Estrous Research Articles

Chronic Caffeine Consumption, Alone or Combined with Agomelatine or Quetiapine, Reduces the Maximum EEG Peak, As Linked to Cortical Neurodegeneration, Ovarian Estrogen Receptor Alpha, and Melatonin Receptor 2

RationaleEvidence of the effects of chronic caffeine (CAFF)-containing beverages, alone or in combination with agomelatine (AGO) or quetiapine (QUET), on electroencephalography (EEG), which is relevant to cognition, epileptogenesis, and ovarian function, remains lacking. Estrogenic, adenosinergic, and melatonergic signaling is possibly linked to the dynamics of these substances.ObjectivesThe brain and ovarian effects of CAFF were compared with those of AGO + CAFF and QUET + CAFF. The implications of estrogenic, adenosinergic, and melatonergic signaling and the brain-ovarian crosstalk were investigated.MethodsAdult female rats were administered AGO (10 mg/kg), QUET (10 mg/kg), CAFF, AGO + CAFF, or QUET + CAFF, once daily for 8 weeks. EEG, estrous cycle progression, and microstructure of the brain and ovaries were examined. Brain and ovarian 17β-estradiol (E2), antimullerian hormone (AMH), estrogen receptor alpha (E2Rα), adenosine receptor 2A (A2AR), and melatonin receptor 2 (MT2R) were assessed.ResultsCAFF, alone or combined with AGO or QUET, reduced the maximum EEG peak, which was positively linked to ovarian E2Rα, negatively correlated to cortical neurodegeneration and ovarian MT2R, and associated with cystic ovaries. A large corpus luteum emerged with AGO + CAFF and QUET + CAFF, antagonizing the CAFF-mediated increased ovarian A2AR and reduced cortical E2Rα. AGO + CAFF provoked TTP delay and increased ovarian AMH, while QUET + CAFF slowed source EEG frequency to δ range and increased brain E2.ConclusionsCAFF treatment triggered brain and ovarian derangements partially antagonized with concurrent AGO or QUET administration but with no overt affection of estrus cycle progression. Estrogenic, adenosinergic, and melatonergic signaling and brain-ovarian crosstalk may explain these effects.

EXPRESSION OF NRDR DIFFERENT ISOFORMS IN MICE UTERUS

Uterus is an important reproductive organ for embryonic growth and development of viviparous animals. Its normal function is regulated by complex endocrine system and multiple genes. NRDR is a retinoic acid metabolizing enzyme with strong retinol oxidation and retinoaldehyde reduction activities. Its function in the reproductive system has been partially studied. In this study, the expression distribution and change of NRDR in in different physiological states and different developmental stages of mouse uterus will be clarified, so as to provide an experimental basis for further research on its function in uterus. Using immunohistochemistry and RT-qPCR, NRDR was proved mainly expressed in mouse endometrial by immunohistochemistry. The expression of two different isoforms NRDR-1 and NRDR-2 in mouse uterus increased gradually with the development of the mouse, and peaked at 15 days after birth. The expression of NRDR-1 has no significant difference during estrous and diestrus in mouse uterus. However, the expression of NRDR-2 in estrous period was significantly higher than that in diestrus; NRDR two isoforms increased during embryo recognition and implantation in mouse uterus, and their expression decreased after implantation. The experimental results of the above expression patterns indicated that NRDR played a very important role in the mouse uterus, which was related to the estrus cycle and embryo implantation, among which the isoforms NRDR-2 might play a major role. The above results provide a basis for further study of the function of NRDR in uterus. The detection of the expression of NRDR in the uterus can provide experimental basis for understanding the molecular mechanism of development and other physiological processes in uterus. Keywords: NRDR; isoforms; uterus; mice

Pharmacologic blockade of nicotinic receptors in the suprachiasmatic nucleus increases ovarian atresia and inhibits follicular growth.

