Diestrous Phase Research Articles

Excessive caffeine intake inhibits steroidogenesis, folliculogenesis and disrupts utero-ovarian tissue histomorphology integrity in experimental rats, and precipitates polycystic ovary syndrome in Sprague-Dawley rats

Polycystic ovarian syndrome (PCOS) is characterized by anovulation and hyperandrogenism symptoms. Caffeine is popularly consumed and it is a legal psychoactive substance. This study evaluated the effect of excessive caffeine intake on utero-ovarian tissue in polycystic ovary syndrome rats. Twenty-four female rats randomized into group A control received 2 ml of normal saline. Group B received 4 mg/kg body weight (bwt) i.p of estradiol valerate (EV) on the first day, Group C received 100 mg/kg bwt of caffeine orally, and Group D received i.p 4 mg/kg bwt EV and 100 mg/kg bwt of caffeine orally. The experiment lasted 30 days. Histology of the ovary and uterus, oxidative and antioxidant, reproductive hormone, lipid profile, inflammatory markers, and apoptosis markers were evaluated.The ovarian histoarchitecture revealed degeneration of the theca cells, granulosa, and corpus luteum, and loss of mucin granules in the uterine tissues in PCOS, CAF, and PCO+CAF. The estrous cycle became irregular, with prolonged diestrous and proestrus phases. Marked rise in oxidative markers and decline in the activities of ovarian enzymatic antioxidants, inflammatory response, caspase-dependent apoptosis, and hormonal imbalance.Excessive caffeine consumption, therefore impaired utero-ovarian integrity, hormones, inflammatory indicators, oxidant and antioxidant parameters, apoptotic markers, and the estrous cycle.

Intrauterine LPS inhibited arcuate Kiss1 expression, LH pulses, and ovarian function in rats.

Uterine inflammatory diseases are a major cause of infertility in humans and domestic animals. The current findings that intrauterine lipopolysaccharide is absorbed in systemic circulation and attenuates ovarian cyclic activities could provide a basis for developing novel treatments to improve fertility. Uterine inflammatory diseases are a major cause of infertility in humans and domestic animals. Circulating lipopolysaccharide (LPS), a bacterial endotoxin causing uterine inflammation, reportedly downregulates the hypothalamic-pituitary-gonadal axis to mediate ovarian dysfunction. In contrast, the mechanism whereby intrauterine LPS affects ovarian function has not been fully clarified. This study aimed to elucidate whether uterine exposure to LPS downregulates hypothalamic kisspeptin gene (Kiss1) expression, gonadotropin release, and ovarian function. Uterine inflammation was induced by intrauterine LPS administration to ovary-intact and ovariectomized female rats. As a result, plasma LPS concentrations were substantially higher in control rats until 48 h post injection, and the estrous cyclicity was disrupted with a prolonged diestrous phase. Three days post injection, the number of Graafian follicles and plasma estradiol concentration were reduced in LPS-treated rats, while numbers of Kiss1-expressing cells in the anteroventral periventricular nucleus and arcuate nucleus (ARC) were comparable in ovary-intact rats. Four days post injection, ovulation rate and plasma progesterone levels reduced significantly while gene expression of interleukin1β and tumor necrosis factor α was upregulated in the ovaries of LPS-treated rats that failed to ovulate. Furthermore, the number of Kiss1-expressing cells in the ARC and pulsatile luteinizing hormone (LH) release were significantly reduced in ovariectomized rats 24 h post injection. In conclusion, these results indicate that intrauterine LPS is absorbed in systemic circulation and attenuates ovarian function. This detrimental effect might be caused, at least partly, by the inhibition of ARC Kiss1 expression and LH pulses along with an induction of ovarian inflammatory response.

Comparative study of DHEA and letrozole induced polycystic ovary syndrome in post-pubertal rats

Aim In order to select a suitable rat model for studying polycystic ovary syndrome (PCOS). Methods Post-pubertal Sprague Dawley (SD) rats were allocated to four groups, abbreviated as the control 1 group, DHEA subcutaneous injection (DHEA) group, control 2 group, letrozole intragastric injection (letrozole) group. Body weight and the estrous cycle were monitored during the modeling. Serum stress hormones and reproductive hormones were evaluated by ELISA. The uterus and ovaries were weighed, ovarian follicle counts were calculated, and AR, LHR, FSHR, and AMH expression were assessed by immunohistochemistry. Results In both model group subjected to the 30-day protocol of DHEA or letrozole, the mean body weights were significantly increased. Rats from both model group exhibited a significant increase of the mean length of the diestrous phase of the estrous cycle, the DHEA group had a longer diestrous phase. There was also a significant increase of serum T, E2, LH, insulin, and a significant decrease of AMH in both model group. There was a significant decrease of ovarian weight, P, and serum FSH, and a significant increase of uterus weight, serum LH/FSH in DHEA model group. There was no significant difference in serum P, FSH, and LH/FSH in letrozole model group. Both two model groups showed significantly higher AR, LHR, and AMH protein expression in rats’ ovaries. FSHR protein expression in DHEA group was lower, and in letrozole model group was not different. Conclusion Compared with letrozole intragastric injection group, the pathological characteristics of DHEA subcutaneous injection group rats were closer to the characteristics of PCOS.

