to (i) define the changes in size and number of follicles populations, (ii) determine the follicular fluid (FF) biochemical and steroid concentrations collected from different-sized follicles (5-9 and ≥ 10 mm) and (iii) compare between biochemical and hormonal concentrations of FF with those in blood plasma in relation to the first two follicular waves of the estrous cycle (days 4 and 13) from normal and cows primed for superovulation. After estrus, cows (n=20) were assigned randomly to each of four treatment groups. Group 1: ovariectomy on day 4 (day 0 = ovulation). Group 2: FSH treatment and ovariectomy on day 4. Group 3: dominant follicle ablation (DFA) on day 8 and ovariectomy on day 13. Group 4: DFA on day 8, FSH treatment and ovariectomy on day 13. Blood samples were collected and FF was aspirated and pooled per follicle class within cow to determine glucose, urea, triglycerides, cholesterol, total protein, albumin, lactate dehydrogenase, alkaline phosphatase, gamma-glutamyl transpeptidase, aspartate aminotransferase, creatin phosphokinase, estradiol-17β and progesterone concentrations. Follicular class×follicular wave interaction was detected for albumin and lactate dehydrogenase. Results showed that FF concentrations of cholesterol increased from medium to large follicles and decreased for urea and aspartate aminotransferase. Tryglycerides and total protein were greater in the second than in the first follicular wave. FSH treatment decreased FF alkaline phosphatase, E2 and P4 concentrations. Quantitative differences between these fluids are discussed with respect to follicular development.

  10. Adrenomedullin2 (ADM2)/intermedin (IMD) in rat ovary: changes in estrous cycle and pregnancy and its role in ovulation and steroidogenesis.

    PubMed

    Chauhan, Madhu; Balakrishnan, Meena; Blesson, Chellakkan S; Yallampalli, Chandra

    2015-02-01

    Adrenomedullin2 (ADM2) is reported to facilitate embryo implantation and placental development. Therefore, the current study was undertaken to identify if ADM2 has a functional role in ovary to facilitate its reproductive actions. This study shows that the expression of ADM2 is differentially regulated in rat estrous cycle and that ADM2 increases the synthesis and secretion of 17beta-estradiol accompanied with an increase in the expression of steroidogenic factor 1 (Sf1), estrogen receptor Esr1, and enzymes involved in steroidogenesis in equine chorionic gonadotropin (eCG)-treated rat ovaries. In addition, inhibition of endogenous ADM2 function in eCG-treated immature rats caused impaired ovulation. Furthermore, the mRNA expression of Adm2 and receptor activity modifying protein 3 is higher in the ovary on Day 18 compared to nonpregnant and pregnant rats on Day 22. ADM2-like immunoreactivity is localized in granulosa cells, blood vessels, oocytes, cumulous oophorus, and corpus luteum of pregnant ovaries, suggesting a potential role for ADM2 in the ovary. This is supported by the presence of ADM2-like immunoreactivity in the corpus luteum during pregnancy and a decline in aromatase immunoreactivity in corpus luteum on Day 9 of gestation in rats infused with ADM2 antagonist during implantation and decidualization phase. Taken together, this study suggests a potential involvement of ADM2 in the rat ovary in regulating synthesis of estradiol to support ovulation and facilitate efficient implantation and placental development for a successful pregnancy.

  11. Buffalo cervico-vaginal fluid proteomics with special reference to estrous cycle: heat shock protein (HSP)-70 appears to be an estrus indicator.

    PubMed

    Muthukumar, Subramanian; Rajkumar, Ramalingam; Karthikeyan, Kandasamy; Liao, Chen-Chung; Singh, Dheer; Akbarsha, Mohammad Abdulkader; Archunan, Govindaraju

    2014-05-01

    Cervico-vaginal fluid (CVF) plays significant roles in coitus, sperm transport, and implantation. It is believed to be a good noninvasive biomarker for various diagnostic purposes. In this study, a comprehensive proteomic analysis of buffalo CVF was performed during the estrous cycle in order to document the protein expressions, utilizing SDS-PAGE, mass spectrometry, and immunoblot. The main objective was to screen the CVF of buffalo for one or more estrus-specific proteins. A total of 416 proteins were identified in the CVF of both estrus and diestrus phases. Out of these proteins, 68 estrus-specific proteins have been extensively reviewed in the protein database. The major physiological functions of estrus CVF proteins appeared to be stress response, immune response, and metabolic. Eventually, the expression level of heat shock protein-70 in the CVF during the estrus phase, as revealed in SDS-PAGE analysis, was higher than during diestrus. The identity of the protein was confirmed by immunoblot analysis as heat shock protein-70. The findings provide a potential lead for the evaluation of these proteins for estrus detection in buffalo because CVF biomarker detection is a noninvasive technique. The mass spectrometric data of identified proteins have been deposited at the ProteomeXchange with the identifier PXD000620.

  12. Effects of chronic DHEA treatment on central and peripheral reproductive parameters, the onset of vaginal opening and the estrous cycle in female rats.

    PubMed

    Iwasa, Takeshi; Matsuzaki, Toshiya; Tungalagsuvd, Altankhuu; Munkhzaya, Munkhsaikhan; Yiliyasi, Mayila; Kato, Takeshi; Kuwahara, Akira; Irahara, Minoru

    2016-09-01

    The neonatal and/or prepubertal androgen milieu affects sexual maturation and reproductive function in adulthood. However, the effects of chronic dehydroepiandrosterone (DHEA) treatment on reproductive functions have not been fully elucidated. Therefore, the reproductive phenotypes and parameters of rats that had been subjected to chronic DHEA treatment were evaluated in this study. The chronic DHEA-treated (from postnatal day 23-12 weeks of age) rats exhibited earlier vaginal opening, indicating that DHEA treatment promotes sexual maturation. In addition, the estrus phase lasted longer in the DHEA-treated rats, suggesting that their estrous cycles had been disrupted. As the DHEA-treated rats' serum luteinizing hormone levels and hypothalamic Kiss1 mRNA expression levels were decreased and their uterine weight was increased, DHEA and/or estrogen might directly affect reproductive phenotypes. While DHEA treatment caused changes in body weight and body composition in chronic testosterone-treated models in previous studies, no such changes were seen in the present study.

  13. [Changes in the monoamine content in different parts of hypothalamus depending on the stages of the estrous cycle].

    PubMed

    Babichev, V N; Adamskaia, E I

    1976-01-01

    Fluorimetric determination of monoamines in various regions of the hypothalamus and at different stages of the estral cycle in rats showed that the serotonin, noradrenaline, and particularly dophamine content changed both in the course of the cycle and at different time (10, 15 and 18 hours) of the same stage of the cycle. Dophamine concentration in the arcuate area--the centre of the tonic activity--reached its maximum at 18 hours of the diestrus-2 (D2) and fell to the minimum at 10 hours of the proestrus (P). Noradrenaline level in the preoptic area increased at 18 hours of the D2 and fell at 10 hours of the P. It is supposed that in the hypothalamic regulation of the estral cycle at least two monoamines (dopamine and noradrenaline) took part; the trigger role belongs to noradrenaline of the preoptic area (the cyclic centre).

  14. Seasonal effects on the endocrine pattern of semi-captive female Asian elephants (Elephas maximus): timing of the anovulatory luteinizing hormone surge determines the length of the estrous cycle.

    PubMed

    Thitaram, C; Brown, J L; Pongsopawijit, P; Chansitthiwet, S; Wongkalasin, W; Daram, P; Roongsri, R; Kalmapijit, A; Mahasawangkul, S; Rojansthien, S; Colenbrander, B; van der Weijden, G C; van Eerdenburg, F J C M

    2008-01-15

    Better breeding strategies for captive Asian elephants in range countries are needed to increase populations; this requires a thorough understanding of their reproductive physiology and factors affecting ovarian activity. Weekly blood samples were collected for 3.9 years from 22 semi-captive female Asian elephants in Thai elephant camps to characterize LH and progestin patterns throughout the estrous cycle. The duration of the estrous cycle was 14.6+/-0.2 weeks (mean+/-S.E.M.; n=71), with follicular and luteal phases of 6.1+/-0.2 and 8.5+/-0.2 weeks, respectively. Season had no significant effect on the overall length of the estrous cycle. However, follicular and luteal phase lengths varied among seasons and were negatively correlated (r=-0.658; P<0.01). During the follicular phase, the interval between the decrease in progestin concentrations to baseline and the anovulatory LH (anLH) surge varied in duration (average 25.9+/-2.0 days, range 7-41, n=23), and was longer in the rainy season (33.4+/-1.8 days, n=10) than in both the winter (22.2+/-4.5 days, n=5; P<0.05) and summer (18.9+/-2.6 days, n=8; P<0.05). By contrast, the interval between the anLH and ovulatory LH (ovLH) surge was more consistent (19.0+/-0.1 days, range 18-20, n=14). Thus, seasonal variation in estrous cycle characteristics were mediated by endocrine events during the early follicular phase, specifically related to timing of the anLH surge. Overall reproductive hormone patterns in Thai camp elephants were not markedly different from those in western zoos. However, this study was the first to more closely examine how timing of the LH surges impacted estrous cycle length in Asian elephants. These findings, and the ability to monitor reproductive hormones in range countries (and potentially in the field), should improve breeding management of captive and semi-wild elephants.

  15. Sex-specific effects of daily exposure to sucrose on spatial memory performance in male and female rats, and implications for estrous cycle stage.

    PubMed

    Abbott, Kirsten N; Morris, Margaret J; Westbrook, R Fred; Reichelt, Amy C

    2016-08-01

    Excessive consumption of sugar sweetened drinks is proposed to produce functional changes in the hippocampus, leading to perturbations in learning and memory. In this study we examined the impact of 2h daily access to 10% sucrose (or no sucrose in controls) on recognition memory tasks in young male and female rats. In Experiment 1 we tested rats on memory tasks reliant on the hippocampus (place recognition), perirhinal cortex (object recognition), and a combination of hippocampus, prefrontal cortex and perirhinal cortex (object-in-place memory). Exposure to sucrose for 2h a day for 14days prior to behavioral testing did not affect object recognition, but impaired spatial memory to an extent in both male and female rats. Male rats exposed to sucrose were impaired at both place recognition and object-in-place recognition, however female rats showed no impairment in object-in-place performance. Plasticity within the hippocampus is known to increase during the proestrus phase of the estrous cycle and is related to higher levels of circulating estrogens. In Experiment 2 we tested place recognition and object-in-place memory in 10% sucrose exposed or non-exposed control female rats both during the metestrus (low estrogen) and proestrus (high estrogen) phases of their cycle on place recognition and object-in-place memory. Both sucrose exposed and control female rats were able to perform place object-in-place recognition correctly during metestrus and proestrus, however sucrose exposed rats were only able to perform place recognition correctly during proestrus. This indicates that when hippocampal function is compromised, endogenous estrogens may boost memory performance in females, and that males may be at more risk of high sugar diet induced cognitive deficits. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Ovarian ultrasonography correlated with fecal progestins and estradiol during the estrous cycle and early pregnancy in giraffes (Giraffa camelopardalis rothschildi).

    PubMed

    Lueders, Imke; Hildebrandt, Thomas B; Pootoolal, Jason; Rich, Peter; Gray, Charlie S; Niemuller, Cheryl A

    2009-11-01

    Fecal and urinary progestin analyses have shown that giraffes express a short reproductive cycle, averaging 15 days, compared with other large ruminants. However, actual ovarian events have not been correlated with the hormonal pattern. In this study, mature cycling female Rothschild giraffes (Giraffa camelopardalis rothschildi) were repeatedly examined by transrectal ultrasonography to correlate ovarian function with changes in fecal progestin (fP4 [n(c) = 6]) and estradiol (fE2 [n(c) = 6]) and serum progestin (n(c) = 2) as measured by enzyme immunoassay. Five females became pregnant and were monitored during early gestation. In this study, we discovered that hormone values for fP4 in cycling giraffes do not correlate with the classic profile of follicular development, ovulation, and luteogenesis. The corpus luteum (CL) and the next dominant follicle were forming simultaneously. A mean +/- SD peak in fE2 of 254.92 +/- 194.76 ng/g and subsequent ovulation occurred as early as 1 day after the fall in fP4. In pregnant giraffes, the CL reached a diameter significantly larger (mean +/- SD, 41.02 +/- 2.70 mm; P = 0.0126) than that during the cycle (33.48 +/- 2.80 mm), while follicular activity and fluctuating fE2 were still present. With this research, we demonstrated that the progesterone profile typically used to characterize the ovarian cycle does not correlate with luteal development in the ovaries of this species. Furthermore, we conclude that the giraffe could have evolved a short reproductive cycle because of the almost parallel order of ovarian events.

  17. [Histochemical detection of glycoproteins and glycosaminoglycans in the respiratory mucosa of albino rats during estrous cycle, pregnancy and puerperium].

    PubMed

    Pontes, P A; Simões, M J; Merzel, J

    1989-11-01

    In this work we attempted to detect, with histochemical methods, the possible modifications in the mucus of the respiratory mucosa of albino female rats during estral cycle, pregnancy and puerperium. Based on its results, it was possible to conclude that: a--There were no modifications in the nature of the epithelial and supraepithelial mucus during the studied periods: b--The Alcian Blue staining from lamina propria is absent during pregnancy and present during puerperium.

  18. Interictal spike frequency varies with ovarian cycle stage in a rat model of epilepsy.

    PubMed Central

    D’Amour, James; Magagna-Poveda, Alejandra; Moretto, Jillian; Friedman, Daniel; LaFrancois, John J.; Pearce, Patrice; Fenton, Andre A.; MacLusky, Neil J.; Scharfman, Helen E.

    2015-01-01

    In catamenial epilepsy, seizures exhibit a cyclic pattern that parallels the menstrual cycle. Many studies suggest that catamenial seizures are caused by fluctuations in gonadal hormones during the menstrual cycle, but this has been difficult to study in rodent models of epilepsy because the ovarian cycle in rodents, called the estrous cycle, is disrupted by severe seizures. Thus, when epilepsy is severe, estrous cycles become irregular or stop. Therefore, we modified kainic acid (KA)- and pilocarpine-induced status epilepticus (SE) models of epilepsy so that seizures were rare for the first months after SE, and conducted video-EEG during this time. The results showed that interictal spikes (IIS) occurred intermittently. All rats with regular 4-day estrous cycles had IIS that waxed and waned with the estrous cycle. The association between the estrous cycle and IIS was strong: if the estrous cycles became irregular transiently, IIS frequency also became irregular, and when the estrous cycle resumed its 4-day pattern, IIS frequency did also. Furthermore, when rats were ovariectomized, or males were recorded, IIS frequency did not show a 4-day pattern. Systemic administration of an estrogen receptor antagonist stopped the estrous cycle transiently, accompanied by transient irregularity of the IIS pattern. Eventually all animals developed severe, frequent seizures and at that time both the estrous cycle and the IIS became irregular. We conclude that the estrous cycle entrains IIS in the modified KA and pilocarpine SE models of epilepsy. The data suggest that the ovarian cycle influences more aspects of epilepsy than seizure susceptibility. PMID:25864929

  19. Interictal spike frequency varies with ovarian cycle stage in a rat model of epilepsy.

    PubMed

    D'Amour, James; Magagna-Poveda, Alejandra; Moretto, Jillian; Friedman, Daniel; LaFrancois, John J; Pearce, Patrice; Fenton, Andre A; MacLusky, Neil J; Scharfman, Helen E

    2015-07-01

    In catamenial epilepsy, seizures exhibit a cyclic pattern that parallels the menstrual cycle. Many studies suggest that catamenial seizures are caused by fluctuations in gonadal hormones during the menstrual cycle, but this has been difficult to study in rodent models of epilepsy because the ovarian cycle in rodents, called the estrous cycle, is disrupted by severe seizures. Thus, when epilepsy is severe, estrous cycles become irregular or stop. Therefore, we modified kainic acid (KA)- and pilocarpine-induced status epilepticus (SE) models of epilepsy so that seizures were rare for the first months after SE, and conducted video-EEG during this time. The results showed that interictal spikes (IIS) occurred intermittently. All rats with regular 4-day estrous cycles had IIS that waxed and waned with the estrous cycle. The association between the estrous cycle and IIS was strong: if the estrous cycles became irregular transiently, IIS frequency also became irregular, and when the estrous cycle resumed its 4-day pattern, IIS frequency did also. Furthermore, when rats were ovariectomized, or males were recorded, IIS frequency did not show a 4-day pattern. Systemic administration of an estrogen receptor antagonist stopped the estrous cycle transiently, accompanied by transient irregularity of the IIS pattern. Eventually all animals developed severe, frequent seizures and at that time both the estrous cycle and the IIS became irregular. We conclude that the estrous cycle entrains IIS in the modified KA and pilocarpine SE models of epilepsy. The data suggest that the ovarian cycle influences more aspects of epilepsy than seizure susceptibility.

  20. Adrenomedullin2 (ADM2)/Intermedin (IMD) in Rat Ovary: Changes in Estrous Cycle and Pregnancy and Its Role in Ovulation and Steroidogenesis1

    PubMed Central

    Chauhan, Madhu; Balakrishnan, Meena; Blesson, Chellakkan S.; Yallampalli, Chandra

    2014-01-01

    ABSTRACT Adrenomedullin2 (ADM2) is reported to facilitate embryo implantation and placental development. Therefore, the current study was undertaken to identify if ADM2 has a functional role in ovary to facilitate its reproductive actions. This study shows that the expression of ADM2 is differentially regulated in rat estrous cycle and that ADM2 increases the synthesis and secretion of 17beta-estradiol accompanied with an increase in the expression of steroidogenic factor 1 (Sf1), estrogen receptor Esr1, and enzymes involved in steroidogenesis in equine chorionic gonadotropin (eCG)-treated rat ovaries. In addition, inhibition of endogenous ADM2 function in eCG-treated immature rats caused impaired ovulation. Furthermore, the mRNA expression of Adm2 and receptor activity modifying protein 3 is higher in the ovary on Day 18 compared to nonpregnant and pregnant rats on Day 22. ADM2-like immunoreactivity is localized in granulosa cells, blood vessels, oocytes, cumulous oophorus, and corpus luteum of pregnant ovaries, suggesting a potential role for ADM2 in the ovary. This is supported by the presence of ADM2-like immunoreactivity in the corpus luteum during pregnancy and a decline in aromatase immunoreactivity in corpus luteum on Day 9 of gestation in rats infused with ADM2 antagonist during implantation and decidualization phase. Taken together, this study suggests a potential involvement of ADM2 in the rat ovary in regulating synthesis of estradiol to support ovulation and facilitate efficient implantation and placental development for a successful pregnancy. PMID:25395681

  1. Transient receptor potential vanilloid 6 (TRPV6) in the mouse brain: Distribution and estrous cycle-related changes in the hypothalamus.

    PubMed

    Kumar, Santosh; Singh, Uday; Singh, Omprakash; Goswami, Chandan; Singru, Praful S

    2017-03-06

    Transient receptor potential vanilloid (TRPV) subfamily of cationic channels have emerged as novel players in neural regulation. Unlike other members of TRPV subfamily, TRPV5 and TRPV6 are highly Ca(2+)-selective. Although TRPV5/TRPV6 transcripts are expressed in mouse brain, understanding the full functional spectrum of these ion channels in the brain is however limited due to the lack of information on their neuroanatomical distribution. We have studied TRPV6 in mouse brain in further detail. In the hypothalamus, while Western blot analysis using TRPV6 specific antiserum showed a distinct ∼95 kDa band corresponding to the molecular weight of TRPV6, transcripts for TRPV6 were detected with RT-PCR. TRPV6-immunoreactive cells/fibers were observed in vascular organ of the lamina terminalis, olfactory bulb, amygdala, hippocampus, septohypothalamic, supraoptic, arcuate (ARC), dorsomedial, and subincertal nuclei. TRPV6-immunoreactive cells/fibers were also observed in the brainstem and cerebellum. Estrogen has emerged as a potential regulator of TRPV6 in peripheral tissues. TRPV6 gene promoter contains estrogen-response element, estrogen activates TRPV6 via estrogen receptor alpha (ERα), and ERα-expressing ARC neurons in mediobasal hypothalamus (MBH) serve as primary site for estradiol feedback. Using double immunofluorescence, co-expression of TRPV6 and ERα was observed in several ARC neurons. MBH of mice during different phases of estrous cycle were subjected to Western blot analysis of TRPV6. Compared to proestrus, a significant reduction (P<0.01) in intensity of TRPV6-immunoreactive band was observed in MBH during metestrus and diestrus phases. While the wide distribution of TRPV6-expressing elements in the brain suggests its role in a range of CNS functions, the ion channel may serve as novel component of the neural pathway mediating effects of estradiol in MBH.

  2. Female sexual behavior, estrous cycle and gene expression in sexually dimorphic brain regions after pre- and postnatal exposure to endocrine active UV filters.

    PubMed

    Faass, Oliver; Schlumpf, Margret; Reolon, Sasha; Henseler, Manuel; Maerkel, Kirsten; Durrer, Stefan; Lichtensteiger, Walter

    2009-03-01

    The developing female brain represents a potential target for estrogenic environmental chemicals because it depends on estrogen but is exposed to low endogenous estrogen levels, thus facilitating competition by exogenous estrogen receptor (ER) agonists. We investigated effects of two estrogenic UV filters, 4-methylbenzylidene camphor (4-MBC) and 3-benzylidene camphor (3-BC). 4-MBC has been detected in human milk, indicating potential exposure of fetus and infant. The two chemicals were administered in chow to rats of the parent generation before mating, during pregnancy and lactation, and to their offspring until adulthood. Female sexual behavior was recorded on videotape in adult female offspring on proestrus evening at the beginning of the dark phase. 4-MBC (7 and 24mg/kg bw/day) and 3-BC (2.4 and 7mg/kg bw/day) reduced proceptive behavior (jump and ear wiggling) and receptive behavior (lordosis quotient), and increased rejection behavior towards the male. Estrous cycles were not affected by 4-MBC but disturbed by 3-BC. mRNAs encoding for genes involved in female sexual behavior, ERalpha, ERbeta, progesterone receptor (PR) and steroid receptor coactivator-1 (SRC-1), were measured by real-time RT-PCR in ventromedial hypothalamic nucleus (VMH) and medial preoptic area of adult male and female offspring (studied in diestrus) after pre- and postnatal exposure to 3-BC (0.24, 0.7, 2.4 and 7mg/kg bw/day). Gene expression was affected in a sex- and region-specific manner. PR mRNA in female VMH was reduced to male levels at dose levels of 2.4 and 7mg/kg bw/day 3-BC. Our data demonstrate that female sexual behavior represents a sensitive target of endocrine disrupters and point to an involvement of PR in VMH.

  3. Influence of body condition and bovine somatotropin on estrous behavior, reproductive performance, and concentrations of serum somatotropin and plasma fatty acids in postpartum Brahman-influenced cows.

    PubMed

    Flores, R; Looper, M L; Rorie, R W; Lamb, M A; Reiter, S T; Hallford, D M; Kreider, D L; Rosenkrans, C F

    2007-05-01

    Ninety-nine multiparous Brahman-influenced (1/4 to 3/8 Brahman) cows were managed to achieve low (BCS = 4.3 +/- 0.1; n = 50) or moderate (BCS = 6.1 +/- 0.1; n = 49) body condition (BC) to determine the influence of bovine somatotropin (bST) on estrous characteristics, reproductive performance, and concentrations of serum GH and plasma NEFA. Beginning 32 d postpartum, cows within each BC were assigned randomly to treatment with or without bST. Non-bST-treated cows received no treatment, and treated cows were administered bST (Posilac, 500 mg s.c.) on d -35, -21, and -7 before initiation of the breeding season. On d -7, all cows received an intravaginal, controlled internal drug-releasing (CIDR) device. On d 0 (initiation of the 70-d breeding season), the CIDR were removed and cows received prostaglandin F2alpha (PGF2alpha). Blood samples were collected from the median caudal vein of the cows at each bST treatment and at d -28 and 0. Estrous behavior was monitored by radiotelemetry during the first 30 d of the breeding season. Growth hormone was increased (P < 0.05) in low and moderate BC cows treated with bST. The percentage of cows detected in estrus during the first 30 d of the breeding season was decreased (P = 0.05) for low BC (64%) compared with moderate BC (82%) cows. The interval to first estrus tended (P = 0.07) to be shorter in low BC-bST-treated cows (3.7 +/- 1.9 d) than in moderate BC-bST-treated cows (9.6 +/- 1.8 d). During the first 30 d of the breeding season, cows in low BC had a decreased (P = 0.02) number of mounts received and increased (P = 0.001) quiescence between mounts compared with cows in moderate BC. The number of mounts received was reduced (P = 0.04) in bST-treated cows. More (P = 0.02) cows treated with bST became pregnant during the first 3 d of the breeding season compared with non-bST-treated cows. The cumulative first-service conception rate tended (P = 0.07) to be greater for bST-low BC cows than non-bST-treated cows in low or

  4. Effect of pubertal status and number of estrous cycles prior to the breeding season on pregnancy rate in beef heifers

    USDA-ARS?s Scientific Manuscript database

    Three experiments were conducted to evaluate whether pubertal status prior to breeding influences pregnancy rate in beef heifers. Records were collected at West Central Research and Extension Center, North Platte, NE from 2002 to 2011 (Exp. 1; n = 1,005) and Gudmundsen Sandhills Laboratory, Whitman,...

  5. Comparison between lactating and non-lactating dairy cows on follicular growth and corpus luteum development, and endocrine patterns of ovarian steroids and luteinizing hormone in the estrous cycles.

    PubMed

    Endo, Natsumi; Nagai, Kiyosuke; Tanaka, Tomomi; Kamomae, Hideo

    2012-10-01

    The dynamics of ovarian follicle, corpus luteum (CL), and peripheral plasma ovarian steroids were compared between lactating and non-lactating cows, and a possible association of pulsatile luteinizing hormone (LH) secretion with the dynamics was examined. Lactating (n=5) and non-lactating (n=5) cows were monitored daily for follicle and CL throughout two consecutive estrous cycles (Day 0: day of ovulation). Blood samples were collected daily and at 15 min intervals for 8h on Days 2, 4, 6, 8, and 14 of the second cycle. Lactating cows had larger CL (25.4 ± 1.8mm vs. 23.5 ± 1.5mm, P<0.01) and greater progesterone concentrations (4.6 ± 1.0ng/ml vs. 3.9 ± 0.9 ng/ml, P<0.01) during mid-luteal phase compared with non-lactating cows. Maximal diameters of the first wave dominant follicle (17.2 ± 1.8mm vs. 15.5 ± 0.8mm) and the ovulatory follicle (17.9 ± 1.2mm vs. 15.2 ± 0.8mm) were greater (P<0.05) in lactating cows than in non-lactating cows during the estrous cycles with two follicular waves, but no significant differences were detected between the groups during the estrous cycles with three follicular waves. Plasma estradiol concentrations did not differ between the groups throughout the experiment. Lactating cows had more LH pulses from Days 2 to 14 than non-lactating cows. These results imply that differences in ovarian dynamics may exist between lactating and non-lactating cows, for which the increased number of LH pulses observed in lactating cows may have responsibility.

  6. Increased squalene concentrations in the clitoral gland during the estrous cycle in rats: an estrus-indicating scent mark?

    PubMed

    Achiraman, Shanmugam; Archunan, Govindaraju; Abirami, Bethunaicken; Kokilavani, Palanivel; Suriyakalaa, Udhayaraj; SankarGanesh, Devaraj; Kamalakkannan, Soundararajan; Kannan, Soundarapandian; Habara, Yoshiaki; Sankar, Ramaiyan

    2011-12-01

    Squalene in the rat clitoral gland is reported to be semi-volatile and may serve as a chemo-signal. The objective was to determine squalene concentrations in the clitoral gland throughout the reproductive cycle. Clitoral glands were extracted with dichloromethane; 23 compounds were identified with Gas Chromatography linked Mass Spectrometry (GC-MS). Since squalene concentrations were significantly higher during proestrus and estrus, and remarkably reduced during metestrus and diestrus, we inferred that it could be an ovulation-indicating chemosignal in the female rat, acting as a scent mark for the male. This hypothesis was tested by investigating its efficacy to attract males, including studying the role of the olfactory-vomeronasal system of the male in perceiving squalene. For detection of squalene, males used their conventional olfactory system when at a distance from the female, whereas the vomeronasal organ was used when they were in close proximity to the female. We concluded that squalene was a female-specific chemosignal that attracted males, and furthermore, that the olfactory-vomeronasal system had an important role in the perception of squalene. Copyright © 2011 Elsevier Inc. All rights reserved.

  7. Altered secretion of selected arachidonic acid metabolites during subclinical endometritis relative to estrous cycle stage and grade of fibrosis in mares.

    PubMed

    Gajos, Katarzyna; Kozdrowski, Roland; Nowak, Marcin; Siemieniuch, Marta J

    2015-08-01

    Mares that fail to become pregnant after repeated breeding, without showing typical signs of clinical endometritis, should be suspected of subclinical endometritis (SE). Contact with infectious agents results in altered synthesis and secretion of inflammatory mediators, including cytokines and arachidonic acid metabolites, and disturbs endometrial functional balance. To address the hypothesis that SE affects the immune endocrine status of the equine endometrium, spontaneous secretion of prostaglandin E(2) (PGE(2)), prostaglandin F(2α) (PGF(2α)), 6-keto-PGF(1α )(a metabolite of prostacyclin I(2)), leukotriene B(4) (LTB(4)), and leukotriene C(4) (LTC(4)) was examined. In addition, secretion of these factors was examined relative to the grade of inflammation, fibrosis, and estrous cycle stage. Eighty-two warmblood mares, of known breeding history, were enrolled in this study. On the basis of histopathologic assessment, mares were classified as suffering from first-grade SE, second-grade SE, or being healthy. The grade of fibrosis and the infiltration of endometrial tissue with polymorphonuclear leukocytes were examined by routine hematoxylin-eosin staining. In mares suffering from SE, the secretion profiles of PGE(2), 6-keto-PGF(1α), LTB(4), and LTC(4) were changed compared to mares that did not suffer from endometritis. The secretion of PGE(2) and 6-keto-PGF1α was increased, whereas that of LTB(4) and LTC(4) was decreased. Secretion of 6-keto-PGF(1α) was increased in first- and second-grade SE (P < 0.01). The concentration of PGI(2) metabolite was increased only in inflamed endometrium, independently of the inflammation grade, but was not affected by fibrosis. Prostaglandin E(2) secretion was increased in second-grade SE (P < 0.05). The secretion of LTB(4) decreased in both first- and second-grade SE (P < 0.05), whereas secretion of LTC(4) was decreased only in second-grade SE (P < 0.05). Fibrosis did not change the secretion profile of PGE(2), PGF(2α), and 6

  8. Effects of lactation and pregnancy on gene expression of endometrium of Holstein cows at day 17 of the estrous cycle or pregnancy.

    PubMed

    Cerri, R L A; Thompson, I M; Kim, I H; Ealy, A D; Hansen, P J; Staples, C R; Li, J L; Santos, J E P; Thatcher, W W

    2012-10-01

    Objectives were to determine effects of lactation and pregnancy on endometrial gene expression on d 17 of the estrous cycle and pregnancy. Heifers (n=33) were assigned randomly after parturition to lactating (L, n=17) or nonlactating (NL, n=16) groups. Cows were subjected to an ovulation synchronization program for a timed artificial insemination (TAI); 10 cows in L and 12 in NL were inseminated. Slaughter occurred 17 d after the day equivalent to TAI, and intercaruncular endometrial tissues were collected. Gene expression was determined by DNA microarray analysis for pregnant (L, n=8; NL, n=6) and noninseminated cyclic (L, n=7; NL, n=4) cows. Differentially expressed genes were selected with a P-value <0.01 and absolute expression >40. In addition, a fold effect >1.5 was used as a criterion for genes affected by pregnancy. In total, 210 genes were differentially regulated by lactation (136 downregulated and 74 upregulated), and 702 genes were differentially regulated by pregnancy (407 downregulated and 295 upregulated). The interaction effect of pregnancy and lactation affected 61 genes. Genes up- and downregulated in pregnant cows were associated with several gene ontology terms, such as defense response and interferon regulatory factor, cell adhesion, and extracellular matrix. The gene ontology analyses of up- and downregulated genes of lactating cows revealed terms related to immunoglobulin-like fold, immune response, COMM domain, and non-membrane-bounded organelle. Several genes upregulated by lactation, such as IGHG1, IGLL1, IGK, and TRD, were related to immune function, particularly for B cells and γδ T cells. Developmental genes related to limb and neural development and glucose homeostasis (e.g., DKK1, RELN, PDK4) were downregulated by lactation, whereas an interaction was also detected for RELN. The stated genes associated with immune function and developmental genes expressed in the endometrium affected by lactational state are possible candidate genes

  9. The effect of rivastigmine on the LPS-induced suppression of GnRH/LH secretion during the follicular phase of the estrous cycle in ewes.

