-
Animals : An Open Access Journal From... Jan 2023The behaviour of oestrous mares is well-known in horse breeding. However, alterations in their physiological and behavioural indices during the whole oestrous cycle are...
The behaviour of oestrous mares is well-known in horse breeding. However, alterations in their physiological and behavioural indices during the whole oestrous cycle are scarcely known. The objective of the study was to analyse changes in cardiac activity variables, rectal and superficial temperatures, behaviour towards humans and conspecifics, and the time of standing and locomotor activity in mares during their oestrous cycle. Fifteen adult mares in oestrus were examined in the morning and evening (six successive days) and in dioestrus (five days-once every third day). The oscillation of physiological and behavioural variables accompanies changes in mares' sexual behaviour. Most physiological variables studied in oestrus indicate the elevated activity of the adrenergic nervous system and, opposite to that, both behaviour towards humans and conspecifics and the time of standing relate to a relaxed state. The end of oestrus, manifested by a rapid decrease in most of the physiological variables studied, is followed by changes of behavioural variables at the beginning of dioestrus. The time of locomotor activity arises at the end of oestrus. The outcomes may contribute to the knowledge of, among others, mare owners who evaluate the oestrus by mares' sexual behaviours without regarding other rhythmically changing variables.
PubMed: 36670751
DOI: 10.3390/ani13020211 -
Journal of Dairy Science Mar 2022Our objective was to determine the effect of inducing an accessory corpus luteum (CL) with human chorionic gonadotropin (hCG; 3,300 IU) on d 7 (hCG7) or 2 accessory CL...
Accessory corpus luteum induced by human chorionic gonadotropin on day 7 or days 7 and 13 of the estrous cycle affected follicular and luteal dynamics and luteolysis in lactating Holstein cows.
Our objective was to determine the effect of inducing an accessory corpus luteum (CL) with human chorionic gonadotropin (hCG; 3,300 IU) on d 7 (hCG7) or 2 accessory CL with hCG on d 7 and 13 (hCG7+13) of the estrous cycle in noninseminated lactating Holstein cows. Cows (n = 86) between 39 and 64 DIM were pretreated with an Ovsynch + CIDR protocol, and only synchronized cows were used (n = 64). The day of the last GnRH of Ovsynch was considered d 0 of the estrous cycle. Follicular and luteal dynamics of cows were evaluated daily during an entire estrous cycle by ovarian ultrasonography. Blood samples were collected daily to measure serum concentration of progesterone (P4). Cows were randomly assigned to CON (n = 22, no treatment), hCG7 (n = 20), or hCG7+13 (n = 22) treatments. Two cows from hCG7+13 failed to ovulate after hCG and were removed from the analyses post-hCG treatment. The first day of luteolysis was considered the day that P4 declined to more than 2 SD of the mean for the 4 consecutive P4 concentrations with the greatest mean in late diestrus for each individual cow. The P4 cut-off for complete luteolysis was <1.0 ng/mL. Mean P4 on d 7 (3.23 ± 0.16 ng/mL) did not differ among treatments. Cows treated with hCG had greater total luteal and original CL volume and serum P4 during diestrus than CON. Cows treated with hCG7+13 had greater serum P4 after d 13 of the cycle than hCG7. Cycles were classified as having atypical cycles if the dominant follicle or future dominant follicle at the time of luteolysis did not ovulate (delayed ovulation; CON, n = 2; hCG7, n = 4; hCG7+13, n = 3), had a short cycle (CON, n = 1), delayed (CON, n = 2) or incomplete luteolysis (CON, n = 1; hCG7, n = 4; hCG7+13, n = 5). The remainder of cycles with normal complete luteolysis followed by ovulation were considered to be typical. Based on blood perfusion, the CON cow with incomplete luteolysis had 2 original CL remaining functional after first onset of luteolysis. The rest of the cows with incomplete luteolysis (9/10) had one or more CL regressing and at least one remaining functional after first onset of luteolysis. No specific pattern for CL side (ipsilateral vs. contralateral to a CL with complete regression) was observed for nonregressed CL. Cows with incomplete luteolysis had a second onset of luteolysis to undergo complete functional luteolysis. The proportion of cows with typical cycle was 73% (16/22) for CON, 60% (12/20) for hCG7, and 55% (11/20) for hCG7+13. Cows with typical cycles treated with hCG (hCG7 and hCG7+13) had a later onset of luteolysis, prolonged time to undergo complete luteolysis, and greater proportion of cows with 3 follicular waves than CON, resulting in a longer interovulatory interval for hCG7 and hCG7+13 than CON. In summary, accessory CL induced by hCG during diestrus not only altered follicular and luteal dynamics but also deferred and prolonged the luteolytic process.