Comparative study of piroxicam and nitroglycerin on prostaglandin-modulated blood and electrolyte indices during di-estrous in female Wistar Rats.

Endogenous prostaglandins are involved in hemostasis, renal excretion of electrolytes, and implicated in dysmenorrhea. Piroxicam and Nitroglycerin are common drugs used in treating dysmenorrhea by inhibiting the cyclooxygenase pathway involved in prostaglandin production. However, studies comparing the effects of these drugs on prostaglandin-modulated hemostasis and renal function are lacking. Fifteen female rats (120-160g) were divided into 3 groups (20 per group), namely Control (distilled water, 0.3 mL), Piroxicam treated (3mg/kg) and Nitroglycerin treated (1 mg/kg). Di-estrous phase was confirmed in animals in each group using the Pipette smear method. Treatment was administered for 4 days covering the estrous cycle. Bleeding and clotting time were assessed and blood concentrations of sodium, potassium, urea and platelet counts were evaluated in all phases. Data were analyzed using one-way ANOVA and Newman-Keuls post-hoc test. Statistical significance was considered at p<0.0. The nitroglycerin-treated group showed significant increases in blood potassium during di-estrous while the piroxicam-treated group showed significant increases in blood potassium, urea and clotting time with a significant decrease in sodium levels during di-estrous compared to controls. Results obtained in other phases were not significant compared to controls. The study showed that Nitroglycerin produces minimum alteration of blood and electrolyte indices compared to piroxicam during di-estrous.

Effect of Methotrexate on Reproductive Function in Female Wistar Rats

This study was designed to investigate the effect of methotrexate on reproductive function in female Wistar rats. Eighteen female rats (120 – 160 g) were used for the estrous cycle and histopathological studies. Methotrexate (0.071 mg/kg) was administered orally on daily basis for 21 and 50 days respectively for the estrous cycle and histological studies. Estrous cycle was carried out using the technique of Marcondes et al., histologies of the ovaries and uteri were also carried out. Data were analysed using descriptive statistics and student’s t-test at p=0.05. Treatment of rats for 21 days with methotrexate (0.071 mg/kg) produced significant (p&lt;0.05) reductions in the proestrous and estrous phase of the estrous cycle as well as significant (p&lt;0.05) increments in the metestrous and diestrous phases of the estrous cycle relative to their respective controls. The histopathological study revealed that treatment of rats with methotrexate (0.071 mg/kg) for 50 days presented with ovarian medullary part that is congested and oedematous as well as with multiple foci of hemorrhage within the endometria. It can therefore be concluded that that methotrexate probably has dominant pro-fertility effect, but also probably induced deleterious effects on the ovaries and uteri in female Wistar rats.

Haemodynamic changes in uterine artery in pregnant, nonpregnant and pyometra affected bitches

Ten no. of non-pregnant bitches in diestrous phase (control group /Group I) were selected along with 120 nos of pregnant bitches (Group II) and 10 nos of bitches showing symptoms of pyometra (Group III) were selected for study of haemodynamics parameters of uterine artery. In pregnant healthy bitches the indices (PSV and EDV) of uterine artery increased progressively with the evolution of pregnancy. RI values found in case of normal dioestrus and pregnant bitches were higher than that of pyometric group bitches. The mean systolic peak velocity in canine uterine artery of nonpregnant dioestrus bitches was 20 cm/s. RI values were ranging between1 - 1.52 (mean of RI =1.280). There is significant difference in the haemodynamic parameters between pregnant and non pregnant animal. PSV and EDV of pregnant animal is comparatively higher than non pregnant dioestrus bitches, but RI value of NP bitches were higher than pregnant bitches and PI values were almost zero. Normal dioestrus and pregnant bitches showed lower blood flow velocities and higher hemodynamic indices when compared to pyometra groups. The blood flow in the uterine artery increases significantly during pyometra and pregnancy which can be used as an important parameter for evaluation of reproductive functionality of bitches.

Pyometra in bitches: A haematological, biochemical and ultrasonographical study

Ten no. of non-pregnant bitches in diestrous phase (control group /Group I) and 10 nos of bitches showing symptoms of pyometra (Group II) were selected for study of haematological, biochemical and haemodynamics parameters. A highly significant difference (P

Alterations of estrous cycle, 3\u03b2 hydroxysteroid dehydrogenase activity and progesterone synthesis in female rats after exposure to hypobaric hypoxia