Reproduction in all mammalian species depends on the growth and maturation of ovarian follicles, that is, folliculogenesis. Follicular development can culminate with the rupture of mature follicles and the consequent expulsion of their oocytes (ovulation) or in atresia, characterized by the arrest of development and eventual degeneration. These processes are regulated by different neuroendocrine signals arising at different hypothalamic nuclei, including the suprachiasmatic nucleus (SCN). In the later, the activation of muscarinic receptors (mAChRs) and nicotinic receptors (nAChRs) by acetylcholine is essential for the regulation of the pre-ovulatory signals that stimulate the rupture of mature follicles. To evaluate the participation of the nAChRs in the SCN throughout the oestrous cycle in the regulation of the hypothalamic-pituitary-ovarian axis. For this purpose, 90-day-old adult female rats in metoestrus, dioestrus, proestrus or oestrus were microinjected into the left- or right-SCN with 0.3 μL of saline solution as vehicle or with 0.225 μg of mecamylamine (Mec), a non-selective antagonist of the nicotinic receptors, diluted in 0.3 μL of vehicle. The animals were sacrificed when they presented vaginal cornification, indicative of oestrus stage, and the effects of the unilateral pharmacological blockade of the nAChRs in the SCN on follicular development, ovulation and secretion of oestradiol and follicle-stimulating hormone (FSH) were evaluated. The microinjection of Mec decreased the serum levels of FSH, which resulted in a lower number of growing and healthy follicles and an increase in atresia. The higher percentage of atresia in pre-ovulatory follicles was related to a decrease in the number of ova shed and abnormalities in oestradiol secretion. We also detected asymmetric responses between the left and right treatments that depended on the stage of the oestrous cycle. The present results allow us to suggest that during all the stages of the oestrous cycle, cholinergic signals that act on the nAChRs in the SCN are pivotal to modulate the secretion of gonadotropins and hence the physiology of the ovaries. Further research is needed to determine if such signals are generated by the cholinergic neurons in the SCN or by cholinergic afferents to the SCN.

Proliferation and apoptosis dynamics of the normal canine mammary gland during the oestrous cycle evaluated by Ki-67 and Caspase-3 indexes.

Understanding the normal physiology of the canine mammary gland (CMG) is crucial, as it provides a foundational reference for understanding canine mammary neoplasms. The relation between the Proliferation Index (PI) indicated by Ki-67 expression, along with the Apoptotic Index (AI) determined through Caspase-3 expression during the oestrous cycle, is inadequately documented in existing literature. This study seeks to offer insights into the interplay between PI and AI in the CMG across oestrous cycle phases. An extensive investigation was conducted on a diverse case series of bitches (n = 18). Oestrous cycle stages were determined through vaginal cytology, histological examination of the reproductive tract and serum progesterone and oestradiol concentrations. The entire mammary chain was histologically examined, and proliferation and apoptosis were assessed via double immunohistochemistry employing anti-Ki-67 and Caspase-3 antibodies. PI and AI were evaluated through a systematic random sampling approach, counting a minimum of 200 cells for each cell type. There was a significantly higher PI during early dioestrus in all mammary gland components, with a greater proportion of positive cells observed in epithelial cells compared to stromal cells. The highest PI was detected in epithelial cells within the end buds. Significant differences were found in Ki-67 labelling across the cranial mammary glands. A positive and strong correlation was noted between progesterone concentration and PI in epithelial cells. The AI remained consistently low throughout the oestrous cycle, with few differences observed across histological components. Caspase-3 labelling displayed the highest positivity in caudal mammary pairs. A negative and moderate correlation was identified between progesterone concentration and AI in interlobular mesenchymal cells. This study highlights the influence of endocrine regulation on cell proliferation indices in mammary tissue, emphasizing the need to consider these hormonal variations in toxicopathological studies involving canine mammary gland.

Estrus detection on different thoroughbred crossbreed horses with vaginal smear and vaginal acidity method

Abstract Breeding manipulation season in racehorses is required to ensure the birth at the specific period (August-December), which will maximize the foal’s age when participating in their first race (July). Therefore, it is important to time the mating of mares using highly accurate estrus detection methods. This research was conducted to identify the differences data using vaginal smear and pH vagina of Thorougbred crossbreed mares in estrus and anestrus phases. Fifteen multiparous mares were conducted with a period of estrus of 19-22d. The result data showed significant differences (P<0.05) in the vaginal cell distribution patterns at each phase of the estrus cycle. The superficial cells predominate (92.43±5.14%) in the estrus phase while significant parabasal cells (87.89±3.09%) predominate in the anestrus phase. The results also showed a significant difference (P<0.05) in vaginal pH which was much more alkaline (8.71±0.25) in the estrus phase while more significantly acidic-normal (6.02±0.26) in the anestrus phase. However, the results showed no difference both in vaginal smear and pH vagina based on pedigree group. Finally, the pattern of superficial cells being more common and vaginal pH levels being higher during estrus may offer a new way to find out when an equine is in estrus.

