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1.
Reprod Domest Anim ; 57 Suppl 5: 94-97, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35689465

RESUMO

The aim of this study was to assess whether vulvar morphometric changes occurring in female pigs during proestrus and oestrus could be objective, accurate and predictive indicators of the onset to oestrus and thus performed artificial inseminations at the most appropriate time. For that purpose, pictures of vulvas from 60 hyperprolific females (30 gilts and 30 sows) during proestrus and oestrus were taken once a day. Vulva measurements (area, perimeter, length and width) on these pictures were performed using the image processing ImageJ software. Gilts and sows showed statistical differences (p < .01) in all vulvar morphometric measurements between proestrus and oestrus. Statistical differences in vulvar metrics were detected 24 h before the onset to oestrus, affecting all vulvar measurements in gilts, whereas only vulvar width was affected in sows. The image analysis used in this study may contribute to the development of smart technology in swine farming.


Assuntos
Estro , Inseminação Artificial , Animais , Feminino , Inseminação Artificial/veterinária , Proestro , Sus scrofa , Suínos , Vulva
2.
J Neuroendocrinol ; 34(6): e13129, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35491086

RESUMO

Throughout the reproductive cycle in rodents, prolactin levels are generally low. In some species, including rats, a prolactin surge occurs on proestrus with peak concentrations coinciding with the preovulatory luteinizing hormone (LH) surge. In mice, however, there are conflicting reports relating to the occurrence and timing of a proestrous prolactin surge. To gain further insight into the incidence and characteristics of this surge in mice, we have used serial tail tip blood sampling and trunk blood collection from both C57BL/6J (inbred) and Swiss Webster (outbred) mouse strains to build a profile of prolactin secretion during proestrus in individual mice. A clearly defined LH surge was detected in most animals, suggesting the blood sampling approach was suitable for detecting patterns of hormone secretion on proestrus. Despite this, levels of prolactin were quite variable between individuals. Overall both mouse strains showed a generalized rise in prolactin levels on the day of proestrus compared with levels seen in diestrus. This pattern is quite distinct from the discreet, circadian-entrained surge observed in rats.


Assuntos
Estro , Prolactina , Animais , Feminino , Hormônio Luteinizante , Camundongos , Camundongos Endogâmicos C57BL , Proestro , Ratos , Ratos Endogâmicos
3.
Behav Neurosci ; 136(5): 349-363, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35254840

RESUMO

The ability to remember sequences of events is fundamental to episodic memory. While rodent studies have examined sex and estrous cycle in episodic-like spatial memory tasks, little is known about these biological variables in memory for sequences of events that depend on representations of temporal context. We investigated the role of sex and estrous cycle in rats during training and testing stages of a cross-species validated sequence memory task (Jayachandran et al., 2019). Rats were trained on a two four-odor sequence memory task delivered on opposite ends of a linear track. Training occurred in six successive stages starting with learning to poke in a nose-port for ≥ 1.2 s; eventually demonstrating sequence memory by holding their nose in the port ≥ 1 s for in-sequence odors and < 1 s for out-of-sequence odors. Performance was analyzed across sex and estrous cycle (proestrus, estrus, metestrus, and diestrus), the latter being determined by cellular composition of a daily vaginal lavage. We found no evidence of sex differences in asymptotic sequence memory performance, similar to humans performing an analogous task (Reeders et al., 2021). Likewise, no differences in sequence memory performance were found across the estrous cycle. Some caveats are that males acquired out-of-sequence trials faster during training with a 3-odor sequence, but this apparent advantage did not carry over to the 4-odor sequence. Additionally, males had shorter poke times overall which seem consistent with a decreased overall response inhibition because they occurred regardless of sequence demands. Together, these results suggest sex and estrous cycle are not major factors in sequence memory capacities. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Ciclo Estral , Estro , Animais , Ciclo Estral/fisiologia , Estro/fisiologia , Feminino , Humanos , Masculino , Metestro/fisiologia , Proestro/fisiologia , Ratos , Memória Espacial
4.
Trop Anim Health Prod ; 54(2): 118, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-35226189