    PubMed

    Herman, A P; Krawczyńska, A; Bochenek, J; Haziak, K; Romanowicz, K; Misztal, T; Antushevich, H; Herman, A; Tomaszewska-Zaremba, D

    2013-05-01

    This study was designed to determine the effect of a potent subcutaneously injected acetylcholinesterase inhibitor, rivastigmine (6mg/animal), on the gonadotropin-releasing hormone (GnRH)/luteinizing hormone (LH) release during inflammation induced by an intravenous lipopolysaccharide (LPS) (400ng/kg) injection in ewes during the follicular phase of the estrous cycle. The results are expressed as the mean values from -2 to -0.5h before and +1 to +3h after treatment. Rivastigmine decreased the acetylcholinesterase concentration in the blood plasma from 176.9±9.5 to 99.3±15.1μmol/min/ml. Endotoxin suppressed LH (5.4±0.6ng/ml) and GnRH (4.6±0.4pg/ml) release; however, the rivastigmine injection restored the LH concentration (7.8±0.8ng/ml) to the control value (7.8±0.7ng/ml) and stimulated GnRH release (7.6±0.8pg/ml) compared to the control (5.9±0.4pg/ml). Immune stress decreased expression of the GnRH gene and its receptor (GnRH-R) in the median eminence as well as LHβ and GnRH-R in the pituitary. In the case of the GnRH and LHβ genes, the suppressive effect of inflammation was negated by rivastigmine. LPS stimulated cortisol and prolactin release (71.1±14.7 and 217.1±8.0ng/ml) compared to the control group (9.0±5.4 and 21.3±3.5ng/ml). Rivastigmine also showed a moderating effect on cortisol and prolactin secretion (43.1±13.1 and 169.7±29.5ng/ml). The present study shows that LPS-induced decreases in GnRH and LH can be reduced by the AChE inhibitor. This action of the AChE inhibitor could result from the suppression of pro-inflammatory cytokine release and the attenuation of the stress response. However, a direct stimulatory effect of ACh on GnRH/LH secretion should also be considered. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Localization of gene and protein expressions of tumor necrosis factor-{alpha} and tumor necrosis factor receptor types I and II in the bovine corpus luteum during the estrous cycle.

    PubMed

    Sakumoto, R; Vermehren, M; Kenngott, R A; Okuda, K; Sinowatz, F

    2011-10-01

    One of the many roles of tumor necrosis factor (TNF)-α is to control mammalian corpus luteum (CL) PG synthesis and apoptotic cell death. Here, the cellular localization of TNF-α and its type I (TNF-RI) and type II (TNF-RII) receptors in bovine luteal tissue were analyzed using in situ hybridization, immunohistochemistry, and quantitative real-time PCR. Transcripts for TNF-α were expressed in bovine CL throughout the estrous cycle, but were significantly more abundant (P < 0.01) at the regressed luteal stage than at the other stages. Localization of TNF-α transcripts and protein were observed in large and small bovine luteal cells, as well as in immune cells. Moreover, transcripts for TNF-RI and TNF-RII were expressed in bovine CL throughout the estrous cycle. The abundance of TNF-RII transcripts was greater (P < 0.01) at the regressed luteal stage than at the other stages, whereas TNF-RI transcript abundance did not significantly change. Expression of TNF-RI and TNF-RII transcripts and proteins were observed in both the large and small luteal cells, and the proteins were also expressed in the immune cells and vascular endothelial cells. These results suggest that TNF-α sources include immune cells, as well as large and small luteal cells, and that TNF-RI and TNF-RII are present in the luteal cells of the bovine CL.

  11. Differential Effects of Dopamine Receptor D1-Type and D2-Type Antagonists and Phase of the Estrous Cycle on Social Learning of Food Preferences, Feeding, and Social Interactions in Mice

    PubMed Central

    Choleris, Elena; Clipperton-Allen, Amy E; Gray, Durene G; Diaz-Gonzalez, Sebastian; Welsman, Robert G

    2011-01-01

    The neurobiological bases of social learning, by which an animal can ‘exploit the expertise of others' and avoid the disadvantages of individual learning, are only partially understood. We examined the involvement of the dopaminergic system in social learning by administering a dopamine D1-type receptor antagonist, SCH23390 (0.01, 0.05, and 0.1 mg/kg), or a D2-type receptor antagonist, raclopride (0.1, 0.3, and 0.6 mg/kg), to adult female mice prior to socially learning a food preference. We found that while SCH23390 dose-dependently inhibited social learning without affecting feeding behavior or the ability of mice to discriminate between differently flavored diets, raclopride had the opposite effects, inhibiting feeding but leaving social learning unaffected. We showed that food odor, alone or in a social context, was insufficient to induce a food preference, proving the specifically social nature of this paradigm. The estrous cycle also affected social learning, with mice in proestrus expressing the socially acquired food preference longer than estrous and diestrous mice. This suggests gonadal hormone involvement, which is consistent with known estrogenic regulation of female social behavior and estrogen receptor involvement in social learning. Furthermore, a detailed ethological analysis of the social interactions during which social learning occurs showed raclopride- and estrous phase-induced changes in agonistic behavior, which were not directly related to effects on social learning. Overall, these results suggest a differential involvement of the D1-type and D2-type receptors in the regulation of social learning, feeding, and agonistic behaviors that are likely mediated by different underlying states. PMID:21525863

  12. Differential effects of dopamine receptor D1-type and D2-type antagonists and phase of the estrous cycle on social learning of food preferences, feeding, and social interactions in mice.

    PubMed

    Choleris, Elena; Clipperton-Allen, Amy E; Gray, Durene G; Diaz-Gonzalez, Sebastian; Welsman, Robert G

    2011-07-01

    The neurobiological bases of social learning, by which an animal can 'exploit the expertise of others' and avoid the disadvantages of individual learning, are only partially understood. We examined the involvement of the dopaminergic system in social learning by administering a dopamine D1-type receptor antagonist, SCH23390 (0.01, 0.05, and 0.1 mg/kg), or a D2-type receptor antagonist, raclopride (0.1, 0.3, and 0.6 mg/kg), to adult female mice prior to socially learning a food preference. We found that while SCH23390 dose-dependently inhibited social learning without affecting feeding behavior or the ability of mice to discriminate between differently flavored diets, raclopride had the opposite effects, inhibiting feeding but leaving social learning unaffected. We showed that food odor, alone or in a social context, was insufficient to induce a food preference, proving the specifically social nature of this paradigm. The estrous cycle also affected social learning, with mice in proestrus expressing the socially acquired food preference longer than estrous and diestrous mice. This suggests gonadal hormone involvement, which is consistent with known estrogenic regulation of female social behavior and estrogen receptor involvement in social learning. Furthermore, a detailed ethological analysis of the social interactions during which social learning occurs showed raclopride- and estrous phase-induced changes in agonistic behavior, which were not directly related to effects on social learning. Overall, these results suggest a differential involvement of the D1-type and D2-type receptors in the regulation of social learning, feeding, and agonistic behaviors that are likely mediated by different underlying states.

  13. Characterization of cytological changes, IgA, IgG and IL-8 levels and pH value in the vagina of prepubertal and sexually mature Ellegaard Göttingen minipigs during an estrous cycle.

    PubMed

    Lorenzen, Emma; Agerholm, Jørgen Steen; Grossi, Anette Blak; Bojesen, Anders Miki; Skytte, Christina; Erneholm, Karin; Follmann, Frank; Jungersen, Gregers

    2016-06-01

    The pig is increasingly used as an advanced animal model of the genital tract in women and knowledge on the genital immune system is therefore needed. In this study, evaluation of vaginal smears revealed that almost no neutrophils or other leukocytes were present in the vaginal mucosa of prepubertal minipigs (n = 10). In sexually mature minipigs (n = 10), evaluated through an estrous cycle, there was an increase in number of mucosal neutrophils and other leukocytes during estrus. The level of total IgA on the vaginal mucosa increased during diestrus. The level of total IgG showed no significant changes through the cycle. The vaginal IgA level in the prepubertal minipigs was similar to the low estrus level in sexually mature minipigs, and the IgG level in prepubertal was similar to the stable level in the sexually mature minipigs. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Hypothyroidism caused by phenobarbital affects patterns of estrous cyclicity in rats.

    PubMed

    Li, Yumei; Kumazawa, Toshihiko; Ishiguro, Tsukasa; Kawakami, Yuriko; Nishitani, Hiromi; Tagawa, Yoshiaki; Matsumoto, Yukiharu

    2011-06-01

    We found that repeated treatment with phenobarbital (PB), a thyroid modulator, resulted in a persistent estrous stage in the present study. Although the effects of PB in blocking the surge release of luteinizing hormone (LH), inducing anovulation and prolonging the diestrous period has been well established, there is still no research describing the appearance of persistent estrous states in normal cycling rats dosed with PB. To further study this phenomenon, female rats exhibiting regular estrous cycle were administered an oral dose of PB for 14 consecutive days. Consecutively, vaginal smears were observed and rats from all the groups were sacrificed and serum hormone levels for prolactin, progesterone, estradiol, triiodothyronin (T3), thyroxine (T4) and thyroid stimulating hormone (TSH) were measured. Pituitary, thyroid, liver, uteri and ovaries were excised, weighed and further subjected to histological observations. We found that PB induced irregular estrous cycles, especially persistent estrus in rats. Histopathologically, the persistent estrous stages are characterized by persistent vaginal cornification in the vagina, cystic follicles and anovulation in the ovaries. Endocrinologically, serum T3 and T4 levels were significantly lower, and TSH was higher in treated-female rats compared to control females. The serum estradiol level and the estradiol/progesterone ratio tend to increase in treated-females. Furthermore, PB-treated animals with irregular estrous cycle were reduced by T4 replacement. Our data indicate that treatment with PB resulted in hypothyroidism and irregular estrous cycle, particularly a persistent estrous stage in normal cycling female rats.

  15. Peripheral Oxytocin in Female Baboons Relates to Estrous state and Maintenance of Sexual Consortships

    PubMed Central

    Moscovice, Liza R.; Ziegler, Toni E.

    2012-01-01

    The neuro-hypophysial hormone oxytocin (OT) has been implicated in female reproductive and maternal behavior and in the formation of pair bonds in monogamous species. Here we measure variation in urinary OT concentrations in relation to reproductive biology and socio-sexual behavior in a promiscuously breeding species, the chacma baboon (Papio hamadryas ursinus). Subjects were members of a habituated group of baboons in the Okavango Delta, Botswana. We collected behavioral data and urine samples from n= 13 cycling females across their estrous cycles and during and outside of short-term, exclusive sexual consortships. Samples were analyzed via Enzyme Immunoassay (EIA) and we used linear mixed models (LMM) to explore the relationship between peripheral OT and a female’s estrous stage and consortship status, her previous reproductive experience and fertility. We also used a Pearson’s correlation to examine the relationship between OT concentrations of consorting females and their extent of behavioral coordination with their consort partners. The results of the LMM indicate that only estrous stage had a significant influence on OT levels. Females had higher OT levels during their periovulatory period than during other stages of their estrous cycle. There were no differences in OT levels between consorting and non-consorting periovulatory females. However, among consorting females, there was a significant positive relationship between urinary OT levels and the maintenance of close proximity between consort partners. Our results suggest that physiological and behavioral changes associated with the initiation and maintenance of short-term inter-sexual relationships in baboons correspond with changes in peripheral OT. PMID:22986337

  16. Alterations in the ability of the bovine pituitary gland to secrete gonadotropins in vitro during the first follicle-stimulating hormone increase of the estrous cycle and in response to exogenous steroids.

    PubMed

    Lane, E A; Padmanabhan, V; Roche, J F; Crowe, M A

    2005-02-01

    The objective was to determine if the endocrine status of the animal dictates the responsiveness of gonadotrophs to estradiol, activin, inhibin and follistatin; hormones implicated in the differential release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). Bovine pituitaries were obtained at 13 (n=8), 30 (n=24) and 66 (n=8) h after the onset of estrus, corresponding to before, during and the end of the first FSH increase of the estrous cycle which follows the pre-ovulatory gonadotropin surge in heifers. Heifers slaughtered at 30 h received no treatment, or were treated with progesterone with or without estradiol before slaughter to suppress the first transient FSH increase. Secretion of FSH from cultured pituitary cells, reflecting the prior in vivo status, was greater (P<0.01) at 30 h than 13 or 66 h, whereas, LH secretion was less (P<0.01) at 13 h compared with 30 h. Treatment with exogenous steroids decreased (P<0.05) the pituitary gland's ability to subsequently secrete FSH and LH. Inhibin and, to a greater extent, estradiol decreased (P<0.01) mean FSH secretion but increased (P<0.05) mean LH secretion. These findings suggest that estradiol and inhibin both have the ability to differentially modulate basal gonadotropin secretion during the first FSH increase of the bovine estrous cycle. Differential regulation of LH and FSH is mediated via an alteration in gonadotropin biosynthesis and basal secretion. Furthermore, the secretory capability of cultured pituitary cells and basal gonadotropin secretion reflect the prior endocrine status of the animal from which pituitaries were obtained.

  17. Meloxicam and Buprenorphine Treatment after Ovarian Transplantation Does Not Affect Estrous Cyclicity and Follicular Integrity in Aged CBA/J Mice

    PubMed Central

    Le, Anna H.; Bonachea, Luis A.; Cargill, Shelley L.

    2014-01-01

    Angiogenesis, the formation of new blood vessels, is important for the survival of ovarian transplants and the restoration of ovarian functions. Without angiogenesis, transplanted ovarian tissue becomes more susceptible to tissue damage and necrosis. Administration of analgesics for pain management has been shown to decrease angiogenesis, which can influence transplant success especially in aged animals. Aging and the effects of hypoxia after transplantation decrease reproductive viability of the ovarian transplant; therefore, it is important to understand the additional effects of analgesics on aged animal models. The present study investigated the effects of two analgesics, buprenorphine, an opiate, and meloxicam, a non-steroidal anti-inflammatory drug (NSAID), on the reproductive indicators related to estrous cyclicity and follicular integrity after ovarian transplantation of young ovaries into aged CBA/J mice. These aged females did not show any different reproductive responses when treated with either buprenorphine or meloxicam. No significant differences were observed in estrous cycle length, the onset of estrous cycling, the regularity of estrous cycles, and the proportion of viable follicles and total number of follicles per ovarian sample across treatment groups. PMID:25153315

  18. Meloxicam and buprenorphine treatment after ovarian transplantation does not affect estrous cyclicity and follicular integrity in aged CBA/J mice.

    PubMed

    Le, Anna H; Bonachea, Luis A; Cargill, Shelley L

    2014-01-01

    Angiogenesis, the formation of new blood vessels, is important for the survival of ovarian transplants and the restoration of ovarian functions. Without angiogenesis, transplanted ovarian tissue becomes more susceptible to tissue damage and necrosis. Administration of analgesics for pain management has been shown to decrease angiogenesis, which can influence transplant success especially in aged animals. Aging and the effects of hypoxia after transplantation decrease reproductive viability of the ovarian transplant; therefore, it is important to understand the additional effects of analgesics on aged animal models. The present study investigated the effects of two analgesics, buprenorphine, an opiate, and meloxicam, a non-steroidal anti-inflammatory drug (NSAID), on the reproductive indicators related to estrous cyclicity and follicular integrity after ovarian transplantation of young ovaries into aged CBA/J mice. These aged females did not show any different reproductive responses when treated with either buprenorphine or meloxicam. No significant differences were observed in estrous cycle length, the onset of estrous cycling, the regularity of estrous cycles, and the proportion of viable follicles and total number of follicles per ovarian sample across treatment groups.

  19. Recovery from Age-Related Infertility under Environmental Light-Dark Cycles Adjusted to the Intrinsic Circadian Period.

    PubMed

    Takasu, Nana N; Nakamura, Takahiro J; Tokuda, Isao T; Todo, Takeshi; Block, Gene D; Nakamura, Wataru

    2015-09-01

    Female reproductive function changes during aging with the estrous cycle becoming more irregular during the transition to menopause. We found that intermittent shifts of the light-dark cycle disrupted regularity of estrous cycles in middle-aged female mice, whose estrous cycles were regular under unperturbed 24-hr light-dark cycles. Although female mice deficient in Cry1 or Cry2, the core components of the molecular circadian clock, exhibited regular estrous cycles during youth, they showed accelerated senescence characterized by irregular and unstable estrous cycles and resultant infertility in middle age. Notably, tuning the period length of the environmental light-dark cycles closely to the endogenous one inherent in the Cry-deficient females restored the regularity of the estrous cycles and, consequently, improved fertility in middle age. These results suggest that reproductive potential can be strongly influenced by age-related changes in the circadian system and normal reproductive functioning can be rescued by the manipulation of environmental timing signals.

  20. Changes in uterine secretion of prostaglandin F2 alpha in response to oxytocin during the estrous cycle, early pregnancy, and estrogen-induced pseudopregnancy in swine.

    PubMed

    Edgerton, L A; Kaminski, M A; Silvia, W J

    1996-09-01

    Thirty-one sows were used in an experiment designed to determine whether the ability of the porcine uterus to release prostaglandin (PG) F2 alpha in response to oxytocin was suppressed in pregnancy and pseudopregnancy. Sows were assigned to one of three treatment groups: nonbred (nonpregnant) controls (n = 8), pseudopregnant (5 mg estradiol benzoate, i.m., daily on Days 11-15 postestrus; n = 8), or bred (bred once daily throughout the estrous period; n = 15). Jugular venous blood samples were collected daily for quantification of progesterone. Pregnancy was determined by uterine examination at slaughter 51-72 days postmating. On the basis of progesterone and embryo recovery, bred sows were classified into three subgroups: confirmed pregnant (n = 4), suspected pregnant based on delayed luteal regression (n = 5), or bred/not pregnant (n = 6). All sows received an injection of oxytocin (30 IU, i.v.) on Days 12, 15, and 18 postestrus. Jugular venous blood samples were collected from 60 min prior to through 120 min after injection of oxytocin for quantification of 13, 14-dihydro-15-keto-PGF2 alpha (PGFM). Magnitude of response above baseline and area under the PGFM response curve (AUC) were calculated for each sow on each day and compared among treatment groups by analysis of variance. Responses in pregnant and suspected-pregnant sows were not different on any day examined; therefore the two groups were combined (n = 9) and considered pregnant for all subsequent analyses. Responses in the nonpregnant and bred/not pregnant sows were pooled and compared to the responses in the pregnant and pseudopregnant sows. Magnitudes of response were similar between these pooled groups on Day 12 (p > 0.5), but were less in pregnant and pseudopregnant sows on Days 15 and 18 (p < 0.01). When nonpregnant and bred/not pregnant sows were compared to each other, the magnitudes of the response were similar on Days 12, 15, and 18 (p > 0.3 on each day). In contrast, when pregnant and

  1. The acute effects of bilateral ovariectomy or adrenalectomy on progesterone, testosterone and estradiol serum levels depend on the surgical approach and the day of the estrous cycle when they are performed

    PubMed Central

    Flores, Angélica; Gallegos, Alma I; Velasco, Jacqueline; Mendoza, Fernando D; Montiel, Cristina; Everardo, Pamela M; Cruz, María-Esther; Domínguez, Roberto

    2008-01-01

    Bilateral ovariectomy or adrenalectomy are experimental tools used to understand the mechanisms regulating the hypothalamus-pituitary-ovarian and the hypothalamus-pituitary-adrenal axis. There is evidence that acute unilateral perforation of the dorsal peritoneum in rats results in significant changes in progesterone, testosterone and estradiol serum concentrations. Because different surgical approaches for unilateral or bilateral ovariectomy or adrenalectomy, sectioning the superior ovarian nerve or the vagus nerve are used, we compare the acute effects on hormone serum concentrations resulting from the unilateral or bilateral dorsal approach to performing bilateral ovariectomy or adrenalectomy with those obtained when an unilateral incision is performed in the ventral abdomen. In general, the progesterone, testosterone and estradiol serum concentrations were higher in animals with ventral approach than in those with dorsal surgery, the effects varying depending on the day of the estrous cycle when surgery was performed. The results suggest that the neural signals arising from different zones of the peritoneum and/or the abdominal wall play different roles in the mechanisms regulating steroid hormones concentrations. PMID:18954455

  2. The acute effects of bilateral ovariectomy or adrenalectomy on progesterone, testosterone and estradiol serum levels depend on the surgical approach and the day of the estrous cycle when they are performed.

    PubMed

    Flores, Angélica; Gallegos, Alma I; Velasco, Jacqueline; Mendoza, Fernando D; Montiel, Cristina; Everardo, Pamela M; Cruz, María-Esther; Domínguez, Roberto

    2008-10-27

    Bilateral ovariectomy or adrenalectomy are experimental tools used to understand the mechanisms regulating the hypothalamus-pituitary-ovarian and the hypothalamus-pituitary-adrenal axis. There is evidence that acute unilateral perforation of the dorsal peritoneum in rats results in significant changes in progesterone, testosterone and estradiol serum concentrations. Because different surgical approaches for unilateral or bilateral ovariectomy or adrenalectomy, sectioning the superior ovarian nerve or the vagus nerve are used, we compare the acute effects on hormone serum concentrations resulting from the unilateral or bilateral dorsal approach to performing bilateral ovariectomy or adrenalectomy with those obtained when an unilateral incision is performed in the ventral abdomen. In general, the progesterone, testosterone and estradiol serum concentrations were higher in animals with ventral approach than in those with dorsal surgery, the effects varying depending on the day of the estrous cycle when surgery was performed. The results suggest that the neural signals arising from different zones of the peritoneum and/or the abdominal wall play different roles in the mechanisms regulating steroid hormones concentrations.

  3. The orphan nuclear receptor SF-1 is involved in the effect of PCBs, DDT, and DDE on the secretion of steroid hormones and oxytocin from bovine luteal cells during the estrous cycle in vitro.

    PubMed

    Mlynarczuk, J; Wrobel, M H; Kotwica, J

    2014-04-15

    The orphan receptor steroidogenic factor-1 (SF-1) is involved in the regulation of ovarian steroidogenesis in cows. It is hypothesized that estrogen-like chlorinated compounds might affect SF-1, and thus impair the function of the ovary. Bovine luteal cells from the estrous cycle (Days: 1-5, 6-10, 11-15, and 16-19) were treated for 50 hours with DDT, 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene, 3,3'4,4'-tetrachlorobiphenyl or 2'2'4,4',5,5'-hexachlorobiphenyl (each at a dose of 10 ng/mL). Luteal cells were also treated with 4-(heptyloxy)phenol (1 × 10(-7) M), an SF-1 agonist, and F0160 (1 × 10(-6) M), an SF-1 blocker, jointly or separately. The secretion of progesterone and oxytocin and the expression of oxytocin precursor (NP-I/OT) messenger RNA were increased (P < 0.05) by all studied xenobiotics and 4-(heptyloxy)phenol, although they were inhibited (P < 0.05) by F0160. However, the xenobiotics did not affect (P > 0.05) SF-1 messenger RNA expression. In summary, SF-1 is involved in the adverse effect of chlorinated xenobiotics on the regulation of the bovine CL.

  4. Shortened estrous cycle length, increased FSH levels, FSH variance, oocyte spindle aberrations, and early declining fertility in aging senescence-accelerated mouse prone-8 (SAMP8) mice: concomitant characteristics of human midlife female reproductive aging.

    PubMed

    Bernstein, Lori R; Mackenzie, Amelia C L; Kraemer, Duane C; Morley, John E; Farr, Susan; Chaffin, Charles L; Merchenthaler, István

    2014-06-01

    Women experience a series of specific transitions in their reproductive function with age. Shortening of the menstrual cycle begins in the mid to late 30s and is regarded as the first sign of reproductive aging. Other early changes include elevation and increased variance of serum FSH levels, increased incidences of oocyte spindle aberrations and aneuploidy, and declining fertility. The goal of this study was to investigate whether the mouse strain senescence-accelerated mouse-prone-8 (SAMP8) is a suitable model for the study of these midlife reproductive aging characteristics. Midlife SAMP8 mice aged 6.5-7.85 months (midlife SAMP8) exhibited shortened estrous cycles compared with SAMP8 mice aged 2-3 months (young SAMP8, P = .0040). Midlife SAMP8 mice had high FSH levels compared with young SAMP8 mice, and mice with a single day of high FSH exhibited statistically elevated FSH throughout the cycle, ranging from 1.8- to 3.6-fold elevation on the days of proestrus, estrus, metestrus, and diestrus (P < .05). Midlife SAMP8 mice displayed more variance in FSH than young SAMP8 mice (P = .01). Midlife SAMP8 ovulated fewer oocytes (P = .0155). SAMP8 oocytes stained with fluorescently labeled antitubulin antibodies and scored in fluorescence microscopy exhibited increased incidence of meiotic spindle aberrations with age, from 2/126 (1.59%) in young SAMP8 to 38/139 (27.3%) in midlife SAMP8 (17.2-fold increase, P < .0001). Finally, SAMP8 exhibited declining fertility from 8.9 pups/litter in young SAMP8 to 3.5 pups/litter in midlife SAMP8 mice (P < .0001). The age at which these changes occur is younger than for most mouse strains, and their simultaneous occurrence within a single strain has not been described previously. We propose that SAMP8 mice are a model of midlife human female reproductive aging.

  5. The effects of kisspeptin agonist canine KP-10 and kisspeptin antagonist p271 on plasma LH concentrations during different stages of the estrous cycle and anestrus in the bitch.

    PubMed

    Albers-Wolthers, C H J; de Gier, J; Rutten, V P M G; van Kooten, P J S; Leegwater, P A J; Schaefers-Okkens, A C; Kooistra, H S

    2016-07-15

    Kisspeptin (KP) plays a key role in the regulation of the hypothalamic-pituitary-gonadal axis via the release of GnRH. As normal KP signaling is essential for reproductive function, it could be an interesting new target for therapeutic interventions, e.g., nonsurgical contraception in dogs. The aims of the present study were to investigate the effect of KP-10 administration on plasma LH concentration in different stages of the reproductive cycle and to investigate the suitability of p271 as KP antagonist in the bitch. Two groups of six adult Beagle bitches were used. In one group, plasma LH concentration was determined before (40 and 0 minutes) and 10, 20, 40, and 60 minutes after the intravenous administration of 0.5-μg/kg body weight (BW) canine KP-10. In the other group, the bitches received a continuous intravenous infusion with p271 (50 μg/kg BW/h) for 3 hours, and 0.5-μg/kg BW canine KP-10 was administered intravenously 2 hours after the start of the p271 infusion. Their plasma LH concentration was determined before (-40 and 0 minutes) and 30, 60, 90, 120, 130, 140, 160, and 180 minutes after the start of the p271 infusion. In both groups, the experiments were performed during the follicular phase, the first and second half of the luteal phase, and during anestrus. Canine KP-10 induced an increase of plasma LH concentration during all estrous cycle stages and anestrus. There was no difference in LH response between the two groups. The lowest LH response was seen during the follicular phase and the highest response during anestrus. The area under the curve (AUC) for LH and LH increment in the follicular phase were lower than those in anestrus. The AUC LH and LH increment in the first half of the luteal phase were lower than those in the second half of the luteal phase and anestrus. The AUC LH and LH increment in the second half of the luteal phase were not different from those in anestrus. Continuous administration of the antagonist p271 did not alter

  6. Elevation of brain allopregnanolone rather than 5-HT release by short term, low dose fluoxetine treatment prevents the estrous cycle-linked increase in stress sensitivity in female rats.

    PubMed

    Devall, Adam J; Santos, Julia M; Fry, Jonathan P; Honour, John W; Brandão, Marcus L; Lovick, Thelma A

    2015-01-01

    Withdrawal from long-term dosing with exogenous progesterone precipitates increased anxiety-linked changes in behavior in animal models due to the abrupt decrease in brain concentration of allopregnanolone (ALLO), a neuroactive metabolite of progesterone. We show that a withdrawal-like effect also occurs during the late diestrus phase (LD) of the natural ovarian cycle in rats, when plasma progesterone and ALLO are declining but estrogen secretion maintains a stable low level. This effect at LD was prevented by short-term treatment with low dose fluoxetine. During LD, but not at other stages of the estrous cycle, exposure to anxiogenic stress induced by whole body vibration at 4 Hz for 5 min evoked a significant decrease in tail flick latency (stress-induced hyperalgesia) and a decrease in the number of Fos-positive neurons present in the periaqueductal gray (PAG). The threshold to evoke fear-like behaviors in response to electrical stimulation of the dorsal PAG was lower in the LD phase, indicating an increase in the intrinsic excitability of the PAG circuitry. All these effects were blocked by short-term administration of fluoxetine (2 × 1.75 mg kg(-1) i.p.) during LD. This dosage increased the whole brain concentration of ALLO, as determined using gas chromatography-mass spectrometry, but was without effect on the extracellular concentration of 5-HT in the dorsal PAG, as measured by microdialysis. We suggest that fluoxetine-induced rise in brain ALLO concentration during LD offsets the sharp physiological decline, thus removing the trigger for the development of anxiogenic withdrawal effects.

  7. Comparison of the effect of lipopolysaccharide on tumor necrosis factor α (TNF-α) secretion and TNF and TNFR1 mRNA levels in feline endometrium throughout the estrous cycle during pyometra and after medroxyprogesterone acetate treatment

    PubMed Central

    JURSZA-PIOTROWSKA, Ewelina; SIEMIENIUCH, Marta J.

    2016-01-01

    Endotoxins released by Gram-negative bacteria are potent stimulators of tumor necrosis factor α (TNF-α) production. The objectives of this study were to evaluate plasma levels of TNF-α, TNF-α secretion, and mRNA levels of TNF and TNF-α receptor type 1 (TNFR1) following exposure to lipopolysaccharide (LPS). For this, we used cultured endometrial cells or organ cultures, throughout the estrous cycle, after hormone treatment with medroxyprogesterone acetate (MPA), and during pyometra. Plasma TNF-α concentrations were increased in animals at estrus (P < 0.05) compared to other groups. In the LPS-challenged endometrium, secretion of TNF-α by tissues collected during estrus increased (P < 0.001) compared to that of other groups. LPS, alone or combined with TNF-α, upregulated TNF gene expression in the feline endometrium at diestrus (P < 0.001 for both treatments), in queens treated short-term with MPA (P < 0.01 and P < 0.05, respectively) and in queens treated long-term with MPA (P < 0.01 and P < 0.001, respectively). During pyometra, TNF and TNFR1 mRNA were increased only after tissues were challenged with TNF-α and LPS (P < 0.001 and P < 0.01, respectively). When cultured endometrial cells were challenged with LPS, the concentration of TNF-α increased only in epithelial cells after 4 h and 12 h (P < 0.05 and P < 0.01, respectively). Since LPS did not affect stromal cells, but TNF-α increased its own transcript after 2 h (P < 0.01), 4 h (P < 0.05) and 12 h (P < 0.001), we assume that stromal cells are not directly involved in pathogen recognition, as was the case for epithelial cells. PMID:27097764

  8. Comparison of the effect of lipopolysaccharide on tumor necrosis factor α (TNF-α) secretion and TNF and TNFR1 mRNA levels in feline endometrium throughout the estrous cycle during pyometra and after medroxyprogesterone acetate treatment.

    PubMed

    Jursza-Piotrowska, Ewelina; Siemieniuch, Marta J

    2016-08-25

    Endotoxins released by Gram-negative bacteria are potent stimulators of tumor necrosis factor α (TNF-α) production. The objectives of this study were to evaluate plasma levels of TNF-α, TNF-α secretion, and mRNA levels of TNF and TNF-α receptor type 1 (TNFR1) following exposure to lipopolysaccharide (LPS). For this, we used cultured endometrial cells or organ cultures, throughout the estrous cycle, after hormone treatment with medroxyprogesterone acetate (MPA), and during pyometra. Plasma TNF-α concentrations were increased in animals at estrus (P < 0.05) compared to other groups. In the LPS-challenged endometrium, secretion of TNF-α by tissues collected during estrus increased (P < 0.001) compared to that of other groups. LPS, alone or combined with TNF-α, upregulated TNF gene expression in the feline endometrium at diestrus (P < 0.001 for both treatments), in queens treated short-term with MPA (P < 0.01 and P < 0.05, respectively) and in queens treated long-term with MPA (P < 0.01 and P < 0.001, respectively). During pyometra, TNF and TNFR1 mRNA were increased only after tissues were challenged with TNF-α and LPS (P < 0.001 and P < 0.01, respectively). When cultured endometrial cells were challenged with LPS, the concentration of TNF-α increased only in epithelial cells after 4 h and 12 h (P < 0.05 and P < 0.01, respectively). Since LPS did not affect stromal cells, but TNF-α increased its own transcript after 2 h (P < 0.01), 4 h (P < 0.05) and 12 h (P < 0.001), we assume that stromal cells are not directly involved in pathogen recognition, as was the case for epithelial cells.

  9. Excitability and Burst Generation of AVPV Kisspeptin Neurons Are Regulated by the Estrous Cycle Via Multiple Conductances Modulated by Estradiol Action123

    PubMed Central

    Wang, Luhong

    2016-01-01

    Abstract The preovulatory secretory surge of gonadotropin-releasing hormone (GnRH) is crucial for fertility and is regulated by a switch of estradiol feedback action from negative to positive. GnRH neurons likely receive estradiol feedback signals via ERα-expressing afferents. Kisspeptin neurons in anteroventral periventricular nucleus (AVPV) are thought to be critical for estradiol-positive feedback induction of the GnRH surge. We examined the electrophysiological properties of GFP-identified AVPV kisspeptin neurons in brain slices from mice on the afternoon of diestrus (negative feedback) and proestrus (positive feedback, time of surge). Extracellular recordings revealed increased firing frequency and action potential bursts on proestrus versus diestrus. Whole-cell recordings were used to study the intrinsic mechanisms of bursting. Upon depolarization, AVPV kisspeptin neurons exhibited tonic firing or depolarization-induced bursts (DIB). Both tonic and DIB cells exhibited bursts induced by rebound from hyperpolarization. DIB occurred similarly on both cycle stages, but rebound bursts were observed more often on proestrus. DIB and rebound bursts were both sensitive to Ni2+, suggesting that T-type Ca2+ currents (ITs) are involved. IT current density was greater on proestrus versus diestrus. In addition to IT, persistent sodium current (INaP) facilitated rebound bursting. On diestrus, 4-aminopyridine-sensitive potassium currents contributed to reduced rebound bursts in both tonic and DIB cells. Manipulation of specific sex steroids suggests that estradiol induces the changes that enhance AVPV kisspeptin neuron excitability on proestrus. These observations indicate cycle-driven changes in circulating estradiol increased overall action potential generation and burst firing in AVPV kisspeptin neurons on proestrus versus diestrus by regulating multiple intrinsic currents. PMID:27280155

  10. [Concentration of monoamines and activity of several enzymes in the arcuate nucleus of the hypothalamus in young and aging rats during the estrous cycle].

