Estrus cycle

The collection and examination method of vaginal smears is the standard for the determination of ovulation or phases of the estrous cycle of rodents used in research. However, this method is time consuming and may not be amenable to continual monitoring of a large number of animals. Infrared thermography has recently emerged as a noninvasive technique that requires relatively little handling of animals. The body temperature of rodents has been shown to correlate with the ocular surface temperature. This study aimed to evaluate the use of thermographic monitoring of the ocular surface for the identification of estrus in rats...

The present research was carried out to assess the serum progesterone (P4 ) concentration and uterine hemodynamics at estrus till ovulation in cyclic cows (N = 130) with healthy or diseased uterus. At estrus, 85 cows were diagnosed with clinical endometritis (CE; n = 44) and sub-clinical endometritis (SCE; n = 41); whereas, 45 cows being served as control namely no endometritis (NE; n = 45) were included in the study. Serum progesterone estimation at 12 - 14 and 40 hr after the onset of estrus and Doppler sonography of both middle uterine arteries were done to envisage the uterine hemodynamics and ovulation...

The estrus cycle in female rodents has been shown to affect a variety of physiological functions. However, little is known about its presumably thorough effect on auditory processing during the sleep-wake cycle and sleep deprivation. Vertex auditory evoked potentials (vAEPs) were evoked by single click tone stimulation and recorded during different stages of the estrus cycle and sleep deprivation performed in metestrus and proestrus in female rats. vAEPs showed a strong sleep-dependency, with the largest amplitudes present during slow wave sleep while the smallest ones during wakefulness...

Immune dysregulation has been summarized as a critical factor in the occurrence and development of Polycystic ovary syndrome (PCOS), but potential mediators and mechanisms remain unclear. Our previous study showed that CD19+ B cells were involved in the pathogenesis of dehydroepiandrosterone (DHEA)-induced PCOS mice. Here, we studied the therapeutic potential of anti-CD19 antibody (aCD19 Ab) on DHEA-induced PCOS mice. The results showed that aCD19 Ab treatment improved ovarian pathological structure and function of PCOS mice, manifested by an increased number of corpus luteum, a decreased number of cystic follicles and atretic follicles, and regular estrus cycles...

Diminished ovarian reserve (DOR) refers to a decrease in the number and/or quality of oocytes, leading to infertility, poor ovarian response and adverse pregnancy outcomes. Currently, the pathogenesis of DOR is largely unknown, and the efficacy of existing therapeutic methods is limited. Therefore, in-depth exploration of the mechanism underlying DOR is highly important for identifying molecular therapeutic targets for DOR. Our study showed that estrogen receptor beta (ERβ) mRNA and protein expression was upregulated in granulosa cells (GCs) from patients with DOR and in the ovaries of DOR model mice...

Premature ovarian insufficiency (POI) patients experience a decline in ovarian function and a reduction in serum reproductive hormones, leading to a significant impact on the outcomes of assisted reproductive technology. Despite the absence of an effective clinical treatment to restore fertility in POI patients, recent research has indicated that cord blood plasma (CBP) derived from human umbilical cord blood (hUCB) may offer therapeutic benefits for various degenerative diseases. The primary aim of this study is to explore approaches for enhancing ovarian function and serum reproductive hormones through the administration of CBP in a murine model...

This study investigates the non-invasive monitoring of the endocrine ovarian activities of captive female golden takins ( Budorcas taxicolor bedfordi ) based on long-term fecal sex steroid hormone metabolite dynamics. Fecal progesterone (P4 ) metabolite dynamics were monitored in nine females for 0.5-15 years between 2004 and 2022. Fecal estradiol-17β (E2 ) and estrone (E1 ) metabolites were measured during certain estrous cycles, and fecal E1 metabolite concentrations were measured during all gestation periods...

PURPOSE: Metformin (MET), a first-line treatment for type 2 diabetes mellitus, restores ovarian function in women with polycystic ovary syndrome. MET has been shown to increase the rate of success for in vitro fertilization when utilized in assisted reproductive technologies. This study was designed to examine the impact of MET on ovarian function and fertility in a mouse model of galactose-induced premature ovarian insufficiency (POI). We further investigated the underlying mechanisms...

BACKGROUND: Primary ovarian insufficiency refers to the loss of ovarian function before the age of 40 years and leads to amenorrhea and infertility. Primary ovarian insufficiency has diverse causes, but a common cause is exposure to gonadotoxic chemotherapy used in cancer treatment. Because of the risk for developing primary ovarian insufficiency, patients who want to preserve their fertility may consider various procedures for fertility preservation. However, current fertility preservation options are highly invasive, carry substantial risks, and have uncertain success rates...

Uterine contraction patterns vary during the ovulatory cycle and during gestation, but prior measurements have produced limited and conflicting information on these patterns. We combined a virally delivered genetically encoded calcium reporter (GCaMP8m) and ultra-widefield imaging in live nonpregnant mice, and characterized uterine calcium dynamics at organ-scale throughout the estrus cycle. At all stages, activity emanated from multiple loci of initiation (LOIs) and had irregular patterns in time. The average frequency of calcium events varied strongly with cycle stage, being lowest in proestrus (0...