RESUMO

The present study, using 16 s rRNA sequencing of the V3-V4 hypervariable region, was aimed to check diversity of vaginal microbiota throughout different stages of the estrous cycle in Bos indicus, with attention to changes in progesterone hormone and microorganism diversity. Metagenomic research was conducted on vaginal swabs obtained from nine healthy Indian Gir cows at estrus (day 0), metestrus (day 04), diestrus (day 12), and proestrus (day 16) phases of the estrous cycle. The findings revealed that the diestrus phase has a different bacterial diversity than the other three estrous cycle phases, implying that progesterone affects bacterial diversity. Proteobacteria and Firmicutes were the most abundant phyla at the phylum level, accounting for 94% of bacterial diversity. Actinobacteriota, Patescibacteria, Cyanobacteria, and Bacteroidota were among the less prevalent phyla observed in all samples. After statistical analysis, Bacillaceae, Alcaligenes, Enterobacteriaceae, and Morganellaceae families were more significant. The Enterobacteriaceae family was found to be lower in the diestrus phase than in the other three phases; in contrast, all statistically significant genera were high at the diestrus phase. The luteal stage had higher levels of Micrococcus, Stenotrophomonas, UGC-010, Massilia, and Methylobacillus than the follicular stage, and statistical analysis revealed substantial difference between the luteal and follicular stages. Lactobacillus genus was present in both the estrus and diestrus phases. This study represents an important step toward the understanding of microbial diversity within different stages of the estrous cycle of Indian cows.


Assuntos
Ciclo Estral , Estro , Animais , Bovinos , Diestro , Feminino , Metestro , Proestro , Progesterona
5.
Epilepsy Behav ; 129: 108615, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35217387

RESUMO

Approximately 70% of women with epilepsy experience additional challenges in seizure exacerbation due to hormonal changes, particularly during fluctuations of estrogen-progesterone levels in the menstrual cycle, which is known as catamenial epilepsy. In animal models of epilepsy, a sustained increase in seizure frequency has been observed in female rats during the proestrus-estrus transition when estrogen levels are high and progesterone levels are low resembling catamenial epilepsy. Cannabidiol (CBD) has been proposed to have anticonvulsant and anti-inflammatory effects, able to decrease seizure duration and increase seizure threshold in rats with epilepsy. However, most studies have used males to investigate the pharmacological effects of CBD on seizures, and the neuroprotective effects of CBD against seizures exacerbated by hormonal fluctuations in females are still little explored. Given this scenario, the aim of the present study was to investigate whether CBD would protect against acute seizures induced by pentylenetetrazole (PTZ) in female rats during a pro-convulsant hormonal phase. Therefore, CBD (50 mg/kg) or saline was administered during the proestrus-estrus transition phase, 1 h prior to induction of seizures with PTZ (60 mg/kg), and the following parameters were recorded: duration, latency to first seizure, as well as percentage of convulsing animals (incidence), mortality, and severity of seizures. Brains were processed for immunohistochemistry for microglial cells (Iba-1), and blood was collected for the analysis of cytokines (IL-1ß, IL-6, IL-10, and TNF-α). Cannabidiol pre-treated rats showed a significant reduction in duration and severity of seizures, and IL-1ß levels, although the latency, incidence of seizures, and mortality rate remained unchanged as well the quantification of microglia in the selected areas. Therefore, acute administration of CBD in a single dose prior to seizure induction showed a partial neuroprotective effect against seizure severity and inflammation, suggesting that female rats in the proconvulsant phase of proestrus-estrus have a low seizure threshold and are more resistant to the anticonvulsant effects of CBD. It appears that other doses or administration windows of CBD may be required to achieve a full protective effect against seizures, suggesting that CBD could be used as an adjunctive therapy during fluctuations of estrogen-progesterone levels. In this sense, considering the hormonal fluctuation as a seizure-potentiating factor, our study contributes to understand the anticonvulsant activity of CBD in females in a pro-convulsant hormonal phase, similar to catamenial seizures in humans.


Assuntos
Canabidiol , Pentilenotetrazol , Animais , Anticonvulsivantes/efeitos adversos , Canabidiol/efeitos adversos , Modelos Animais de Doenças , Estro , Feminino , Humanos , Masculino , Pentilenotetrazol/farmacologia , Proestro , Ratos , Convulsões/induzido quimicamente , Convulsões/tratamento farmacológico
6.
Theriogenology ; 181: 1-7, 2022 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-34998022