Topics: Animals; Cattle; Chorionic Gonadotropin; Corpus Luteum; Dinoprost; Estrous Cycle; Estrus Synchronization; Female; Gonadotropin-Releasing Hormone; Lactation; Luteolysis; Progesterone
PubMed: 34955260
DOI: 10.3168/jds.2021-20619 -
Journal of Visualized Experiments : JoVE Aug 2021The current methodology establishes a reproducible, standardized, and cost-effective approach to monitoring the estrous cycle of female Sprague Dawley (SD) adolescent...
The current methodology establishes a reproducible, standardized, and cost-effective approach to monitoring the estrous cycle of female Sprague Dawley (SD) adolescent rats. This study demonstrates the complexity of hormonal cycles and the broad spectrum of understanding required to construct a reliable and valid monitoring technique. Through an in-depth examination of principal experimental design and procedural elements, this description of the cycle and its fundamental principles provides a framework for further understanding and deconstructs misconceptions for future replication. Along with an outline of the sample collection process employing vaginal lavage, the procedure describes the mechanism of data categorization into the four-stage model of proestrus, estrus, metestrus, and diestrus. These stages are characterized by a new proposed approach, utilizing the 4 categorizing determinants of vaginal fluid condition, cell type(s) present, cell arrangement, and cell quantity at the time of collection. Variations of each stage, favorable and unfavorable samples, the distinction between cyclicity and acyclicity, and graphic depictions of the collected categorizing components are presented alongside effective interpretive and organizational practices of the data. Overall, these tools allow for the publication of quantifiable data ranges for the first time, leading to the standardization of categorization factors upon replication.
Topics: Animals; Estrous Cycle; Female; Humans; Metestrus; Rats; Rats, Sprague-Dawley; Rodentia; Vaginal Douching
PubMed: 34515690
DOI: 10.3791/62884 -
Archives of Razi Institute Aug 2023Ginseng is known as the king of all herbs in terms of antioxidant and anti-inflammatory activities and recently has become more involved in the treatment of neurological...
Ginseng is known as the king of all herbs in terms of antioxidant and anti-inflammatory activities and recently has become more involved in the treatment of neurological diseases. In this regard, this study aimed to determine the effects of on pentylenetetrazol-induced epilepsy during the estrus cycle. For this purpose, 30 rats were randomly divided into five groups, namely control (saline), valproic acid (VPA, 75 mg/kg), (50 mg/kg), (100 mg/kg), and (150 mg/kg) with four subgroups (proestrus, estrus, metestrus, and diestrus). Subsequently, the initiation time of myoclonic seizures (ITMS), initiation time of tonic-clonic seizures (ITTS), and seizure duration (SD) were determined. According to the results, ITMS and ITTS significantly increased in the VPA-treated group (<0.05). (100 and 150 mg/kg) administration significantly increased ITMS and ITTS (<0.05). Moreover, the ITMS and ITTS in -treated rats were significantly higher in luteal phases, compared to the follicular phase (<0.05). In addition, pretreatment with VPA significantly decreased SD, compared to the control group (<0.05). A significant decrease in SD was observed in the rats pretreated with (100 and 150 mg/kg) (<0.05). Seizure duration significantly decreased in animals that received in luteal phases, compared to the follicular phase (<0.05). These results suggested that have anticonvulsant effects that are more prominent during the luteal phase than the follicular phase.