Failure of senolytic treatment to prevent cognitive decline in a female rodent model of aging.

There are sex differences in vulnerability and resilience to the stressors of aging and subsequent age-related cognitive decline. Cellular senescence occurs as a response to damaging or stress-inducing stimuli. The response includes a state of irreversible growth arrest, the development of a senescence-associated secretory phenotype, and the release of pro-inflammatory cytokines associated with aging and age-related diseases. Senolytics are compounds designed to eliminate senescent cells. Our recent work indicates that senolytic treatment preserves cognitive function in aging male F344 rats. The current study examined the effect of senolytic treatment on cognitive function in aging female rats. Female F344 rats (12 months) were treated with dasatinib (1.2 mg/kg) + quercetin (12 mg/kg) or ABT-263 (12 mg/kg) or vehicle for 7 months. Examination of the estrus cycle indicated that females had undergone estropause during treatment. Senolytic treatment may have increased sex differences in behavioral stress responsivity, particularly for the initial training on the cued version of the watermaze. However, pre-training on the cue task reduced stress responsivity for subsequent spatial training and all groups learned the spatial discrimination. In contrast to preserved memory observed in senolytic-treated males, all older females exhibited impaired episodic memory relative to young (6-month) females. We suggest that the senolytic treatment may not have been able to compensate for the loss of estradiol, which can act on aging mechanisms for anxiety and memory independent of cellular senescence.

Features of mammary gland morphology in domestic carnivores

The mammary gland is a target organ for hormones in the hypothalamus, pituitary gland, thyroid gland, and ovaries. In the postnatal period of animal ontogenesis, breast growth, and development are determined by the estrous cycle and pregnancy. One of the most pressing problems in morphology, mammology, and reproductology of animals is the study of the structure of the breast at the macro and microscopic levels. However, modern studies on the morphology of animals' breasts are mainly devoted to the features of pathomorphological changes in the breast during carcinogenesis. The work aims to conduct a scientific review of the study of normal breast morphology in domestic carnivores. Electronic publication searches have been conducted in the Web of Science, Scopus, PubMed, and Google Scholar databases over the past 20 years. The principles of objectivity and a comprehensive attitude to studying the chosen problem are used. The authors of the review article review the current scientific literature and summarize current knowledge on the features of dog and cat breast morphology. The anatomical structure of the breast of animals is presented with an emphasis on its topography. According to the description of the microscopic structure of the breast, its main structural components are characterized by secretory parts (alveoli and tubes) and intraparticle excretory ducts. Anatomical characteristics of the nerves, blood, and lymphatic vessels of the mammary glands of dogs and cats are presented. Morphological changes in the mammary gland of dogs and cats at different stages of the estrus cycle and during pregnancy are described; in particular, the mammary gland is at rest (inactive) during proestrus and estrus. According to diestrus, due to an increase in progesterone levels, successive morphological changes occur, in particular, stromal and ductal proliferation; early development of lobules with branching ducts and proliferation of alveoli; the dominance of glandular tissue with large lobules containing secretory material; early regression, an increase in interparticle connective tissue, eosinophilic protein secretion in dilated ducts and alveoli. Complete involution of the alveoli and tubes of the breast is recorded at the end of the anestrus. The described anatomical and microscopic features of the structure of the mammary glands of dogs and cats are relevant for the comparative morphology of carnivores at different stages of the sexual cycle and during pregnancy. Data on blood supply, lymphatic drainage, and innervation of the breast are essential for its functional characteristics in normal and pathological conditions, particularly for developing a reasonable model of breast extirpation in malignant tumors.

The Influence of Selected Factors on Changes in Locomotion Activity during Estrus in Dairy Cows.