RESUMO

This study evaluated the relationship between proestrus length and follicular size, estrous behavior, and pregnancy rate in Bos taurus beef heifers subjected to fixed-time artificial insemination (FTAI). A total of 911 heifers received a synchronization treatment protocol for FTAI (J-Synch) consisting of an intravaginal progesterone device for 6 d, estradiol benzoate at the time of device insertion cloprostenol sodium and eCG at device removal and GnRH at the time of FTAI. The presence or absence of a corpus luteum (CL) was determined by ultrasonography at device insertion and all heifers were tail painted at device removal for estrus detection at the time of FTAI. For the establishment of different periods of proestrus length (i.e., interval from device removal to FTAI), GnRH was administered i.m. at 48 h (n = 308), 60 h (n = 290) or 72 h (n = 313) after device removal. The diameter of the largest follicle at the time of GnRH administration was determined by ultrasonography, expression of estrous was determined by percentage of tail paint removal, and FTAI was performed at the time of GnRH administration in all heifers. The diameter of the largest follicle was greater when GnRH/FTAI was performed at 72 or 60 h (12.9 ± 0.2 mm and 12.8 ± 0.1 mm, respectively) than at 48 h (12.2 ± 0.1 mm, P < 0.05). The proportion of heifers in estrus tended to be greater when GnRH/FTAI was performed at 72 h (77.0%, 137/178) than at 48 h (68.2%, 122/179; P = 0.06), and intermediate at 60 h (71.4%, 120/168). Pregnancy rate tended to be greater in heifers with the longest (72 h: 70.0%, 219/313) than the shortest (48 h: 63.6%, 196/308; P < 0.1) proestrus length, while 60 h proestrus length was intermediate (63.1%, 183/290; P= NS). Pregnancy rate was affected by the presence of a CL at device insertion (71.3%, 352/494 in heifers with a CL, vs. 59.0%, 246/417 for those without a CL; P < 0.01). For those heifers bearing a CL, pregnancy rate was greater in heifers with a 72 h proestrus length (77.0%, 134/174) than with 48 or 60 h proestrus length (67.7%, 107/158 and 68.5%, 111/162; respectively; P < 0.05). In heifers without a CL, proestrus length did not affect pregnancy rate. In summary, extending proestrus length by delaying the interval from device removal to GnRH/FTAI from 48 to 72 h, was associated with a greater diameter of the preovulatory follicle, greater proportion of heifers expressing estrus at the time of FTAI, and greater pregnancy rate in cycling beef heifers.


Assuntos
Sincronização do Estro , Inseminação Artificial , Animais , Bovinos , Estro , Feminino , Hormônio Liberador de Gonadotropina , Inseminação Artificial/veterinária , Gravidez , Taxa de Gravidez , Proestro , Progesterona
7.
Exp Clin Psychopharmacol ; 30(2): 127-131, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33001695

RESUMO

Heroin intake decreases markedly during proestrus in normally cycling female rats; however, it is not known whether estradiol, progesterone, or both hormones are responsible for these decreases in heroin intake. The purpose of the present study was to examine the roles of estradiol and progesterone in heroin intake by artificially inducing a proestrus state in ovariectomized rats. To this end, ovariectomized female rats were implanted with intravenous catheters and trained to self-administer heroin (0.0075 mg/kg/infusion) on a fixed ratio (FR1) schedule of reinforcement. After 1 week of training, rats were tested at weekly intervals with estradiol (0.005 mg, sc) or vehicle 22 hr before a test session and progesterone (0.125 mg, sc) or vehicle 0.5 hr before a test session to artificially mimic the naturally occurring hormone concentrations characteristic of late proestrus. Administration of estradiol 22 hr prior to testing and progesterone 0.5 hr prior to testing significantly reduced heroin intake relative to the previous training day and vehicle control. It is interesting that this same effect was observed when only estradiol, but not progesterone, was administered. These data suggest that estradiol but not progesterone is responsible for the proestrus-induced decreases in heroin intake previously reported in normally cycling female rats. These findings differ from those reported previously with stimulants and suggest that estrogen-based pharmacotherapies may be of value to women with opioid use disorder. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Estradiol , Heroína , Animais , Estradiol/farmacologia , Feminino , Heroína/farmacologia , Humanos , Proestro , Progesterona/farmacologia , Ratos
8.
Pol Merkur Lekarski ; 49(294): 420-425, 2021 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-34919085

RESUMO

The rat uterus is an important female reproductive organ that has essential for the organism's reproduction. That is why it is necessary to understand all the rat uterus' morphological features as a perfect biomodel for studying the molecular peculiarities of the female reproductive system and pathologies development in experimental studies. AIM: The aim of research was to perform the comprehensive morphological analysis of the uterine in intact female rats. MATERIALS AND METHODS: The uterine of reproductive-aged intact female rats were used in this research. The cytological study of vaginal smears, histological (H and E), and immunohistochemical (estrogen, progesterone, and Ki-67 receptors) analysis of uterus tissues were used for light microscopic examination. RESULTS: The rat's vaginal smears' cytological features showed a specific qualitative cellular composition (variation of leukocytes, nucleated and anucleated cornified epithelial cells) in different estrous cycle phases (proestrus, estrus, metestrus, and diestrus). Uterine histology showed the structural regularities of parenchymal and stromal components with clear differentiation on the endometrium, myometrium and perimetrium. It was presented uterus sensitivity to the influence of the sex hormones (positive to estrogen and progesterone receptors) and the variable cellular proliferation activity (Ki-67 expression) in the organ wall. CONCLUSIONS: Our research demonstrated that the rats« uterus has a unique structural organization, sex hormones sensitivity, and variable proliferation in the parenchymal and stromal components. The rat estrous cycle should be considered while studying the morphological features of the uterus. The rat's uterus may serve as an acceptable object for modeling various pathological processes with the following results' extrapolation.