    PubMed

    Grantyn', V A

    1976-07-01

    The arcuate nucleus (AN) and the median eminence (ME) of the hypothalamus were investigated in young and ageing female rats. During the estral cycle (EC) the monoamine (MA) content, the monoaminoxidase (MAO), NADP and NAD-diaphorase activities were determined in the AN, and the MA content and the activity of alkaline phosphatase (AP) -- in the ME. In young rats in the proestrus-estrus there was an increase in the activity of the NADP and NAD-diaphorase and of the MA content, but a decrease of the MAO activity. This indicated an intensified function of the nucleus at these stages of the EC. Accumulation of the MA in the ME was noted in the diestrus, while in the proestrus their concentration sharply fell; on the other hand, the activity of the AP was considerably increased. In the ageing rats the dynamics of the indices under study during the EC were largely unchanged. However, the functional activity of the AN proved to increase, and in the ME and elevation of the MA concentration and disturbance of its release from the nerve terminals was seen.

  11. Endometrial IL-1beta, IL-6 and TNF-alpha, mRNA expression in mares resistant or susceptible to post-breeding endometritis. Effects of estrous cycle, artificial insemination and immunomodulation.

    PubMed

    Fumuso, Elida; Giguère, Steeve; Wade, José; Rogan, Dragan; Videla-Dorna, Ignacio; Bowden, Raúl A

    2003-11-15

    Endometrial mRNA expression of the pro-inflammatory cytokines interleukin-1beta (IL-1beta), interleukin-6 (IL-6), and tumor necrosis factor alpha (TNF-alpha) was assessed in mares resistant (RM) or susceptible (SM) to persistent post-breeding endometritis (PPBE). Eight RM and eight SM, were selected based on reproductive records and functional tests out of a herd of 2,000 light cross-type mares. Three experiments were done to study transcription patterns in (i) basal conditions; (ii) after artificial insemination (AI); and (iii) after administration of an immunomodulator at time of artificial insemination. Endometrial biopsies were taken during consecutive cycles: (i) at estrus, when follicles reached 35 mm and at diestrus (7 +/- 1 days after ovulation); (ii) at 24 h post-AI, with dead semen (estrus) and in diestrus; (iii) at 24 h after treatment with a Mycobacterium phlei cell-wall extract (MCWE) preparation and AI (with dead semen), and at diestrus. mRNA expression was quantitated by real time PCR. Under basal conditions, SM had significantly higher mRNA expression of all cytokines in estrus and of IL-1beta and TNF-alpha in diestrus, compared to RM. After AI, there were no differences between RM and SM in estrus; however, mRNA expression for all three pro-inflammatory cytokines was higher than under basal conditions. In diestrus, RM showed significantly lower IL-1beta and TNF-alpha mRNA expression than SM. When MCWE was administered at time of AI, no differences between cytokine induction from RM and SM were found. Globally, mRNA expression for all three cytokines correlated well among themselves when expression was high. The present study showed that (i) in basal conditions RM had lower mRNA expression of pro-inflammatory cytokines than SM with no effect of estrous cycle; (ii) AI upregulated mRNA expression for all three cytokines in both RM and SM, with persistance in diestrus in the latter; (iii) treatment with MCWE at time of AI down-regulated mRNA expression

  12. Protocol for Studying Extinction of Conditioned Fear in Naturally Cycling Female Rats

    PubMed Central

    Maeng, Lisa Y.; Cover, Kara K.; Landau, Aaron J.; Milad, Mohammed R.; Lebron-Milad, Kelimer

    2015-01-01

    Extinction of conditioned fear has been extensively studied in male rodents. Recently, there have been an increasing number of studies indicating that neural mechanisms for certain behavioral tasks and response behaviors are different in females and males. Using females in research studies can represent a challenge because of the variation of gonadal hormones during their estrous cycle. This protocol describes well-established procedures that are useful in investigating the role of estrogen in fear extinction memory consolidation in female rats. Phase of the estrous cycle and exogenous estrogen administration prior to extinction training can influence extinction recall 24 hr later. The vaginal swabbing technique for estrous phase identification described here aids the examination and manipulation of naturally cycling gonadal hormones. The use of this basic rodent model may further delineate the mechanisms by which estrogen can modulate fear extinction memory in females. PMID:25741747

  13. Induction of mammary tumors in rat by intraperitoneal injection of NMU: histopathology and estral cycle influence.

    PubMed

    Rivera, E S; Andrade, N; Martin, G; Melito, G; Cricco, G; Mohamad, N; Davio, C; Caro, R; Bergoc, R M

    1994-11-11

    In order to obtain an experimental model we induced mammary tumors in female Sprague-Dawley rats. The carcinogen N-nitroso-N-methylurea (NMU) was injected intraperitoneally (i.p.) at doses of 50 mg/kg body weight when animals were 50, 80 and 110 days old. Tumor sizes were measured with a caliper and their growth parameters and histopathological properties were tested. For 100 rats, 88.4% of developed lesions were ductal carcinomas, histologically classified as 52.8% cribiform variety, 30.6% solid carcinoma. Metastases in liver, spleen and lung were present. Other primary tumors were detected with low incidence. The influence of the rat estrous cycle during the first exposure to intraperitoneal NMU injection was studied. The latency period in estrus, proestrus and diestrus was 82 +/- 15, 77 +/- 18 and 79 +/- 18 days, respectively. Tumor incidence was significantly higher in estrus (95.2%) than proestrus (71.4%) or diestrus (77.4), (P < 0.01). Mean number or tumors per animal was similar among the three groups (4.4 +/- 3.2, 3.8 +/- 3.6, 3.2 +/- 1.8). The procedure described appears to be the simplest method for inducing experimental mammary tumors in rats.

  14. Lunar Cycle Influences Spontaneous Delivery in Cows

    PubMed Central

    Yonezawa, Tomohiro; Uchida, Mona; Tomioka, Michiko; Matsuki, Naoaki

    2016-01-01

    There is a popular belief that the lunar cycle influences spontaneous delivery in both humans and cattle. To assess this relationship, we investigated the synodic distribution of spontaneous deliveries in domestic Holstein cows. We used retrospective data from 428 spontaneous, full-term deliveries within a three-year period derived from the calving records of a private farm in Hokkaido, Japan. Spontaneous birth frequency increased uniformly from the new moon to the full moon phase and decreased until the waning crescent phase. There was a statistically significant peak between the waxing gibbous and full moon phases compared with those between the last quarter and the waning crescent. These changes were clearly observed in deliveries among multiparous cows, whereas they were not evident in deliveries among nulliparous cows. These data suggest the utility of dairy cows as models for bio-meteorological studies, and indicate that monitoring lunar phases may facilitate comprehensive understanding of parturition. PMID:27580019

  15. Lunar Cycle Influences Spontaneous Delivery in Cows.

    PubMed

    Yonezawa, Tomohiro; Uchida, Mona; Tomioka, Michiko; Matsuki, Naoaki

    2016-01-01

    There is a popular belief that the lunar cycle influences spontaneous delivery in both humans and cattle. To assess this relationship, we investigated the synodic distribution of spontaneous deliveries in domestic Holstein cows. We used retrospective data from 428 spontaneous, full-term deliveries within a three-year period derived from the calving records of a private farm in Hokkaido, Japan. Spontaneous birth frequency increased uniformly from the new moon to the full moon phase and decreased until the waning crescent phase. There was a statistically significant peak between the waxing gibbous and full moon phases compared with those between the last quarter and the waning crescent. These changes were clearly observed in deliveries among multiparous cows, whereas they were not evident in deliveries among nulliparous cows. These data suggest the utility of dairy cows as models for bio-meteorological studies, and indicate that monitoring lunar phases may facilitate comprehensive understanding of parturition.

  16. Influence of Solar Cycles on Earthquakes

    NASA Astrophysics Data System (ADS)

    Tavares, M.

    2011-12-01

    This research inspects possible influence of solar cycles on earthquakes through of statistical analyses. We also discussed the mechanism that would drive the occurrence of increasing of earthquakes during solar maxima. The study was based on worldwide earthquakes events during approximately four hundred years (1600-2010). The increase of earthquakes events followed the Maxima of Solar cycle, and also depends on the tectonic plate location. From 1600 until 1645 events increased during the Maxima in some of the tectonic plates as Pacific, Arabian and South America. The earthquakes analyzed during two grand solar minima, the Maunder (1645-1720) and the Dalton (1790-1820) showed a decrease in the number of earthquakes and the solar activity. It was observed during these minima a significant number of events at specific geological features. After the last minima (Dalton) the earthquakes pattern increased with solar maxima. The calculations showed that events increasing during solar maxima most in the Pacific, South America or Arabian until 1900. Since there were few records during these three centuries we needed additional analysis on modern data. We took the last four solar cycles events (1950-2010) and made similar calculations. The results agreed with the former calculations. It might be that the mechanism for the Sun-Earth connection relies on the solar wind speed. In both records (1600-1900) and (1950-2010) the results showed a significant increase in earthquakes events in some of the tectonic plates linked to solar maxima. The Solar wind energy striking the Earth's magnetosphere affects the entire environment because the pressure on the region increases and the magnetosphere shrinks sometimes four Earth's radii. This sudden compression causes earthquakes in specific plates. During the times of solar minima the pressure from the solar wind on the earth decreases, then the magnetosphere expands and earthquakes happen in a different pattern according to the

  17. INFLUENCE OF THE DRINKING WATER DISINFECTION BY-PRODUCT DIBROMOACETIC ACID ON RAT ESTROUS CYCLICITY AND OVARIAN FOLLICULAR STEROID RELEASE IN VITRO

    EPA Science Inventory

    The drinking water disinfection by-product, dibromoacetic acid (DBA) has been reported to affect gonadal functions in the male rat. However, there is little information regarding its influence on female reproductive activity. Consequently, the present study investigated the eff...

  18. INFLUENCE OF THE DRINKING WATER DISINFECTION BY-PRODUCT DIBROMOACETIC ACID ON RAT ESTROUS CYCLICITY AND OVARIAN FOLLICULAR STEROID RELEASE IN VITRO

    EPA Science Inventory

    The drinking water disinfection by-product, dibromoacetic acid (DBA) has been reported to affect gonadal functions in the male rat. However, there is little information regarding its influence on female reproductive activity. Consequently, the present study investigated the eff...

  19. Estrous detection by monitoring ventral tail base surface temperature using a wearable wireless sensor in cattle.

    PubMed

    Miura, Ryotaro; Yoshioka, Koji; Miyamoto, Toru; Nogami, Hirofumi; Okada, Hironao; Itoh, Toshihiro

    2017-05-01

    In the present study, the ventral tail base surface temperature (ST) was monitored using a wearable wireless sensor for estrus detection in cattle. Relationships among ST, behavioral estrus expression, ovulation, and changes in hormone profiles during the estrous cycle were examined. Holstein Friesian or Japanese Black female cattle were used in summer (August-September), autumn (October-November) and winter (January-February; three animals per season). On Day 11 of the estrous cycle (Day 0=the day of ovulation), the sensor was attached to the surface of the ventral tail base and ST was measured every 2min until Day 11 of the next estrous cycle. Hourly maximum ST values were used for analysis. To exclude circadian rhythm and seasonal effects, ST changes were expressed as residual temperatures (RT=actual ST - mean ST for the same hour on the previous 3days). Obvious circadian rhythms of the ST were observed and daily changes in the ST significantly differed among seasons. There was no significant seasonal difference, however, in the RT. The mean RT increased significantly ∼24 compared with ∼48h before ovulation. The mean maximum RT was 1.27±0.30°C, which was observed 5.6±2.4h after the onset of estrus, 2.4±1.3h before LH peak, and 26.9±1.2h before ovulation. The ST of the ventral tail base could be monitored throughout the estrous cycle and could detect a substantial change around the time of expression of behavioral estrus. Calculation and analysis of the RT could be useful for automatic estrous detection. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. Activation of extrasynaptic δ-GABAA receptors globally or within the posterior-VTA has estrous-dependent effects on consumption of alcohol and estrous-independent effects on locomotion.

    PubMed

    Melón, Laverne C; Nolan, Zachary T; Colar, Delphine; Moore, Eileen M; Boehm, Stephen L

    2017-09-01

    Recent reports support higher than expected rates of binge alcohol consumption among women and girls. Unfortunately, few studies have assessed the mechanisms underlying this pattern of intake in females. Studies in males suggest that alcohol concentrations relevant to the beginning stages of binge intoxication may selectively target tonic GABAergic inhibition mediated by GABAA receptor subtypes expressing the δ-subunit protein (δ-GABAARs). Indeed, administration of agonists that interact with these δ-GABAARs prior to alcohol access can abolish binge drinking behavior in male mice. These δ-GABAARs have also been shown to exhibit estrous-dependent plasticity in regions relevant to drug taking behavior, like the hippocampus and periaqueductal gray. The present experiments were designed to determine whether the estrous cycle would alter binge drinking, or our ability to modulate this pattern of alcohol use with THIP, an agonist with high selectivity and efficacy at δ-GABAARs. Using the Drinking-in-the-Dark (DID) binge-drinking model, regularly cycling female mice were given 2h of daily access to alcohol (20%v/v). Vaginal cytology or vaginal impedance was assessed after drinking sessions to track estrous status. There was no fluctuation in binge drinking associated with the estrous cycle. Both Intra-posterior-VTA administration of THIP and systemic administration of the drug was also associated with an estrous cycle dependent reduction in drinking behavior. Pre-treatment with finasteride to inhibit synthesis of 5α-reduced neurosteroids did not disrupt THIP's effects. Analysis of δ-subunit mRNA from posterior-VTA enriched tissue samples revealed that expression of this GABAA receptor subunit is elevated during diestrus in this region. Taken together, these studies demonstrate that δGABAARs in the VTA are an important target for binge drinking in females and confirm that the estrous cycle is an important moderator of the pharmacology of this GABAA receptor subtype

  1. [Influence of chosen metals on the citric acid cycle].

    PubMed

    Rojczyk-Gołebiewska, Ewa; Kucharzewski, Marek

    2013-03-01

    Industrial activity growth influenced not only technological progress, but also had negative effects on human natural environment. It results among others in increased human exposition to heavy metals. In case of detoxication mechanisms disturbance in organism, heavy metals cumulate in tissues causing mutations and disrupting metabolism, including Krebs cycle. Recent studies have revealed that iron, zinc and manganese have especially strong influence on Krebs cycle. These elements act as cofactors or inhibitors regulating activity of particular enzymes of this cycle, which has a reflection in cellular energy production disturbances.

  2. Identification and profiling of microRNAs from ovary of estrous Kazakh sheep induced by nutritional status in the anestrous season.

    PubMed

    Yang, Heng; Lin, Shan; Lei, Xiaoping; Yuan, Cong; Tian, Zhanwei; Yu, Yaosheng; Zhao, Zongsheng; Chen, Jingbo

    2016-12-01

    Estrous regulation in sheep has an important role in the sheep industry in improving production of meat and wool. It has been reported that an enhanced nutritional status can induce estrus resulting in an end of the anestrous season earlier than occurs in ewes with a lesser nutritional status. However, the endocrine and physiological mechanisms that induce the increased incidence of estrus remains unclear. In the present study, the differences in amounts and characteristics of miRNAs in ewes at estrus or during the anestrous season were screened by using the Illumina HiSeq sequencing technology. In total, 294 miRNAs, including 174 novel miRNA candidates, were identified in ewes with an enhanced nutritional status (OEN) through assessment of the OEN library for this group and 307 miRNAs including 186 novel miRNA candidates were identified in the ewes with a lesser nutritional status (OAN) through assessing the OAN library, among which there were nine conserved and 104 novel miRNAs in differential amounts between the two libraries. Based on poly (A) q-PCR, six miRNAs were assessed to verify the accuracy of the library database. Furthermore, the family of the known miRNAs, the target genes and related pathways were also analyzed. The results indicated that the nutritional status had important roles in estrous regulation in sheep. The PLA2G4D can directly regulate ovarian follicle development, or indirectly influence leptin secretion involved in the regulation of the reproductive endocrine and physiological systems during the anestrous season. The identification of significantly different miRNAs expanded the repertoire of sheep miRNAs that have been examined and could contribute to further studies on the molecular mechanism of regulation of initiation of estrous cycles in previously anestrous ewes as influenced by different nutritional status. Copyright © 2016. Published by Elsevier B.V.

  3. Estrous asynchrony causes low birth rates in wild female chimpanzees.

    PubMed

    Matsumoto-Oda, Akiko; Ihara, Yasuo

    2011-02-01

    Estrous cycle asynchrony likely functions to elevate individual females' sexual attractiveness during female mate choice. Female chimpanzees show physiological estrus as anogenital swelling. Copulations are concentrated during the period of maximal tumescence, which is called the estrous period. A group of female chimpanzees in Mahale Mountains National Park, Tanzania, was shown to display asynchrony in both maximal tumescence and periovulatory periods. We tested the hypothesis that females establish asynchronous maximal tumescence or periovulatory periods with respect to other females to increase copulation frequency and birth opportunities (Hypothesis 1). We analyzed differences in birth rates between four asynchronous years and five nonasynchronous years. Counter to Hypothesis 1, females in periovulatory periods during asynchronous years showed significantly lower birth rates than those in nonasynchronous years. In addition, periovulatory females copulated more frequently on days on which no other female in a periovulatory period was present. These results suggest that birth rates tend to decrease when females experience nonoverlapping ovulation cycles, although copulation frequency is high. Such a decrease in the birth rate may have resulted from the cost associated with multiple copulations. We tested two other hypotheses: paternity confusion (Hypothesis 2) and sperm competition (Hypothesis 3). Both of these hypotheses were partially supported. The highest-ranking male most effectively monopolized access to receptive females when relatively few other males and receptive females from the party (or subgroup) were present. The viability of Hypotheses 2 and 3 requires that dominant males are able to hinder a female from mating with other males. Given that the male-biased operational sex ratio created by female asynchrony is likely to reduce the efficiency of mate guarding by dominant males, an asynchronous female may gain a fitness benefit by increasing the

  4. The influence of exogenous progestin on the occurrence of proestrous or estrous signs, plasma concentrations of luteinizing hormone and estradiol in deslorelin (GnRH agonist) treated anestrous bitches.

    PubMed

    Sung, M; Armour, A F; Wright, P J

    2006-10-01

    The objectives of this study were to confirm: (i) whether progestin treatment suppressed GnRH agonist-induced estrus in anestrous greyhound bitches; and (ii) the site of progestin action (i.e. pituitary, ovary). All bitches received a deslorelin implant on Day 0 and blood samples were taken from -1 h to +6 h. Five bitches were treated with megestrol acetate (2 mg/kg orally once daily) from -7 d to +6 d (Group 1) and 10 bitches were untreated controls (Group 2). Proestrous or estrous signs were observed in 4 of 5 bitches in Group 1, and 4 of 10 bitches in Group 2 (P = 0.28). The plasma LH responses (area under the curve from 0 to 6h after implantation) were higher (P = 0.008) in Group 2 than in Group 1. Plasma LH responses were similar (P = 0.59) in bitches showing signs of proestrus or estrus (responders) and in non-responders. The plasma estradiol responses (calculated as for LH response) were greater in Group 1 than in Group 2 (P = 0.048), and in responders than in non-responders (P = 0.02). (i) progestin treatment (a) did not suppress the incidence of bitches showing deslorelin-induced proestrus or estrus, and (b) was associated with a reduced pituitary responsiveness and an increased ovarian responsiveness to deslorelin treatment; (ii) the occurrence of proestrous or estrous signs reflected increased ovarian responsiveness to induced gonadotrophin secretion and not increased pituitary responsiveness to deslorelin.

  5. Evaluation of Antral Follicle Count and Ovarian Morphology in Crossbred Beef Cows: Investigation of Influence of Stage of the Estrous Cycle, Age, and Birth Weight

    USDA-ARS?s Scientific Manuscript database

    Depletion of the ovarian reserve is associated with reproductive senescence in mammalian females, and there is a positive relationship between the size of the ovarian reserve and the number of antral follicles on the surface of the ovary. Therefore, we conducted a series of experiments to investiga...

  6. Effect of Mimosa pudica root extract on vaginal estrous and serum hormones for screening of antifertility activity in albino mice.

    PubMed

    Ganguly, Mausumi; Devi, Nirada; Mahanta, Rita; Borthakur, Mridul K

    2007-12-01

    Several plants are traditionally used as birth control agents by the rural people in India. Mimosa pudica is one of the folk medicinal plants commonly used as antifertility agent in some places in India. The present work was carried out to evaluate the claimed antifertility effect of the plant by carrying out pharmacological studies with the root extract of the plant. Air-dried roots of M. pudica were extracted using methanol. Dried methanol extract of the root was administered orally to Swiss albino mice for 21 consecutive days. Estrous cycle, reproductive hormones (LH, FSH, prolactin, estradiol and progesterone) and number of litters produced were studied in both control and extract-administered groups by using standard methods. Phytochemical studies of the methanolic root extract were carried out using qualitative and thin-layer chromatography methods. M. pudica root extract, when administered orally at a dose of 300 mg/kg body weight/day, prolonged the length of the estrous cycle with significant increase in the duration of the diestrous phase and reduced the number of litters in albino mice. The number of litters was increased in the posttreatment period. The analysis of the principal hormones (LH, FSH, prolactin, estradiol and progesterone) involved in the regulation of the estrous cycle showed that the root extract altered gonadotropin release and estradiol secretion. The root extract of M. pudica has antifertility effect as it prolongs the estrous cycle and disturbs the secretion of gonadotropin hormones in albino mice. The decrease in FSH level in the proestrus and estrus stages in the extract-administered group compared with those of control animals indicates the disturbance of estrous cycle and ovulation through suppression of FSH.

  7. The Influence of Eccentricity Cycles on Exoplanet Habitability

    NASA Astrophysics Data System (ADS)

    Baskin, N. J. K.; Fabrycky, D. C.; Abbot, D. S.

    2015-12-01

    In our search for habitable exoplanets, it is important to understand how planetary habitability is influenced by orbital configurations that differ from those of the terrestrial planets in our Solar system. In particular, observational surveys have revealed the prevalence of planetary systems around binary stars. Within these systems, the gravitational influence of a companion star can induce libration in the eccentricity of the planet's orbit (referred to as Kozai Cycles) on timescales as short as thousands of years. The resulting fluctuations in stellar flux at the top of the atmosphere can potentially induce dramatic variations in surface temperatures, with direct implications for the planet's habitability prospects. We investigate this research problem using two steps. First, we utilize the MERCURY N-body integrator in order to calculate the eccentricity of a hypothetical Earth-analogue under the gravitational influence of a stellar companion. Second, we run a coupled Global Climate Model (GCM) at various stages of a cycle provided by the MERCURY runs in order to examine if the increase in insolation renders the planet uninhabitable. This work will allow us to better understand how Kozai cycles influence the boundaries of a planet's habitable zone.

  8. Effect of stress on the expression of GnRH and GnRH receptor (GnRH-R) genes in the preoptic area-hypothalamus and GnRH-R gene in the stalk/median eminence and anterior pituitary gland in ewes during follicular phase of the estrous cycle.

    PubMed

    Ciechanowska, Magdalena; Lapot, Magdalena; Malewski, Tadeusz; Misztal, Tomasz; Mateusiak, Krystyna; Przekop, Franciszek

    2007-01-01

    The RT-PCR (reverse transcription polymerase chain reaction) technique was used to analyze GnRH mRNA and GnRH-R mRNA in the preoptic area, anterior and ventromedial hypothalamus, and GnRH-R mRNA in the stalk/median eminence and anterior pituitary gland of follicular ewes subjected to short (3 h during one day) or prolonged (5 h daily during four consecutive days) footshock stimulation. To analyze relationship between expression of GnRH and GnRH-R genes with LH secretion the blood samples were collected at 10 min intervals to determine LH levels in control and stressed animals. The concentration of GnRH mRNA increased significantly in the preoptic area, anterior and ventromedial hypothalamus of ewes subjected to short stress. The prolonged stressful stimuli significantly decreased GnRH mRNA levels in all analyzed structures. In short stressed ewes the significant augmentation of mRNA encoding GnRH-R was detected in the preoptic area, entire hypothalamus, stalk/median eminence and anterior pituitary gland. The GnRH-R mRNA was significantly reduced in all tested structures of animals subjected to prolonged footshocking except for the preoptic area, where GnRH-R mRNA did not differ from control values. The changes in GnRH mRNA and GnRH-R mRNA levels under short or prolonged stress were associated with an increase or decrease of LH concentration in blood plasma, suggesting the existence of a direct relationship between GnRH mRNA and GnRH-R mRNA expression with LH secretion. The results indicate that the expression of both GnRH gene and GnRH-R gene, as well as LH secretion in ewes during the follicular phase of the estrous cycle, are dependent upon the kind of stress.

  9. Sperm penetration into cervical mucus in vitro. III. Effect of freezing on estrous bovine cervical mucus

    SciTech Connect

    Lee, W.I.; Gaddum-Rosse, P.; Blandau, R.J.

    1981-08-01

    The influence of the storages period on estrous bovine cervical mucus after it was stored in the freezing compartment of the laboratory refrigerator was evaluated by an in vitro sperm penetration test with human spermatozoa, laser light-scattering, and a spinnbarkeit test. Data obtained from the sperm penetration test were analyzed by a mathematical model that correlates the sperm motility with the sperm transport rate and the penetrability of the mucus. The tests showed that estrous bovine cervical mucus can be stored for up to 4 weeks at -12 degrees C without a change in its physical properties. The results of this study strengthen the suggestion that bovine mucus could be employed as a substitute for human cervical mucus.

  10. Male hamsters discriminate estrous state from vaginal secretions and individuals from flank marks

    PubMed Central

    delBarco-Trillo, Javier; LaVenture, Alex B.; Johnston, Robert E.

    2009-01-01

    It is clear that male hamsters discriminate between the odors of individual, conspecific females, as shown by using habituation-dishabituation methods. However, it is not clear from past research whether male hamsters are able to discriminate between the odors of estrous and non-estrous females. A series of habituation-dishabituation experiments were conducted to determine whether males discriminated between different estrous cycle states using two female secretions, those from flank glands and vaginal secretions. We found that, when habituated to a female flank-gland secretion, males discriminated between this female and a second female on the test trial, whether both were in estrus, both were in diestrus, or one was in estrus and the other in diestrus. There was no difference, however, in the magnitude of their dishabituation response toward flank-gland odors of females in estrus and diestrus. These results suggest that males use flank-gland odors to gain information primarily about individuals. When tested with vaginal secretions in habituation-dishabituation tests, males only showed differences in investigation when the second female was in estrus, indicating that males use vaginal secretions to gain information primarily about reproductive state. PMID:19615611

  11. Influencing Factors on Life-Cycle Cost of Mooring Facilities

    NASA Astrophysics Data System (ADS)

    Sato, Wataru; Yokota, Hiroshi; Hashimoto, Katsufumi; Furuya, Koichi; Kato, Hirotoshi

    It is required that infrastructure should satisfy performance requirement through their service life based on an appropriate life cycle management strategy. Now adays, to determine the maintenance strategy and to consider the appropriate timing and method of intervention, the life-cycle cost (LCC) has been widely used as one of the decision-making indices. However, many factors influence on the estimation of LCC and they have not been adequately investigated. In this paper, the authors have made analytical investigation to quantify the influence of important factors on the results of LCC estimation. Four kinds of mooring facilities are focused; two of them are open-type wharves and the other two are sheet pile type quay walls having different design water depths. Prediction of deterioration progress and performance degradation is made by using the Markov models. The influences of structural sizes, transition probability in the Markov model, design service life, periodic inspection and methods of intervention on LCC were investigated. The influence of those factors has been discussed based on the calculated results of LCC by creating the maintenance scenarios for model mooring facilities.

  12. Female Fear: Influence of Estrus Cycle on Behavioral Response and Neuronal Activation

    PubMed Central

    Chen, Wei; Shields, Jessica; Huang, Wei; King, Jean A

    2009-01-01

    Our observation that male rats innate fear response differed with hormonal status, as well as the higher prevalence of fear and anxiety disorders in human females led to the current investigation of the impact of phases of the estrous cycle on innate fear responding. Female rats in different phases of the cycle were exposed to an innate fear-inducing stimulus (2,5-dihydro- 2,4,5-trimethylthiazoline, TMT odor) and monitored for changes in behavior and brain activation. Behavioral data showed freezing responses to TMT were significantly enhanced during estrus as compared to other phases of the cycle. This data was supported by significant increases in pixel intensity in cortical and sub-cortical regions in estrus compared to proestrus and diestrus. Imaging results demonstrated significant increases in brain activation in the somatosensory and insular cortices when comparing estrus to diestrus. There were significant increases in neural activity in the BNST and septum in estrus as compared to proestrus. Additionally, the hippocampus, hypothalamus, olfactory system, and cingulate cortex show significant increases in the estrus phase when compared to both diestrus and proestrus. Taken together, these results suggest that the female's hormonal status may be correlated with alterations in both neuronal and behavioral indices of fear. PMID:19428610

  13. The influence of catalysts on biofuel life cycle analysis (LCA)

    DOE PAGES

    Benavides, Pahola Thathiana; Cronauer, Donald C.; Adom, Felix K.; ...

    2017-01-21

    Catalysts play an important role in biofuel production but are rarely included in biofuel life cycle analysis (LCA). In this work, we estimate the cradle-to-gate energy consumption and greenhouse gas (GHG) emissions of Pt/γ-Al2O3, CoMo/γ-Al2O3, and ZSM-5, catalysts that could be used in processes to convert biomass to biofuels. We also consider the potential impacts of catalyst recovery and recycling. Integrating the energy and environmental impacts of CoMo/γ-Al2O3 and ZSM-5 into an LCA of renewable gasoline produced via in-situ and ex-situ fast pyrolysis of a blended woody feedstock revealed that the ZSM-5, with cradle-to-gate GHG emissions of 7.7 kg CO2e/kg,more » could influence net life-cycle GHG emissions of the renewable gasoline (1.7 gCO2e/MJ for the in-situ process, 1.2 gCO2e/MJ for the ex-situ process) by up to 14% depending on the loading rate. CoMo/γ-Al2O3 had a greater GHG intensity (9.6 kg CO2e/kg) than ZSM-5, however, it contributed approximately only 1% to the life-cycle GHG emissions of the renewable gasoline because of the small amount of this catalyst needed per kg of biofuel produced. As a result, given that catalysts can contribute significantly to biofuel life-cycle GHG emissions depending on the GHG intensity of their production and their consumption rates, biofuel LCAs should consider the potential influence of catalysts on LCA results.« less

  14. The influence of catalysts on biofuel life cycle analysis (LCA)

    DOE PAGES

    Benavides, Pahola Thathiana; Cronauer, Donald C.; Adom, Felix K.; ...

    2017-01-21

    Catalysts play an important role in biofuel production but are rarely included in biofuel life cycle analysis (LCA). In this work, we estimate the cradle-to-gate energy consumption and greenhouse gas (GHG) emissions of Pt/γ-Al2O3, CoMo/γ-Al2O3, and ZSM-5, catalysts that could be used in processes to convert biomass to biofuels. We also consider the potential impacts of catalyst recovery and recycling. Integrating the energy and environmental impacts of CoMo/γ-Al2O3 and ZSM-5 into an LCA of renewable gasoline produced via in-situ and ex-situ fast pyrolysis of a blended woody feedstock revealed that the ZSM-5, with cradle-to-gate GHG emissions of 7.7 kg CO2e/kg,more » could influence net life-cycle GHG emissions of the renewable gasoline (1.7 gCO2e/MJ for the in-situ process, 1.2 gCO2e/MJ for the ex-situ process) by up to 14% depending on the loading rate. CoMo/γ-Al2O3 had a greater GHG intensity (9.6 kg CO2e/kg) than ZSM-5, however, it contributed approximately only 1% to the life-cycle GHG emissions of the renewable gasoline because of the small amount of this catalyst needed per kg of biofuel produced. As a result, given that catalysts can contribute significantly to biofuel life-cycle GHG emissions depending on the GHG intensity of their production and their consumption rates, biofuel LCAs should consider the potential influence of catalysts on LCA results.« less

  15. Menstrual cycle influences on voice and speech in adolescent females.

    PubMed

    Meurer, Elisea M; Garcez, Vera; von Eye Corleta, Helena; Capp, Edison

    2009-01-01

    The objective of this study is to characterize voice intensity and stability of fundamental frequency, formants and diadochokinesis, vocal modulations, rhythms, and speed of speech in adolescents during follicular and luteal phases of the menstrual cycle. Twenty-three adolescent females who were nonusers of oral contraceptives participated in a cross-sectional study of menstrual cycle influences on voicing and speaking tasks. Acoustic analyses were performed during both phases of the menstrual cycle using the Kay Elemetrics Computer Speech Lab Software Package. Data were analyzed using Student's paired sample t test. Phono-articulatory parameters were similar in both phases of the menstrual cycle (fundamental frequency: 192.6+/-23.9 Hz; minimum formant 891.7+/-110.3 Hz; and maximum formant: 2471.5+/-203.6 Hz). In diadochokinesis, they had a speed of 5.6+/-0.6 seg/s and vocal intensity was 61.5+/-2.6 dB. The mean values for the variations in voice modulations were as follows: anger (21.7+/-8.7 Hz)cycle, the speed of speech was 5.2+/-0.6 seg/s in meaningful sentences and 1.9+/-0.2 seg/s in meaningless sentences. In conclusion, the adolescents showed similar voice fundamental frequency and intensity, formants, speed of speech, and suprasegmental speech parameters. The results shown in this study may be used as standard of acoustic phono-articulatory for adolescents.

  16. Factors Influencing Phosphorous Cycling in Biogeochemical 'Hot Spots'

    NASA Astrophysics Data System (ADS)

    Saia, S. M.; Walter, M. T.; Buda, A. R.; Carrick, H. J.; Regan, J. M.