The objective of this study was the evaluation of the locomotion activity of heifers and Holstein dairy cows during estrus. We have analyzed the locomotion activity using the Heatime RuminAct device on 180 cows (32 heifers and 148 dairy cows) and we evaluated a total of 633 estrus cycles during the reference period of 3 days before estrus, 3 days after estrus, and on the day ofestrus occurrence. The datawere analyzed using the DataFlowTM II program. The locomotion of cows was expressed in the units of locomotion activity in 24 h (u.24 h-1). During the reference period of 3 days before estrus, the cows showed locomotion activity of 558 u.24 h-1, with an increase in locomotion activity on the day of estrus of 836 u.24 h-1, and, during the reference period of 3 days after estrus, the level of locomotion activity decreased to 537 836 u.24 h-1, which is a similar level of locomotion activity to the reference period before estrus. Through the statistical analysis, we evaluated the impact of parity, lactation stage, milk yield, and individuality on changes in locomotion activity during estrus and throughout the reference period, and we found a significant effect of parity (F = 13.41, p < 0.001) on changes in the locomotion activity of dairy cows during estrus. Based on these results, this research offers fresh perspectives on assessing specific factors affecting the locomotion activity of dairy cows during estrus through the practical application of electronic systems for estrus detection on dairy farms.

Reproductive Activity of Socorro Island Merino Ewes and Their Crosses with Pelibuey under Heat Stress Conditions.

An experiment was carried out to evaluate the effect of spring and autumn seasons on the reproductive activity of Merino Socorro Island ewes and their crosses with Pelibuey under heat stress (HS) conditions in the tropics. All ewes (n = 80) were randomly assigned to one of two breeds during the first and second periods, respectively: (1) Twenty Socorro Island Merino ewes (SIM) and (2) 20 Pelibuey Crossbred ewes (PBC). Animals were fed the same diet and given water ad libitum. All statistical analyses were performed using SAS statistical software 9.12 procedures. In both seasons, a mean of more than 80 U of maximum THI was obtained, while in spring and autumn, the minimum THI exceeded 30 and 40 U, respectively. All animals were in oestrus and ovulated in both seasons. The frequency of animals in spring during the first 48 h of oestrus expression was greater (p < 0.05) than 48-55 h but similar (p > 0.05) than 55-65 h; in autumn during the first 48 h and 48-55 h were similar (p > 0.05), but different (p < 0.05) than 55-65 h. The duration of oestrus expression was longer in the spring than in the autumn (p < 0.05). The frequency of animals was higher (p < 0.05) in SIM than in PBC ewes during the first oestrus cycle (1-17 d) and was also higher (p < 0.05) in PBC than in SIM ewes during the second oestrus cycle (18-35 d). The SIM ewes produced more (p < 0.05) progesterone (P4) than the PBC ewes. During the sampling days of the oestrus cycle, more P4 was created in autumn than in spring (p < 0.05). Both breeds showed severe HS. In the future, ewes treated under assisted reproductive programs in the tropics may improve reproductive efficiency.

Rapid label-free impedimetric detection of progesterone enhanced by immunomagnetic bead-based competitive immunoreaction

Detecting progesterone (P4) concentration in cow serum is essential for monitoring the pregnancy progress after fertilization and is significant for the dairy farming industry and veterinary medicine. This study reports enzyme-free immunomagnetic beads (IMBs)-based competitive immunoassay for detecting P4 by P4-bovine serum albumin (BSA)-modified biosensors. The anti-P4 antibody-conjugated IMBs serve as collectors to capture P4 in undiluted serum samples to prevent the biosensor surface from biosample contamination and as insulated labels to report the electron-transfer resistance signal of electrochemical impedance spectroscopy (EIS) measurement. The IMBs and P4-containing samples were mixed for 15−30 min, capable of obtaining stable P4@IMB complexes. The 0.2-kGauss pulsed magnetic field (PMF) of the 20-s pulse width and 20-s relaxation time applied for 5 min can shorten the immunoreaction time between the P4@IMBs and the P4-BSA-modified biosensor and reduce the IMB's nonspecific adsorption on the biosensor surface. This competitive immunoassay's cut-off value and detection limit were 7.71 ng/mL and 7.33 ng/mL, respectively, which is lower than the serum's P4 plateau concentration (over 8 ng/mL) of dairy cows on days 6–16 of estrus cycles and that in pregnancy. The IMB-based immunoassay combining the PMF attraction and the label-free EIS measurement exhibits promising potential for rapidly detecting P4 in undiluted serum.