Assuntos
Estro , Útero , Animais , Diestro , Feminino , Metestro , Proestro , Ratos
9.
Endocrinology ; 162(6)2021 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-33824970

RESUMO

Coordination of ovulation and behavior is critical to reproductive success in many species. During the female estrous cycle, the preovulatory gonadotropin surge occurs when ovarian follicles reach maturity and, in rodents, it begins just before the daily onset of activity, ensuring that ovulation coincides with sex behavior. Timing of the surge relies on projections from the suprachiasmatic nucleus (SCN), the locus of the central circadian clock, to hypothalamic circuits that regulate gonadotropin secretion. The cellular mechanisms through which the SCN controls these circuits and gates the preovulatory surge to the appropriate estrous cycle stage, however, are poorly understood. We investigated in mice the functional impact of SCN arginine-vasopressin (AVP) neuron projections to kisspeptin (Kiss1) neurons in the rostral periventricular area of the third ventricle (RP3VKiss1), responsible for generating the preovulatory surge. Conditional anterograde tracing revealed that SCNAVP neurons innervate approximately half of the RP3VKiss1 neurons. Optogenetic activation of SCNAVP projections in brain slices caused an AVP-mediated stimulation of RP3VKiss1 action potential firing in proestrus, the cycle stage when the surge is generated. This effect was less prominent in diestrus, the preceding cycle stage, and absent in estrus, following ovulation. Remarkably, in estrus, activation of SCNAVP projections resulted in GABA-mediated inhibition of RP3VKiss1 neuron firing, an effect rarely encountered in other cycle stages. Together, these data reveal functional plasticity in SCNAVP neuron output that drives opposing effects on RP3VKiss1 neuron activity across the ovulatory cycle. This might contribute to gating activation of the preovulatory surge to the appropriate estrous cycle stage.


Assuntos
Relógios Circadianos/fisiologia , Ciclo Estral/fisiologia , Neurônios/fisiologia , Potenciais de Ação/fisiologia , Animais , Arginina Vasopressina/genética , Arginina Vasopressina/metabolismo , Mapeamento Encefálico , Plasticidade Celular/fisiologia , Ritmo Circadiano/fisiologia , Feminino , Kisspeptinas/metabolismo , Camundongos , Camundongos Transgênicos , Neurônios/metabolismo , Proestro/fisiologia , Núcleo Supraquiasmático/metabolismo , Núcleo Supraquiasmático/fisiologia
10.
Physiol Behav ; 234: 113372, 2021 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-33647267

RESUMO

It is unclear whether all animal models of anxiety-like states developed using males are appropriate for use in females. In females, tests involving a learning component might be influenced not only by estrous cycle stage on the test day but also by the stage during the conditioning process. We used two tests - conditioned freezing (CF) and fear potentiated startle (FPS) to compare responsiveness of male rats and females conditioned and/or tested in proestrus (P) or late diestrus (LD). For CF all rats displayed a similar freezing response regardless of sex or estrous cycle stage. In terms of FPS, males and females conditioned in P and tested in P or LD, and females conditioned in LD and tested in LD all showed potentiated startle. The response waned during the test session in males and in females conditioned in P, but not in those conditioned in LD. In contrast, FPS was not apparent in the first half of the test session in females conditioned in LD and tested in P but developed in the second half. We suggest that fear learning during P and LD is robust but may be initially be obscured in rats tested in P because of generalization to the CS due to high estrogen. Estrous cycle stage is an important consideration which must be taken into account in designing behavioural tests in females.


Assuntos
Ciclo Estral , Reflexo de Sobressalto , Animais , Medo , Feminino , Masculino , Proestro , Ratos , Ratos Sprague-Dawley
11.
Psychopharmacology (Berl) ; 238(4): 969-978, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33404736

RESUMO

RATIONALE: Heroin intake decreases during the proestrus phase of the estrous cycle in female rats. Circulating concentrations of both estradiol and progesterone peak during proestrus, and it is not known which of these hormones, or their combination, are responsible for these effects. OBJECTIVES: The purpose of this study was to determine the effects of estradiol, progesterone, and their combination on heroin self-administration in female rats. METHODS: In Experiment 1, the estrous cycle of intact female rats was tracked daily. If a rat was in proestrus, either the estrogen receptor antagonist, raloxifene, the progesterone receptor antagonist, mifepristone, or their combination was administered 30 min prior to a heroin self-administration session. In Experiment 2, separate groups of ovariectomized female rats were treated chronically with exogenous estradiol, progesterone, estradiol + progesterone, or vehicle, and heroin intake was examined over a 100-fold dose range. RESULTS: In Experiment 1, raloxifene, but not mifepristone, significantly blocked proestrus-associated decreases in heroin intake. In Experiment 2, estrogentreated rats self-administered less heroin than any other group and significantly less heroin than rats treated with progesterone. CONCLUSIONS: These data suggest that (1) estradiol but not progesterone is responsible for proestrus-associated decreases in heroin intake and (2) estradiol decreases heroin intake relative to progesterone. These data differ from those reported previously with stimulants and suggest that estrogen-based pharmacotherapies may be of value to women with opioid use disorder.