Topics: Animals; Female; Rats; Anticonvulsants; Estrus; Ginsenosides; Pentylenetetrazole; Seizures; Valproic Acid
PubMed: 38226383
DOI: 10.32592/ARI.2023.78.4.1359 -
Anatomy & Cell Biology Mar 2020Increased food consumption rich in fat and carbohydrate and sedentary lifestyle have seriously increased the rates of obesity and obesity-associated diseases in...
Increased food consumption rich in fat and carbohydrate and sedentary lifestyle have seriously increased the rates of obesity and obesity-associated diseases in developed countries. Female mice with diet-induced obesity exhibit infertility and thus can serve as a model for human polycystic ovary syndrome. The aim of the present study was to examine how ovary is affected by diet-induced obesity. The effects of high-fat diet (HFD) on ovary morphology in mice fed with HFD were investigated using unbiased stereological methods. The ovary of mice fed with HFD (n=8, C1090-60, Altromine) for 9 weeks, were compared with that of mice fed with standard chow diet (n=8, C1090-10, Altromine). Stereological parameters were obtained in diestrus cycle. The samples were processed through routine and standard paraffin embedding and were serially sectioned in 5-µm thickness then, every 10th section was saved, stained with Crossman's triple stain for counting and measuring. In all sampled sections mean follicle numbers, diameters, total ovarian volume cortex to medulla ratio (Vv), ovum to cell ratio in secondary follicle were examined in all sampled sections. The present results showed that weight of ovarian and amount of intraperitoneal adipose tissue and the body weight markedly increased in obese mice when compared with control groups. Moreover, follicle numbers (except primordial follicles) and diameters were significantly increased in obese mice. Cortex to medulla ratio (Vv) and ovum to cell ratio in secondary follicle were also considerably different between experimental and the control groups. The present findings indicate that obesity adversely affects overall ovarian morphology.
PubMed: 32274250
DOI: 10.5115/acb.19.082 -
American Journal of Physiology. Heart... Dec 2022With the increasing appreciation for sex as a biological variable and the inclusion of female mice in research, it is important to understand the influence of the...
With the increasing appreciation for sex as a biological variable and the inclusion of female mice in research, it is important to understand the influence of the estrous cycle on physiological function. Sex hormones are known to modulate vascular function, but the effects of the mouse estrous cycle phase on arterial stiffness, endothelial function, and arterial estrogen receptor expression remain unknown. In 23 female C57BL/6 mice (6 mo of age), we determined the estrous cycle stage via vaginal cytology and plasma hormone concentrations. Aortic stiffness, assessed by pulse wave velocity, was lower during the estrus phase compared with diestrus. In ex vivo assessment of isolated pressurized mesenteric and posterior cerebral arteries, the responses to acetylcholine, insulin, and sodium nitroprusside, as well as nitric oxide-mediated dilation, were not different between estrous cycle phases. In the aorta, expression of phosphorylated estrogen receptor-α was higher for mice in estrus compared with mice in proestrus. In the cerebral arteries, gene expression for estrogen receptor-β () was lowest for mice in estrus compared with diestrus and proestrus. These results demonstrate that the estrus phase is associated with lower in vivo large artery stiffness in mice. In contrast, ex vivo resistance artery endothelial function is not different between estrous cycle phases. Estrogen receptor expression is modulated by the estrus cycle in an artery-dependent manner. These results suggest that the estrous cycle phase should be considered when measuring in vivo arterial stiffness in young female mice. To design rigorous vascular research studies using young female rodents, the influence of the estrous cycle on vascular function must be known. We found that in vivo aortic stiffness was lower during estrus compared with the diestrus phase in female mice. In contrast, ex vivo mesenteric and cerebral artery endothelial function did not differ between estrous cycle stages. These results suggest that the estrous cycle stage should be accounted for when measuring in vivo arterial stiffness.
Topics: Mice; Female; Animals; Vascular Stiffness; Receptors, Estrogen; Pulse Wave Analysis; Mice, Inbred C57BL; Estrous Cycle; Estrogens; Arteries
PubMed: 36240435
DOI: 10.1152/ajpheart.00369.2022 -
The Journal of Histochemistry and... Apr 2020Interleukin-33 (IL-33) is an IL-1 family cytokine with pleiotropic effects on diverse cell types. Dysregulated IL-33 signaling has been implicated in pregnancy-related...