Genetic analysis of health traits and their associations with longevity, fertility, production, and conformation traits in Holstein cattle

Health traits have high economic values in dairy cattle breeding, which can cause considerable financial loss through involuntary culling. In this study, fourteen health traits were analysed, including five composite health traits: reproductive disorders, udder health (UH), digestive disorders, metabolic disorders, locomotory diseases (LD), and nine independent health traits: gestation disorders and peripartum disorders, irregular estrus cycle and sterility, metritis (ME), mastitis (MA), abomasal displacement (AD), enteritis (EN), and ketosis, claw diseases (CD), laminitis complex. This study analysed variance components for health traits through both single and bivariate repeatability animal models. All health traits showed low heritability, ranging from 0.001 to 0.025. Most of the health traits in five categories showed negative genetic correlations, ranging from −0.012 (CD and EN) to −0.634 (ME and EN). Strong positive genetic correlations appeared within the same category, ranging from 0.469 (EN and AD) to 0.994 (UH and MA, LD and CD). Furthermore, approximate genetic correlations were evaluated between health traits and routinely collected traits (longevity, fertility, production, and conformation). In general, the low to moderate approximate genetic correlations were estimated between health traits and routinely collected traits. The estimated correlations between health traits and longevity, fertility, production, and conformation traits could provide an indirect reference for disease−resistance breeding in Holstein cattle.

Infertility in POMC-deficient mice

The pro-opiomelanocortin (POMC) gene is expressed in the hypothalamus and pituitary and its product is cleaved into several peptides including the melanocyte stimulating hormones (α, β, or γ-MSH), adrenocorticotropic hormone (ACTH), and beta-endorphin. Alpha-MSH is involved in regulating appetite, sexual behavior, and melanin, while ACTH regulates secretion of glucocorticoids from the adrenal cortex. Humans who have a POMC mutation either produce an abnormally short version of POMC or are missing the protein completely and therefore lack these hormones. This has biological consequences including red hair and fair skin, early-onset obesity (due to severe hyperphagia), and potentially hypothyroidism, hypogonadism, and infertility. Many of these same effects are seen with mice containing this deficiency. We are interested in studying infertility through a mouse model of hypothalamic-specific POMC-deficiency. These mice also experience early-onset obesity and infertility. Estradiol is a key reproductive hormone that is essential for fertility. POMC deficiency may lead to hypogonadism, which can cause low levels of estrogen so we hypothesize that POMC-deficient mice have reduced estrogen levels, which may contribute to their infertility. To test this hypothesis, we will measure estrogen levels in POMC-deficient mice at different stages of the estrus cycle using an estradiol ELISA kit. We expect the POMC-deficient mice to have lower estrogen levels than control mice. We also plan to use liquid chromatography mass spectrometry (LC-MS) to measure estrogen levels. Before collecting the blood samples, vaginal cell samples are obtained and viewed under a microscope to analyze the ratio of cells and determine which stage the females were in—proestrus, estrus, metestrus, or diestrus. Blood samples are then collected into 1.5 mL microcentrifuge tubes with 10 microliters of 0.5 M EDTA to prevent blood clotting. After blood is collected, it is centrifuged at 2,000 g for 20 minutes at 4 degrees Celsius. The plasma is then stored at -80 degrees Celsius until analysis. Based on preliminary results we expect the POMC deficient mice to have reduced estrogen and/or altered levels throughout the cycle. So far, our results have indicated that POMC-deficient female mice have abnormal estrus cycles and also reduced uterine weights. The conclusions from this study will help us understand more about the causes of infertility in POMC-deficient mice, which may also lead to greater understanding on how to treat humans with infertility due to a POMC mutation. Support for this research was provided by IRACDA grant NIHK12GM111725 to Z.T. and UVU Scholarly Activities Grant to A.G. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Estrus detection of PE goats using the ASM application and confirmed by vagina cytology

The estrus cycle is the initial stage of increasing the milk production of PE goats. Estrus detection in PE goats is generally done manually by looking for signs of sound, restlessness, and aggression. The use of voice recording applications to detect estrus has been carried out, one of which is ASM. However, to increase the accuracy of detection based on ASM audio-visual, it is necessary to confirm the cytological status of bovine vaginal cells. This study aimed to detect estrus using audio-visual and vaginal cytology of goats. Eight female PE goats were observed on small breeders for their reproductive cycle, behavior, vocalization with ASM, and cell cytology sampling through vaginal mucus. They are processing data using Spearman rank correlation (SD). The results show aggressive behavior, frequent voices, and signs of clear discharge, and the tail is often moved. ASM detected the sound of goats in estrus at 430.0 Hz – 494.3 Hz and confirmed the superficial cell status, which predominated in PE goats. It can be concluded that the audio of goats in the 472 Hz range recorded using the ASM application can be used as a reference that goats are in estrus and ready to be mated.