Assuntos
Estradiol/administração & dosagem , Heroína/administração & dosagem , Progesterona/administração & dosagem , Animais , Estradiol/farmacologia , Estro/fisiologia , Feminino , Heroína/farmacologia , Mifepristona/administração & dosagem , Mifepristona/farmacologia , Proestro/fisiologia , Progesterona/farmacologia , Ratos , Ratos Long-Evans
12.
Cell Tissue Res ; 383(3): 1183-1190, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33242171

RESUMO

Accurate identification of the murine estrous cycle using vaginal exfoliative cytology is the initial and crucial step for controlled reproduction of this species. However, it is generally difficult to discriminate each stage of the cycle, and thus to select pro-estrous mice for mating. To increase the accuracy of identification of the pro-estrous stage, we re-evaluated the vaginal fold histology and modified the method of exfoliative cytology. Tissue fixation using methanol in Carnoy's solution but not paraformaldehyde, combined with Alcian blue staining but not the conventional Giemsa staining, resulted in better manifestation of mucosal cell layers in the vaginal epithelium just above the keratinized layer. This mucous layer in the fold histology was found to form specifically in the pro-estrous and late di-estrous stages, and the mucous cells exfoliated in smear samples only in the pro-estrous stage. This novel method was found, by a blinded test, to increase the rate of accurate identification of the pro-estrous stage compared to the conventional method (80% vs 50%). Consistent with this finding, the mating experiment with "pro-estrous" females selected by the novel method revealed a significantly higher success rate than that with the conventional method (78.0% vs 47.5%). Thus, our study demonstrates vaginal exfoliative mucous cells as a better potential marker to detect the "receptive" state of female mice that leads to an improved success rate of mating.


Assuntos
Células Epiteliais/citologia , Proestro , Reprodução , Vagina/citologia , Animais , Feminino , Masculino , Camundongos , Camundongos Endogâmicos ICR
13.
Behav Brain Res ; 397: 112952, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33017640

RESUMO

Low concentrations of ovarian hormones, among other factors, are associated with greater vulnerability to negative effects of environmental stressors and may trigger anxiety symptoms in females. The flavonoid chrysin (5,7-dihydroxyflavone) exerts anxiolytic-like effects in male and ovariectomized female rats, but it is unknown if chrysin could reduce anxiety-like behavior that naturally occurs through the ovarian cycle phases. The present study evaluated the effect of chrysin on anxiety-like behavior associated with the ovarian cycle phases in rats and the participation of γ-aminobutyric acid-A (GABAA) receptors in these actions. The acute effects of chrysin (2 mg/kg) were investigated in female cycling Wistar rats in the elevated plus maze, locomotor activity test, and light/dark test. Diazepam (2 mg/kg) was used as reference anxiolytic drug. The participation of GABAA receptor in the anxiolytic actions of chrysin was explored by pretreating the rats with the noncompetitive GABAA chloride ion channel antagonist picrotoxin (1 mg/kg). Chrysin and diazepam prevented anxiety-like behavior that was associated with the metestrus-diestrus phase in both the elevated plus maze and light/dark test, and these effects were reversed by picrotoxin, with no significant changes in spontaneous locomotor activity. No significant motor effects of chrysin were detected in either behavioral test during proestrus-estrus or metestrus-diestrus phases, whereas diazepam produced motor hypoactivity in the locomotor activity test during proestrus-estrus phase. These results indicate that the flavonoid chrysin prevents anxiety-like behavior that naturally occurs during metestrus-diestrus in two unconditioned models that are used to evaluate anxiety-like behavior, and these effects were mediated by actions on GABAA receptors.


Assuntos
Ansiolíticos/farmacologia , Ansiedade/tratamento farmacológico , Comportamento Animal/efeitos dos fármacos , Diazepam/farmacologia , Ciclo Estral/efeitos dos fármacos , Flavonoides/farmacologia , Antagonistas de Receptores de GABA-A/farmacologia , Animais , Ansiolíticos/administração & dosagem , Diazepam/administração & dosagem , Diestro/efeitos dos fármacos , Estro/efeitos dos fármacos , Feminino , Flavonoides/administração & dosagem , Antagonistas de Receptores de GABA-A/administração & dosagem , Metestro/efeitos dos fármacos , Picrotoxina/farmacologia , Proestro/efeitos dos fármacos , Ratos , Ratos Wistar
14.
Croat Med J ; 61(4): 346-353, 2020 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-32881433