    2015-12-01

    Anthropogenic alteration of the phosphorus (P) cycle has led to subsequent soil and water quality issues. For example, P build up in soils due to historic fertilizer application may become biologically available and exacerbate eutrophication and anoxia in nearby water bodies. In the humid Northeastern United States, storm runoff transports P and also stimulates biogeochemical processes, these locations are termed biogeochemical 'hot spots'. Many studies have looked at nitrogen and carbon cycling in biogeochemical hot spots but few have focused on P. We hypothesize the periodic wetting and drying of biogeochemical hot spots promotes a combination of abiotic and biotic processes that influence the mobility of P. To test this hypothesis, we took monthly soil samples (5 cm deep) from May to October in forest, pasture, and cropped land near Ithaca, NY. In-situ measurements taken with each sample included volumetric soil moisture and soil temperature. We also analyzed samples for 'runoff generated' phosphate, nitrate, and sulfate (from 0.01 M CaCl2 extraction), Fe(II), percent organic matter, pH, as well as oxalate extractable and total P, Al, and Fe. We used linear mixed effects models to test how runoff generated phosphate concentrations vary with soil moisture and whether other environmental factors strengthen/weaken this relationship. The knowledge gained from this study will improve our understanding of P cycling in biogeochemical hot spots and can be used to improve the effectiveness of agricultural management practices in the Northeastern United States.

  17. Elevated CO2 influences microbial carbon and nitrogen cycling

    PubMed Central

    2013-01-01

    Background Elevated atmospheric CO2 (eCO2) has been shown to have significant effects on terrestrial ecosystems. However, little is known about its influence on the structure, composition, and functional potential of soil microbial communities, especially carbon (C) and nitrogen (N) cycling. A high-throughput functional gene array (GeoChip 3.0) was used to examine the composition, structure, and metabolic potential of soil microbial communities from a grassland field experiment after ten-year field exposure to ambient and elevated CO2 concentrations. Results Distinct microbial communities were established under eCO2. The abundance of three key C fixation genes encoding ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco), carbon monoxide dehydrogenase (CODH) and propionyl-CoA/acetyl-CoA carboxylase (PCC/ACC), significantly increased under eCO2, and so did some C degrading genes involved in starch, cellulose, and hemicellulose. Also, nifH and nirS involved in N cycling were significantly stimulated. In addition, based on variation partitioning analysis (VPA), the soil microbial community structure was largely shaped by direct and indirect eCO2-driven factors. Conclusions These findings suggest that the soil microbial community structure and their ecosystem functioning for C and N cycling were altered dramatically at eCO2. This study provides new insights into our understanding of the feedback response of soil microbial communities to elevated CO2 and global change. PMID:23718284

  18. Influence of sulfur compounds on the terrestrial carbon cycle

    NASA Astrophysics Data System (ADS)

    Eliseev, A. V.

    2015-11-01

    Using the climate model developed at the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), numerical experiments have been conducted in line with the Coupled Model Intercomparison Project Phase 5 (CMIP5), but scaling the anthropogenic emissions of sulfur compounds into the troposphere by ±25%. Two types of impacts of sulfur compounds on climate and the global carbon cycle are considered: climate impact (CI, associated with the influence of tropospheric sulfates on climate and, as a consequence, on the carbon cycle characteristics) and ecological impact (EI, associated with the influence of SO2 on the rate of photosynthesis of terrestrial plants). The climate impact was found to be generally more important than the ecological one. However, in a number of regions, the EI is comparable to CI, including in the southeast parts of North America and, especially, of Asia. The contribution of EI to the change in global characteristics of terrestrial ecosystems in the 20th century is likewise considerable. The CI is generally more sensitive to the uncertainty in anthropogenic emissions of sulfur compounds into the troposphere than the EI.

  19. Exotic Earthworm Influence on Nitrogen Cycling in FACE Forest Soils

    NASA Astrophysics Data System (ADS)

    Top, S. M.; Filley, T. R.

    2010-12-01

    Exotic earthworm invasion in northern North American forests has the potential to significantly alter nitrogen and carbon cycling in forest soils, through litter layer losses, loss of organic horizon, and changes in fine root density. Earthworm influence on nitrogen cycling is currently being investigated in the free-air CO2 enrichment (FACE) sites at Rhinelander, WI. Because of the 13C depleted CO2 used in the FACE experiment and a 15N addition to the soil, this system affords an ideal opportunity to determine the impact of earthworm activity on soil organic matter dynamics by tracking the relative abundance and stable isotope compositions of biopolymers (amino acids, etc.) isolated in earthworms fecal pellets and soils. The 15N and 13C isotope composition of earthworm fecal matter from epigeic (litter and organic matter horizon dwelling) and endogeic (predominantly mineral soil dwelling) species highlighted their distinct role in litter, surface soil, and deeper soil movement through the soil. Specifically, endogeic fecal matter exhibited a lower uptake of FACE-derived C and a more enriched 15N signal. Nitrogen content of soil between the control and elevated CO2 treatments is not significantly different; however, elevated CO2 treatments exhibited relative depletion in both the soil and root 15N with respect to controls. The loss of 15N in the roots and the top 5 cm of the soil under elevated CO2, suggests that there is greater cycling power with increased below ground productivity and earthworm activity under elevated CO2, as higher abundances of earthworms exist in the elevated CO2 treatments. Amino acid extractions from the soil and fecal matter are ongoing and will help clarify the details regarding molecular nitrogen cycling.

  20. Influences of Vegetation Phenological Shifts on Water and Energy Cycle

    NASA Astrophysics Data System (ADS)

    Xu, X.; Riley, W. J.; Koven, C. D.

    2015-12-01

    Remote sensed vegetation indices and field measurements have demonstrated that climate change has influenced vegetation phenology. The phenological changes are expressed in shifts in the timing of spring vegetation activity and the length of the active growing season. According to NDVI data from NOAA and GIMMS, the length of the active growing season north of 45°N has extended by 12 days due to 8 days advancement in spring and 4 days prolongation in autumn between July 1981 and June 1991. The same NDVI dataset from July 1981 to December 1999 has shown the growing season increased by 18 days in Eurasia and 12 days in North America. Phenology regulates vegetation interactions with climate by influencing the energy, water and carbon cycles. Here, we use observations and the Community Land Model 4.5 (CLM4.5) in offline mode and coupled with CESM to evaluate influences of shifts in phenology on energy and water budget and partitioning and on interactions with the atmosphere. Satellite retrieved leaf area index (LAI) is used to prescribe shifts in vegetation phenology in CLM4.5. We find that phenological advancement of 12 days over the past few decades can result in monthly mean changes of (-5-7 Wm-2) in latent heat and (-5-9Wm-2) in sensible heat balance over wide regions. We will discuss (1) the capability of current climate models to predict the impacts of phenological shifts on climate change, (2) seasonal to annual changes in energy and water cycles in response to phenological shifts, (3) the spatial heterogeneity in phenological-induced energy and water partitioning in different plant functional types across regions and continents, and (4) phenology and plant-climate interactions in changing climate.

  1. Previous experience influences pacing during 20 km time trial cycling.

    PubMed

    Micklewright, D; Papadopoulou, E; Swart, J; Noakes, T

    2010-10-01

    To investigate how experience and feedback influence pacing and performance during time trial cycling. Twenty-nine cyclists performed three 20 km cycling time trials using a Computrainer. The first two time trials (TT1 and TT2) were performed (1) without any performance feedback (n = 10), (2) with accurate performance feedback (n = 10) or (3) with false feedback showing the speed to be 5% greater than the actual speed (n = 9). All participants received full feedback during the third time trial (TT3), and their performance and pacing data were compared against TT2. Completion time, average power and average speed did not change among the false feedback group, but their pacing strategy did change as indicated by a lower average cadence, 89.2 (SD 5.2) vs 96.4 (6.8) rpm, p<0.05, and higher power during the first 5 km (SMD = 39, 36, 36, 27 and 27 W for 1-5 km respectively). Pacing changed among the blind feedback group indicated by a faster completion time, 35.9 (3.1) vs 36.8 (4.4) min, p<0.05, and power increases during the final 5 km (SMD = 14, 13, 18, 23 and 53 W for 16-20 km respectively). No performance or pacing changes were observed among the accurate feedback group. Pacing is influenced by an interaction between feedback and previous experience. Conscious cognitive processes that lead to ratings of perceived exertion and pacing appear to be influenced by previous experience.

  2. Influence of Plants on Chlorine Cycling in Terrestrial Environments

    NASA Astrophysics Data System (ADS)

    Montelius, Malin; Thiry, Yves; Marang, Laura; Ranger, Jacques; Cornelis, Jean-Thomas; Svensson, Teresia; Bastviken, David

    2016-04-01

    Chlorine (Cl), one of the 20 most abundant elements on Earth, is crucial for life as a regulator of cellular ionic strength and an essential co-factor in photosynthesis. Chlorinated organic compounds (Clorg) molecules are surprisingly abundant in soils, in fact many studies during the last decades show that Clorg typically account for more than 60% of the total soil Cl pool in boreal and temperate forest soils and frequently exceed chloride (Cl-) levels. The natural and primarily biotic formation of this Clorg pool has been confirmed experimentally but the detailed content of the Clorg pool and the reasons for its high abundance remains puzzling and there is a lack of Cl budgets for different ecosystems. Recently, the radioisotope 36Cl has caused concerns because of presence in radioactive waste, a long half-life (301 000 years), potential high mobility, and limited knowledge about Cl residence times, speciation and uptake by organisms in terrestrial environments. The chlorination of organic molecules may influence the pool of available Cl- to organisms and thereby the Cl cycling dynamics. This will prolong residence times of total Cl in the soil-vegetation system, which affects exposure times in radioactive 36Cl isotope risk assessments. We tested to what extent the dominating tree species influences the overall terrestrial Cl cycling and the balance between Cl- and Clorg. Total Cl and Clorg were measured in different tree compartments and soil horizons in the Breuil experimental forest, Bourgogne, established in 1976 and located at Breuil-Chenue in Eastern France. The results from this field experiment show how the dominating tree species affected Cl cycling and accumulation over a time period of 30 years. Cl uptake by trees as well as content of both total Cl and Clorg in soil humus was much higher in experimental plots with coniferous forests compared to deciduous forests. The amounts of Clorg found in plant tissue indicate significant Clorg production inside

  3. The influence of steroids on noradrenaline-mediated contractile reactivity of the superficial nasal and facial veins in cycling gilts.

    PubMed

    Grzegorzewski, W J; Muszak, J; Wasowska, B; Jan, B; Stefańczyk-Krzymowska, S

    2012-01-01

    The nasal venous blood may be directed through the facial vein into the systemic circulation or through the frontal vein into the venous cavernous sinus of the perihypophyseal vascular complex, where hormones and pheromones permeate from the venous blood into the arterial blood supplying the brain and hypophysis. The present study was designed to determine the effect of noradrenaline (NA) on the tension of the nasal, frontal and facial veins of cycling gilts, and influence of ovarian steroid hormones on NA-mediated contractile reactivity. Additionally, the enzyme dopamine-beta-hydroxylase catalysing the conversion of dopamine to noradrenaline (DbetaH) was immunolocalized in these vessels. Among three studied veins, the frontal proximal vein, that fulfill a key role in the supply of the nasal venous blood into the venous cavernous sinus, reacted to NA most strongly (P < 0.001) and this reaction was weaker in the periestrous period than in luteal phase (P < 0.001). Inversely, the reaction to NA of the facial proximal vein, that carry blood to the peripheral circulation, was stronger in the periestrous period than in luteal phase (P < 0.05). P4, E2 and T significantly lowered NA-mediated tension of the frontal proximal vein during the periestrous period (P < 0.001), while in the luteal phase P4 might antagonize relaxing effect of E2 to this vessel. The result suggests that supply of the nasal venous blood into the venous cavernous sinus is greater during the periestrous period than during the luteal phase. DbetaH was clearly expressed in the muscular layer of the isolated superficial nasal and facial veins of gilts in both studied stages of the estrous cycle. We suggest that the reactivity of the superficial veins of the nose and face to NA combined with the previously demonstrated reactivity of these veins to steroid ovarian hormones and male steroid pheromones may regulate the access of priming pheromone androstenol (resorebed in the nasal cavity) to the brain of

  4. Differential leaflet mortality may influence biogeochemical cycling following tropical cyclones.

    PubMed

    Marler, Thomas E; Ferreras, Ulysses

    2014-01-01

    Intensity of tropical cyclones is expected to increase in the coming century, and an improved understanding of their influence on biogeochemical cycles would benefit ecologists and conservationists. We studied the November 2013 Typhoon Haiyan damage to observe that numerous examples of partial leaf necrosis on intact leaves of trees in the Cycadaceae and Arecaceae families resulted, leaving behind a copious amount of arboreal dead leaf material attached to live leaves. The decay process of this form of arboreal litter has not been previously studied. When compared with decay of ground litter or detached litter suspended in the canopy, we predict the decay process of this form of arboreal litter will include increased photooxidation, leaching, and comminution by detritivorous insects and mites; but decreased catabolism of organic molecules by saprophytic organisms.

  5. Influence of soil moisture-carbon cycle interactions on the terrestrial carbon cycle over Europe

    NASA Astrophysics Data System (ADS)

    Mystakidis, Stefanos; Davin, Edouard L.; Gruber, Nicolas; Seneviratne, Sonia I.

    2016-04-01

    Water availability is a crucial limiting factor for terrestrial ecosystems, but relatively few studies have quantitatively assessed the influence of soil moisture variability on the terrestrial carbon cycle. Here, we investigate the role of soil moisture variability and state in the contemporary terrestrial carbon cycle over Europe. For this we use a Regional Earth System Model (RESM) based on the COSMO-CLM Regional Climate Model, coupled to the Community Land Model version 4.0 (CLM4.0) and its carbon-nitrogen module. The simulation setup consists of a control simulation over the period 1979-2010 in which soil moisture is interactive and three sensitivity simulations in which soil moisture is prescribed to a mean, a very dry or a very wet seasonal cycle without inter-annual variability. The cumulative net biome productivity varies markedly between the different experiments ranging from a strong sink of up to 6PgC in the wet experiment to a source of up to 1.2PgC in the dry experiment. Changes in the land carbon uptake are driven by a combination of two factors: the direct impact of soil moisture on plant's carbon uptake (essentially in southern Europe) and an indirect effect through changes in temperature affecting ecosystem respiration (mainly in central and northern Europe). We find that removing temporal variations in soil moisture dampens interannual variations in terrestrial carbon fluxes (Gross Primary Productivity, respiration, Net Biome Productivity) by more than 50% over most of Europe. Moreover, the analysis reveals that on annual scale about two-thirds of central Europe and about 70% of southern Europe display statistically significant effect of drying and/or wetting on the terrestrial carbon budget and its components. Our findings confirm the crucial role of soil moisture in determining the magnitude and the inter-annual variability in land CO2 uptake which is a key contributor to the year-to-year variations in atmospheric CO2 concentration.

  6. Estrous phase alters social behavior in a polygynous but not a monogamous Peromyscus species.

    PubMed

    Karelina, Kate; Walton, James C; Weil, Zachary M; Norman, Greg J; Nelson, Randy J; Devries, A Courtney

    2010-07-01

    The social organization of rodent species determines behavioral patterns for both affiliative and agonistic encounters. The neuropeptide oxytocin has been implicated in the mediation of social behavior; however, variability in both neuropeptide expression and social behavior within a single species indicates an additional mediating factor. The purpose of the present comparative study was to investigate social behaviors in naïve mixed-sex pairs of monogamous Peromyscus californicus and polygynous Peromyscus leucopus. We identified substantial inter- and intra-specific variability in the expression of affiliative and agonistic behaviors. Although all P. californicus tested engaged in frequent and prolonged intervals of social contact and rarely engaged in aggressive behaviors, P. leucopus exhibited significant variability in both measures of social behaviors. The naturally occurring differences in social behavior displayed by P. leucopus vary across the estrous cycle, and correspond to hypothalamic oxytocin, as well as circulating oxytocin and glucocorticoid concentrations. These results provide evidence for a rhythm in social behavior across the estrous cycle in polygynous, but not monogamous, Peromyscus species. Copyright 2010 Elsevier Inc. All rights reserved.

  7. Estrous and endocrine responses of lactating Holsteins to forced ventilation during summer.

    PubMed

    Younas, M; Fuquay, J W; Smith, A E; Moore, A B

    1993-02-01

    Fourteen lactating and cycling Holsteins in each of two summers were assigned randomly to pens in a free-stall barn either with or without overhead fans to study the effect of fan cooling on certain endocrine and behavioral responses during the estrous cycle. After an adjustment period of 8 d in the first summer and 21 d in the second summer, jugular cannulas were inserted, and 25 mg of PGF2 alpha were injected. After injection, blood samples were collected frequently for 84 h in the first summer and 88 h in the second summer, followed by collection three times weekly for 3 wk thereafter each summer. Rectal temperatures were lower in the group cooled by fans than in the control group each summer. Luteal progesterone secretion tended to be greater in the fan group each summer; area under the luteal phase curve was significantly higher than for controls during the second summer. There was tendency for more preovulatory surges of LH and higher estrous responses rates in the fan group during the second summer. Thus, fan cooling of lactating dairy cows for several weeks before anticipated breeding provides potential for more efficient reproductive performance during the summer.

  8. [Influence of the ovarian cycle on the central nervous system].

    PubMed

    Kuhl, H

    2002-04-01

    Estradiol, progesterone and some of their metabolites modulate the activity of neurotransmitters and neuropeptides in the CNS. The distribution and concentrations of sex steroids in the various CNS regions is partly dependent on the serum levels, but also on the local synthesis of the steroids. In general, estradiol and testosterone exert a stimulatory, progesterone an inhibitory effect on neuronal activities which are mediated by excitatory (e.g. glutamate, aspartate), and inhibitory amino acids (e.g. GABA) and neuropeptides (e.g. beta-endorphin), respectively. Gonadotropin release is primarily governed by the rhythm of pulsatile secretion of GnRH in the hypothalamus which is controlled by estradiol and progesterone by means of inhibitory or stimulatory modulation of the amplitude and frequency of GnRH pulses. The discharges of GnRH neurons triggered by excitatory amino acids are modulated by estradiol, while the inhibitory effect of progesterone is mediated by GABA and beta-endorphin which cause hyperpolarization of the GnRH neurons and consequently a reduced pulse frequency. The pulse amplitudes are primarily influenced by estradiol, but neuropeptide Y, neurotensin and noradrenaline contribute to their preovulatory enhancement. The postovulatory rise in core temperature is caused by the increasing level of progesterone and its metabolite 3 alpha-pregnanolone, respectively. Despite of this, up to 20% of ovulatory cycles do not show any rise in body temperature. Although 3 alpha-pregnanolone has sedative activities, there is no change in sleep quality during the luteal phase due to their low serum levels. It could be demonstrated that performance on tests of articulatory and fine motor skills are enhanced in the late follicular phase as compared to the menstruation phase, while spatial ability was better during menses. Estrogens may influence mood and well-being in a favorable manner, while in predisposed women progesterone may cause symptoms of premenstrual

  9. Influence of Cutting Cycle and Spacing on Coppice Sycamore Yield

    Treesearch

    H. E. Kennedy

    1975-01-01

    Cutting cycle significantly affected total aboveground dry-weight yields, which were greater with the 2-, 3-, and 4-year cycles than with the I-year. For all cutting cycles, significantly higher yields were obtained with 2- by 5-foot spacings than with 4 by 5. Dry-weight yields ranged from 3,229 pounds per acre per year for the I-year cutting cycle spaced at 4 by 5...

  10. QBO as Potential Amplifier of Solar Cycle Influence

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mangel, John G.; Wolff, Charles L.; Porter, Hayden S.

    2006-01-01

    The solar cycle (SC) effect in the lower atmosphere has been linked observationally to the quasi-biennial oscillation (QBO) of the zonal circulation. Salby and Callaghan (2000) in particular analyzed the QBO covering more than 40 years and found that it contains a large SC signature at 20 km. We discuss a 3D study in which we simulate the QBO under the influence of the SC. For a SC period of 10 years, the relative amplitude of radiative forcing is taken to vary with height: 0.2% (surface), 2% (50 km), 20% (100 km and above). This model produces in the lower stratosphere a relatively large modulation of the QBO, which appears to come from the SC and qualitatively agrees with the observations. The modulation of the QBO, with constant phase relative to the SC, is shown to persist at least for 50 years, and it is induced by a SC modulated annual oscillation that is hemispherically symmetric and confined to low latitudes.

  11. Evidence that the lunar cycle influences human sleep.

    PubMed

    Cajochen, Christian; Altanay-Ekici, Songül; Münch, Mirjam; Frey, Sylvia; Knoblauch, Vera; Wirz-Justice, Anna

    2013-08-05

    Endogenous rhythms of circalunar periodicity (∼29.5 days) and their underlying molecular and genetic basis have been demonstrated in a number of marine species [1, 2]. In contrast, there is a great deal of folklore but no consistent association of moon cycles with human physiology and behavior [3]. Here we show that subjective and objective measures of sleep vary according to lunar phase and thus may reflect circalunar rhythmicity in humans. To exclude confounders such as increased light at night or the potential bias in perception regarding a lunar influence on sleep, we retrospectively analyzed sleep structure, electroencephalographic activity during non-rapid-eye-movement (NREM) sleep, and secretion of the hormones melatonin and cortisol found under stringently controlled laboratory conditions in a cross-sectional setting. At no point during and after the study were volunteers or investigators aware of the a posteriori analysis relative to lunar phase. We found that around full moon, electroencephalogram (EEG) delta activity during NREM sleep, an indicator of deep sleep, decreased by 30%, time to fall asleep increased by 5 min, and EEG-assessed total sleep duration was reduced by 20 min. These changes were associated with a decrease in subjective sleep quality and diminished endogenous melatonin levels. This is the first reliable evidence that a lunar rhythm can modulate sleep structure in humans when measured under the highly controlled conditions of a circadian laboratory study protocol without time cues.

  12. Influence of soil structure on nutrient cycling using microfluidic techniques

    NASA Astrophysics Data System (ADS)

    Arellano Caicedo, Carlos; Aleklett, Kristin; Ohlsson, Pelle; Hammer, Edith

    2017-04-01

    The rising of atmospheric CO2 levels and its effects on global warming make it necessary to understand the elements that regulate such levels and furthermore try to slow down the CO2 accumulation in the atmosphere. The exchange of carbon between soil and atmosphere plays a significant role in the atmospheric carbon budget. Soil organisms deposit organic compounds on and in soil aggregates, either as exudates or dead remains. Much of this dead organic material is quickly recycled, but a portion, however, will stay in the soil for long term. Evidence suggests that micro-scale biogeochemical interactions could play a highly significant role in degradation or persistence of organic matter in soils, thus, soil physical structure might play a decisive role in preventing accessibility of nutrients to microorganisms. For studying effects of spatial microstructure on soil nutrient cycles, we have constructed artificial habitats for microbes that simulate soil structures. Microfluidic, so called Lab-on-a-chip technologies, are one of the tools used to achieve our purpose. Such micro-habitats consist of pillar structures of difference density and surface area, tunnels with increasing depth, and mazes of increasing complexity to simulate different stages of soil aggregation. Using microscopy and analytical chemistry, we can follow the growth of microorganisms inoculated into the "soil chip" as well as the chemical degradation of organic matter compounds provided as nutrient source. In this way, we want to be able to predict how soil structure influences soil microbial activity leading to different effects on the carbon cycle. Our first results of a chip inoculated with natural soil showed a succession of organisms colonizing channels leading to dead-end arenas, starting with a high presence of bacteria inside the chip during the first days. Fungal hyphae growth gradually inside the channels until it finally occupied the big majority of the spaces isolating bacteria which

  13. Influence of driving cycles on unit emissions from passenger cars

    NASA Astrophysics Data System (ADS)

    Joumard, R.; André, M.; Vidon, R.; Tassel, P.; Pruvost, C.

    Small samples of petrol engine or diesel cars, equipped with or without catalysts, were tested over 36 driving cycles divided into four categories - standard cycles and three sets of cycles more representative of real-world driving conditions. The tests addressed standard gaseous pollutants and fuel consumption and also less frequently measured pollutant such as CH 4. In the first part of this paper we examine cold emissions in order to assess the duration of the cold start impact and the representativity of the cold ECE15 cycle. Then unit emissions are compared over the four driving cycle families. As compared to representative cycles, the standardised cycles underestimate hot emissions by almost 50% for petrol engine cars and 30% for diesel vehicles. Conversely, the results obtained for the three representative cycle families are in relatively close agreement with each other - within approximately 10%. However, the cinematic properties of the three families differ. Finally, we demonstrate that weighting all emission data equally, not taking into account the weight of each cycle in overall traffic, introduces significant biases, particularly when plotting emission vs. average speed curves.

  14. [Effects of a short-term diet of precooked corn flour on the vaginal cycle, in rats placed in various conditions of environmental illumination].

    PubMed

    Lopez de Onate, R; Giammanco, S; Carollo, F; Ernandes, M; Paderni, M A

    1989-03-01

    The aim of this research is to study the effects of a diet almost devoid of tryptophan, which is given by a feeding with precooked yellow corn meal (corn mush), on the alterations of the estrous cycle of animals in several conditions of environmental lighting. Indeed, it is known that cerebral serotonin influences the releasing of LH and consequently the ovulation. The different types of environmental lighting are: 1) Natural (alternating Day-Night = L/D). 2) Continuous dark (D/D). 3) Continuous light by sodium steams (L/L sodium). 4) Continuous light by fluorescent neon tubes (L/L neon). The muricide behaviour is studied by comparison rat-mouse. The feeding with precooked yellow corn meal (diet lacking of tryptophan) unchains in the 100% of the observations the CEA (Constant Estrous Anovulatory), and significantly shrinks the estral cycle in the female Wistar Rat in several conditions of environmental lighting.

  15. Voluntary Exercise Improves Estrous Cyclicity in Prenatally Androgenized Female Mice Despite Programming Decreased Voluntary Exercise: Implications for Polycystic Ovary Syndrome (PCOS)

    PubMed Central

    Homa, Lori D.; Burger, Laura L.; Cuttitta, Ashley J.; Michele, Daniel E.

    2015-01-01

    Prenatal androgen (PNA) exposure in mice produces a phenotype resembling lean polycystic ovary syndrome. We studied effects of voluntary exercise on metabolic and reproductive parameters in PNA vs vehicle (VEH)-treated mice. Mice (8 wk of age) were housed individually and estrous cycles monitored. At 10 weeks of age, mice were divided into groups (PNA, PNA-run, VEH, VEH-run, n = 8–9/group); those in the running groups received wheels allowing voluntary running. Unexpectedly, PNA mice ran less distance than VEH mice; ovariectomy eliminated this difference. In ovary-intact mice, there was no difference in glucose tolerance, lower limb muscle fiber types, weight, or body composition among groups after 16 weeks of running, although some mitochondrial proteins were mildly up-regulated by exercise in PNA mice. Before running, estrous cycles in PNA mice were disrupted with most days in diestrus. There was no change in cycles during weeks 1–6 of running (10–15 wk of age). In contrast, from weeks 11 to 16 of running, cycles in PNA mice improved with more days in proestrus and estrus and fewer in diestrus. PNA programs reduced voluntary exercise, perhaps mediated in part by ovarian secretions. Exercise without weight loss improved estrous cycles, which if translated could be important for fertility in and counseling of lean women with polycystic ovary syndrome. PMID:26360506

  16. Cycling on a Bike Desk Positively Influences Cognitive Performance

    PubMed Central

    Torbeyns, Tine; De Pauw, Kevin; Decroix, Lieselot; Van Cutsem, Jeroen

    2016-01-01

    Purpose Cycling desks as a means to reduce sedentary time in the office has gained interest as excessive sitting has been associated with several health risks. However, the question rises if people will still be as efficient in performing their desk-based office work when combining this with stationary cycling. Therefore, the effect of cycling at 30% Wmax on typing, cognitive performance and brain activity was investigated. Methods After two familiarisation sessions, 23 participants performed a test battery [typing test, Rey auditory verbal learning test (RAVLT), Stroop test and Rosvold continuous performance test (RCPT)] with electroencephalography recording while cycling and sitting on a conventional chair. Results Typing performance, performance on the RAVLT and accuracy on the Stroop test and the RCPT did not differ between conditions. Reaction times on the Stroop test and the RCPT were shorter while cycling relative to sitting (p < 0.05). N200, P300, N450 and conflict SP latency and amplitude on the Stroop test and N200 and P300 on the RCPT did not differ between conditions. Conclusions This study showed that typing performance and short-term memory are not deteriorated when people cycle at 30% Wmax. Furthermore, cycling had a positive effect on response speed across tasks requiring variable amounts of attention and inhibition. PMID:27806079

  17. Lack of Influence of the Menstrual Cycle on Blood Lactate.

    ERIC Educational Resources Information Center

    Lamont, Linda S.

    1986-01-01

    Nine healthy women were tested before, during, and after exercise during the follicular and luteal phases of their menstrual cycles to determine the effect of menstruation on blood lactate levels. Findings are discussed. (Author/MT)

  18. Lack of Influence of the Menstrual Cycle on Blood Lactate.

    ERIC Educational Resources Information Center

    Lamont, Linda S.

    1986-01-01

    Nine healthy women were tested before, during, and after exercise during the follicular and luteal phases of their menstrual cycles to determine the effect of menstruation on blood lactate levels. Findings are discussed. (Author/MT)

  19. [Influences of lunar cycle in labor: myth or scientific finding?].

    PubMed

    Bueno, Aline; Iessi, Isabela Lovizutto; Damasceno, Débora Cristina

    2010-01-01

    Superstitions are found everywhere in our lives, and medicine, a profession that is prides itself on an evidence-based approach to treatment, is not exempt. A superstition that pervades the labor and delivery floor is that it is busier during certain phases of the lunar cycle, specifically the full moon. Although some studies have demonstrated an increase in deliveries that are related to the lunar cycle, there has been disagreement about when, in the lunar cycle, the peak volume occurs. Front to the divergence of the existent results in the literature to relate the events of the lunar cycle with deliveries, the aim of this review was to accomplish the literature in the attempt of explaining this popular culture with base in the results presented by different researchers.

  20. INFLUENCE OF RESIDENTIAL HVAC DUTY CYCLE ON INDOOR AIR QUALITY

    EPA Science Inventory

    Measurements of duty cycle, the fraction of time the heating and cooling (HVAC) system was operating, were made in homes during the spring season of the RTP Particulate Matter Panel Study and the Tampa Asthmatic Children's Study. A temperature sensor/logger placed on an outlet...

  1. How trees influence the hydrological cycle in forest ecosystems

    Treesearch

    Barbara J. Bond; Frederick C. Meinzer; J. Renee Brooks

    2007-01-01

    Ultimately, the quest of ecohydrology (or hydroecology) is to apply fundamental knowledge from hydrology, ecology, atmospheric science, and related disciplines to solve real world problems involving biological systems and hydrologic cycles. Achieving this goal requires sharing information across disciplines, and this chapter is structured toward that end. Our aim is to...

  2. INFLUENCE OF RESIDENTIAL HVAC DUTY CYCLE ON INDOOR AIR QUALITY

    EPA Science Inventory

    Measurements of duty cycle, the fraction of time the heating and cooling (HVAC) system was operating, were made in homes during the spring season of the RTP Particulate Matter Panel Study and the Tampa Asthmatic Children's Study. A temperature sensor/logger placed on an outlet...

  3. Kinetics of the viral cycle influence pharmacodynamics of antiretroviral therapy.

    PubMed

    Sedaghat, Ahmad R; Wilke, Claus O

    2011-09-12

    More and more antiretroviral therapies are being developed for treatment of HIV infection. The in-vivo efficacy of these drugs is commonly predicted based on in-vitro measures of antiviral effect. One primary in-vitro measure is the IC50, the amount of drug required for 50% inhibition of viral replication. We have previously shown that HIV life-cycle kinetics impact clinically observed HIV viral dynamics. Here we present a mathematical model of how they affect the pharmacodynamics of antiretroviral drugs. We find that experimentally measured antiretroviral IC50s are determined by three factors: (i) intrinsic drug properties (e.g. drug-target binding), (ii) kinetics of the HIV life cycle, and (iii) kinetics of drug-inhibited infected cells. Our model predicts that the IC50 is a declining function of the duration of the drug-susceptible stage in the host cell. We combine our model with known viral life-cycle kinetics to derive a measure of intrinsic properties, reflecting drug action, for known antiretroviral drugs from previously measured IC50s. We show that this measure of intrinsic drug property correlates very well with in vitro-measured antiviral activity, whereas experimentally measured IC50 does not. Our results have implications for understanding pharmacodynamics of and improving activity of antiretroviral drugs. Our findings predict that drug activity can be improved through co-administration of synergistic drugs that delay the viral life cycle but are not inhibitory by themselves. Moreover, our results may easily extend to treatment of other pathogens.

  4. Influence of Cycle Temperature on the Wear Resistance of Vermicular Iron Derivatized with Bionic Surfaces

    NASA Astrophysics Data System (ADS)

    Sui, Qi; Zhang, Peng; Zhou, Hong; Liu, Yan; Ren, Luquan

    2016-11-01

    Depending on their applications, such as in brake discs, camshafts, etc., the wear behavior of vermicular iron is influenced by the thermal cycling regime. The failure of a working part during its service life is a consequence of both thermal fatigue and wear. Previously, the wear and thermal fatigue resistance properties of vermicular iron were separately investigated by researchers, rather than a study combining these two factors. In the present work, the effect of cycle temperature on the wear resistance of specimens with bionic units processed by laser has been investigated experimentally. The wear behavior pre- and post-thermal cycling has also been investigated, and the influence of different cycle temperatures on the wear resistance is discussed. The results indicate that the thermal cycling regime brought about negative influences with varying degrees, on the material properties, such as the microstructures, micro-hardness, cracks, and oxidation resistance properties. All these factors synergistically reduced the wear resistance of vermicular iron. In particular, the negative influence apparently increased with an increase in cycle temperature. Nevertheless, the post-thermal-cycle wear resistance of the specimens with bionic units was superior to those without bionic units. Hence, the laser bionic process is an effective way to improve the performance of vermicular iron in combined thermal cycling and wear service conditions.