Interleukin-33 (IL-33) is an IL-1 family cytokine with pleiotropic effects on diverse cell types. Dysregulated IL-33 signaling has been implicated in pregnancy-related disorders, including preeclampsia and recurrent pregnancy loss, and in ovarian function in women undergoing controlled ovarian stimulation for in vitro fertilization. To date, expression of IL-33 and its receptor subunit, ST2, in the female reproductive tract remains poorly characterized. We identify IL-33-expressing oocytes surrounded by ST2-expressing granulosa cells at all stages of follicular development, in addition to IL-33 and ST2 non-endothelial cells in the ovarian stroma and theca layer in ovaries from adult mice. These expression patterns are similar in estrus- and diestrus-stage adults and in pubescent mice, suggesting a role for IL-33 signaling in ovarian function throughout development and in the estrous cycle. In the uterus, we find expression of IL-33 and ST2 in glandular and luminal epithelia during estrus and at the initiation of pregnancy. Uterine IL-33 expression was modulated by the estrous cycle and was reduced in pubescent females. Last, superovulation increases transcripts for IL-33 and the soluble form of ST2 (sST2) in ovaries, and for IL-33 in uteri. Collectively, our findings lay the foundation for studies identifying cell type-specific requirements for IL-33/ST2 signaling in the establishment and maintenance of mouse pregnancy.
Topics: Animals; Female; Interleukin-1 Receptor-Like 1 Protein; Interleukin-33; Male; Mice; Mice, Inbred C57BL; Ovary; Pregnancy; Superovulation; Uterus
PubMed: 32108542
DOI: 10.1369/0022155420911049 -
Journal of Biomechanics Jan 2019Mounting evidence suggests that cells within soft tissues seek to maintain a preferred biomechanical state. Residual stress is defined as the stress that remains in a...
Mounting evidence suggests that cells within soft tissues seek to maintain a preferred biomechanical state. Residual stress is defined as the stress that remains in a tissue when all external loads are removed and contributes to tissue mechanohomeostasis by decreasing the transmural gradient of wall stress. Current computational models of pelvic floor mechanics, however, often do not consider residual stress. Residual strain, a result of residual stress can be quantitatively measured through opening angle experiments. Therefore, the objective of this study is to quantify the regional variations in opening angles along the murine female reproductive system at estrus and diestrus, to quantify residual strain in the maintenance state of sexually mature females. Further, evidence suggests that hydrophilic glycosaminoglycan/proteoglycans are integral to cervical remodeling. Thus, variations in opening angles following hypo-osmotic loading are evaluated. Opening angle experiments were performed along the murine reproductive system in estrus (n = 8) and diestrus (n = 8) and placed in hypo-osmotic solution. Measurements of thickness and volume were also obtained for each group. Differences (p < 0.05) in opening angle were observed with respect to region and loading, however, differences with respect to estrous stage were not significant. Thickness values were significant (p < 0.05) with respect to region only. The effects of both estrous cycle and region resulted in significant differences (p < 0.05) in observed volume. The observed regional differences indicate variation in the stress-free state among the reproductive system which may have implications for future computational models to advance women's reproductive health.
Topics: Animals; Biomechanical Phenomena; Cervix Uteri; Estrous Cycle; Female; Mice; Osmosis; Reproduction; Stress, Mechanical
PubMed: 30458959
DOI: 10.1016/j.jbiomech.2018.11.001 -
Hormones and Behavior Mar 2020The majority of HIV patients present with neuroendocrine dysfunction and ~50% experience co-morbid neurological symptoms including motor, affective, and cognitive...
Combined HIV-1 Tat and oxycodone activate the hypothalamic-pituitary-adrenal and -gonadal axes and promote psychomotor, affective, and cognitive dysfunction in female mice.