RESUMO

AIM: To determine the changes in skin temperature and brown adipose tissue (BAT) activity throughout the estrous cycle as well as the regularity of the estrous cycle in mice. METHODS: We assessed the differences in the duration of the estrous cycle and its phases between 3- and 8-month-old female mice (n=18). Skin temperature and BAT activity were measured by infrared technology and compared with human menstrual cycle. RESULTS: Young and old female mice did not differ significantly in the estrous cycle length. However, young animals had longer diestrus and shorter proestrus phase. In contrast with women, mice showed age-dependent changes in body temperature and BAT activity during the estrus cycle. CONCLUSION: Establishing the pattern of temperature and BAT activity changes could be used to determine the estrous cycle phase before performing experiments without disturbing the animal. However, since the regulation of BAT activity during the estrous cycle was age-dependent, very complex, and varied significantly from women, further studies are needed to develop a non-invasive method for determining the phase of the estrous cycle.


Assuntos
Tecido Adiposo Marrom/metabolismo , Ciclo Estral/fisiologia , Temperatura Cutânea/fisiologia , Termografia/métodos , Animais , Animais de Laboratório , Estro/fisiologia , Feminino , Raios Infravermelhos , Camundongos , Camundongos Endogâmicos C57BL , Proestro/fisiologia
15.
Acta Histochem ; 122(8): 151630, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32992122

RESUMO

Visfatin is a crucial adipokine, which also regulates ovarian functions in many animals. Mice estrous cycle is characterized by a dynamic complex physiological process in the reproductive system. Expression of various factors changes during the estrous cycle in the ovary. To the best of our knowledge, no previous study has been conducted on the expression of visfatin in mice ovaries during the estrous cycle. Therefore, we investigated the localization and expression of visfatin protein in the ovary of mice during the estrous cycle. Western blot analysis showed the elevated expression of visfatin in proestrus and lowest in diestrus. Immunohistochemical localization of visfatin showed intense staining in the corpus luteum of proestrus and diestrus ovaries. Thecal cells, granulosa cells, and oocytes also showed the presence of visfatin. Expression of ovarian visfatin was correlated to BCL2 and active caspase3 expression and exhibited a significant positive correlation. Furthermore, in vivo inhibition of visfatin by FK866 in the proestrus ovary down-regulated active caspase3 and PCNA expression, and up-regulated the BCL2 expression. These results suggest the role of visfatin in the proliferation and apoptosis of the follicles and specific localization of visfatin in the corpus luteum also indicate its role in corpus luteum function, which may be in progesterone biosynthesis and regression of old corpus luteum. However, further study is required to support these findings. In conclusion, visfatin may also be regulating follicular growth during the estrous cycle by regulating proliferation and apoptosis.


Assuntos
Corpo Lúteo/metabolismo , Citocinas/genética , Células da Granulosa/metabolismo , Nicotinamida Fosforribosiltransferase/genética , Oócitos/metabolismo , Células Tecais/metabolismo , Acrilamidas/farmacologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/genética , Caspase 3/genética , Caspase 3/metabolismo , Proliferação de Células/efeitos dos fármacos , Corpo Lúteo/citologia , Corpo Lúteo/efeitos dos fármacos , Corpo Lúteo/crescimento & desenvolvimento , Citocinas/antagonistas & inibidores , Citocinas/metabolismo , Diestro/efeitos dos fármacos , Diestro/genética , Inibidores Enzimáticos/farmacologia , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Células da Granulosa/citologia , Células da Granulosa/efeitos dos fármacos , Imuno-Histoquímica , Camundongos , Nicotinamida Fosforribosiltransferase/antagonistas & inibidores , Nicotinamida Fosforribosiltransferase/metabolismo , Oócitos/citologia , Oócitos/efeitos dos fármacos , Piperidinas/farmacologia , Proestro/efeitos dos fármacos , Proestro/genética , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Células Tecais/citologia , Células Tecais/efeitos dos fármacos
16.
J Therm Biol ; 92: 102662, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32888565

RESUMO

Our aim was to evaluate the application of infrared thermography (IRT) to detect body surface temperature variation of body regions during the proestrus and estrus phases of the reproductive cycle of Gyr heifers and investigate environmental factors that could affect these measurements. Fifty-seven heifers were submitted to an ovulation synchronization protocol. This was followed by monitoring the heifers every 12 h over 60 h. Heifers were monitored for rectal and vaginal temperature using a digital thermometer. The surface temperature of the eye, vulva, and muzzle regions were monitored by IRT. Meteorological data was recorded for temperature and humidity. Observation of sexual behavior was performed to monitor estrus onset. Transrectal ultrasonography was used to identify the dominant follicle and confirm ovulation of all heifers. We observed a decrease in temperature of the rectum and vagina, as well as in the eye and vulva regions within the first 12 h after the completion of the synchronization. This period coincides with the expected proestrus phase of the estrous cycle. A progressive increase in all temperatures was noticed in the following 36 h, which coincides with the estrus phase of the reproductive cycle. The regions evaluated around the vulva and eye exhibited the highest temperature and experienced less environmental distortion than the muzzle area thermographs. Environmental factors, such as rainfall and temperature-humidity index, influenced the IRT readings altering the radiation patterns detected. In conclusion, IRT is an effective method to detect temperature variation during the proestrus and estrus phases in Gyr heifers. Furthermore, biological and environmental effects should be considered when collecting and interpreting IRT data in livestock.