  5. Airway exposure to multi-walled carbon nanotubes disrupts the female reproductive cycle without affecting pregnancy outcomes in mice.

    PubMed

    Johansson, H K L; Hansen, J S; Elfving, B; Lund, S P; Kyjovska, Z O; Loft, S; Barfod, K K; Jackson, P; Vogel, U; Hougaard, K S

    2017-05-30

    The use of multiwalled carbon nanotubes (MWCNT) is increasing due to a growing use in a variety of products across several industries. Thus, occupational exposure is also of increasing concern, particularly since airway exposure to MWCNTs can induce sustained pulmonary acute phase response and inflammation in experimental animals, which may affect female reproduction. This proof-of-principle study therefore aimed to investigate if lung exposure by intratracheal instillation of the MWCNT NM-400 would affect the estrous cycle and reproductive function in female mice. Estrous cycle regularity was investigated by comparing vaginal smears before and after exposure to 67 μg of NM-400, whereas reproductive function was analyzed by measuring time to delivery of litters after instillation of 2, 18 or 67 μg of NM-400. Compared to normal estrous cycling determined prior to exposure, exposure to MWCNT significantly prolonged the estrous cycle during which exposure took place, but significantly shortened the estrous cycle immediately after the exposed cycle. No consistent effects were seen on time to delivery of litter or other gestational or litter parameters, such as litter size, sex ratio, implantations and implantation loss. Lung exposure to MWCNT interfered with estrous cycling. Effects caused by MWCNTs depended on the time of exposure: the estrous stage was particularly sensitive to exposure, as animals exposed during this stage showed a higher incidence of irregular cycling after exposure. Our data indicates that MWCNT exposure may interfere with events leading to ovulation.

  6. Diurnal cycle influences peripheral and brain iron levels in mice.

    PubMed

    Unger, Erica L; Earley, Christopher J; Beard, John L

    2009-01-01

    Iron movement between organ pools involves a dynamic equilibrium of iron efflux and uptake, and homeostatic mechanisms are likely involved in providing iron to cells and organs when required. Daily iron levels in the plasma pool fluctuate with the diurnal cycle, but clear explanations regarding the objectives and regulation of the flux are lacking. The association between diurnal cycle and iron flux is relevant in the disease of restless legs syndrome (RLS), where individuals display diurnal deficits in motor control, have impaired brain iron metabolism, and perhaps altered iron uptake from the plasma pool. The goal of the present study was to examine diurnal variations in peripheral and regional brain iron to evaluate iron flux between organs in iron-sufficient and iron-deficient mice. In mice fed control diet, liver iron was elevated 30-40%, and plasma iron was reduced 20-30% in the active dark period compared with the inactive light phase. Dietary iron deficiency eliminated this variation in liver iron in male and female mice and in plasma iron in male mice. Reductions in ventral midbrain and nucleus accumbens iron and ferritin were apparent in iron-deficient mice during both diurnal phases, but only during the light phase was an approximately 25% reduction in whole brain iron observed, suggesting different brain iron requirements between phases. These data demonstrate that iron flux between organs is sensitive to diurnal regulatory biology. Importantly, variations in brain iron may have temporal implications regarding neural functioning and may contribute to the diurnal cycle-dependent symptoms of RLS.

  7. Tibial acceleration variability during consecutive gait cycles is influenced by the menstrual cycle.

    PubMed

    Clark, Ross A; Bartold, Simon; Bryant, Adam L

    2010-07-01

    The relationship between the phases of the menstrual cycle and injury risk remains unclear. Neuromuscular function may be compromised during menstruation, which could result in reduced cyclicality of movement patterns. We hypothesize that mediolateral (varus/valgus) knee acceleration during running gait will possess increased variability during menstruation when compared to approximately ovulation in women who do not take the monophasic oral contraceptive pill (MOCP). Thirty-six women (18 MOCP users: MOCP group and 18 non-pill users: NP group) performed six-minute treadmill running trials at 10 km h(-1) with an accelerometer fixed to the proximal tibia. Trials were performed at menstruation and approximately equal ovulation (for the MOCP group at a similar stage of the cycle) in a randomized order. The cyclicality of gross mediolateral tibial acceleration during 15 consecutive strides was assessed using combined wavelet and autocorrelation analysis. Longitudinal and anteroposterior accelerations were also examined. Repeated measures analysis of variance (ANOVA) tests were performed to assess differences at each stage of the menstrual cycle (alpha=0.05). Gross mediolateral acceleration in the NP group had significantly (P=0.022) increased variability at the time of menstruation compared to approximately equal ovulation, and was also significantly (P=0.011) more variable than the MOCP group at the corresponding time point. No significant difference was observed for any measure in the MOCP group. Increased variability in the NP users at menstruation may be a result of compromised motor control strategies. This provides further evidence of variability in performance and motor control during menstruation, and may have implications for a female athlete's risk of injury. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  8. The influence of reactive oxygen species on cell cycle progression in mammalian cells.

    PubMed

    Verbon, Eline Hendrike; Post, Jan Andries; Boonstra, Johannes

    2012-12-10

    Cell cycle regulation is performed by cyclins and cyclin dependent kinases (CDKs). Recently, it has become clear that reactive oxygen species (ROS) influence the presence and activity of these enzymes and thereby control cell cycle progression. In this review, we first describe the discovery of enzymes specialized in ROS production: the NADPH oxidase (NOX) complexes. This discovery led to the recognition of ROS as essential players in many cellular processes, including cell cycle progression. ROS influence cell cycle progression in a context-dependent manner via phosphorylation and ubiquitination of CDKs and cell cycle regulatory molecules. We show that ROS often regulate ubiquitination via intermediate phosphorylation and that phosphorylation is thus the major regulatory mechanism influenced by ROS. In addition, ROS have recently been shown to be able to activate growth factor receptors. We will illustrate the diverse roles of ROS as mediators in cell cycle regulation by incorporating phosphorylation, ubiquitination and receptor activation in a model of cell cycle regulation involving EGF-receptor activation. We conclude that ROS can no longer be ignored when studying cell cycle progression. Copyright © 2012 Elsevier B.V. All rights reserved.

  9. Influence Deforestation on Hydrological Cycle at Amazon Basin

    NASA Astrophysics Data System (ADS)

    Cohen, J. C.; Beltrao, J.; Gandu, A. W.

    2007-05-01

    The last three decades, the Amazon Basin has been affected for the occupation with consequence large deforestation. The principal area deforested is located from Maranhao state to Rondonia state. This area is common called "Arc Deforestation", and representing the transition between two important Brazilian ecosystems, Amazon Forest and Savanna Region. Theses ecosystems have precious biodiversity, and it has population about 10.331.000. The objective of this work was to evaluate the impact of arc deforestation on the hydrological cycle at Amazon basin, using BRAMS (Brazilian developments on the Regional Atmospheric Modeling System) including a model of dynamic vegetation, called GEMTM (General Energy and Mass Transport Model). In this study, numerical simulations were performed with a high spatial resolution regional model that allows capture some mesoscale aspects associated to the land used, topography, coastlines and large rivers. In order to predict the impact of the arc deforestation over the hydrological cycle, it was run two model simulations, conducted over a one-year period. In the first simulation, designated "control", it was used the scenarios derived from Soares Filho (2002), for the year 2002, in governance situation. In the second simulation called "deforestation", it was used the scenarios for the 2050, derived from results of Soares-Filho with governance, too. The higher-resolution regional modeling revealed important features of the deforestation process, displaying some associated mesoscale effects that are not typically represented in similar Global Circulation Model simulations. Near coastal zones and along large rivers, deforestation resulted in reduced precipitation. However, it was predicted increased precipitation over mountainous areas, especially on mountain slopes facing river valleys. Then, these higher-resolution simulations showed that, in general, orography, coastline profile and large river distribution play important roles in

  10. Influence of acetaminophen on performance during time trial cycling.

    PubMed

    Mauger, Alexis R; Jones, Andrew M; Williams, Craig A

    2010-01-01

    To establish whether acetaminophen improves performance of self-paced exercise through the reduction of perceived pain, 13 trained male cyclists performed a self-paced 10-mile (16.1 km) cycle time trial (TT) following the ingestion of either acetaminophen (ACT) or a placebo (PLA), administered in randomized double-blind design. TT were completed in a significantly faster time (t(12) = 2.55, P < 0.05) under the ACT condition (26 min 15 s +/- 1 min 36 s vs. 26 min 45 s +/- 2 min 2 s). Power output (PO) was higher during the middle section of the TT in the ACT condition, resulting in a higher mean PO (P < 0.05) (265 +/- 12 vs. 255 +/- 15 W). Blood lactate concentration (B[La]) and heart rate (HR) were higher in the ACT condition (B[La] = 6.1 +/- 2.9 mmol/l; HR = 87 +/- 7%max) than in the PLA condition (B[La] = 5.1 +/- 2.6 mmol/l; HR = 84 +/- 9%max) (P < 0.05). No significant difference in rating of perceived exertion (ACT = 15.5 +/- 0.2; PLA = 15.7 +/- 0.2) or perceived pain (ACT = 5.6 +/- 0.2; PLA = 5.5 +/- 0.2) (P > 0.05) was observed. Using acetaminophen, participants cycled at a higher mean PO, with an increased HR and B[La], but without changes in perceived pain or exertion. Consequently, completion time was significantly faster. These findings support the notion that exercise is regulated by pain perception, and increased pain tolerance can improve exercise capacity.

  11. Influences on Marital Satisfaction during the Middle Stages of the Family Life Cycle.

    ERIC Educational Resources Information Center

    Steinberg, Laurence; Silverberg, Susan B.

    1987-01-01

    Examined influence of adolescent development, parent-adolescent relationship, and psychological characteristics of midlife adults on marital satisfaction during transitional period of the family life cycle between childhood and adolescence. Marital satisfaction during the family's adolescent years was negatively influenced by distance in the…

  12. Concentrations of steroid hormones, estrous, ovarian and reproductive responses in sheep estrous synchronized with different prostaglandin-based protocols.

    PubMed

    Fierro, S; Viñoles, C; Olivera-Muzante, J

    2016-04-01

    To determine estrous, ovarian and reproductive responses after different prostaglandin (PG)-based protocols, ewes were assigned to groups PG10, PG12, PG14 or PG16 (twoPG injections administered 10, 12, 14 or 16 days apart; respectively). Experiment I (n=132) was conducted to evaluate the estrous response, ovulation rate (OR), conception and fertility. Experiment II (n=24) was conducted to evaluate ovarian follicle growth, steroid concentrations and the interval from the second PG injection to estrus (PG-estrus) and ovulation (PG-ovulation). Estrous response was less with the PG16 (P<0.05) treatment, and the extent of estrous synchrony was greater with the PG10 and PG12 treatments. Ovarian follicle growth and the intervals for the variables PG-estrus, PG-ovulation and OR were similar among groups (P>0.05). From 8 to 4 days before estrus, progesterone (P4) concentrations were greater for the PG14 and PG16 than for the PG10 and PG12 (P<0.05) groups. There were more days where concentrations of P4 were above 3.18 nmol/L with the PG14 and PG16 than PG10 and PG12 (P<0.05) treatments. Use of the PG14 and PG16 treatments resulted in greater estradiol (E2) at estrus and 12h later than use of the PG10 and PG12 treatments. A positive correlation was observed between the duration of the luteal phase and maximum E2 concentrations, and between duration of the luteal phase and days with E2 concentrations above 10 pmol/L. Conception and fertility were greater with use of the PG14 compared with PG10 and PG12 (P<0.05) treatments. The administration of two PG injections 10, 12, 14 or 16 days apart resulted in different durations of the luteal phase that were positively associated with E2 concentrations and the reproductive outcome. The shorter luteal phases were associated with greater synchrony in time of estrus. The intervals for the variables PG-estrus, PG-ovulation and OR were similar among groups. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Mesoscale Influences of Wind Farms Throughout a Diurnal Cycle

    NASA Astrophysics Data System (ADS)

    Fitch, A. C.; Lundquist, J. K.; Olson, J. B.

    2012-12-01

    Few observations are available to give insight into the interaction between large wind farms and the boundary layer. As wind farm deployment increases, questions are arising on the potential impact on meteorology within and downwind of large wind farms. While large-eddy simulation can provide insight into the detailed interaction between individual turbines and the boundary layer, to date it has been too computationally expensive to simulate wind farms with large numbers of turbines and the resulting wake far downstream. Mesoscale numerical weather prediction models provide the opportunity to investigate the flow in and around large wind farms as a whole, and the resulting impact on meteorology. To this end, we have implemented a wind farm parameterization in the Weather Research and Forecasting (WRF) model, which represents wind turbines by imposing a momentum sink on the mean flow; converting kinetic energy into electricity and turbulent kinetic energy (TKE). The parameterization improves upon previous models, basing the atmospheric drag of turbines on the thrust coefficient of a modern commercial turbine. In addition, the source of TKE varies with wind speed, reflecting the amount of energy extracted from the atmosphere by the turbines that does not produce electrical energy. We simulate a wind farm covering 10x10 km over land, consisting of 100 turbines each of nominal power output of 5 MW. Results will be presented showing how the wake structure varies dramatically over a diurnal cycle characteristic of a region in the Great Plains of the US, where wind farm deployment is planned. At night, a low-level jet forms within the rotor area, which is completely eliminated by energy extraction within the wind farm. The deep stable layer and lack of higher momentum air aloft at this time maximises the wind deficit and the length of the wake. The presentation will discuss the maximum reduction of wind speed within and downwind from the farm, and the wake e

  14. Influence of saddle setback on pedalling technique effectiveness in cycling.

    PubMed

    Menard, Mathieu; Domalain, Mathieu; Decatoire, Arnaud; Lacouture, Patrick

    2016-11-01

    Besides its regulation by Union Cycliste Internationale, the evidence relating saddle setback to pedalling performance remains inconclusive. This study investigates the influence of saddle setback on pedalling effectiveness through two indexes: an index of pedalling force effectiveness and an index of pedalling work effectiveness. Eleven cyclists were assessed six saddle setback conditions while pedalling at a steady power output of 200 W and cadence of 90 rpm. A force sensor was integrated within the seat post to compute the centre of pressure on the saddle. From instrumented pedals, an index of force effectiveness (ratio between the force directed perpendicular to the crank arm and the total force applied to the pedal) and an index of work effectiveness (based on the minimisation of negative crank work) were calculated. In comparison with a forward position, sitting backward significantly decreased 5% cumulative total work, increased index of work effectiveness (84.2 ± 3.7 vs. 82.0 ± 4.7%), and increased index of force effectiveness (41.7 ± 2.9 vs. 39.9 ± 3.7 and 36.9 ± 0.7%). Thus, while it was previously reported that sitting more forward favours maximal power, this study demonstrates that it also leads to a decreased effectiveness in steady-state pedalling.

  15. The influence of training status, age, and muscle fiber type on cycling efficiency and endurance performance.

    PubMed

    Hopker, James G; Coleman, Damian A; Gregson, Hannah C; Jobson, Simon A; Von der Haar, Tobias; Wiles, Jonathan; Passfield, Louis

    2013-09-01

    The purpose of this study was to assess the influence of age, training status, and muscle fiber-type distribution on cycling efficiency. Forty men were recruited into one of four groups: young and old trained cyclists, and young and old untrained individuals. All participants completed an incremental ramp test to measure their peak O2 uptake, maximal heart rate, and maximal minute power output; a submaximal test of cycling gross efficiency (GE) at a series of absolute and relative work rates; and, in trained participants only, a 1-h cycling time trial. Finally, all participants underwent a muscle biopsy of their right vastus lateralis muscle. At relative work rates, a general linear model found significant main effects of age and training status on GE (P < 0.01). The percentage of type I muscle fibers was higher in the trained groups (P < 0.01), with no difference between age groups. There was no relationship between fiber type and cycling efficiency at any work rate or cadence combination. Stepwise multiple regression indicated that muscle fiber type did not influence cycling performance (P > 0.05). Power output in the 1-h performance trial was predicted by average O2 uptake and GE, with standardized β-coefficients of 0.94 and 0.34, respectively, although some mathematical coupling is evident. These data demonstrate that muscle fiber type does not affect cycling efficiency and was not influenced by the aging process. Cycling efficiency and the percentage of type I muscle fibers were influenced by training status, but only GE at 120 revolutions/min was seen to predict cycling performance.

  16. Sex and menstrual cycle phase at encoding influence emotional memory for gist and detail.

    PubMed

    Nielsen, Shawn E; Ahmed, Imran; Cahill, Larry

    2013-11-01

    Sex influences on emotional memory have received increasing interest over the past decade. However, only a subset of this previous work explored the influence of sex on memory for central information (gist) and peripheral detail in emotional versus neutral contexts. Here we examined the influence of sex and menstrual cycle phase at encoding on memory for either an emotional or neutral story, specifically with respect to the retention of gist and peripheral detail. Healthy naturally cycling women and men viewed a brief, narrated, three-phase story containing neutral or emotionally arousing elements. One week later, participants received a surprise free recall test for story elements. The results indicate that naturally cycling women in the luteal (high hormone) phase of the menstrual cycle at encoding show enhanced memory for peripheral details, but not gist, when in the emotional compared with neutral stories (p<.05). In contrast, naturally cycling women in the follicular (low hormone) phase of the menstrual cycle at encoding did not show enhanced memory for gist or peripheral details in the emotional compared with neutral stories. Men show enhanced memory for gist, but not peripheral details, in the emotional versus neutral stories (p<.05). In addition, these sex influences on memory cannot be attributed to differences in attention or arousal; luteal women, follicular women, and men performed similarly on measures of attention (fixation time percentage) and arousal (pupil diameter changes) during the most arousing phase of the emotional story. These findings suggest that sex and menstrual cycle phase at encoding influence long term memory for different types of emotional information.

  17. Influence of Menstrual Cycle Phase on Neural and Craving Responses to Appetitive Smoking Cues in Naturally Cycling Females

    PubMed Central

    Jagannathan, Kanchana; Wetherill, Reagan R.; Johnson, Barbara; Kelly, Shannon; Langguth, Jamison; Mumma, Joel; Childress, Anna Rose

    2015-01-01

    Introdu ction: Functional magnetic resonance imaging (fMRI) has been used extensively in an attempt to understand brain vulnerabilities that mediate maladaptive responses to drug cues. Using perfusion fMRI, we have consistently shown reward-related activation (medial orbitofrontal cortex/ventral striatum) to smoking cues (SCs). Because preclinical and clinical studies generally show that progesterone may reduce reward and craving, we hypothesized that females in the follicular phase of the cycle (FPs; when progesterone levels are low) would have greater reward-related neural responses to SCs compared with females in the luteal phase (LPs). Methods: Sated cigarette-dependent premenopausal naturally cycling females underwent pseudo-continuous arterial spin-labeled perfusion fMRI during exposure to 10-min audio visual clips of appetitive SCs and non-SCs. Brain responses to SCs relative to non-SCs were examined among females grouped according to menstrual cycle (MC) phase at the time of scanning (22 FPs, 15 LPs). Craving scores were acquired pre- and post-SC exposure. Results: FPs showed increased neural responses to SCs compared with non-SCs in the medial orbitofrontal cortex (p ≤ .05corrected), whereas LPs did not. FPs reported SC-elicited craving (p ≤ .005), whereas LPs did not. Within FPs, SC-induced craving correlated with increased neural responses in the anterior insula (r = 0.73, p < .0001). Conclusions: FPs may be more vulnerable to relapse during appetitive SC exposure than LPs. Because the influence of MC phase on drug cue neural activity has not been examined, these results contribute to our knowledge of the neurobiological underpinnings of responses to drug cues, and they highlight the importance of monitoring menstrual cycle phase in all areas of addiction research. PMID:25762748

  18. The influence of 3D kinematic and electromyographical parameters on cycling economy.

    PubMed

    Sinclair, Jonathan; Hebron, Jack; Atkins, Stephen; Hurst, Howard; Taylor, Paul J

    2014-01-01

    Economy is considered to be a key factor for the determination of performance in endurance events such as cycling. There have been no investigations which have related cycling economy to simultaneous measurements of 3D kinematics and muscular activation. This study examined selected biomechanical and neuromuscular parameters which have the strongest association with cycling economy. Twenty-five trained cyclists (31.27 ± 3.19 years) completed steady state cycling time trials at a workload of 180 W. Simultaneous measurements of 3D kinematics and electromyographical parameters were obtained. Continuous measurements of expired gases were used to provide a measure of cycling economy. A multiple regression analysis showed that key parameters of peak knee extension velocity and mean activity of the rectus femoris muscles were significant predictors of VO2 during steady state cycling (P < 0.01). This study has documented the key biomechanical parameters pertinent to cycling economy. As economy has been shown to influence aerobic performance, future work should focus on optimising these parameters to improve cycling economy.

  19. Longitudinal, seasonal and solar cycle variation in lunar tide influence on the equatorial electrojet

    NASA Astrophysics Data System (ADS)

    Yizengaw, Endawoke; Carter, Brett A.

    2017-04-01

    It has been well documented that the lunar tidal waves can modulate the ionospheric electrodynamics and create a visible influence on the equatorial electrojet (EEJ). The lunar tide influence gets intensified around noon, primarily during new and full Moon periods. However, the longitudinal, seasonal and solar cycle variability in the lunar tide influence on ionospheric current systems is not well understood yet. In order to investigate this, 17 years (1998-2014) of extensive magnetometer observations at four longitudinal sectors (western American, western and eastern African, and Asian) have been analyzed. All observations performed during magnetically active periods (Kp>3) have been excluded for this study to eliminate storm contributions to the geomagnetic field variation at the geomagnetic equator. This study's quantitative analysis revealed significant longitudinal, seasonal and solar cycle dependence of the lunar tide influence on the equatorial electrojet.

  20. Cyclic Variation of Cellular Clock Proteins in the Mouse Estrous Ovary

    PubMed Central

    Wiggins, George; Legge, Michael

    2016-01-01

    Background: The mammalian ovary is controlled by a number of biological rhythms, which regulate the recruitment and release of mature oocytes. The main objective of this study was to investigate the role of cellular clock proteins during follicle maturation in the mouse estrous ovary. Methods: Immunohistochemical (IHC) studies were performed on ovaries from 50 estrous staged mice culled at two time points of 09:00 [day] and 01:00 [mid-point of the dark cycle]. Six antibodies were used to identify the expression of core cellular clock proteins (BMAL1, CLOCK, CRY1, CRY2, PER1 and PER2) within the ovary and four follicle stages, primordial, primary, antral and corpus lutea. IHC data was scored using the Allred protocol and significance determined by Mann-Whitney tests. Differences were considered significant at p<0.05. Results: All four follicle stages presented greater BMAL1 and CLOCK protein scores during the day and up regulation of CRY1-2 and PER1-2 at night. In primordial follicles, BMAL1 and CLOCK increases were significant (p<0.05) and CRY-1 and PER-1 were highly significant (p<0.001), and CRY-2 did not reach significance. Primary follicles demonstrated a similar response with BMAL1 and CLOCK, and CRY-1, PER-1-2 all reaching significant expression (p<0.05; p<0.001; p<0.001 respectively). CRY-2 expression was not significant. Antral follicles did not show significant BMAL1 or CLOCK expression, CRY-1 and PER-1 were highly significant (p<0.001) and CRY-2 had a small but significant increase (p<0.05). Corpus lutea demonstrated significant BMAL1 increase but CLOCK had no significant variation. CRY-1, PER1-2 increases were highly significant (p<0.001) and CRY-2 was up regulated but failed to reach significance. Conclusion: The ovary demonstrated a cellular clock response to the light: dark cycle and in addition, as the ovarian follicles mature changes in the positive and negative arms of both clock responsive proteins were observed. PMID:27920997

  1. Use of chi square periodogram in the analysis of estrous rhythmicity.

    PubMed

    Refinetti, R

    1991-02-01

    The usefulness of the chi square periodogram procedure for the analysis of estrous rhythmicity was investigated. Sokolove-Bushell's Q statistic was found to have a chi square distribution at the small degrees of freedom involved in estrous rhythmicity in rodents (i.e., rhythmicity with periods of 2-7 days). Consequently, the significance of the peaks in the periodogram can be effectively evaluated. The effects of multiple-period rhythmicity and of random noise added to periodical data were also investigated. Overall, the analysis of simulated as well as empirical data indicated that the chi square periodogram is an excellent tool for the evaluation of estrous rhythmicity.

  2. Influence of coupling of sorption and photosynthetic processes on trace element cycles in natural waters

    USGS Publications Warehouse

    Fuller, C.C.; Davis, J.A.

    1989-01-01

    Chemical and biological processes have important roles in the transport and cycling of trace elements in natural waters, but their complex interactions are often not well understood. Trace-element concentrations may, for example, be controlled by adsorption-desorption reactions at mineral surfaces, with the equilibrium strongly influenced by pH. Variations in pH due to photosynthetic activity should result in concentration fluctuations as the adsorption-desorption equilibrium shifts with pH. To investigate these interactions, we have studied the effect of diurnal cycling of pH on dissolved arsenate in a perennial stream contaminated with arsenic. As expected, a diurnal cycle in arsenate concentration was observed, but surprisingly, the arsenate cycle lags several hours behind the pH cycle. Laboratory experiments show that the lag results from a slow approach to sorption equilibrium. Our observations demonstrate that the coupling of photosynthesis and sorption processes may have an important influence on the cycling of many trace elements and emphasize the importance of understanding sorption kinetics in modelling these processes.

  3. On the Influence of the Solar Bi-Cycle on Comic Ray Modulatio

    NASA Astrophysics Data System (ADS)

    Lifter, N. Part Xxvii: A. Defect Of The Solar Dynamo. B.; Scissors, K.; Sprucener, H.

    In this presentation we propose a new paradigm that explains the different lengths of individual solar Hale cycles. It proves beneficial to distinguish between a so-called inHale and ex-Hale cycle, which together form the solar bi-cycle. We carefully analyzed the influence of so-called complex mode excitations (CMEs) on comic ray modulation, in particular on the drifts of the comic isotope O+3 , which we found to induce characteristic anisotropies. This comic isotope anisotropy (CIA) is caused by the wellknown north-south asymmetry (NSA) and can be observed as a rare Forbush increase (FBI). The latter is linked to the solar magnetic field which appears to have a chaotic behaviour (for details see part I-XXVI). Especially during an ex-Hale cycle magnetic flux is pseudo-pneumatically escaping through a coronal hole. Consequently, the solar dynamo can no longer operate efficiently, i.e. is defect.

  4. Influence of driving cycles on exhaust emissions and fuel consumption of gasoline passenger car in Bangkok.

    PubMed

    Nutramon, Tamsanya; Supachart, Chungpaibulpatana

    2009-01-01

    The influence of different driving cycles on their exhaust emissions and fuel consumption rate of gasoline passenger car was investigated in Bangkok based on the actual measurements obtained from a test vehicle driving on a standard chassis dynamometer. A newly established Bangkok driving cycle (BDC) and the European driving cycle (EDC) which is presently adopted as the legislative cycle for testing automobiles registered in Thailand were used. The newly developed BDC is constructed using the driving characteristic data obtained from the real on-road driving tests along selected traffic routes. A method for selecting appropriate road routes for real driving tests is also introduced. Variations of keyed driving parameters of BDC with different driving cycles were discussed. The results showed that the HC and CO emission factors of BDC are almost two and four times greater than those of EDC, respectively. Although the difference in the NOx emission factor is small, the value from BDC is still greater than that of EDC by 10%. Under BDC, the test vehicle consumes fuel about 25% more than it does under EDC. All these differences are mainly attributed to the greater proportion of idle periods and higher fluctuations of vehicle speed in the BDC cycle. This result indicated that the exhausted emissions and fuel consumption of vehicles obtained from tests under the legislative modal-type driving cycle (EDC) are significantly different from those actually produced under real traffic conditions especially during peak periods.

  5. The influence of the hydrologic cycle on the extent of sea ice with climatic implications

    NASA Technical Reports Server (NTRS)

    Dean, Ken; Gosink, Joan

    1991-01-01

    The role was analyzed of the hydrologic cycle on the distribution of sea ice, and its influence on forcings and fluxes between the marine environment and the atmosphere. River discharge plays a significant role in degrading the sea ice before any melting occurs elsewhere along the coast. The influence is considered of river discharge on the albedo, thermal balance, and distribution of sea ice. Quantitative atmospheric-hydrologic models are being developed to describe these processes in the coastal zone. Input for the models will come from satellite images, hydrologic data, and field observations. The resulting analysis provides a basis for the study of the significance of the hydrologic cycle throughout the Arctic Basin and its influence on the regional climate as a result of possible climatic scenarios. The area offshore from the Mackenzie River delta was selected as the study area.

  6. Ability of mice to detect estrous odor in bovine urine: roles of hormones and behavior in odor discrimination.

    PubMed

    Rameshkumar, Kamatchi; Achiraman, Shanmugam; Karthikeyan, Kandasamy; Archunan, Govindaraju

    2008-04-01

    This study was designed to evaluate the ability of mice to discriminate cow urinary odor from different reproductive phases, with a view toward detecting the estrous phase. Experiments were also carried out to establish the relationship between androgen and mouse behaviors during estrous detection. Further, the study was also intended to establish the relationship between androgen and behaviors in estrous detection. Bovine urine was collected during estrus and non-estrous periods, i.e., prepubertal, preovulatory, ovulatory, postovulatory, pregnancy, and lactation. Behavioral analyses were carried out in a Y-maze apparatus, in which the mice were acclimatized in before odor-preference tests. The number and duration of visits, and grooming behavior by male responders towards the urine samples, were recorded. Intact male mice showed a higher response towards estrus urine samples than towards non-estrous urine. By contrast, orchidectomized mice failed to discriminate estrous urine, whereas castrated mice treated with testosterone regained the ability to discriminate estrus odor. A higher level of grooming behavior was found in males exposed to estrous urine than to urine of other phases. These results suggest that normal mice have the ability to detect estrus, and that this discriminating ability is androgen dependent. The grooming behavior shown by males in response to estrous urine may be taken as a key parameters in estrous detection. The results further suggest that bovine estrous urine produces specific odors that probably involve both intraspecific and interspecific communication.

  7. Influence of duty cycle on the power-duration relationship: observations and potential mechanisms.

    PubMed

    Broxterman, R M; Ade, C J; Wilcox, S L; Schlup, S J; Craig, J C; Barstow, T J

    2014-02-01

    The highest sustainable rate of aerobic metabolism [critical power (CP)] and the finite amount of work that can be performed above CP (W' [curvature constant]) were determined under two muscle contraction duty cycles. Eight men completed at least three constant-power handgrip tests to exhaustion to determine CP and W' for 50% and 20% duty cycles, while brachial artery blood flow (Q̇BA) and deoxygenated-[hemoglobin + myoglobin] (deoxy-[Hb+Mb]) were measured. CP was lower for the 50% duty cycle (3.9 ± 0.9 W) than the 20% duty cycle (5.1 ± 0.8 W; p < 0.001), while W' was not significantly different (50% duty cycle: 452 ± 141 J vs. 20% duty cycle: 432 ± 130 J; p > 0.05). At the same power output, Q̇BA and deoxy-[Hb + Mb] achieved higher end-exercise values for the 20% duty cycle (9.87 ± 1.73 ml·s(-1); 51.7 ± 4.7 μM) than the 50% duty cycle (7.37 ± 1.76 ml·s(-1), p < 0.001; 44.3 ± 2.4 μM, p < 0.03). These findings indicate that blood flow influences CP, but not W'.

  8. Menstrual cycle influence on cognitive function and emotion processing—from a reproductive perspective

    PubMed Central

    Sundström Poromaa, Inger; Gingnell, Malin

    2014-01-01

    The menstrual cycle has attracted research interest ever since the 1930s. For many researchers the menstrual cycle is an excellent model of ovarian steroid influence on emotion, behavior, and cognition. Over the past years methodological improvements in menstrual cycle studies have been noted, and this review summarizes the findings of methodologically sound menstrual cycle studies in healthy women. Whereas the predominant hypotheses of the cognitive field state that sexually dimorphic cognitive skills that favor men are improved during menstrual cycle phases with low estrogen and that cognitive skills that favor women are improved during cycle phases with increased estrogen and/or progesterone, this review has not found sufficient evidence to support any of these hypotheses. Mental rotation has gained specific interest in this aspect, but a meta-analysis yielded a standardized mean difference in error rate of 1.61 (95% CI −0.35 to 3.57), suggesting, at present, no favor of an early follicular phase improvement in mental rotation performance. Besides the sexually dimorphic cognitive skills, studies exploring menstrual cycle effects on tasks that probe prefrontal cortex function, for instance verbal or spatial working memory, have also been reviewed. While studies thus far are few, results at hand suggest improved performance at times of high estradiol levels. Menstrual cycle studies on emotional processing, on the other hand, tap into the emotional disorders of the luteal phase, and may be of relevance for women with premenstrual disorders. Although evidence at present is limited, it is suggested that emotion recognition, consolidation of emotional memories, and fear extinction is modulated by the menstrual cycle in women. With the use of functional magnetic resonance imaging, several studies report changes in brain reactivity across the menstrual cycle, most notably increased amygdala reactivity in the luteal phase. Thus, to the extent that behavioral changes

  9. Influence of Age, Reproductive Cycling Status, and Menstruation on the Vaginal Microbiome in Baboons (Papio anubis)

    PubMed Central

    UCHIHASHI, M.; BERGIN, I. L.; BASSIS, C. M.; HASHWAY, S. A.; CHAI, D.; BELL, J. D.