The majority of HIV patients present with neuroendocrine dysfunction and ~50% experience co-morbid neurological symptoms including motor, affective, and cognitive dysfunction, collectively termed neuroHIV. In preclinical models, the neurotoxic HIV-1 regulatory protein, trans-activator of transcription (Tat), promotes neuroHIV pathology that can be exacerbated by opioids. We and others find gonadal steroids, estradiol (E) or progesterone (P), to rescue Tat-mediated pathology. However, the combined effects of Tat and opioids on neuroendocrine function and the subsequent ameliorative capacity of gonadal steroids are unknown. We found that conditional HIV-1 Tat expression in naturally-cycling transgenic mice dose-dependently potentiated oxycodone-mediated psychomotor behavior. Tat increased depression-like behavior in a tail-suspension test among proestrous mice, but decreased it among diestrous mice (who already demonstrated greater depression-like behavior); oxycodone reversed these effects. Combined Tat and oxycodone produced apparent behavioral disinhibition of anxiety-like responding which was greater on diestrus than on proestrus. These mice made more central entries in an open field, but spent less time there and demonstrated greater circulating corticosterone. Tat increased the E:P ratio of circulating steroids on diestrus and acute oxycodone attenuated this effect, but repeated oxycodone exacerbated it. Corticotropin-releasing factor was increased by Tat expression, acute oxycodone exposure, and was greater on diestrus compared to proestrus. In human neuroblastoma cells, Tat exerted neurotoxicity that was ameliorated by E (1 or 10 nM) or P (100, but not 10 nM) independent of oxycodone. Oxycodone decreased gene expression of estrogen and κ-opioid receptors. Thus, neuroendocrine function may be an important target for HIV-1 Tat/opioid interactions.
Topics: Animals; Anxiety; Cognitive Dysfunction; Drug Combinations; Female; Gonadal Steroid Hormones; Gonads; HIV Infections; HIV-1; Humans; Hypothalamo-Hypophyseal System; Mice; Mice, Transgenic; Mood Disorders; Neurotoxicity Syndromes; Oxycodone; Pituitary-Adrenal System; Psychomotor Disorders; Tumor Cells, Cultured; tat Gene Products, Human Immunodeficiency Virus
PubMed: 31821792
DOI: 10.1016/j.yhbeh.2019.104649 -
Journal of Psychopharmacology (Oxford,... Dec 2022Cannabidiol (CBD), the major non-psychoactive constituent of cannabis, has therapeutic potential for the treatment of anxiety. Most preclinical studies investigate only...
RATIONALE
Cannabidiol (CBD), the major non-psychoactive constituent of cannabis, has therapeutic potential for the treatment of anxiety. Most preclinical studies investigate only acute effects of CBD and only in males, yet the drug is most likely to be used over a sustained period in clinical practice.
OBJECTIVES
The objectives of this study were to investigate the anxiolytic-like effect of CBD in female rats compared to males and to determine whether the responsiveness of females was influenced by the stage of the estrous cycle.
METHODS
We carried out experiments to compare the effect of CBD in male and female rats in the elevated plus maze (EPM) in response to acute and short-term (4 days) administration through a complete cycle in females.
RESULTS
Male and female rats behaved in a similar manner in the EPM, but females in the late diestrus (LD) phase exhibited more anxiety-like behavior than at other stages, the difference reaching statistical significance compared to proestrus stages. CBD produced anxiolytic-like effects in both sexes, but female rats were responsive only in LD and 10-fold lower dose than males. After sub-chronic (4 days) treatment, responsiveness to CBD was maintained in females in LD, but females in proestrus remained unresponsive to CBD treatment.
CONCLUSIONS
We suggest that there are sex differences in the anxiolytic-like effects of CBD in rats that reflect different underlying mechanisms: based on literature data, gonadal hormone status linked to GABA receptor expression in females, and 5-HT receptor activation in males.
Topics: Female; Male; Rats; Animals; Anti-Anxiety Agents; Cannabidiol; Elevated Plus Maze Test; Sex Characteristics; Rats, Wistar; Anxiety; Receptors, GABA-A
PubMed: 36239039
DOI: 10.1177/02698811221125440