Assuntos
Bovinos/fisiologia , Estro , Temperatura Cutânea , Termografia/métodos , Animais , Temperatura Corporal , Feminino , Raios Infravermelhos , Proestro , Reprodução
17.
Int J Mol Sci ; 21(16)2020 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-32796585

RESUMO

The orofacial pain pathway projects to the parabrachial and amygdala, and sex steroids have been shown to affect neuronal activity in these regions. GABA positive cells in the amygdala are influenced by sex steroid metabolites to affect pain, and sex steroids have been shown to alter the expression of genes in the parabrachial, changing neuronal excitability. Mechanisms by which sex steroids affect amygdala and parabrachial signaling are unclear. The expression of genes in the parabrachial and amygdala in diestrus (low estradiol) and proestrus (high estradiol) female rats were evaluated in this study. First, varicella zoster virus was injected into the whisker pad of female rats to induce a pain response. Second, gene expression was quantitated using RNA-seq one week after injection. Genes that had the greatest change in expression and known to function in pain signaling were selected for the quantitation of protein content. Protein expression of four genes in the parabrachial and seven genes in the amygdala were quantitated by ELISA. In the parabrachial, neurexin 3 (Nrnx3) was elevated at proestrus. Nrnx3 has a role in AMPA receptor and GABA signaling. Neuronatin (Nnat) and protein phosphatase, Mg2+/Mn2+ dependent 1E (Ppm1e) were elevated in the parabrachial of diestrus animals both genes having a role in pain signaling. Epoxide hydroxylase (Ephx2) was elevated in the parabrachial at proestrus and the vitamin D receptor (Vdr) was elevated in the amygdala. Ephx2 antagonists and vitamin D have been used to treat neuropathic pain. In conclusion, sex steroids regulate genes in the parabrachial and amygdala that might result in the greater pain response observed during diestrus.


Assuntos
Tonsila do Cerebelo/metabolismo , Diestro/genética , Regulação da Expressão Gênica , Herpesvirus Humano 3/fisiologia , Injeções , Proestro/genética , Animais , Epóxido Hidrolases/metabolismo , Feminino , Proteínas do Tecido Nervoso/metabolismo , Neuralgia/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Receptores de Calcitriol/metabolismo
18.
Biol Reprod ; 103(3): 643-653, 2020 08 21.
Artigo em Inglês | MEDLINE | ID: mdl-32352507

RESUMO

Changes in circulating progesterone (P4) and estradiol (E2) during proestrus produce dynamic changes in endometrial function and pituitary release of gonadotropins. Independent and combined effects of P4 and E2 on endometrium and pituitary were evaluated. In a preliminary study, an exogenous hormone model of proestrus was created by removal of corpus luteum and follicles ≥5 mm followed by gradual removal of intravaginal P4 implants during 18 h and treatment with increasing doses of estradiol benzoate during 48 h to mimic proestrus using high E2 (n = 9) or low E2 (n = 9). Decreased P4, increased E2, and increased endometrial area (EA) simulated proestrus in high-E2 cows and this was used subsequently. The main experiment used a 2 × 2 factorial design with: high E2 and low P4 (n = 11); high E2 and high P4 (n = 11); low E2 and high P4 (n = 11); low E2 and low P4 (n = 10). At 48 h, gonadotropin-releasing hormone (GnRH)-induced luteinizing hormone (LH) and follicle stimulating hormone (FSH) release was determined. Variables were analyzed using PROCMIXED of Statistical Analysis System. The EA increased dramatically during 48 h only in high-E2 and low-P4 cows. For FSH, high-E2 cows had greater area under the curve (AUC) and FSH peak after GnRH than low E2, with mild negative effects of high P4. For LH, concentration at peak and AUC were 2-fold greater in high E2 compared to low-E2 groups, with low P4 also 2-fold greater than high-P4 groups. Thus, maximal changes in uterus and pituitary during proestrus depend on both low P4 and high E2, but different physiologic responses are regulated differently by E2 and P4. Changes in endometrium depend on low P4 and high E2, whereas GnRH-induced FSH secretion primarily depends on high E2, and GnRH-induced LH secretion is independently increased by high E2 or reduced by high P4.