    2015-01-01

    The vaginal microbiome is believed to influence host health by providing protection from pathogens and influencing reproductive outcomes such as fertility and gestational length. In humans, age-associated declines in diversity of the vaginal microbiome occur in puberty and persist into adulthood. Additionally, menstruation has been associated with decreased microbial community stability. Adult female baboons, like other non-human primates (NHPs), have a different and highly diverse vaginal microbiome compared to that of humans, which is most commonly dominated by Lactobacillus spp. We evaluated the influence of age, reproductive cycling status (cycling vs. non-cycling) and menstruation on the vaginal microbiome of 38 wild-caught, captive female olive baboons (Papio anubis) by culture-independent sequencing of the V3–V5 region of the bacterial 16S rRNA gene. All baboons had highly diverse vaginal microbial communities. Adult baboons had significantly lower microbial diversity in comparison to subadult baboons, which was attributable to decreased relative abundance of minor taxa. No significant differences were detected based on cycling state or menstruation. Predictive metagenomic analysis showed uniformity in relative abundance of metabolic pathways regardless of age, cycle stage, or menstruation, indicating conservation of microbial community functions. This study suggests that selection of an optimal vaginal microbial community occurs at puberty. Since decreased diversity occurs in both baboons and humans at puberty, this may reflect a general strategy for selection of adult vaginal microbial communities. Comparative evaluation of vaginal microbial community development and composition may elucidate mechanisms of community formation and function that are conserved across host species or across microbial community types. These findings have implications for host health, evolutionary biology, and microbe-host ecosystems. PMID:25676781

  10. Influence of age, reproductive cycling status, and menstruation on the vaginal microbiome in baboons (Papio anubis).

    PubMed

    Uchihashi, M; Bergin, I L; Bassis, C M; Hashway, S A; Chai, D; Bell, J D

    2015-05-01

    The vaginal microbiome is believed to influence host health by providing protection from pathogens and influencing reproductive outcomes such as fertility and gestational length. In humans, age-associated declines in diversity of the vaginal microbiome occur in puberty and persist into adulthood. Additionally, menstruation has been associated with decreased microbial community stability. Adult female baboons, like other non-human primates (NHPs), have a different and highly diverse vaginal microbiome compared to that of humans, which is most commonly dominated by Lactobacillus spp. We evaluated the influence of age, reproductive cycling status (cycling vs. non-cycling) and menstruation on the vaginal microbiome of 38 wild-caught, captive female olive baboons (Papio anubis) by culture-independent sequencing of the V3-V5 region of the bacterial 16S rRNA gene. All baboons had highly diverse vaginal microbial communities. Adult baboons had significantly lower microbial diversity in comparison to subadult baboons, which was attributable to decreased relative abundance of minor taxa. No significant differences were detected based on cycling state or menstruation. Predictive metagenomic analysis showed uniformity in relative abundance of metabolic pathways regardless of age, cycle stage, or menstruation, indicating conservation of microbial community functions. This study suggests that selection of an optimal vaginal microbial community occurs at puberty. Since decreased diversity occurs in both baboons and humans at puberty, this may reflect a general strategy for selection of adult vaginal microbial communities. Comparative evaluation of vaginal microbial community development and composition may elucidate mechanisms of community formation and function that are conserved across host species or across microbial community types. These findings have implications for host health, evolutionary biology, and microbe-host ecosystems. © 2015 Wiley Periodicals, Inc.

  11. Increased cleavage and blastocyst rate in ewes treated with bovine somatotropin 5 days before the end of progestin-based estrous synchronization.

    PubMed

    Montero-Pardo, A; Hernández-Cerón, J; Rojas-Maya, S; Valencia, J; Rodríguez-Cortez, A; Gutiérrez, C G

    2011-05-01

    Treatment with bovine somatotropin (bST) during estrous synchronization increased fertility and prolificacy in sheep. In the present study, a single dose of bST 5 days before the end of progestin treatment improved cleavage and embryo development. Stage of estrous cycle was synchronized in ewes (n=32) with progestin and superovulation was induced by use of FSH. Five days before the end of progestin treatment, ewes were randomly assigned to two groups: bST group (n=16) received a depot injection of 125 mg of bST sc (Lactotropina, Elanco, México) and the control group (n=16) received saline solution. Estrous was detected with rams fitted with an apron every 2 h and estrous sheep were mated every 8 h whilst in estrous. Embryos were recovered on Day 7 post mating, assessed microscopically and fixed in 4% paraformaldehyde. Cell number in blastocysts was counted after Hoechst 33342 staining. Plasma concentrations of IGF-I, insulin and progesterone were determined in eight sheep per group from the day of bST treatment to the day of embryo recovery. Cleavage rate, percentage of transferable embryos (transferable embryos/cleaved) and percentage of embryos reaching the blastocyst stage (blastocyst/cleaved) were compared between groups by logistic regression. IGF-I, insulin and progesterone plasma concentrations were analyzed by ANOVA for repeated measurements and cell number by ANOVA. Cleavage rate was greater (P<0.01) in bST treatment group (86%) than in the control group (62%). Similarly, the proportion of embryos reaching the blastocyst stage (bST=68.7 vs control=42.5) and the number of cells per blastocyst (bST group 91.8±5.5 compared to control group 75±6) were greater (P<0.01) in the bST-treated sheep. Plasma concentrations of IGF-I and insulin were greater (P<0.01) in the bST-treated group. No changes were observed in progesterone concentrations (P=0.5). It is concluded that bST injection 5 days before progestin removal increases cleavage rate and the proportion of

  12. Quantifying the Amplitude, Structure and Influence of Model Error During Ocean Analysis and Forecast Cycles

    DTIC Science & Technology

    2013-09-30

    Pinardi and L.M. Berliner, 2011: Ocean ensemble forecasting, Part I: Mediterranean winds from a Bayesian hierarchical model . Q. J. Roy. Meteorol...Quantifying the Amplitude, Structure and Influence of Model Error during Ocean Analysis and Forecast Cycles Andrew M. Moore...Department of Ocean Sciences , 1156 High St. University of California Santa Cruz CA 95064 Phone: (831) 459-4632 fax: (831) 459-4882 email: ammoore

  13. Influence of the 11-Year Solar Cycle on Variations of Cosmic Ray Intensity

    NASA Astrophysics Data System (ADS)

    Ma, L. H.; Han, Y. B.; Yin, Z. Q.

    2009-03-01

    The monthly cosmic ray intensity (CRI) time series from Climax, Huancayo, Moscow, Kiel, and Calgary are used to investigate the presence of the 11-year periodic component with special attention paid to the solar influence on these variations. The results show obvious 11-year temporal characteristics in CRI variations. We also find a close anticorrelation between the 11-year solar cycle and CRI variations and time delays of the CRI relative to solar activity.

  14. Continuous exposure to sexually active rams extends estrous activity in ewes in spring.

    PubMed

    Abecia, J A; Chemineau, P; Flores, J A; Keller, M; Duarte, G; Forcada, F; Delgadillo, J A

    2015-12-01

    Sexual activity in sheep is under photoperiodic control, which is the main environmental factor responsible for the seasonality of reproduction. However, other natural environmental factors such as presence of conspecifics can slightly influence the timing of onset and offset of the breeding season. In goats, we have found that the continuous presence of bucks that were rendered sexually active out of season by previous exposure to long days, prevented goats from displaying seasonal anestrus, which suggests that the relative contribution of photoperiod in controlling seasonal anestrus should be reevaluated in small ruminant species. The aim of this study was to assess whether the presence of sexually active rams that had been stimulated by artificial photoperiod and melatonin implants, reduces seasonal anestrus in sheep, by prolonging ovulatory activity in spring. Ewes were assigned to one of two groups (n = 16 and 15), which were housed in two separate barns, and kept in contact, either with the treated or the control rams between March and July. Vasectomized rams were either exposed to 2 months of long days followed by the insertion of three subcutaneous melatonin implants (treated rams, n = 8), or exposed to natural light conditions (control rams, n = 2). Estrus was monitored daily, and weekly plasma progesterone analyses indicated ovulatory activity. Ewes that were exposed to treated rams exhibited a higher proportion of monthly estrus than ewes exposed to the control rams (P < 0.05). Thirteen of 15 ewes (one ewe was not considered because of the presence of persistent CL) exposed to stimulated rams exhibited estrous behavior in a cyclic manner. In contrast, all ewes exposed to control rams stopped estrous activity for a period of time during the study, such that this group exhibited a significantly longer anestrous season (mean ± standard error of the mean 89 ± 9 days) than did the ewes housed with treated rams (26 ± 10 days; P < 0

  15. Influence of creep damage on the low cycle thermal-mechanical fatigue behavior of two tantalum base alloys

    NASA Technical Reports Server (NTRS)

    Sheffler, K. D.; Doble, G. S.

    1972-01-01

    Low cycle fatigue tests have been performed on the tantalum base alloys T-111 and ASTAR 811C with synchronized, independently programmed temperature and strain cycling. The thermal-mechanical cycles applied fell into three basic categories: these were isothermal cycling, in-phase thermal cycling, and out-of-phase thermal cycling. In-phase cycling was defined as tensile deformation associated with high temperature and compressive deformation with low temperature, while out-of-phase thermal cycling was defined as the reverse case. The in-phase thermal cycling had a pronounced detrimental influence on the fatigue life of both alloys, with the life reduction being greater in the solid solution strengthened T-111 alloy than in the carbide strengthened ASTAR 811C alloy. The out-of-phase tests also showed pronounced effects on the fatigue life of both alloys, although not as dramatic.

  16. HIV infection is influenced by dynamin at 3 independent points in the viral life cycle.

    PubMed

    Aggarwal, Anupriya; Hitchen, Tina L; Ootes, Lars; McAllery, Samantha; Wong, Andrew; Nguyen, Khanh; McCluskey, Adam; Robinson, Phillip J; Turville, Stuart G

    2017-06-01

    CD4 T cells are important cellular targets for HIV-1, yet the primary site of HIV fusion remains unresolved. Candidate fusion sites are either the plasma membrane or from within endosomes. One area of investigation compounding the controversy of this field, is the role of the protein dynamin in the HIV life cycle. To understand the role of dynamin in primary CD4 T cells we combined dynamin inhibition with a series of complementary assays based on single particle tracking, HIV fusion, detection of HIV DNA products and active viral transcription. We identify 3 levels of dynamin influence on the HIV life cycle. Firstly, dynamin influences productive infection by preventing cell cycle progression. Secondly, dynamin influences endocytosis rates and increases the probability of endosomal fusion. Finally, we provide evidence in resting CD4 T cells that dynamin directly regulates the HIV fusion reaction at the plasma membrane. We confirm this latter observation using 2 divergent dynamin modulating compounds, one that enhances dynamin conformations associated with dynamin ring formation (ryngo-1-23) and the other that preferentially targets dynamin conformations that appear in helices (dyngo-4a). This in-depth understanding of dynamin's roles in HIV infection clarifies recent controversies and furthermore provides evidence for dynamin regulation specifically in the HIV fusion reaction. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. Influence of Freeze-Thaw Cycles on RNA Integrity of Gastrointestinal Cancer and Matched Adjacent Tissues.

    PubMed

    Hu, Ying; Han, Haibo; Wang, Yixue; Song, Lijie; Cheng, Xiaojing; Xing, Xiaofang; Dong, Bin; Wang, Xiaohong; Chen, Meng; Zhang, Lianhai; Ji, Jiafu

    2017-06-01

    Comparative analysis of RNA expression profiles between cancer and adjacent noncancerous tissues is an important part of cancer research. High-quality RNA is essential for consistent, reliable results, especially for identification of cancer biomarkers. However, the impact of freeze-thaw cycles on the quality of RNA both in gastrointestinal cancer and paired adjacent tissues is still unclear. To investigate the influence of freeze-thaw cycles on RNA integrity and overall histomorphology of gastrointestinal cancer and paired adjacent noncancerous tissues. Gastrointestinal cancer and matched adjacent noncancerous tissues were frozen and thawed twice before extracting RNA. Total RNA in each sample was extracted with TRIzol reagents and the RNA integrity was assessed by RNA integrity number (RIN) on an Agilent Bioanalyzer. Light microscopy was then used to assess tissue composition and morphology. RIN values for all samples tended to decrease in correlation with the frequency of freeze-thawing. With an RIN cutoff value of 6, RNA extracted from pancreatic cancer tissues was not qualified after the first freeze-thaw cycle. Moreover, all RNA extracted from adjacent noncancerous tissues had nonqualifying RIN scores after the first freeze-thaw cycle, except for liver tissues. Microscopically, all samples displayed qualified tissue morphology regardless of freeze-thaw cycle frequency. Freeze-thawing affects the RNA integrity, but not the tissue morphology of gastrointestinal cancer and paired adjacent noncancerous tissues. Furthermore, the RNA extracted from adjacent noncancerous tissues is more easily degraded than that in cancer tissues.

  18. Transition into daylight saving time influences the fragmentation of the rest-activity cycle.

    PubMed

    Lahti, Tuuli A; Leppämäki, Sami; Ojanen, Sanna-Maria; Haukka, Jari; Tuulio-Henriksson, Annamari; Lönnqvist, Jouko; Partonen, Timo

    2006-01-19

    Daylight saving time is widely adopted. Little is known about its influence on the daily rest-activity cycles. We decided to explore the effects of transition into daylight saving time on the circadian rhythm of activity. We monitored the rest-activity cycles with the use of wrist-worn accelerometer on a sample of ten healthy adults for ten days around the transition into summer time. Identical protocols were carried out on the same individuals in two consecutive years, yielding data on 200 person-days for analysis in this study. There was no significant effect on the rest-activity cycle in the sample as a whole. Fragmentation of the rest-activity cycle was enhanced in a subgroup of persons having sleep for eight hours or less (P = 0.04) but reduced in those who preferred to sleep for more than eight hours per night (P = 0.05). The average level of motor activity was increased in persons having the morning preference for daily activity patterns (P = 0.01). Transition into daylight saving time may have a disruptive effect on the rest-activity cycle in those healthy adults who are short-sleepers or more of the evening type.

  19. Transition into daylight saving time influences the fragmentation of the rest-activity cycle

    PubMed Central

    Lahti, Tuuli A; Leppämäki, Sami; Ojanen, Sanna-Maria; Haukka, Jari; Tuulio-Henriksson, Annamari; Lönnqvist, Jouko; Partonen, Timo

    2006-01-01

    Background Daylight saving time is widely adopted. Little is known about its influence on the daily rest-activity cycles. We decided to explore the effects of transition into daylight saving time on the circadian rhythm of activity. Methods We monitored the rest-activity cycles with the use of wrist-worn accelerometer on a sample of ten healthy adults for ten days around the transition into summer time. Identical protocols were carried out on the same individuals in two consecutive years, yielding data on 200 person-days for analysis in this study. Results There was no significant effect on the rest-activity cycle in the sample as a whole. Fragmentation of the rest-activity cycle was enhanced in a subgroup of persons having sleep for eight hours or less (P = 0.04) but reduced in those who preferred to sleep for more than eight hours per night (P = 0.05). The average level of motor activity was increased in persons having the morning preference for daily activity patterns (P = 0.01). Conclusion Transition into daylight saving time may have a disruptive effect on the rest-activity cycle in those healthy adults who are short-sleepers or more of the evening type. PMID:16423282

  20. Stride cycle influences on goal-directed head movements made during walking.

    PubMed

    Peters, Brian T; van Emmerik, Richard E A; Bloomberg, Jacob J

    2006-08-01

    Horizontal head movements were studied in six subjects as they made rapid horizontal gaze adjustments while walking. The aim of the present research was to determine if gait cycle events alter the head movement response to a visual target acquisition task. Gaze shifts of approximately 40 degrees were elicited by a step change in the position of a visual target from a central location to a second location in the left or right horizontal periphery. The timing of the target position change was constrained to occur at 25%, 50%, 75% and 100% of the stride cycle. The trials were randomly presented as the subjects walked on a treadmill at their preferred speed (range: 1.25-1.48 m/s, mean: 1.39+/-0.09 m/s). Analyses focused on the movement onset latencies of the head and eyes and on the peak velocity and saccade amplitude of the head movement response. The head and eye movement onset latencies were not affected by either the direction of the target change or the point in the gait cycle during which the target relocation occurred. However, the presence of an interaction between the gait cycle events and the direction of the visual target shift for both the amplitude and peak velocity of the head movement response indicates that the head movement responses to visual target changes can be influenced by the phase of the gait cycle during which the target relocation takes place.

  1. Duty Cycling Influences Current Generation in Multi-Anode Environmental Microbial Fuel Cells

    SciTech Connect

    Gardel, EJ; Nielsen, ME; Grisdela, PT; Girguis, PR

    2012-05-01

    Improving microbial fuel cell (MFC) performance continues to be the subject of research, yet the role of operating conditions, specifically duty cycling, on MFC performance has been modestly addressed. We present a series of studies in which we use a 15-anode environmental MFC to explore how duty cycling (variations in the time an anode is connected) influences cumulative charge, current, and microbial composition. The data reveal particular switching intervals that result in the greatest time-normalized current. When disconnection times are sufficiently short, there is a striking decrease in current due to an increase in the overall electrode reaction resistance. This was observed over a number of whole cell potentials. Based on these results, we posit that replenishment of depleted electron donors within the biofilm and surrounding diffusion layer is necessary for maximum charge transfer, and that proton flux may be not limiting in the highly buffered aqueous phases that are common among environmental MFCs. Surprisingly, microbial diversity analyses found no discernible difference in gross community composition among duty cycling treatments, suggesting that duty cycling itself has little or no effect. Such duty cycling experiments are valuable in determining which factors govern performance of bioelectrochemical systems and might also be used to optimize field-deployed systems.

  2. From START to FINISH: the influence of osmotic stress on the cell cycle.

    PubMed

    Radmaneshfar, Elahe; Kaloriti, Despoina; Gustin, Michael C; Gow, Neil A R; Brown, Alistair J P; Grebogi, Celso; Romano, M Carmen; Thiel, Marco

    2013-01-01

    The cell cycle is a sequence of biochemical events that are controlled by complex but robust molecular machinery. This enables cells to achieve accurate self-reproduction under a broad range of different conditions. Environmental changes are transmitted by molecular signalling networks, which coordinate their action with the cell cycle. The cell cycle process and its responses to environmental stresses arise from intertwined nonlinear interactions among large numbers of simpler components. Yet, understanding of how these pieces fit together into a coherent whole requires a systems biology approach. Here, we present a novel mathematical model that describes the influence of osmotic stress on the entire cell cycle of S. cerevisiae for the first time. Our model incorporates all recently known and several proposed interactions between the osmotic stress response pathway and the cell cycle. This model unveils the mechanisms that emerge as a consequence of the interaction between the cell cycle and stress response networks. Furthermore, it characterises the role of individual components. Moreover, it predicts different phenotypical responses for cells depending on the phase of cells at the onset of the stress. The key predictions of the model are: (i) exposure of cells to osmotic stress during the late S and the early G2/M phase can induce DNA re-replication before cell division occurs, (ii) cells stressed at the late G2/M phase display accelerated exit from mitosis and arrest in the next cell cycle, (iii) osmotic stress delays the G1-to-S and G2-to-M transitions in a dose dependent manner, whereas it accelerates the M-to-G1 transition independently of the stress dose and (iv) the Hog MAPK network compensates the role of the MEN network during cell division of MEN mutant cells. These model predictions are supported by independent experiments in S. cerevisiae and, moreover, have recently been observed in other eukaryotes.

  3. The influence of cycling temperature and cycling rate on the phase specific degradation of a positive electrode in lithium ion batteries: A post mortem analysis

    NASA Astrophysics Data System (ADS)

    Darma, Mariyam Susana Dewi; Lang, Michael; Kleiner, Karin; Mereacre, Liuda; Liebau, Verena; Fauth, Francois; Bergfeldt, Thomas; Ehrenberg, Helmut

    2016-09-01

    The influence of cycling temperatures and cycling rates on the cycling stability of the positive electrode (cathode) of commercial batteries are investigated. The cathode is a mixture of LiMn2O4 (LMO), LiNi0.5Co0.2Mn0.3O2 (NCM) and LiNi0.8Co0.15Al0.05O2 (NCA). It is found that increasing the cycling temperature from 25 °C to 40 °C is detrimental to the long term cycling stability of the cathode. Contrastingly, the improved cycling stability is observed for the cathodes cycled at higher charge/discharge rate (2C/3C instead of 1C/2C). The microstructure analysis by X-ray powder diffraction reveals that a significant capacity fading and an increased overvoltage is observed for NCM and NCA in all the fatigued cathodes. After high number of cycling (above 1500 cycles), NCM becomes partially inactive. In contrast to NCM and NCA, LMO shows a good cycling stability at 25 °C. A pronounced degradation of LMO is only observed for the fatigued cathodes cycled at 40 °C. The huge capacity losses of NCM and NCA are most likely because the blended cathodes were cycled up to 4.12 V vs. the graphite anode during the cycle-life test (corresponds to 4.16 V vs. Li+/Li); which is beyond the stability limit of the layered oxides below 4.05 V vs. Li+/Li.

  4. Influence of the menstrual cycle on flight simulator performance after alcohol ingestion.

    PubMed

    Mumenthaler, M S; O'Hara, R; Taylor, J L; Friedman, L; Yesavage, J A

    2001-07-01

    Previous studies investigating the influence of the menstrual cycle on cognitive functioning of women after alcohol ingestion have obtained inconsistent results. The present study tested the hypothesis that flight simulator performance during acute alcohol intoxication and 8 hours after drinking differs between the menstrual and the luteal phase of the menstrual cycle. White female pilots (N = 24) were tested during the menstrual and the luteal phases of their menstrual cycles. On each test day they performed a baseline simulator flight, consumed 0.67 g/kg ethanol, and performed an acute-intoxication and an 8-hour-carryover simulator flight. Subjects reached highly significant increases in estradiol (E2) as well as progesterone (P) levels during the luteal test day. Yet, there were no significant differences in overall flight performance after alcohol ingestion between the menstrual and luteal phases during acute intoxication or at 8-hour carryover. We found no correlations between E, or P levels and overall flight performance. However, there was a statistically significant Phase x Order interaction: Pilots who started the experiment with their menstrual day were less susceptible to the effects of alcohol during the second test day than were pilots who started with their luteal day. The tested menstrual cycle phases and varying E2 and P levels did not significantly influence postdrink flight performance. Because the present study included a comparatively large sample size and because it involved complex "real world" tasks (piloting an aircraft), we believe that the present findings are important. We hope that our failure to detect menstrual cycle effects will encourage researchers to include women in their investigations of alcohol effects and human performance.

  5. Influence of the type of working fluid in the lower cycle and superheated steam parameters in the upper cycle on effectiveness of operation of binary power plant

    NASA Astrophysics Data System (ADS)

    Stachel, Aleksander A.; Wiśniewski, Sławomir

    2015-03-01

    In the paper presented have been the results of the analysis of effectiveness of operation of binary power plant consisting of combined two Clausius-Rankine cycles, namely the binary cycle with water as a working fluid in the upper cycle and organic substance as a working fluid in the lower cycle, as well as a single fluid component power plant operating also in line with the C-R cycle for superheated steam, with water as a working fluid. The influence of the parameters of superheated steam in the upper cycle has been assessed as well as the type of working fluid in the lower cycle. The results of calculations have been referred to the single-cycle classical steam power plant operating at the same parameters of superheated steam and the same mass flow rate of water circulating in both cycles. On the basis of accomplished analysis it has been shown that the binary power plant shows a greater power with respect to the reference power plant.

  6. Anti-diabetic potentials of Momordica charantia and Andrographis paniculata and their effects on estrous cyclicity of alloxan-induced diabetic rats.

    PubMed

    Reyes, B A S; Bautista, N D; Tanquilut, N C; Anunciado, R V; Leung, A B; Sanchez, G C; Magtoto, R L; Castronuevo, P; Tsukamura, H; Maeda, K-I

    2006-04-21

    Momordica charantia and Andrographis paniculata are the commonly used herbs by the diabetic patients in Pampanga, Philippines. While the anti-diabetic potential of Momordica charantia is well established in streptozocin- or alloxan-induced diabetic animals, the anti-diabetic potential of Andrographis paniculata in alloxan-induced diabetic rat is not known. Neither the effects of these herbs on estrous cyclicity of alloxan-induced diabetic rats are elucidated. Thus, in these experiments, Momordica charantia fruit juice or Andrographis paniculata decoction was orally administered to alloxan-induced diabetic rats. Rats that were treated with Momordica charantia and Andrographis paniculata had higher body weight (BW) compared with diabetic positive control (P < 0.01) from day 22 to day 27 (D27) but exhibited lower BW than the non-diabetic control (P < 0.05). These rats had lower feed (P < 0.05) and liquid intakes (P < 0.01) compared with diabetic positive control from day 17 to D27, but similar with the non-diabetic control. The blood glucose levels in these groups were significantly reduced from day 12 to D27 compared with diabetic positive control (P < 0.01), however, comparable with non-diabetic control. The diabetic positive control had extended mean estrous cycles (8 days) compared to Momordica charantia and Andrographis paniculata-treated diabetic rats (5 days; P < 0.05). Our results suggest that the anti-diabetic potentials of Momordica charantia and Andrographis paniculata could restore impaired estrous cycle in alloxan-induced diabetic rats.

  7. The Influence of Free Space Environment in the Mission Life Cycle: Material Selection

    NASA Technical Reports Server (NTRS)

    Edwards, David L.; Burns, Howard D.; de Groh, Kim K.

    2014-01-01

    The natural space environment has a great influence on the ability of space systems to perform according to mission design specification. Understanding the natural space environment and its influence on space system performance is critical to the concept formulation, design, development, and operation of space systems. Compatibility with the natural space environment is a primary factor in determining the functional lifetime of the space system. Space systems being designed and developed today are growing in complexity. In many instances, the increased complexity also increases its sensitivity to space environmental effects. Sensitivities to the natural space environment can be tempered through appropriate design measures, material selection, ground processing, mitigation strategies, and/or the acceptance of known risks. The design engineer must understand the effects of the natural space environment on the space system and its components. This paper will discuss the influence of the natural space environment in the mission life cycle with a specific focus on the role of material selection.

  8. [Oxidative metabolism of main and accessory olfactory bulbs, limpic system and hypothalamus during the estral cycle of the rat (author's transl)].

    PubMed

    Sánchez-Criado, J E

    1979-06-01

    The in vitro oxidative metabolism of hypothalamus, olfactory and limbic systems from female rats in the estrous cycle have been measured. The accessory olfactory bulb becomes most active during diestrous when the hypothalamus reaches its lowest values.

  9. Solving the influence maximization problem reveals regulatory organization of the yeast cell cycle.

    PubMed

    Gibbs, David L; Shmulevich, Ilya

    2017-06-01

    The Influence Maximization Problem (IMP) aims to discover the set of nodes with the greatest influence on network dynamics. The problem has previously been applied in epidemiology and social network analysis. Here, we demonstrate the application to cell cycle regulatory network analysis for Saccharomyces cerevisiae. Fundamentally, gene regulation is linked to the flow of information. Therefore, our implementation of the IMP was framed as an information theoretic problem using network diffusion. Utilizing more than 26,000 regulatory edges from YeastMine, gene expression dynamics were encoded as edge weights using time lagged transfer entropy, a method for quantifying information transfer between variables. By picking a set of source nodes, a diffusion process covers a portion of the network. The size of the network cover relates to the influence of the source nodes. The set of nodes that maximizes influence is the solution to the IMP. By solving the IMP over different numbers of source nodes, an influence ranking on genes was produced. The influence ranking was compared to other metrics of network centrality. Although the top genes from each centrality ranking contained well-known cell cycle regulators, there was little agreement and no clear winner. However, it was found that influential genes tend to directly regulate or sit upstream of genes ranked by other centrality measures. The influential nodes act as critical sources of information flow, potentially having a large impact on the state of the network. Biological events that affect influential nodes and thereby affect information flow could have a strong effect on network dynamics, potentially leading to disease. Code and data can be found at: https://github.com/gibbsdavidl/miergolf.

  10. Solving the influence maximization problem reveals regulatory organization of the yeast cell cycle

    PubMed Central

    Shmulevich, Ilya

    2017-01-01

    The Influence Maximization Problem (IMP) aims to discover the set of nodes with the greatest influence on network dynamics. The problem has previously been applied in epidemiology and social network analysis. Here, we demonstrate the application to cell cycle regulatory network analysis for Saccharomyces cerevisiae. Fundamentally, gene regulation is linked to the flow of information. Therefore, our implementation of the IMP was framed as an information theoretic problem using network diffusion. Utilizing more than 26,000 regulatory edges from YeastMine, gene expression dynamics were encoded as edge weights using time lagged transfer entropy, a method for quantifying information transfer between variables. By picking a set of source nodes, a diffusion process covers a portion of the network. The size of the network cover relates to the influence of the source nodes. The set of nodes that maximizes influence is the solution to the IMP. By solving the IMP over different numbers of source nodes, an influence ranking on genes was produced. The influence ranking was compared to other metrics of network centrality. Although the top genes from each centrality ranking contained well-known cell cycle regulators, there was little agreement and no clear winner. However, it was found that influential genes tend to directly regulate or sit upstream of genes ranked by other centrality measures. The influential nodes act as critical sources of information flow, potentially having a large impact on the state of the network. Biological events that affect influential nodes and thereby affect information flow could have a strong effect on network dynamics, potentially leading to disease. Code and data can be found at: https://github.com/gibbsdavidl/miergolf. PMID:28628618

  11. Influence of process parameters on the weld lines formation in rapid heat cycle molding

    NASA Astrophysics Data System (ADS)

    Fiorotto, Marco; Lucchetta, Giovanni

    2011-05-01

    The insufficient entanglement of the molecular chains at the v-notch of a weld line impairs the mechanical strength and the surface quality of a plastic product. The rapid heat cycle molding technology (RHCM) has been recently used to enhance surface appearance of the parts, by thermally cycling the mold surface temperature. The mold temperature is the key of RHCM technology because it significantly affects productivity, energy efficiency and the quality of the final polymer part. In this work the influence of mold temperature on the weld lines depth and roughness were studied. Three different materials were tested. To investigate the influence of process parameters, a special mold insert was designed and manufactured. Weld lines geometry and roughness were quantitatively characterized by means of a profilometer. Experimental results show that is possible to increase the temperature to 10° C lower than the glass transition to obtain a high-gloss parts without weld lines with a significant reduction of cycle time and energy consumption.

  12. Bottom-up processes influence the demography and life-cycle phenology of Hawaiian bird communities.

    PubMed

    Wolfe, Jared D; Ralph, C John; Wiegardt, Andrew

    2017-08-05

    Changes in climate can indirectly regulate populations at higher trophic levels by influencing the availability of food resources in the lower reaches of the food web. As such, species that rely on fruit and nectar food resources may be particularly sensitive to these bottom-up perturbations due to the strength of their trophic linkages with climatically-influenced plants. To measure the influence of climatically-mediated, bottom-up processes, we used climate, bird capture, bird count, and plant phenology data from the Big Island of Hawaii to construct a series of structural equation and abundance models. Our results suggest that fruit and nectar-eating birds arrange life cycle events around climatically-influenced food resources, while some of these same food resources also influence seasonal patterns of abundance. This trend was particularly strong for two native nectarivores, 'I'iwi and 'Apapane, where we found that the dissimilar timing of molting and breeding activity was associated with peak abundance of the two most common flowers at our study site which, in turn, were each driven by dissimilar climatic cues. Given the rapidly changing Hawaiian climate, we suggest that determining behavioral plasticity, or evolutionary capacity of birds to mitigate changes in climatically-influenced food resources, should be recognized as a future research priority. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. Mammal diversity influences the carbon cycle through trophic interactions in the Amazon.

    PubMed

    Sobral, Mar; Silvius, Kirsten M; Overman, Han; Oliveira, Luiz F B; Rabb, Ted K; Fragoso, José M V

    2017-10-09

    Biodiversity affects many ecosystem functions and services, including carbon cycling and retention. While it is known that the efficiency of carbon capture and biomass production by ecological communities increases with species diversity, the role of vertebrate animals in the carbon cycle remains undocumented. Here, we use an extensive dataset collected in a high-diversity Amazonian system to parse out the relationship between animal and plant species richness, feeding interactions, tree biomass and carbon concentrations in soil. Mammal and tree species richness is positively related to tree biomass and carbon concentration in soil-and the relationship is mediated by organic remains produced by vertebrate feeding events. Our research advances knowledge of the links between biodiversity and carbon cycling and storage, supporting the view that whole community complexity-including vertebrate richness and trophic interactions-drives ecosystem function in tropical systems. Securing animal and plant diversity while protecting landscape integrity will contribute to soil nutrient content and carbon retention in the biosphere.A high-diversity Amazonian system reveals the influence of mammalian diversity on the carbon cycle, mediated through vertebrate feeding events.

  14. Environmental cycling of cellulosic thermal insulation and its influence on fire performance

    NASA Astrophysics Data System (ADS)

    Lawson, J. R.

    1984-08-01

    A study was conducted on climatological data for eleven cities located throughout the United States. Findings from this environmental study were used to develop conditioning cycles for a research project on the influence of environments on the fire performance of loose-fill cellulosic thermal insulation. Six cellulosic insulation materials with different compositions of fire retardant chemicals at an add-on level of 25% by weight were specially manufactured for this study. These materials were tested for fire performance using the smoldering combustion test and the attic flooring radiant panel test to establish a baseline. After the materials were exposed to the various environmental cycles, they were tested for fire performance. Results from these tests show that environmental exposure can have a significant effect on the fire performance of cellulosic insulation materials and indicates that long term fire protection provided by fire retardant compounds may be limited.

  15. Environmental cycling of cellulosic thermal insulation and its influence on fire performance

    SciTech Connect

    Lawson, J.R.

    1984-08-01

    A study was conducted on climatological data for eleven cities located throughout the United States. Findings from this environmental study were used to develop conditioning cycles for a research project on the influence of environments on the fire performance of loose-fill cellulosic thermal insulation. Six cellulosic insulation materials with different compositions of fire retardant chemicals at an add-on level of 25% by weight were specially manufactured for this study. These materials were tested for fire performance using the smoldering combustion test and the attic flooring radiant panel test to establish a baseline. After the materials were exposed to the various environmental cycles, they were tested for fire performance. Results from these tests show that environmental exposure can have a significant effect on the fire performance of cellulosic insulation materials and indicates that long term fire protection provided by fire retardant compounds may be limited.