Buffalo is a silent heat animal and doesn't show prominent signs of estrous like cattle so it becomes difficult for farmers to determine the receptivity of the animal based purely on the animal behaviour. India, having a huge population size, needs to produce more milk for the population. Successful artificial insemination greatly depends on the receptivity of the animal. Hence the present study aimed to identify the changes in the metabolome of the buffalo. GC-MS based mass spectrometric analysis was deployed for the determination of estrous by differential expression of metabolites...

The female reproductive tract (FRT) undergoes extensive remodeling during reproductive cycling. This recurrent remodeling and how it shapes organ-specific aging remains poorly explored. Using single-cell and spatial transcriptomics, we systematically characterized morphological and gene expression changes occurring in ovary, oviduct, uterus, cervix, and vagina at each phase of the mouse estrous cycle, during decidualization, and into aging. These analyses reveal that fibroblasts play central-and highly organ-specific-roles in FRT remodeling by orchestrating extracellular matrix (ECM) reorganization and inflammation...

In mammals, progesterone and estrogens affect the stress response. The study aimed to compare the physiological and behavioral responses to the social isolation of ewes during the estrus or luteal phase. Estrous and diestrous ewes (n = 10 and 8 respectively) were individually isolated in a novel place for 10 min. Ewes' behavior was recorded during the test. Cortisol, blood proteins and glucose concentrations, and the skin surface temperature were determined before and after the test. Cortisol increased immediately after the test ended ( P = 0...

Regular exercise has numerous health benefits, but the human population displays significant variability in exercise participation. Rodent models, such as voluntary wheel running (VWR) in rats, can provide insight into the underlying mechanisms of exercise behavior and its regulation. In this study, we focused on the role of estrogen on VWR in female rats. Female rats run more than males, and we aimed to determine to what extent running levels in females were regulated by estrogen signaling. The running behavior of rats (duration, speed, and total distance run) was measured under normal physiological conditions, ovariectomy (OVX), and estrogen replacement in an OVX background...

Polycystic ovary syndrome (PCOS) is a set of endocrine disorder syndrome characterized by ovulation disorder. Increased insulin resistance (IR) and compensatory hyperinsulinemia play a vital role in the pathogenesis of PCOS. Therefore, insulin sensitizing agents have been studied in the treatment of PCOS. Berberine (BBR) has been proved to alleviate IR in patients with PCOS, but the mechanism remained unclear. This study was aimed to verify the regulatory mechanism of BBR on PCOS-IR rats. Firstly, we established a female rat PCOS-IR model induced by dehydroepiandrosterone (DHEA) and found that estrus cycle was disrupted in the PCOS-IR group, serum fasting insulin (FINS) level and the homeostasis model assessment of insulin resistance (HOMA-IR) index were significantly higher than normal control group...

Endometrial epidermal growth factor (EGF) shows a cyclic change with two peaks on days 2-4 and days 13-14 of the estrous cycle. In repeat breeder cows, loss of the peaks has been associated with reduced fertility. By infusing seminal plasma (SP) and osteopontin (OPN) derived from SP and milk into the vagina, their EGF profile and fertility are restored. However, SP is difficult to obtain, and both SP and OPN can transmit infectious diseases. While OPN can be sourced from recombinant protein without this risk, recombinant bovine OPN (rOPN) expressed in Escherichia coli should be examined for its effects on the EGF profile, since it does not undergo posttranslational modification, which is important for its biological activity...

The arcuate nucleus kisspeptin (ARNKISS) neurons represent the gonadotropin-releasing hormone (GnRH) pulse generator that likely drives pulsatile gonadotropin secretion in all mammals. Using an improved GCaMP fiber photometry system enabling long-term continuous recordings, we aimed here to establish a definitive profile of ARNKISS neuronal activity across the murine estrous cycle. As noted previously, a very substantial reduction in the frequency of ARNKISS neuron synchronization events (SEs) occurs on late proestrus and extends into estrus...

Introduction: Endocannabinoids and exogenous cannabinoids are potent regulators of feeding behavior and energy metabolism. Stimulating cannabinoid receptor signaling enhances appetite, particularly for energy-dense palatable foods, and promotes energy storage. To elucidate the underlying cellular mechanisms, we investigate here the potential role of astrocytic endocannabinoid 2-arachidonoylglycerol (2-AG). Astrocytes provide metabolic support for neurons and contribute to feeding regulation but the effect of astrocytic 2-AG on feeding is unknown...

The genes encoding for estrogen receptor ( ESR2 ) and follicle-stimulating hormone receptor ( FSHR ) play crucial roles in ovarian follicular development. This study aimed to determine the expression levels of miRNAs predicted against FSHR and ESR2 mRNAs in follicular cells related to their target genes during the estrous cycle in canines. Antral follicles were dissected from 72 ovaries following ovariohysterectomies. MiRNAs regulating FSHR and ESR2 genes were selected from miRNA databases, and mature miRNA and mRNA expression profiling was performed using real-time polymerase chain reaction (PCR)...

Two studies were conducted to evaluate the effects of the follicular wave on ovarian function and fertility in dairy heifers and lactating cows. In study 1, the estrous cycle of the selected Holstein heifers was initially synchronized using two intra-muscular prostaglandin F2α (PGF2α ) administrations 11 days apart. Heifers in group FFW (n = 14) received an intra-muscular 500 μg PGF2α administration on day 7 after detecting standing estrus, while Heifers in group SFW (n = 14) were administered PGF2α 13 days after detecting standing estrus...