Molecular characterization and expression profile of the ALDH1A1 gene and its functions in yak luteal cells

The ALDH1A1 gene encodes a cytoplasmic member of the aldehyde dehydrogenase 1 family, which plays an important role in regulating animal reproductive performance, including estrus cycle and embryonic development. The aim of this study was to characterize ALDH1A1 activity in ovaries of 3–5 year-old yaks and to determine its effects on cell proliferation, apoptosis, and progesterone secretion in luteal cells (LCs). The coding sequence (CDS) of the ALDH1A1 gene was cloned by reverse transcription-PCR and immunohistochemical analysis was used to confirm localization of the ALDH1A1 protein in the ovary. To assess the activity of ALDH1A1 in regulating progesterone secretion, si-ALDH1A1 was transfected into LCs in vitro and progesterone levels in LC supernatants were measured by ELISA. The interference efficiency was assessed by real-time quantitative PCR (RT-qPCR) and immunofluorescence staining, and cell proliferation and apoptosis were evaluated by EdU and TUNEL staining, respectively. The cloned ALDH1A1 sequence contained 1462 bp, encoding 487 amino acids. Immunohistochemical analysis showed that ALDH1A1 protein expression, which was significantly higher in LCs, was mainly found in antral follicles and the corpus luteum (CL). The expression of ALDH1A1 mRNA in LCs was effectively inhibited by si-ALDH1A1transfection, and progesterone secretion was markedly decreased along with the significant down-regulation of progesterone pathway-related genes, STAR, CYP11A1, CYP19A1, CYP17A1, 3β-HSD, and HSD17B1. Knockdown of ALDH1A1 mRNA expression decreased cell proliferation and increased apoptosis in LCs. The mRNA expression of the proliferation-related genes, PCNA, CCND1, CCNB1 and CDC25A, was significantly down-regulated, while expression of the apoptosis-promoting CASP3 gene was significantly increased. In summary, we characterized the yak ALDH1A1 gene and revealed that ALDH1A1 knockdown promoted apoptosis, repressed cell proliferation, and decreased progesterone secretion by yak LCs, potentially by regulating the mRNA expression of genes related to proliferation, apoptosis, and progesterone synthesis and secretion.

Repeated-dose toxicity and toxicokinetic study of isobutylparaben in rats subcutaneously treated for 13weeks.

Parabens have historically served as antimicrobial preservatives in a range of consumables such as food, beverages, medications, and personal care products due to their broad-spectrum antibacterial and antifungal properties. Traditionally, these compounds were believed to exhibit low toxicity, causing minimal irritation, and possessing limited sensitization potential. However, recent evidence suggests that parabens might function as endocrine-disrupting chemicals (EDCs). Consequently, extensive research is underway to elucidate potential human health implications arising from exposure to these substances. Among these parabens, particular concerns have been raised regarding the potential adverse effects of iso-butylparaben (IBP). Studies have specifically highlighted its potential for inducing hormonal disruption, significant ocular damage, and allergic skin reactions. This study aimed to evaluate the prolonged systemic toxicity, semen quality, and estrus cycle in relation to endocrine disruption endpoints, alongside assessing the toxicokinetic behavior of IBP in Sprague-Dawley rats following a 13-week repeated subcutaneous administration. The rats were administered either the vehicle (4% Tween 80) or IBP at dosage levels of 2, 10, and 50mg/kg/day for 13weeks. Blood collection for toxicokinetic study was conducted on three specified days: day 1 (1st), day 30 (2nd), and day 91 (3rd). Systemic toxicity assessment and potential endocrine effects were based on various parameters including mortality rates, clinical signs, body weights, food and water consumption, ophthalmological findings, urinalysis, hematological and clinical biochemistry tests, organ weights, necropsy and histopathological findings, estrus cycle regularity, semen quality, and toxicokinetic behavior. The findings revealed that IBP induced local irritation at the injection site in males at doses ≥ 10mg/kg/day and in females at 50mg/kg/day; however, systemic toxicity was not observed. Consequently, the no-observed-adverse-effect level (NOAEL) for IBP was determined to be 50mg/kg/day in rats of both sexes, indicating no impact on the endocrine system. The toxicokinetics of IBP exhibited dose-dependent systemic exposure, reaching a maximum dose of 50mg/kg/day, and repeated administration over 13weeks showed no signs of accumulation.