  16. Influences of menstrual cycle position and sex hormone levels on spontaneous intrusive recollections following emotional stimuli

    PubMed Central

    Ferree, Nikole K.; Kamat, Rujvi; Cahill, Larry

    2011-01-01

    Spontaneous intrusive recollections (SIRs) are known to follow emotional events in clinical and nonclinical populations. Previous work in our lab has found that women report more SIRs than men after exposure to emotional films, and that this effect is driven entirely by women in the luteal phase of the menstrual cycle. To replicate and extend this finding, participants viewed emotional films, provided saliva samples for sex hormone concentration analysis, and estimated SIR frequency following film viewing. Women in the luteal phase reported significantly more SIRs than did women in the follicular phase, and SIR frequency significantly correlated with salivary progesterone levels. The results are consistent with an emerging pattern in the literature suggesting that menstrual cycle position of female participants can potently influence findings in numerous cognitive domains. The potential implications of these results for disorders characterized by intrusions, such as post-traumatic stress disorder, are also discussed. PMID:21353599

  17. The influence of sea ice albedo on the global hydrological cycle

    NASA Astrophysics Data System (ADS)

    Subramanian, A. C.; Eisenman, I.; Bordoni, S.

    2013-12-01

    The idea that Arctic sea ice retreat might influence precipitation outside the polar region has garnered considerable interest in recent years. As sea ice recedes, it alters the climate system due to factors including a change in surface albedo, which has been suggested to affect the hydrological cycle in the midlatitudes and tropics. Here we examine how sea ice influences the response of the global hydrological cycle to climate change in the broader context of climates ranging from an ice-covered earth to an ice-free earth. We use an idealized general circulation model (GCM) with and without an ice-albedo feedback, i.e., with either a constant surface albedo or a temperature-dependent surface albedo indicating sea ice or ice-free ocean. This work builds on the results of O'Gorman & Schneider (2008), who simulated the hydrological cycle in a wide range of climates using an idealized GCM without an ice-albedo feedback and found that the amount of absorbed shortwave radiation plays a key role in regulating how much global-mean precipitation is possible. Intriguingly, we find that the inclusion of the ice-albedo feedback causes an increase in global-mean precipitation despite a decrease in absorbed shortwave radiation. The atmospheric circulation is also more vigorous in the presence of the ice-albedo feedback, with a higher eddy kinetic energy and a stronger Hadley circulation. Both results are consistent with an increased meridional temperature gradient due to less absorbed solar radiation in the high latitudes. Large-scale condensation, rather than convection, is the main contributor to the changes in the hydrological cycle caused by the ice-albedo feedback, especially in the midlatitude storm tracks, where eddies tend to be more energetic in the presence of a steeper meridional temperature gradient. The results are interpreted using energy and angular momentum budget constraints and additional simulations with varied parameter values.

  18. Microstructural Influences on Very High Cycle Fatigue Crack Initiation in Ti-6246 (PREPRINT)

    DTIC Science & Technology

    2008-04-01

    surface (in degrees). Facet # 1 2 3 4 5a 5b 6 7 8 9 Angle 46 45 39 19 26 35 33 31 32 21 Table II. Orientation of facets (in degrees). Facet # 1* 2 3 4 ...TYPE 3. DATES COVERED (From - To) April 2008 Journal Article Preprint 4 . TITLE AND SUBTITLE MICROSTRUCTURAL INFLUENCES ON VERY HIGH CYCLE...FATIGUE CRACK INITIATION IN Ti-6246 (PREPRINT) 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 62102F 6 . AUTHOR(S

  19. Seasonal variation in assisted conception cycles and the influence of photoperiodism on outcome in in vitro fertilization cycles.

    PubMed

    Wood, Simon; Quinn, Alison; Troupe, Stephen; Kingsland, Charles; Lewis-Jones, Iwan

    2006-12-01

    The effect of seasonality and daylight length on mammalian reproduction leading to spring births has been well established, and is known as photoperiodism. In assisted reproduction there is much greater uncertainty as to the effect of seasonality. This was a 4-year retrospective analysis of 2709 standardised cycles of IVF/ICSI. Data was analysed with regard to the 1642 cycles occurring during the months of extended daylight (Apr-Sept) and those 1067 cycles during winter months of restricted light length (Oct-Mar). The results showed that there was significant improvement in assisted conception outcomes in cycles performed in summer (lighter) months with more efficient ovarian stimulation 766iu v880iu/per oocyte retrieved (p=0.006). There was similarly a significantly improved implantation rate per embryo transferred 11.42% vs 9.35% (p=0.011) and greater clinical pregnancy rate 20% vs 15% (p=0.0033) during summer cycles. This study appears to demonstrate a significant benefit of increased daylight length on outcomes of IVF/ICSI cycles. Whilst the exact mechanism of this is unclear, it would seem probable that melatonin may have actions at multiple sites and on multiple levels of the reproductive tract, and may exert a more profound effect on outcomes of assisted conception cycles than has been previously considered.

  20. Influence of noncircular chainring on male physiological parameters in hand cycling.

    PubMed

    Zeller, Sebastian; Abel, Thomas; Smith, Paul M; Strueder, Heiko K

    2015-01-01

    The purpose of this study was to examine the influence of a noncircular chainring (NCC) compared with a conventional circular chainring (CC) on hand cycling performance. Eleven nondisabled male participants with no hand cycling experience initially completed an incremental exercise test. Afterward, the participants completed two 20 s sprint tests, followed by a 20 min endurance test and then another two 20 s sprint tests. An NCC and a CC were used in random order on two separate occasions. To compare the effects of the NCC and CC on power data of the sprint tests and metabolic response during the endurance test, a two-way analysis of variance for repeated measures was used. Average power values of the sprint tests showed no significant difference between NCC and CC, but over time, values of the first and third sprint tests were higher than those of the second and fourth sprint tests for both chainrings. Values of energy expenditure (kilojoules), gross efficiency (percentage), and net efficiency (percentage) after 10 and 20 min during the endurance test using NCC and CC showed no significant differences (p > 0.05) either between tests or over time. Under the current test conditions and focusing on physiological parameters, a performance optimization using an NCC in hand cycling could not be proven.

  1. Does the reproductive cycle influence sleep patterns in women with sleep complaints?

    PubMed

    Hachul, H; Andersen, M L; Bittencourt, L R A; Santos-Silva, R; Conway, S G; Tufik, S

    2010-12-01

    The aim of the present study was to investigate how prominent gynecological factors (regular/irregular menstrual cycle, premenstrual complaints, or menopause) can influence both subjective and objective sleep data. A total of 931 women who sought clinical assistance because of a sleep complaint were included in the investigation. All subjects filled out a sleep and gynecological questionnaire prior to undergoing a polysomnography (PSG) recording. Premenopausal women with an irregular menstrual cycle were more likely to report sleep difficulties (related to falling sleep and insomnia symptoms) than those with a regular cycle (odds ratio 2.1; 95% confidence interval 1.2-3.5). These women showed increased light sleep stages and awakenings. Premenstrual complaints were reported by a higher percentage of women with periodic leg movement, lower time in saturation under 90%, and higher sleep efficiency. A lower percentage of women who took hormonal contraceptives reported snoring, had fewer arousals and longer REM latency compared to those not taking hormonal contraceptives. Menopausal women with hot flushes had more restless leg complaints. Awake time was shorter in hormone therapy users compared with non-users. Women with menopause are more likely to have an apnea-hypoapnea index greater than 5/h. The present findings suggest that gynecological status is associated with subjective sleep quality and objective sleep parameters in women with sleep complaints.

  2. Influence of temperature difference calculation method on the evaluation of Rankine cycle performance

    NASA Astrophysics Data System (ADS)

    Morisaki, Takafumi.; Ikegami, Yasuyuki.

    2014-02-01

    In the new century, energy and environmental problems are becoming more critical, and the development of natural energy is desired. Low-grade Thermal Energy Conversion (LTEC) is refocused as one of the renewable energy methods. The usefulness of LTEC is expected using hot springs and waste heat. In the case of the Rankine cycle using ammonia as the working fluid, the thermal properties of the working fluid changes in the evaporator. The traditional evaluation method of heat exchanger performance is the LMTD (Logarithmic Mean Temperature Difference) method. On the other hand, the GMTD (Generalized Mean Temperature Difference) method allows the variation of thermal properties in the heat exchanger. The aim of this study is to compare the two methods for the calculation of temperature differences and the corresponding influence on the total performance of the Rankine cycle that is operated using ammonia as a working fluid. As a result, the thermal efficiency of the Rankine cycle is greater than that of the LMTD method. Moreover, the computable range of the GMTD calculation method is less than that of the LMTD calculation method.

  3. Temperature and Cyanobacterial Bloom Biomass Influence Phosphorous Cycling in Eutrophic Lake Sediments

    PubMed Central

    Chen, Mo; Ye, Tian-Ran; Krumholz, Lee R.; Jiang, He-Long

    2014-01-01

    Cyanobacterial blooms frequently occur in freshwater lakes, subsequently, substantial amounts of decaying cyanobacterial bloom biomass (CBB) settles onto the lake sediments where anaerobic mineralization reactions prevail. Coupled Fe/S cycling processes can influence the mobilization of phosphorus (P) in sediments, with high releases often resulting in eutrophication. To better understand eutrophication in Lake Taihu (PRC), we investigated the effects of CBB and temperature on phosphorus cycling in lake sediments. Results indicated that added CBB not only enhanced sedimentary iron reduction, but also resulted in a change from net sulfur oxidation to sulfate reduction, which jointly resulted in a spike of soluble Fe(II) and the formation of FeS/FeS2. Phosphate release was also enhanced with CBB amendment along with increases in reduced sulfur. Further release of phosphate was associated with increases in incubation temperature. In addition, CBB amendment resulted in a shift in P from the Fe-adsorbed P and the relatively unreactive Residual-P pools to the more reactive Al-adsorbed P, Ca-bound P and organic-P pools. Phosphorus cycling rates increased on addition of CBB and were higher at elevated temperatures, resulting in increased phosphorus release from sediments. These findings suggest that settling of CBB into sediments will likely increase the extent of eutrophication in aquatic environments and these processes will be magnified at higher temperatures. PMID:24682039

  4. Influence of increased body mass and body composition on cycling anaerobic power.

    PubMed

    Maciejczyk, Marcin; Wiecek, Magdalena; Szymura, Jadwiga; Szygula, Zbigniew; Brown, Lee E

    2015-01-01

    Recent evidence suggests that not only body fat (BF) but high lean body mass (HLBM) adversely affects aerobic performance and may reduce aerobic endurance performance as well. However, the influence of body composition on anaerobic performance remains controversial. This study aimed to examine the effects of increased body mass (BM) and body composition on cycling anaerobic power. Peak power (PP) and mean power (MP) measurements were conducted in 2 groups of men with similar total BM but different body compositions resulting from (a) high level of BF [HBF group] or (b) high level of lean body mass [HLBM group] and in a control group. Peak power and MP were calculated in absolute values, relative to BM and lean body mass (LBM), and using allometric scaling. Absolute PP and MP were significantly higher in the HLBM group compared with the control and HBF groups. However, PP and MP relative to BM and using allometric scaling were similar in the HLBM and control groups, yet significantly higher than in the HBF group. There were no significant differences between groups in PP and MP when presented relative to LBM. Therefore, it seems that it is not BM but rather body composition that affects PP. Increased BM, resulting from increased LBM, does not adversely affect cycling anaerobic power, but a BM increase resulting from an increase in BF may adversely affect PP. Therefore, coaches and athletes should avoid excess BF to maximize cycling anaerobic power.

  5. The influence of elliptical chainrings on 10 km cycling time trial performance.

    PubMed

    Peiffer, Jeremiah J; Abbiss, Chris R

    2010-12-01

    The use of elliptical chainrings (also called chainwheels or sprockets) has gained considerable interest in the amateur and professional cycling community. Nevertheless, we are unaware of any scientific studies that have examined the performance benefits of using elliptical chainrings during an actual performance trial. Therefore, this study examined the influence of elliptical chainring use on physiological and performance parameters during a 10 km cycling time trial. Nine male cyclists completed, in a counterbalanced order, three 10 km cycling time trials using either a standard chainring or an elliptical chainring at two distinct settings. An attempt was made to blind the cyclists to the type of chainring used until the completion of the study. During the 10 km time trial, power output and heart rate were recorded at a frequency of 1 Hz and RPE was measured at 3, 6, and 8.5 km. Total power output was not different (P = .40) between the circular (340 ± 30 W) or either elliptical chainring condition (342 ± 29 W and 341 ± 31 W). Similarly, no differences (P = .73) in 2 km mean power output were observed between conditions. Further, no differences in RPE were observed between conditions measured at 3, 6, and 8.5 km. Heart rate was significantly greater (P = .02) using the less aggressive elliptical setting (174 ± 10 bpm) compared with the circular setting (171 ± 9 bpm). Elliptical chainrings do not appear to provide a performance benefit over traditional circular chainrings during a mid-distance time trial.

  6. Topoisomerase II Inhibitors and Poisons, and the Influence of Cell Cycle Checkpoints.

    PubMed

    D Arcy, Nicholas; Gabrielli, Brian

    2017-01-01

    Interactions between the decatenation checkpoint and Topoisomerase II (TopoII) are vital for maintaining integrity of the genome. Agents that target this enzyme have been in clinical use in cancer therapy for over 30 years with great success. The types of compounds that have been developed to target TopoII are broadly divided into poisons and catalytic inhibitors. The TopoII poisons are in clinical use as anti-cancer therapies, although in common to most chemotherapeutic agents, they display considerable normal tissue toxicity. Inhibition of the TopoIIb isoform has been implicated in this cytotoxicity. Response to TopoII active agents is determined by several factors, but cell cycle checkpoints play a large role in sensitivity and resistance. The G2/M phase checkpoints are of particular importance in considering the effectiveness of these drugs and are reviewed in this article. Functionality of the ATM dependent decatenation checkpoint may represent a new avenue for selective cancer therapy. Here we review the function of TopoII, the anti-cancer mechanisms and limitations of current catalytic inhibitors and poisons, and their influence on cell cycle checkpoints. We will also assess potential new mechanisms for targeting this enzyme to limit normal tissue toxicity, and how the cell cycle checkpoint triggered by these drugs may provide an alternative and possibly better target for novel therapies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  7. Solar Cycle Influence on Ionospheric Outflows and Implications for Geomagnetic Activity

    NASA Astrophysics Data System (ADS)

    Lotko, W.; Brambles, O. J.; Zhang, B.; Wiltberger, M. J.

    2011-12-01

    Global simulations have shown that the presence of ionospheric ions in the magnetosphere has a major influence on geospace dynamics including, among other effects, modifications of the ionospheric potential and currents, inflation of the magnetosphere, intensification of the ring current and development of sawtooth oscillations. The hemispheric fluence of ionospheric outflows changes during the solar cycle in two fundamental ways. First and most importantly for superthermal outflows, the fluence increases with geomagnetic activity, which itself exhibits complex solar cycle dependence. Thus enhanced geomagnetic activity induced by the stronger solar wind driving prevalent around solar maximum increases ion outflow and mass loading of the magnetosphere. Second and perhaps more importantly for thermal outflows, an increase in solar EUV flux at solar maximum causes the underlying thermosphere and ionosphere to expand. The result is an increase, on average, in both the dayside flux and the hemispheric fluence of ionospheric outflows, especially O+, at solar maximum. Aspects of these influences are demonstrated in global simulations. When outflows driven by Alfvénic Poynting fluxes flowing toward the ionosphere are included in the simulations, weak to moderate solar wind driving typical of solar minimum (e.g., as measured by the Vasyliunas et al. (1982) SW-M coupling parameter) tends to produce steady magnetospheric convection states and isolated substorms. Moderate to strong solar driving more typical of solar maximum tends to promote more intense substorms and sawtooth oscillations. It is difficult based on the current state-of-the-art global simulations that include the effects of ionospheric outflows to fully systematize the solar cycle dependence of the impacts of ionospheric outflows on magnetospheric dynamics because the effects of the outflow depend on its flux and bulk properties, e.g., composition, field-aligned velocity and thermal energy, and the

  8. Male influence on oestrous cycles in female woolly opossum (Caluromys philander).

    PubMed

    Perret, M; Ben M'Barek, S

    1991-03-01

    Plasma progesterone concentrations and the occurrence of oestrous cycles were studied in isolated woolly opossums subsequently subjected to male influences during a 40-day period. Pairing (N = 48) or exposure to male urine (N = 15) resulted in all females exhibiting oestrous during the stimulation phase, providing evidence that the activation of ovarian activity in the woolly opossum involves pheromonal cues from males. The latency of occurrence of oestrous in stimulated females depended upon their sexual state before male stimulation. In anoestrous females, the mean latency was 20.7 +/- 0.9 days (N = 35), a value which agrees with the duration of the follicular phase. In females which first entered oestrous before male stimulation, the latency of induced oestrous was inversely correlated to the date of occurrence of the previous oestrous. The inter-oestrous interval was normal (38.1 +/- 1 days, N = 5) when females were in oestrous at the beginning of male stimulation. In contrast, the inter-oestrous interval was significantly shortened (28.7 +/- 2 days, N = 7) or lengthened (51.1 +/- 1.7 days, N = 16) depending on whether females were in the luteal or follicular phases at the beginning of male stimulation. During pairing several females became pregnant and gave birth 24 +/- 0.9 days (N = 13) after copulation. In the woolly opossum, the response to male influences involves mechanisms similar to those observed in eutherians and results in enhancement and synchronization of oestrous cycles in females. Pheromonal interactions could play an important role in synchronizing oestrous cycles in wild females during the dry season, a period when animals regroup to feed on spatially localized food resources.

  9. Influence of lunar cycles on growth of Ashwagandha (Withania somnifera [L.] Dunal)

    PubMed Central

    Tavhare, Swagata D.; Nishteswar, K.; Shukla, Vinay J.

    2015-01-01

    Introduction: Ayurvedic classics have advocated to collect the medicinal plants according to part used and seasons in order to get desired pharmacological action and therapeutic benefits. The logic behind this principle is being validated by recent researches. Aim: To analyze the influence of lunar cycles on growth of Ashwagandha in Shishira and Greeshma Ritu (winter and summer season). Materials and Methods: Fourteen small crops of Ashwagandha of average size 10 cm were collected on October 7, 2013, from institute campus and then replantation was done at Charaka Herbal Garden, Gujarat Ayurved University, Jamnagar in an area of 60 cm × 60 cm (l × b). No fertilizers or pesticides were used. The plants were watered daily and plants were uprooted as per lunar cycles for analysis. Eight samples were collected and observed during Shishira and Greeshma season on Pournima (full moon) and Amavasya (new moon) days. The measurements were taken thrice and average values were taken into consideration for study purpose. The variations in morphological characteristics such as length, breadth, weight, and number of roots and twigs were studied through statistical procedure of principle component analysis, which makes interpretation of all possible related variables. Results: Root weight (RW), pith diameter (PD) and internodal distance (ID) were found to be increased on full moon days as compared to new moon days. The maximum RW was observed during Greeshma Aashadha Pournima. Conclusion: The study has shown a definite influence of lunar cycles on the growth of the plant parts assessed by RW, PD, and ID that have found to be increased on full moon days as compared to new moon days. PMID:27313411

  10. Influence of lunar cycles on growth of Ashwagandha (Withania somnifera [L.] Dunal).

    PubMed

    Tavhare, Swagata D; Nishteswar, K; Shukla, Vinay J

    2015-01-01

    Ayurvedic classics have advocated to collect the medicinal plants according to part used and seasons in order to get desired pharmacological action and therapeutic benefits. The logic behind this principle is being validated by recent researches. To analyze the influence of lunar cycles on growth of Ashwagandha in Shishira and Greeshma Ritu (winter and summer season). Fourteen small crops of Ashwagandha of average size 10 cm were collected on October 7, 2013, from institute campus and then replantation was done at Charaka Herbal Garden, Gujarat Ayurved University, Jamnagar in an area of 60 cm × 60 cm (l × b). No fertilizers or pesticides were used. The plants were watered daily and plants were uprooted as per lunar cycles for analysis. Eight samples were collected and observed during Shishira and Greeshma season on Pournima (full moon) and Amavasya (new moon) days. The measurements were taken thrice and average values were taken into consideration for study purpose. The variations in morphological characteristics such as length, breadth, weight, and number of roots and twigs were studied through statistical procedure of principle component analysis, which makes interpretation of all possible related variables. Root weight (RW), pith diameter (PD) and internodal distance (ID) were found to be increased on full moon days as compared to new moon days. The maximum RW was observed during Greeshma Aashadha Pournima. The study has shown a definite influence of lunar cycles on the growth of the plant parts assessed by RW, PD, and ID that have found to be increased on full moon days as compared to new moon days.

  11. Muskie lunacy: does the lunar cycle influence angler catch of muskellunge (Esox masquinongy)?

    USGS Publications Warehouse

    Vinson, Mark R.; Angradi, Ted R.

    2014-01-01

    We analyzed angling catch records for 341,959 muskellunge (Esox masquinongy) from North America to test for a cyclic lunar influence on the catch. Using periodic regression, we showed that the number caught was strongly related to the 29-day lunar cycle, and the effect was consistent across most fisheries. More muskellunge were caught around the full and new moon than at other times. At night, more muskellunge were caught around the full moon than the new moon. The predicted maximum relative effect was ≈5% overall. Anglers fishing exclusively on the peak lunar day would, on average, catch 5% more muskellunge than anglers fishing on random days. On some lakes and at night, the maximum relative effect was higher. We obtained angler effort data for Wisconsin, Mille Lacs (MN), and Lake Vermilion (MN). For Lake Vermilion there was a significant effect of the lunar cycle on angler effort. We could therefore not conclude that the lunar effect on catch was due to an effect on fish behavior alone. Several factors affected the amount of variation explained by the lunar cycle. The lunar effect was stronger for larger muskellunge (>102 cm) than for smaller fish, stronger in midsummer than in June or October, and stronger for fish caught at high latitudes (>48°N) than for fish caught further south. There was no difference in the lunar effect between expert and novice muskellunge anglers. We argue that this variation is evidence that the effect of the lunar cycle on catch is mediated by biological factors and is not due solely to angler effort and reflects lunar synchronization in feeding. This effect has been attributed to variation among moon phases in lunar illumination, but our results do not support that hypothesis for angler-caught muskellunge.

  12. Blood Removal Influences Pacing During a 4-Minute Cycling Time Trial.

    PubMed

    Lawler, Nathan G; Abbiss, Chris R; Raman, Aaron; Fairchild, Timothy J; Maker, Garth L; Trengove, Robert D; Peiffer, Jeremiah J

    2017-01-17

    To examine the influence of manipulating aerobic contribution following whole blood removal on pacing patterns, performance and energy contribution during self-paced middle distance cycling. Seven male cyclists (33 ± 8 y) completed an incremental cycling test followed 20 min later by a 4-min self-paced cycling time trial (4MMP) on six separate occasions over 42 d. The initial two sessions acted as a familiarisation and baseline testing after which 470 mL of blood was removed with the remaining sessions performed 24 h, 7 d, 21 d and 42 d following blood removal. During all 4MMP trials, power output, V̇O2, and aerobic and anaerobic contribution to power were determined. 4MMP average power output significantly decreased by 7 ± 6%, 6 ± 8% and 4 ± 6% at 24 h, 7 d and 21 d following blood removal, respectively. Compared with baseline, aerobic contribution during the 4MMP was significantly reduced by 5 ± 4%, 4 ± 5% and 4 ± 10% at 24 h, 7 d and 21 d, respectively. The rate of decline in power output upon commencement of the 4MMP was significantly attenuated and was 76 ± 20%, 72 ± 24% and 75 ± 35% lower than baseline at 24 h, 21 d and 42 d, respectively. The results indicate that the removal of 470 mL of blood reduces aerobic energy contribution, alters pacing patterns and decreases performance during self-paced cycling. These findings indicate the importance of aerobic energy distribution during self-paced middle distance events.

  13. Muskie Lunacy: Does the Lunar Cycle Influence Angler Catch of Muskellunge (Esox masquinongy)?

    PubMed Central

    Vinson, Mark R.; Angradi, Ted R.

    2014-01-01

    We analyzed angling catch records for 341,959 muskellunge (Esox masquinongy) from North America to test for a cyclic lunar influence on the catch. Using periodic regression, we showed that the number caught was strongly related to the 29-day lunar cycle, and the effect was consistent across most fisheries. More muskellunge were caught around the full and new moon than at other times. At night, more muskellunge were caught around the full moon than the new moon. The predicted maximum relative effect was ≈5% overall. Anglers fishing exclusively on the peak lunar day would, on average, catch 5% more muskellunge than anglers fishing on random days. On some lakes and at night, the maximum relative effect was higher. We obtained angler effort data for Wisconsin, Mille Lacs (MN), and Lake Vermilion (MN). For Lake Vermilion there was a significant effect of the lunar cycle on angler effort. We could therefore not conclude that the lunar effect on catch was due to an effect on fish behavior alone. Several factors affected the amount of variation explained by the lunar cycle. The lunar effect was stronger for larger muskellunge (>102 cm) than for smaller fish, stronger in midsummer than in June or October, and stronger for fish caught at high latitudes (>48°N) than for fish caught further south. There was no difference in the lunar effect between expert and novice muskellunge anglers. We argue that this variation is evidence that the effect of the lunar cycle on catch is mediated by biological factors and is not due solely to angler effort and reflects lunar synchronization in feeding. This effect has been attributed to variation among moon phases in lunar illumination, but our results do not support that hypothesis for angler-caught muskellunge. PMID:24871329

  14. Muskie Lunacy: does the lunar cycle influence angler catch of muskellunge (Esox masquinongy)?

    PubMed

    Vinson, Mark R; Angradi, Ted R

    2014-01-01

    We analyzed angling catch records for 341,959 muskellunge (Esox masquinongy) from North America to test for a cyclic lunar influence on the catch. Using periodic regression, we showed that the number caught was strongly related to the 29-day lunar cycle, and the effect was consistent across most fisheries. More muskellunge were caught around the full and new moon than at other times. At night, more muskellunge were caught around the full moon than the new moon. The predicted maximum relative effect was ≈5% overall. Anglers fishing exclusively on the peak lunar day would, on average, catch 5% more muskellunge than anglers fishing on random days. On some lakes and at night, the maximum relative effect was higher. We obtained angler effort data for Wisconsin, Mille Lacs (MN), and Lake Vermilion (MN). For Lake Vermilion there was a significant effect of the lunar cycle on angler effort. We could therefore not conclude that the lunar effect on catch was due to an effect on fish behavior alone. Several factors affected the amount of variation explained by the lunar cycle. The lunar effect was stronger for larger muskellunge (>102 cm) than for smaller fish, stronger in midsummer than in June or October, and stronger for fish caught at high latitudes (>48°N) than for fish caught further south. There was no difference in the lunar effect between expert and novice muskellunge anglers. We argue that this variation is evidence that the effect of the lunar cycle on catch is mediated by biological factors and is not due solely to angler effort and reflects lunar synchronization in feeding. This effect has been attributed to variation among moon phases in lunar illumination, but our results do not support that hypothesis for angler-caught muskellunge.

  15. Influence of the curing cycles on the fatigue performance of unidirectional glass fiber reinforced epoxy composites

    NASA Astrophysics Data System (ADS)

    Hüther, Jonas; Brøndsted, Povl

    2016-07-01

    During the manufacturing process of fiber reinforced polymers the curing reaction of the resin results in shrinkage of the resin and introduces internal stresses in the composites. When curing at higher temperatures in order to shorten up the processing time, higher curing stresses and thermal stresses are built up and frozen, as residual stresses occur. In the present work, a glass fiber reinforced epoxy composite laminate with an unidirectional architecture based on non-crimp fabrics with backing fibers is investigated. Three different curing cycles (time-temperature cycles) are used, leading to different levels of internal stresses. The mechanical properties, static strength and fatigue life time, are measured in three different directions of the material, i.e. the fiber direction, 0°, the 30° off axis direction, and the 90° direction transverse to the fiber direction. It is experimentally demonstrated that the resulting residual stresses barely influences the quasi-static mechanical properties of reinforced glass-fiber composites. It is found that the fatigue performance in the 0° direction is significantly influenced by the internal stresses, whereas the fatigue performance in the off axes directions so is not significantly influenced of these stresses. This is related to the observations that the damage mechanisms in the off axes directions are mainly related to shear failure in the matrix and in the interface between fiber and matrix and different from the damage mechanisms in the fiber direction, where the damage initiates in the transverse backing fibers and is directly related to fiber fractures in the load-carrying axial fiber bundles.

  16. Influence of mold surface temperature on polymer part warpage in rapid heat cycle molding

    NASA Astrophysics Data System (ADS)

    Berger, G. R.; Pacher, G. A.; Pichler, A.; Friesenbichler, W.; Gruber, D. P.

    2014-05-01

    Dynamic mold surface temperature control was examined for its influence on the warpage. A test mold, featuring two different rapid heat cycle molding (RHCM) technologies was used to manufacture complex plate-shaped parts having different ribs, varying thin-wall regions, and both, circular and rectangular cut-outs. The mold's nozzle side is equipped with the areal heating and cooling technology BFMOLD®, where the heating/cooling channels are replaced by a ball-filled slot near the cavity surface flooded through with hot and cold water sequentially. Two local electrical ceramic heating elements are installed into the mold's ejection side. Based on a 23 full-factorial design of experiments (DoE) plan, varying nozzle temperature (Tnozzle), rapid heat cycle molding temperature (TRHCM) and holding pressure (pn), specimens of POM were manufactured systematically. Five specimens were examined per DoE run. The resulting warpage was measured at 6 surface line scans per part using the non-contact confocal topography system FRT MicroProf®. Two warpage parameters were calculated, the curvature of a 2nd order approximation a, and the vertical deflection at the profile center d. Both, the influence strength and the acting direction of the process parameters and their interactions on a and d were calculated by statistical analysis. Linear mathematical process models were determined for a and d to predict the warpage as a function of the process parameter settings. Finally, an optimum process setting was predicted, based on the process models and Microsoft Excel GRG solver. Clear and significant influences of TRHCM, pn, Tnozzle, and the interaction of TRHCM and pn were determined. While TRHCM was dominant close to the gate, pn became more effective as the flow length increased.

  17. Influence of seasonal cycles in Martian atmosphere on entry, descent and landing sequence

    NASA Astrophysics Data System (ADS)

    Marčeta, Dušan; Šegan, Stevo; Rašuo, Boško

    2014-05-01

    The phenomena like high eccentricity of Martian orbit, obliquity of the orbital plane and close alignment of the winter solstice and the orbital perihelion, separately or together can significantly alter not only the level of some Martian atmospheric parameters but also the characteristics of its diurnal and seasonal cycle. Considering that entry, descent and landing (EDL) sequence is mainly driven by the density profile of the atmosphere and aerodynamic characteristic of the entry vehicle. We have performed the analysis of the influence of the seasonal cycles of the atmospheric parameters on EDL profiles by using Mars Global Reference Atmospheric Model (Mars-GRAM). Since the height of the deployment of the parachute and the time passed from the deployment to propulsion firing (descent time) are of crucial importance for safe landing and the achievable landing site elevation we paid special attention to the influence of the areocentric longitude of the Sun (Ls) on these variables. We have found that these variables have periodic variability with respect to Ls and can be very well approximated with a sine wave function whose mean value depends only on the landing site elevation while the amplitudes and phases depend only on the landing site latitude. The amplitudes exhibit behavior which is symmetric with respect to the latitude but the symmetry is shifted from the equator to the northern mid-tropics. We have also noticed that the strong temperature inversions which are usual for middle and higher northern latitudes while Mars is around its orbital perihelion significantly alter the descent time without influencing the height of the parachute deployment. At last, we applied our model to determine the dependence of the accessible landing region on Ls and found that this region reaches maximum when Mars is around the orbital perihelion and can vary 50° in latitude throughout the Martian year.

  18. Effects of an anti-androgen and 5 alpha-reductase inhibitors on estrus duration in the cycling female rat.

    PubMed

    Erskine, M S

    1983-04-01

    Five experiments examined the role of circulating androgens in the control of sexual behavior (lordosis) in the intact cycling rat. The androgen receptor blocker, flutamide (FLU), was administered daily to cycling rats beginning on the day of estrus, and lordotic responsiveness was measured on the 2nd subsequent proestrus day and on the day of estrus. FLU-treated females showed significantly higher levels of lordosis throughout the end of the period of estrus than controls (Experiment 1). Neither the maximal levels of lordosis seen on the evening of proestrus nor the time of onset of estrous responsiveness during the preceeding afternoon were affected by FLU (Experiment 2). Serum estradiol concentrations seen on the morning of proestrus (Experiment 3) did not differ between FLU- and vehicle-treated animals. The weak 5 alpha-reductase inhibitor, testosterone-17 beta-carboxylic acid (17 beta C), prolonged slightly, but did not significantly lengthen, the period of estrus (Experiment 4), while the highly potent steroidal 5 alpha-reductase inhibitor, 4 MA, significantly increased the rate at which estrous behavior declined on the day of estrus (Experiment 5). Circulating androgens do not appear to affect the maximal level of sexual receptivity displayed nor the time of estrus onset; however, they may govern the duration of the period of estrus by influencing the rate of estrus termination.

  19. The influence of quarantine on reproductive cycling in wild-caught Baboons (Papio anubis).

    PubMed

    Liechty, Emma R; Wang, Diane Y; Chen, Emily; Chai, Daniel; Bell, Jason D; Bergin, Ingrid L

    2015-12-01

    Stress impacts nonhuman primate menstrual cycle length but the impact of quarantine is unknown. A retrospective analysis was performed on cycle data from 31 wild-caught baboons during and following quarantine. Cycling initiated in 94 days (19-181) and length normalized within 4-6 cycles. Quarantine significantly impacts menstrual cycle length.