Assuntos
Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Estradiol/farmacologia , Hormônio Liberador de Gonadotropina/farmacologia , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Progesterona/farmacologia , Animais , Área Sob a Curva , Bovinos , Corpo Lúteo/efeitos dos fármacos , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Proestro/efeitos dos fármacos , Progesterona/sangue , Útero/efeitos dos fármacos
19.
J Am Assoc Lab Anim Sci ; 59(3): 282-287, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32241334

RESUMO

Vaginal cytology is the most common method of monitoring the estrous cycle in rats; however, this test requires specific technical training and can be subject to interpretation. Vaginal impedance offers a quicker and less technically challenging alternative and has been used successfully to identify estrus in normally cycling breeder rats. We hypothesize that vaginal impedance can also be used to stage the estrous cycle in rats that have been given luteinizing hormone releasing hormone (LHRH) for timed mating. Vaginal impedance measurements and vaginal cytology were performed in LHRH-primed female rats (n = 36) at the expected peak of proestrus and paired with proven stud males. Breeding success was determined by gross necropsy to detect embryo implantation sites in the female rats. We found that the predictive rates of vaginal cytology and impedance measurement for proestrus were similar; however, both methods resulted in high proportions of false positive and false negative determinations (28% and 31%, respectively). We further hypothesized that females respond to LHRH at variable rates, resulting in variable times of peak proestrus. To test this, vaginal impedance measurements were performed multiple times throughout the expected day of proestrus in LHRH-primed female rats (n = 36). Females were either paired with a male 24 h after reaching the proestrus threshold (n = 18) or paired according to our standard protocol at 1300 h on the day after the expected proestrus (n = 18). Sequential measurements reduced false positive and negative rates (14% and 8%, respectively). Pregnancy rates did not differ based on the time of pairing during expected estrus. Overall, we determined vaginal impedance can be more successful than vaginal cytology at identifying proestrus in the rat, but only if multiple measurements are taken.


Assuntos
Ciclo Estral , Ratos/fisiologia , Técnicas Reprodutivas/veterinária , Vagina/fisiologia , Técnicos em Manejo de Animais , Animais , Impedância Elétrica , Feminino , Hormônio Luteinizante/agonistas , Masculino , Gravidez , Proestro/fisiologia
20.
J Neuroendocrinol ; 32(3): e12836, 2020 03.
Artigo em Inglês | MEDLINE | ID: mdl-32062869

RESUMO

The present study aimed to determine whether an i.c.v. administration of allopregnanolone (ALLO) rapidly modifies the hypothalamic and ovarian 3ß-hydroxysteroid dehydrogenase (3ß-HSD) enzymatic activity and gene expression in in vivo and ex vivo systems in pro-oestrus (PE) and dioestrus I (DI) rats. Animals were injected with vehicle, ALLO, bicuculline or bicuculline plus ALLO and were then killed. In the in vivo experiment, the hypothalamus, ovaries and serum were extracted and analysed. In the ex vivo experiment, the superior mesenteric ganglion - ovarian nerve plexus - ovary system was extracted and incubated during 120 minutes at 37 ºC. The serum and ovarian compartment fluids were used to determine progesterone by radioimmunoanalysis. In the in vivo experiments, ALLO caused a decrease in hypothalamic and ovarian 3ß-HSD enzymatic activity during PE. During DI, ALLO increased hypothalamic and ovarian 3ß-HSD activity and gene expression. The ovarian 3ß-HSD activity increased in both stages in the ex vivo system; gene expression increased only during DI. ALLO induced an increase in serum progesterone only in D1 and in the ovarian incubation liquids in both stages. All findings were reversed by an injection of bicuculline before ALLO. Ovarian steroidogenic changes could be attributed to signals coming from ganglion neurones, which are affected by the acute central neurosteroid stimulation. The i.c.v. administration of ALLO via the GABAergic system altered 3ß-HSD activity and gene expression, modulating the neuroendocrine axis. The present study reveals the action that ALLO exerts on the GABAA receptor in both the central and peripheral nervous system and its relationship with hormonal variations. ALLO is involved in the "fine tuning" of neurosecretory functions as a potent modulator of reproductive processes in female rats.


Assuntos
3-Hidroxiesteroide Desidrogenases/metabolismo , Hipotálamo/efeitos dos fármacos , Neuroesteroides/administração & dosagem , Ovário/efeitos dos fármacos , Pregnanolona/administração & dosagem , Animais , Diestro/efeitos dos fármacos , Diestro/metabolismo , Feminino , Expressão Gênica/efeitos dos fármacos , Hipotálamo/enzimologia , Injeções Intraventriculares , Ovário/metabolismo , Proestro/efeitos dos fármacos , Proestro/metabolismo , Progesterona/sangue , Ratos
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