Evaluation of the anti‐PCOS Potential of Ethanolic Extract of Ocimum Gratissimum (Linn.) Leaf in Letrozole‐Induced Polycystic Ovarian Syndrome in Wistar Rats

AbstractThis study investigated the effect of ethanolic extract of Ocimum gratissimum leaves (EEOGL) on letrozole‐induced polycystic ovarian syndrome (PCOS) and determine the possible binding effects of compounds identified in EEOGL using molecular docking method. After the induction using letrozole (1 mg/kg), normal (n=4) and PCOS (n=16; 4 groups of 4 animals/group) were treated for 14 days orally with distilled water (1 ml/kg), metformin (500 mg/kg), clomiphene‐citrate (2 mg/kg), and EEOGL (50 and 100 mg/kg). 47 compounds were docked to androgen receptor (AR), estrogen receptor (ER), fructose‐1,6‐bisphosphate (FBP), and phosphoenolpyruvate‐carboxykinase (PEPCK) using Vina. The result obtained revealed that letrozole‐induced PCOS rats exhibited altered oestrous cycle and administration of the EEOGL at 50 mg/kg significantly (p&lt;0.05) decreased the serum insulin, testosterone, luteinizing hormone (LH), Low Density Lipoprotein (LDL), total cholesterol (TC), triglyceride while serum concentration of Follicle stimulating hormone (FSH), estradiol, and High‐Density Lipoprotein (HDL) were significantly (p&lt;0.05) increased compared to the control. However, administration of 100 mg/kg of the EEOGL did not reverse elevated insulin and LH levels. Molecular docking revealed four compounds with at high binding affinity for at least one of the proteins studied compared to standard drugs. Ethanolic extracts of O. gratissimum has the potential to regulate the reproductive‐induced alterations in PCOS rats.

Perinatal bisphenol S exposure exacerbates the oxidative burden and apoptosis in neonatal ovaries by suppressing the mTOR/autophagy axis

Bisphenol S (BPS) is an emerging environmental endocrine disruptor capable of crossing the placental barrier, resulting in widespread exposure to pregnant women due to its extensive usage. However, the impact of perinatal maternal exposure to BPS on reproductive health in offspring and the underlying molecular mechanism remain underexplored. In this study, gestational ICR mice were provided with drinking water containing 3.33 mg/L BPS to mimic possible human exposure in some countries. Results demonstrated that BPS accelerated the breakdown of germ-cell cysts and the assembly of primordial follicles in neonates, leading to oocyte over-loss. Furthermore, the expression levels of folliculogenesis-related genes (Kit, Nobox, Gdf9, Sohlh2, Kitl, Bmp15, Lhx8, Figla, and Tgfb1) decreased, thus compromising oocyte quality and disrupting early folliculogenesis dynamics. BPS also disrupted other aspects of offspring reproduction, including advancing puberty onset, disrupting the estrus cycle, and impairing fertility. Further investigation found that BPS exposure inhibited the activities and expression levels of antioxidant-related enzymes in neonatal ovaries, leading to the substantial accumulation of MDA and ROS. The increased oxidative burden exacerbated the intracellular apoptotic signaling, manifested by increased expression levels of pro-apoptotic markers (Bax, Caspase 3, and Caspase 9) and decreased expression levels of anti-apoptotic marker (Bcl2). Concurrently, BPS inhibited autophagy by increasing p-mTOR/mTOR and decreasing p-ULK1/ULK1, subsequently down-regulating autophagy flux-related biomarkers (LC3b/LC3a and Beclin-1) and impeding the degradation of autophagy substrate p62. However, the imbalanced crosstalk between autophagy, apoptosis and oxidative stress homeostasis was restored after rapamycin treatment. Collectively, the findings demonstrated that BPS exposure induced reproductive disorders in offspring by perturbing the mTOR/autophagy axis, and such autophagic dysfunction exacerbated redox imbalance and promoted excessive apoptosis. These results provide novel mechanistic insights into the role of autophagy in mitigating BPS-induced intergenerational reproductive dysfunction.