  20. Influence of Inspiratory Muscle Training on Ventilatory Efficiency and Cycling Performance in Normoxia and Hypoxia

    PubMed Central

    Salazar-Martínez, Eduardo; Gatterer, Hannes; Burtscher, Martin; Naranjo Orellana, José; Santalla, Alfredo

    2017-01-01

    The aim of this study was to analyse the influence of inspiratory muscle training (IMT) on ventilatory efficiency, in normoxia and hypoxia, and to investigate the relationship between ventilatory efficiency and cycling performance. Sixteen sport students (23.05 ± 4.7 years; 175.11 ± 7.1 cm; 67.0 ± 19.4 kg; 46.4 ± 8.7 ml·kg−1·min−1) were randomly assigned to an inspiratory muscle training group (IMTG) and a control group (CG). The IMTG performed two training sessions/day [30 inspiratory breaths, 50% peak inspiratory pressure (Pimax), 5 days/week, 6-weeks]. Before and after the training period subjects carried out an incremental exercise test to exhaustion with gas analysis, lung function testing, and a cycling time trial test in hypoxia and normoxia. Simulated hypoxia (FiO2 = 16.45%), significantly altered the ventilatory efficiency response in all subjects (p < 0.05). Pimax increased significantly in the IMTG whereas no changes occurred in the CG (time × group, p < 0.05). Within group analyses showed that the IMTG improved ventilatory efficiency (VE/VCO2 slope; EqCO2VT2) in hypoxia (p < 0.05) and cycling time trial performance [WTTmax (W); WTTmean (W); PTF(W)] (p < 0.05) in hypoxia and normoxia. Significant correlations were not found in hypoxia nor normoxia found between ventilatory efficiency parameters (VE/VCO2 slope; LEqCO2; EqCO2VT2) and time trial performance. On the contrary the oxygen uptake efficiency slope (OUES) was highly correlated with cycling time trial performance (r = 0.89; r = 0.82; p < 0.001) under both conditions. Even though no interaction effect was found, the within group analysis may suggest that IMT reduces the negative effects of hypoxia on ventilatory efficiency. In addition, the data suggest that OUES plays an important role in submaximal cycling performance. PMID:28337149

  1. Influence of Inspiratory Muscle Training on Ventilatory Efficiency and Cycling Performance in Normoxia and Hypoxia.

    PubMed

    Salazar-Martínez, Eduardo; Gatterer, Hannes; Burtscher, Martin; Naranjo Orellana, José; Santalla, Alfredo

    2017-01-01

    The aim of this study was to analyse the influence of inspiratory muscle training (IMT) on ventilatory efficiency, in normoxia and hypoxia, and to investigate the relationship between ventilatory efficiency and cycling performance. Sixteen sport students (23.05 ± 4.7 years; 175.11 ± 7.1 cm; 67.0 ± 19.4 kg; 46.4 ± 8.7 ml·kg(-1)·min(-1)) were randomly assigned to an inspiratory muscle training group (IMTG) and a control group (CG). The IMTG performed two training sessions/day [30 inspiratory breaths, 50% peak inspiratory pressure (Pimax), 5 days/week, 6-weeks]. Before and after the training period subjects carried out an incremental exercise test to exhaustion with gas analysis, lung function testing, and a cycling time trial test in hypoxia and normoxia. Simulated hypoxia (FiO2 = 16.45%), significantly altered the ventilatory efficiency response in all subjects (p < 0.05). Pimax increased significantly in the IMTG whereas no changes occurred in the CG (time × group, p < 0.05). Within group analyses showed that the IMTG improved ventilatory efficiency (VE/VCO2 slope; EqCO2VT2) in hypoxia (p < 0.05) and cycling time trial performance [WTTmax (W); WTTmean (W); PTF(W)] (p < 0.05) in hypoxia and normoxia. Significant correlations were not found in hypoxia nor normoxia found between ventilatory efficiency parameters (VE/VCO2 slope; LEqCO2; EqCO2VT2) and time trial performance. On the contrary the oxygen uptake efficiency slope (OUES) was highly correlated with cycling time trial performance (r = 0.89; r = 0.82; p < 0.001) under both conditions. Even though no interaction effect was found, the within group analysis may suggest that IMT reduces the negative effects of hypoxia on ventilatory efficiency. In addition, the data suggest that OUES plays an important role in submaximal cycling performance.

  2. Influence of Reproductive Aging of the Cow on Luteal Function and Period 1 mRNA Expression

    USDA-ARS?s Scientific Manuscript database

    In rodents, disruption of the circadian clock genes results in increased incidence of anovulation, irregular estrous cycles, decreased luteal function, and accelerated reproductive ageing. In cattle, reproductive ageing is associated with decreased numbers of follicles in the ovary, decreased lutea...

  3. The influence of woody encroachment on the nitrogen cycle: fixation, storage and gas loss

    NASA Astrophysics Data System (ADS)

    Soper, F.; Sparks, J. P.

    2015-12-01

    Woody encroachment is a pervasive land cover change throughout the tropics and subtropics. Encroachment is frequently catalyzed by nitrogen (N)-fixing trees and the resulting N inputs potentially alter whole-ecosystem N cycling, accumulation and loss. In the southern US, widespread encroachment by legume Prosopis glandulosa is associated with increased soil total N storage, inorganic N concentrations, and net mineralization and nitrification rates. To better understand the effects of this process on ecosystem N cycling, we investigated patterns of symbiotic N fixation, N accrual and soil N trace gas and N2 emissions during Prosopis encroachment into the southern Rio Grande Plains. Analyses of d15N in foliage, xylem sap and plant-available soil N suggested that N fixation rates increase with tree age and are influenced by abiotic conditions. A model of soil N accrual around individual trees, accounting for atmospheric inputs and gas losses, generates lifetimes N fixation estimates of up to 9 kg for a 100-year-old tree and current rates of 7 kg N ha-1 yr-1. However, these N inputs and increased soil cycling rates do not translate into increased N gas losses. Two years of field measurements of a complete suite of N trace gases (ammonia, nitrous oxide, nitric oxide and other oxidized N compounds) found no difference in flux between upland Prosopis groves and adjacent unencroached grasslands. Total emissions for both land cover types average 0.56-0.65 kg N ha-1 yr-1, comparable to other southern US grasslands. Additional lab experiments suggested that N2 losses are low and that field oxygen conditions are not usually conducive to denitrification. Taken together, results suggest that this ecosystem is currently experiencing a period of net N accrual under ongoing encroachment.

  4. Factors influencing serum progesterone level on triggering day in stimulated in vitro fertilization cycles.

    PubMed

    Park, Ju Hee; Jee, Byung Chul; Kim, Seok Hyun

    2015-06-01

    Elevated serum progesterone (P) levels on triggering day have been known to affect the pregnancy rate of in vitro fertilization (IVF). This study aimed to identify the possible factors influencing serum P levels on triggering day in stimulated IVF cycles. Three hundred and thirty consecutive fresh IVF cycles were included in the study. All cycles were first attempts and were performed in a single infertility center. The indications for IVF were male factor infertility (n=114), ovulatory infertility (n=84), endometriosis (n=61), tubal infertility (n=59), unexplained infertility (n=41), and uterine factor infertility (n=39). A luteal long protocol of a gonadotropin-releasing hormone (GnRH) agonist (n=184) or a GnRH antagonist protocol (n=146) was used for pituitary suppression. Ovarian sensitivity was defined as the serum estradiol level on triggering day per 500 IU of administered gonadotropins (OS[a]) or the retrieved oocyte number per 500 IU of administered gonadotropins (OS[b]). Univariate analysis revealed that the serum P level on triggering day was associated with the serum estradiol level on triggering day (r=0.379, p<0.001), the number of follicles ≥14 mm (r=0.247, p<0.001), the number of retrieved oocytes (r=0.384, p<0.001), and ovarian sensitivity (OS[a]: r=0.245, p<0.001; OS[b]: r=0.170, p=0.002). The woman's age, body mass index, antral follicle count, and basal serum follicle stimulating hormone and estradiol levels were not associated with serum P level on triggering day. The serum P level on triggering day did not show significant variation depending on the type or cause of infertility, pituitary suppression protocol, or the type of gonadotropins used. The serum P level on triggering day was closely related to the response to ovarian stimulation.

  5. Factors influencing serum progesterone level on triggering day in stimulated in vitro fertilization cycles

    PubMed Central

    Park, Ju Hee; Jee, Byung Chul

    2015-01-01

    Objective Elevated serum progesterone (P) levels on triggering day have been known to affect the pregnancy rate of in vitro fertilization (IVF). This study aimed to identify the possible factors influencing serum P levels on triggering day in stimulated IVF cycles. Methods Three hundred and thirty consecutive fresh IVF cycles were included in the study. All cycles were first attempts and were performed in a single infertility center. The indications for IVF were male factor infertility (n=114), ovulatory infertility (n=84), endometriosis (n=61), tubal infertility (n=59), unexplained infertility (n=41), and uterine factor infertility (n=39). A luteal long protocol of a gonadotropin-releasing hormone (GnRH) agonist (n=184) or a GnRH antagonist protocol (n=146) was used for pituitary suppression. Ovarian sensitivity was defined as the serum estradiol level on triggering day per 500 IU of administered gonadotropins (OS[a]) or the retrieved oocyte number per 500 IU of administered gonadotropins (OS[b]). Results Univariate analysis revealed that the serum P level on triggering day was associated with the serum estradiol level on triggering day (r=0.379, p<0.001), the number of follicles ≥14 mm (r=0.247, p<0.001), the number of retrieved oocytes (r=0.384, p<0.001), and ovarian sensitivity (OS[a]: r=0.245, p<0.001; OS[b]: r=0.170, p=0.002). The woman's age, body mass index, antral follicle count, and basal serum follicle stimulating hormone and estradiol levels were not associated with serum P level on triggering day. The serum P level on triggering day did not show significant variation depending on the type or cause of infertility, pituitary suppression protocol, or the type of gonadotropins used. Conclusion The serum P level on triggering day was closely related to the response to ovarian stimulation. PMID:26161336

  6. A model of the ocean iron cycle and its influence on biological production

    NASA Astrophysics Data System (ADS)

    Dutkiewicz, S.; Parekh, P.; Follows, M.

    2003-04-01

    Biological productivity in large regions of the ocean, specifically high nutrient, low chlorophyll regions, is limited by the deficit in iron relative to other nutrients. We have developed a parameterization of the iron cycle of the world's oceans which attempts to explicitly represent the processes by which this deficit in iron occurs. We have implemented this parameterization in the context of the MIT three dimensional global ocean model and examined the consequences for nutrient distributions, new production and primary production. The iron model parameterizes the mechanisms of scavenging of iron onto sinking particles and complexation with an organic ligand and is driven by specified aeolian flux patterns. First, using an idealized representation of export production, limited by light, phosphate and iron, the model reproduces the broad features of the observed ocean phosphate and iron distributions. We replace the simplified export parameterization with an explicit, but highly idealized, ecosystem model. The model represents a simplified food web with two phytoplankton size classes and a single grazer. The base currency for this model is phosphorus, but the larger phytoplankton class (i.e. diatoms) is also limited by silica. Both classes are limited by the availability of iron. The results of this model are also generally consistent with the observed patterns of phosphate and iron. In addition, the model captures the broad features of the distributions and cycles of silica, chlorophyll and primary production. We will also explore the sensitivities of this model to the forcing fields (e.g. aeolian iron flux) and parameter choices of the ecosystem model. This model represents a step towards the explicit representation of the ocean iron cycle, and its biogeochemical influences, in global biogeochemical models.

  7. Motor modules of human locomotion: influence of EMG averaging, concatenation, and number of step cycles

    PubMed Central

    Oliveira, Anderson S.; Gizzi, Leonardo; Farina, Dario; Kersting, Uwe G.

    2014-01-01

    Locomotion can be investigated by factorization of electromyographic (EMG) signals, e.g., with non-negative matrix factorization (NMF). This approach is a convenient concise representation of muscle activities as distributed in motor modules, activated in specific gait phases. For applying NMF, the EMG signals are analyzed either as single trials, or as averaged EMG, or as concatenated EMG (data structure). The aim of this study is to investigate the influence of the data structure on the extracted motor modules. Twelve healthy men walked at their preferred speed on a treadmill while surface EMG signals were recorded for 60s from 10 lower limb muscles. Motor modules representing relative weightings of synergistic muscle activations were extracted by NMF from 40 step cycles separately (EMGSNG), from averaging 2, 3, 5, 10, 20, and 40 consecutive cycles (EMGAVR), and from the concatenation of the same sets of consecutive cycles (EMGCNC). Five motor modules were sufficient to reconstruct the original EMG datasets (reconstruction quality >90%), regardless of the type of data structure used. However, EMGCNC was associated with a slightly reduced reconstruction quality with respect to EMGAVR. Most motor modules were similar when extracted from different data structures (similarity >0.85). However, the quality of the reconstructed 40-step EMGCNC datasets when using the muscle weightings from EMGAVR was low (reconstruction quality ~40%). On the other hand, the use of weightings from EMGCNC for reconstructing this long period of locomotion provided higher quality, especially using 20 concatenated steps (reconstruction quality ~80%). Although EMGSNG and EMGAVR showed a higher reconstruction quality for short signal intervals, these data structures did not account for step-to-step variability. The results of this study provide practical guidelines on the methodological aspects of synergistic muscle activation extraction from EMG during locomotion. PMID:24904375

  8. Influence of the solar cycle on the Polar-night Jet Oscillation

    NASA Astrophysics Data System (ADS)

    Kuroda, Yuhji

    2017-04-01

    The Polar-night Jet Oscillation (PJO) is the dominant mode of stratospheric variability in the Southern Hemisphere (SH), and persists from mid-winter to spring. The influence of the 11-year solar cycle on modulation of the PJO from late winter to spring is examined using observations and three 42-year simulations from a chemistry-climate model. The only variation applied to model boundary conditions was the strength of ultraviolet radiation (UV). This is set at two times larger than observations to enhance the strength of the solar signal. Simulations show a downward propagation of the stratospheric signal into the troposphere from late winter to spring, which tends to be enhanced as UV strength increases. This result is similar to observations, but with a 1-2 month lag. The behavior of the PJO with respect to wave-mean flow interactions is examined using a newly developed momentum budget analysis as well as wave-energy analysis. We suggest that UV modulation of the interactions between planetary waves and zonal-mean flow in the stratosphere, rather than direct diabatic processes as suggested in a previous study, is the source of solar cycle modulation of the PJO.

  9. Duty Cycle of Deformational Loading Influences the Growth of Engineered Articular Cartilage.

    PubMed

    Ng, Kenneth W; Mauck, Robert L; Wang, Christopher C-B; Kelly, Terri-Ann N; Ho, Mandy M-Y; Chen, Faye Hui; Ateshian, Gerard A; Hung, Clark T

    2009-09-01

    This study examines how variations in the duty cycle (the duration of applied loading) of deformational loading can influence the mechanical properties of tissue engineered cartilage constructs over one month in bioreactor culture. Dynamic loading was carried out with three different duty cycles: 1 h on/1 h off for a total of 3 h loading/day, 3 h continuous loading, or 6 h of continuous loading per day, with all loading performed 5 days/week. All loaded groups showed significant increases in Young's modulus after one month (vs. free swelling controls), but only loading for a continuous 3 and 6 h showed significant increases in dynamic modulus by this time point. Histological analysis showed that dynamic loading can increase cartilage oligomeric matrix protein (COMP) and collagen types II and IX, as well as prevent the formation of a fibrous capsule around the construct. Type II and IX collagen deposition increased with increased with duration of applied loading. These results point to the efficacy of dynamic deformational loading in the mechanical preconditioning of engineered articular cartilage constructs. Furthermore, these results highlight the ability to dictate mechanical properties with variations in mechanical input parameters, and the possible importance of other cartilage matrix molecules, such as COMP, in establishing the functional material properties of engineered constructs.

  10. Factors influencing the life cycle burdens of the recovery of energy from residual municipal waste.

    PubMed

    Burnley, Stephen; Coleman, Terry; Peirce, Adam

    2015-05-01

    A life cycle assessment was carried out to assess a selection of the factors influencing the environmental impacts and benefits of incinerating the fraction of municipal waste remaining after source-separation for reuse, recycling, composting or anaerobic digestion. The factors investigated were the extent of any metal and aggregate recovery from the bottom ash, the thermal efficiency of the process, and the conventional fuel for electricity generation displaced by the power generated. The results demonstrate that incineration has significant advantages over landfill with lower impacts from climate change, resource depletion, acidification, eutrophication human toxicity and aquatic ecotoxicity. To maximise the benefits of energy recovery, metals, particularly aluminium, should be reclaimed from the residual bottom ash and the energy recovery stage of the process should be as efficient as possible. The overall environmental benefits/burdens of energy from waste also strongly depend on the source of the power displaced by the energy from waste, with coal giving the greatest benefits and combined cycle turbines fuelled by natural gas the lowest of those considered. Regardless of the conventional power displaced incineration presents a lower environmental burden than landfill.

  11. Influence of cycle exercise on acetone in expired air and skin gas.

    PubMed

    Yamai, Kazuaki; Ohkuwa, Tetsuo; Itoh, Hiroshi; Yamazaki, Yoshihiko; Tsuda, Takao

    2009-01-01

    This study investigated the influence of cycle exercise on acetone concentration in expired air and skin gas. The subjects for this experiment were eight healthy males. Subjects performed a continuous graded exercise test on a cycle ergometer. The workloads were 360 (1.0 kg), 720 (2.0 kg), 990 (2.75 kg) kgm/min, and each stage was 5 min in duration. A pedaling frequency of 60 rpm was maintained. Acetone concentration was analyzed by gas chromatography. The acetone concentration in expired air and skin gas during exercise at 990 kgm/min intensity was significantly increased compared with the basal level. The skin-gas acetone concentration at 990 kgm/min significantly increased compared with the 360 kgm/min (P < 0.05). The acetone excretion of expired air at 720 kgm/min and 990 kgm/min significantly increased compared with the basal level (P < 0.05). Acetone concentration in expired air was 4-fold greater than skin gas at rest and 3-fold greater during exercise (P < 0.01). Skin gas acetone concentration significantly related with expired air (r = 0.752; P < 0.01). This study confirmed that the skin-gas acetone concentration reflected that of expired air.

  12. Intertidal Concentrations of Microplastics and Their Influence on Ammonium Cycling as Related to the Shellfish Industry.

    PubMed

    Cluzard, Melanie; Kazmiruk, Tamara N; Kazmiruk, Vasily D; Bendell, L I

    2015-10-01

    Microplastics are ubiquitous within the marine environment. The last 10 years have seen research directed at understanding the fate and effect of microplastics within the marine environment; however, no studies have yet addressed how concentrations of these particles could affect sedimentary processes such as nutrient cycling. Herein we first determine the concentration and spatial distribution of microplastics within Baynes Sound, a key shellfish-growing area within coastal British Columbia (BC). We also determined sediment grain size and % organic matter (OM) such that we could relate spatial patterns in sediment microplastic concentrations to sedimentary processes that determine zones of accretion and erosion. Using field-determined concentrations of microplastics, we applied laboratory microcosms studies, which manipulated sediment concentrations of microplastics, OM, and bivalves to determine the influence of sediment microplastics on ammonium cycling within intertidal sediments. Concentrations of microplastics determined within the intertidal sediment varied spatially and were similar to those found in other coastal regions of high urban use. Concentrations were independent of grain size and OM suggesting that physical processes other than those that govern natural sediment components determine the fate of microplastics within sediments. Under laboratory conditions, concentrations of ammonium were significantly greater in the overlying water of treatments with microplastics, clams, and OM compared with treatments without microplastics. These preliminary studies suggest that high concentrations of microplastics have the potential to alter key sedimentary processes such as ammonium flux. This could have serious implications, for example, contributing to eutrophication events in regions of the coast that are highly urbanized.

  13. Influence of the solar cycle on the Polar-night Jet Oscillation in the Southern Hemisphere

    NASA Astrophysics Data System (ADS)

    Kuroda, Yuhji; Deushi, Makoto

    2016-10-01

    The Polar-night Jet Oscillation (PJO) is the dominant mode of stratospheric variability in the Southern Hemisphere and persists from midwinter to spring. The influence of the 11 year solar cycle on modulation of the PJO from late winter to spring is examined using observations and three 42 year simulations from a chemistry-climate model. The only variation applied to model boundary conditions was the strength of ultraviolet (UV) radiation. This is set at 2 times larger than observations to enhance the strength of the solar signal. Simulations show a downward propagation of the stratospheric signal into the troposphere from late winter to spring, which tends to be enhanced as UV strength increases. This result is similar to observations but with a 1-2 month lag. The behavior of the PJO with respect to wave-mean flow interactions is examined using a newly developed momentum budget analysis as well as wave energy analysis. We suggest that UV modulation of the interactions between planetary waves and zonal-mean flow in the stratosphere, rather than direct diabatic processes as suggested in a previous study, is the source of solar cycle modulation of the PJO.

  14. The QBO as Potential Amplifier and Conduit to Lower Altitudes of Solar Cycle Influence

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.; Chan, Kwing L.; Porter, Hayden S.

    2005-01-01

    The solar cycle (SC) effect in the lower atmosphere has been linked observationally to the Quasi-biennial Oscillation (QBO), which is generated primarily by small-scale gravity waves. Salby and Callaghan analyzed the QBO observations covering more than 40 years and found that it contains a relatively large SC signature at 20 km. Following up on a 2D study with our Numerical Spectral Model (NSM), we discuss here a 3D study in which we simulated the QBO under the influence of the SC. For a SC period of 10 years, the amplitude of the relative variations of radiative forcing is taken to vary from 0.2% at the surface to 2% at 50 km to 20% at 100 km and above. This model produces in the lower stratosphere a relatively large modulation of the QBO, which appears to be related to the SC and is in qualitative agreement with the observations. Further studies are needed, (1) to determine whether the effect is real and the results are robust and (2) to explore the mechanism(s) that may amplify the SC effect. Quasi-decadal oscillations, generated internally by the QBO interacting with the seasonal cycles, may interfere with or aid the SC effect.

  15. The factors influencing car use in a cycle-friendly city: the case of Cambridge

    PubMed Central

    Carse, Andrew; Goodman, Anna; Mackett, Roger L.; Panter, Jenna; Ogilvie, David

    2013-01-01

    Encouraging people out of their cars and into other modes of transport, which has major advantages for health, the environment and urban development, has proved difficult. Greater understanding of the influences that lead people to use the car, particularly for shorter journeys, may help to achieve this. This paper examines the predictors of car use compared with the bicycle to explore how it may be possible to persuade more people to use the bicycle instead of the car. Multivariable logistic regression was used to examine the socio-demographic, transport and health-related correlates of mode choice for work, shopping and leisure trips in Cambridge, a city with high levels of cycling by UK standards. The key findings are that commuting distance and free workplace parking were strongly associated with use of the car for work trips, and car availability and lower levels of education were associated with car use for leisure, shopping and short-distanced commuting trips. The case of Cambridge shows that more policies could be adopted, particularly a reduction in free car parking, to increase cycling and reduce the use of the car, especially over short distances. PMID:24954981

  16. The factors influencing car use in a cycle-friendly city: the case of Cambridge.

    PubMed

    Carse, Andrew; Goodman, Anna; Mackett, Roger L; Panter, Jenna; Ogilvie, David

    2013-04-01

    Encouraging people out of their cars and into other modes of transport, which has major advantages for health, the environment and urban development, has proved difficult. Greater understanding of the influences that lead people to use the car, particularly for shorter journeys, may help to achieve this. This paper examines the predictors of car use compared with the bicycle to explore how it may be possible to persuade more people to use the bicycle instead of the car. Multivariable logistic regression was used to examine the socio-demographic, transport and health-related correlates of mode choice for work, shopping and leisure trips in Cambridge, a city with high levels of cycling by UK standards. The key findings are that commuting distance and free workplace parking were strongly associated with use of the car for work trips, and car availability and lower levels of education were associated with car use for leisure, shopping and short-distanced commuting trips. The case of Cambridge shows that more policies could be adopted, particularly a reduction in free car parking, to increase cycling and reduce the use of the car, especially over short distances.

  17. Selection of organic process and source indicator substances for the anthropogenically influenced water cycle.

    PubMed

    Jekel, Martin; Dott, Wolfgang; Bergmann, Axel; Dünnbier, Uwe; Gnirß, Regina; Haist-Gulde, Brigitte; Hamscher, Gerd; Letzel, Marion; Licha, Tobias; Lyko, Sven; Miehe, Ulf; Sacher, Frank; Scheurer, Marco; Schmidt, Carsten K; Reemtsma, Thorsten; Ruhl, Aki Sebastian

    2015-04-01

    An increasing number of organic micropollutants (OMP) is detected in anthropogenically influenced water cycles. Source control and effective natural and technical barriers are essential to maintain a high quality of drinking water resources under these circumstances. Based on the literature and our own research this study proposes a limited number of OMP that can serve as indicator substances for the major sources of OMP, such as wastewater treatment plants, agriculture and surface runoff. Furthermore functional indicators are proposed that allow assessment of the proper function of natural and technical barriers in the aquatic environment, namely conventional municipal wastewater treatment, advanced treatment (ozonation, activated carbon), bank filtration and soil aquifer treatment as well as self-purification in surface water. These indicator substances include the artificial sweetener acesulfame, the anti-inflammatory drug ibuprofen, the anticonvulsant carbamazepine, the corrosion inhibitor benzotriazole and the herbicide mecoprop among others. The chemical indicator substances are intended to support comparisons between watersheds and technical and natural processes independent of specific water cycles and to reduce efforts and costs of chemical analyses without losing essential information.

  18. Lunar cycles at mating do not influence sex ratio at birth in horses.

    PubMed

    Aguilar, J J; Cuervo-Arango, J; Santa Juliana, L

    2015-02-01

    It is scientifically demonstrated that lunar cycles have important effects on several biological events. Controversy exists about the lunar influence on human and animal parturition. In addition, in the horse industry, especially in Polo Horse breeders of Argentina and around the world there is a higher demand for female offspring than for males. The objective of this study was to determine whether there is a significant association between the lunar phase at the time of mating and the sex ratio at birth in horses. The Argentinean Stud Book provided information related to all matings registered for Thoroughbred and Arab horses between 2003 and 2011. Statistical associations were tested between dates of matings at different lunar phases or days and sex ratio at birth. A total of 65.535 gestations were studied. Overall, sex ratio at birth resulted in 33.396 fillies (50.96%) and 32.139 colts (49.04%). The percentages of males and females at birth were not statistically different amongst the different lunar phases or days. We can strongly conclude that managing the breeding dates in relation to lunar cycles in order to manipulate the sex ratio of the offspring is not a viable option in horses.

  19. The QBO as Potential Amplifier and Conduit to Lower Altitudes of Solar Cycle Influence?

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.; Porter, Hayden S.

    2005-01-01

    The solar cycle (SC) effect in the lower atmosphere has been linked observationally to the Quasi-biennial Oscillation (QBO), which is generated primarily by small-scale gravity waves (GW). Following up on a 2D study with our Numerical Spectral Model (NSM), we discuss here a 3D study in which we simulated the QBO under the influence of the SC. For a SC period of 10 years, the relative amplitude of radiative forcing is taken to vary exponentially with height, i.e., 0.2% at the surface, 2% at 50 km, 20% at 100 km and above. Applying spectral analysis to filter out and identify the SC signature, this model produces a relatively large modulation in the QBO of the lower stratospheric circulation, which is in qualitative agreement with the results obtained by Salby and Callaghan (2000) who analyzed zonal wind observations covering more than 40 years. The modeled SC modulation of the QBO extends to high latitudes where it produces temperature variations of about 1 K in the troposphere below 10 km. We report that the SC also generates in the model a hemispherically symmetric Equatorial Annual Oscillation (EAO, with 12-month period) that is largely confined to low latitudes. Under the influence of the GWs, the SC modulated EA0 propagates down into the lower stratosphere like the QBO. As is the case for the QBO, the energy of this EA0 is partially redistributed by the meridional circulation and planetary waves, presumably, to generate measurable SC signatures in the tropospheric temperature of the polar regions, which may be related to the so called Arctic Oscillation (Thompson and Wallace, 1998). The larger SC influence at higher altitudes is apparently transferred to the lower and denser regions of the atmosphere by tapping the momentum from the upward propagating GWs that drive the oscillations. The SC modulation of the QBO period could prove to be very effective in this process, as our earlier 2D study indicated. Further studies are needed, (1) to make sure that the SC

  20. The QBO as Potential Amplifier and Conduit to Lower Altitudes of Solar Cycle Influence

    NASA Technical Reports Server (NTRS)

    Mayr, Hans G.; Mengel, John G.; Porter, Hayden S.

    2005-01-01

    In several papers, the solar cycle (SC) effect in the lower atmosphere has been linked to the Quasi-biennial Oscillation (QBO), which is generated primarily by small-scale gravity waves. Salby and Callaghan (2000) analyzed the observed zonal winds of the QBO over more than 40 years and found that it contains a relatively large SC signature at 20 km. Following up on an earlier 2D study with our global-scale Numerical Spectral Model (NSM), we discuss here a 3D study with the QBO under the influence of the SC. For a SC period of 10 years, the amplitude of the relative variations of radiative forcing is taken to vary for simplicity from 0.2% at the surface to 2% at 50 km to 20% at 100 km and above. Covering a limited time span of 40 years, this model produces in the lower stratosphere a relatively large modulation of the QBO, which appears to be related to the SC and is in qualitative agreement with the observations. Some of the energy in the QBO, confined to low latitudes primarily, is redistributed globally by the meridional circulation and planetary waves presumably, so that a measurable SC modulation is generated in the tropospheric temperatures of the polar regions. Further studies are needed, (1) to determine whether the effect is real and prevails in more extensive simulations and whether the results are robust when shorter integration steps are employed, and (2) to explore the mechanism(s) that may ample the apparent SC influence of the UV radiation extending into the lower atmosphere. Quasi-decadal oscillations, generated internally by the QBO interacting with the seasonal cycles, may interfere with or aid the SC effect.

  1. [Modeling the Influencing Factors of Karstification and Karst Carbon Cycle in Laboratory].

    PubMed

    Zhao, Rui-yi; Lü, Xian-fu; Duan, Yi-fan

    2015-08-01

    To analyze the influencing factors of karstification and karst carbon cycle, a simulation experiment was carried out and 6 soil columns were designed. The results showed that the content of H2O4, hydrodynamic condition and thickness of the soil had important influence on karstification and karst carbon cycle. For the soil columns which were covered by the same thickness of soil, the concentrations of Ca2+ + Mg2+ and SO4(2-) followed the order of B20-2 > B20-1 > B20-3, B50-2 > B50-1 > B50-3. This meant that input of H2SO4 enhanced the karstification and increasing infiltration water had significant dilution effect on the chemical properties. For the soil columns with different thickness of soil but with the same slag pile and hydrodynamic conditions, the concentrations of Ca2+ + Mg2+ and SO4(2-) followed the order of B50-1 > B20-1, B50-2 > B20-2, B50-3 > B20-3. It was demonstrated that more carbonate rock was dissolved under the thick soil columns. In addition, the net consumption of CO2 mainly depended on the content of H2SO4 in this experiment due to slight contribution of H2CO3 to carbonate rock dissolution. More content of H2SO4 brought about less net consumption of C02, but B50-2 was an exception. Organic matter and other nutrients might be input into deep soil with the slag pile, and they promoted the production of soil C)2. Therefore, more CO2 was consumed due to the increased contribution of H2CO to karstification.

  2. Familiarization Protocol Influences Reproducibility of 20-km Cycling Time-Trial Performance in Novice Participants.

    PubMed

    Hibbert, Andrew W; Billaut, François; Varley, Matthew C; Polman, Remco C J

    2017-01-01

    Introduction: Exercise performance is reproducible in experienced athletes; however, less trained participants exhibit greater variability in performance and pacing. To reduce variability, it is common practice to complete a familiarization prior to experimental testing. However, there are no clear guidelines for familiarizing novice participants to a cycling time-trial (TT), and research findings from novice populations may still be influenced by learning effects. Accordingly, the aims of this study were to establish the variability between TTs after administering differing familiarization protocols (duration or type) and to establish the number of familiarization trials required to limit variability over multiple trials. Methods: Thirty recreationally active participants, with no prior experience of a TT, performed a 20-km cycling TT on five separate occasions, after completing either a full (FF, 20-km TT, n = 10), a half (HF, 10-km TT, n = 10) or an equipment familiarization (EF, 5-min cycling, n = 10). Results: Variability of TT duration across five TTs was the lowest after completing FF (P = 0.69, η p(2) = 0.05) compared to HF (P = 0.08, η p(2) = 0.26) and EF (P = 0.07, η p(2) = 0.21). In the FF group after TT2, the effect size for changes in TT duration was small (d < 0.49). There were large differences between later TTs in HF (d = 1.02, TT3-TT4) and EF (d = 1.12, TT4-TT5). The variability in mean power output profiles between trials was lowest within FF, with a similar pacing profile reproduced between TT3-TT5. Discussion: Familiarization of the exercise protocol influenced reproducibility of pacing and performance over multiple, maximal TTs, with best results obtained after a full experience of the exercise compared to HF and EF. The difference of TT1 to later TTs indicates that one familiarization is not adequate in reducing the variability of performance for novice participants. After the FF and an additional TT, performance changes between TTs were

  3. Influence of Observed Diurnal Cycles of Aerosol Optical Depth on Aerosol Direct Radiative Effect

    NASA Technical Reports Server (NTRS)

    Arola, A.; Eck, T. F.; Huttunen, J.; Lehtinen, K. E. J.; Lindfors, A. V.; Myhre, G.; Smirinov, A.; Tripathi, S. N.; Yu, H.

    2013-01-01

    The diurnal variability of aerosol optical depth (AOD) can be significant, depending on location and dominant aerosol type. However, these diurnal cycles have rarely been taken into account in measurement-based estimates of aerosol direct radiative forcing (ADRF) or aerosol direct radiative effect (ADRE). The