Efficacy and safety of mesenchymal stem cell therapy for ovarian ageing in a mouse model

BackgroundOvarian ageing is one of the major issues that impacts female fertility. Mesenchymal stem cell (MSC)-based therapy has made impressive progress in recent years. However, the efficacy and safety of MSCs, as nonautologous components, remain to be further verified.MethodsTwo common sources of MSCs, umbilical cord-derived MSCs (UC-MSCs) and adipose tissue-derived MSCs (AD-MSCs), were orthotopically transplanted into a mouse model of ovarian ageing to evaluate their therapeutic effects. The safety of the treatment was further evaluated, and RNA sequencing was performed to explore the underlying mechanisms involved.ResultsAfter orthotopic transplantation of MSCs into the ovary, the oestrous cycle, ovarian weight, number and proportion of primary follicles, granulosa cell proliferation, and angiogenesis were improved. The effects of AD-MSCs were superior to those of UC-MSCs in several indices, such as post-transplant granulosa cell proliferation, ovarian weight and angiogenesis. Moreover, the tumorigenesis, acute toxicity, immunogenicity and biodistribution of MSCs were evaluated, and both AD-MSCs and UC-MSCs were found to possess high safety profiles. Through RNA sequencing analysis, enhancement of the MAPK cascade was observed, and long-term effects were mainly linked to the activation of immune function.ConclusionsOrthotopic transplantation of MSCs displays significant efficacy and high safety for the treatment of ovarian ageing in mice.

Taurine dynamics in serum during the oestrous cycle in buffaloes.

Estrus identification is one of the common issues in buffaloes because of their short estrus duration and silent estrus problem. Hence, specific biomarkers facilitating in identifying the estrus stage would be helpful to buffalo farmers and researchers. In our previous studies, taurine, a non-protein amino acid that helps in the secretion of reproductive hormones such as GnRH, was found to be associated with postpartum anestrus in buffaloes. Therefore, the present study was conducted to explore the level of taurine in serum during different stages of the oestrous cycle in healthy cyclic buffaloes. Blood samples were collected from healthy cyclic buffaloes (n = 4), and taurine was estimated at the estrus (0th day), proestrus (-2nd day), metestrus (3rd day) and diestrus (+10th day) stages using TLC method. The days of the oestrous cycle were determined by ultrasonography and observation of behavioural signs by trained professionals. The results revealed that taurine was consistently present in the serum. However, the highest concentration of taurine was observed at the proestrus (0.20 ± 0.03 mg/mL) stage, which was greater (p < .05) than metestrus (0.10 ± 0.05 mg/mL) and diestrus (0.13 ± 0.03 mg/mL) stages, but comparable with the estrus stage. These results were also validated in the simulated population datasets of population size 6 to 10,000. Further, ROC curve analysis for the large simulated population indicated the efficiency of taurine to distinguish proestrus from metestrus and diestrus stages at a lower cutoff value of <0.1643 mg/mL with 60% sensitivity and specificity. Therefore, the present study concludes that serum taurine concentration could help in detecting proestrus stage of buffalo estrous cycle.

Sex similarities and dopaminergic differences in interval timing.

Rodent behavioral studies have largely focused on male animals, which has limited the generalizability and conclusions of neuroscience research. Working with humans and rodents, we studied sex effects during interval timing that requires participants to estimate an interval of several seconds by making motor responses. Interval timing requires attention to the passage of time and working memory for temporal rules. We found no differences between human females and males in interval timing response times (timing accuracy) or the coefficient of variance of response times (timing precision). Consistent with prior work, we also found no differences between female and male rodents in timing accuracy or precision. In female rodents, there was no difference in interval timing between estrus and diestrus cycle stages. Because dopamine powerfully affects interval timing, we also examined sex differences with drugs targeting dopaminergic receptors. In both female and male rodents, interval timing was delayed after administration of sulpiride (D2-receptor antagonist), quinpirole (D2-receptor agonist), and SCH-23390 (D1-receptor antagonist). By contrast, after administration of SKF-81297 (D1-receptor agonist), interval timing shifted earlier only in male rodents. These data illuminate sex similarities and differences in interval timing. Our results have relevance for rodent models of both cognitive function and brain disease by increasing representation in behavioral neuroscience. (PsycInfo Database Record (c) 2024 APA, all rights reserved).