The underlying mechanism regulating hypoxia induced alteration in female steroid hormones is first time explored in this study. To understand the mechanistic approach, female Sprague- Dawley rats were exposed to acute and chronic hypobaric hypoxia (282 mm-Hg, ~7620 m, 6 hours, 3 and 7 days). Estrous cycle, body weight, plasma progesterone and estradiol levels, morphology, histology and two key steroidogenic enzymes: 3ß hydroxysteroid dehydrogenase (HSD) and 17ß HSD activity of ovary and adrenal gland were studied. A persistent diestrous phase and a significant decrease in body weight were found in chronic hypoxia groups. Histological study suggested degenerative changes in ovarian corpus luteum of 7 days chronic hypobaric hypoxia (7CHH) group and a declined percentage of adrenocortical cells in 3 days chronic hypobaric hypoxia (3CHH) and 7CHH groups. Plasma estradiol level was unaltered, but progesterone level was decreased significantly in all hypoxic groups. Ovarian 3ß HSD activity was decreased significantly with increasing days of hypoxic treatment along with a significantly low adrenal 3ß HSD activity in 7CHH. In conclusion, hypobaric hypoxia causes a state of low circulatory progesterone level in females likely due to the degenerative changes in the female ovarian and adrenal tissues together with low steroidogenic 3ß HSD enzyme activity.

OR06-1 Melanocortins Act on Kiss1 Neurons to Regulate Reproduction in Females

Reproduction, controlled by the excitatory action of the neuropeptide kisspeptin, is an energy costly function for the organism and, therefore, it is tightly regulated by metabolic factors. Among those, hypothalamic melanocortins are essential in the control of metabolism. Inactivating mutations in the proopiomelanocortin (Pomc) gene or melanocortin receptor 4 (Mc4r) cause severe obesity and subfertility in humans and mice. However, whether the reproductive impairment is a direct consequence of the lack of melanocortin signaling, or indirect resulting from the obesity phenotype, remains unknown. α-MSH (derived from Pomc) stimulates LH release and this action has been shown to be mediated by Kiss1 neurons. We evaluated the expression of Mc4r in Kiss1 neurons, and using dual fluorescence in situ hybridization (RNAscope), we showed that Kiss1 neurons of the arcuate nucleus (Kiss1ARC) and the anteroventral periventricular/periventricular nucleus (Kiss1AVPV/PeN) express Mc4r. Mc4r colocalized with 84% of Kiss1ARC and with 74% of Kiss1AVPV/PeN, suggesting that Kiss1 neurons are a direct target of melanocortins. In order to evaluate the involvement of Kiss1 neurons in the reproductive role of melanocortins, we ablated Mc4r specifically from Kiss1 neurons by generating a specific Kiss1-Mc4rKO (Kiss1-cre+/Mc4r-lox+/+) mouse line. We found that Kiss1-Mc4rKO females exhibit disrupted estrous cycles with prolonged diestrous phases and delayed puberty onset compared to their control littermates, without developing obesity during the time of the study. The reproductive phenotype of Kiss1-Mc4rKO males was not affected. When central injections of an Mc4r selective agonist were performed on Kiss1-Mc4rKO intact males and their control littermates, LH levels were significantly increased to the same extend in both groups at 15 min post-injections, suggesting that, in the male, α-MSH controls LH levels through a Kiss1 neuron independent mechanism. Taken together, these results support a direct role of melanocortins on Kiss1 neurons in the control of GnRH release in female mice. Overall, understanding the neuroendocrine mechanisms underlying the metabolic regulation of reproduction will help improve the fertility rates in patients affected by metabolic disturbances. Keywords: Kisspeptin, α-MSH, Melanocortins, Mc4r, Reproduction

Abstract 096: Progesterone Upregulates Endothelial Mineralocorticoid Receptor Expression Which Predisposes Female Mice to Obesity-Induced Endothelial Dysfunction

Compelling evidence indicates a higher efficacy of mineralocorticoid receptor (MR) blockade for the treatment of cardiovascular disease in females with obesity and diabetes than in males, however, the origin of this sex-specific effect is unknown. We have shown that leptin induces endothelial dysfunction in obese female mice via aldosterone-dependent activation of MR and that only female mice develop endothelial dysfunction (vasorelaxation to acetylcholine) in response to aldosterone ex vivo . Therefore, we hypothesized that females express higher endothelial MR (ECMR) expression than males which predisposes females to obesity-associated endothelial dysfunction. RT-PCR analysis in isolated aortic endothelial cells of Balb/C mice revealed a higher NR3C2 (MR gene) expression in females compared to males (2.9±0.5-fold from male, P&lt;0.05), however, no such difference was observed in non-endothelial cells. Similarly, human adipose tissue endothelial cells exhibited higher ECMR mRNA expression than males (2.1±0.1 fold from male). Female sex-hormone suppression (ovariectomy) decreased ECMR expression in female mice (-0.8±0.2-fold from sham), which was restored by progesterone supplementation (-0.1±0.1-fold from sham). NR3C2 mRNA gradually increased with progesterone in diestrous (1.6±0.1-fold from estrous) phase and increased further in pregnancy day 16 (9.2±0.2-fold from estrous). Furthermore, progesterone dose-dependently increased ECMR protein expression in human endothelial cells in vitro (P&lt;0.05). Increases in ECMR associated with higher progesterone levels in diestrus and pregnant females were associated with an increased sensitivity to leptin-induced endothelial dysfunction in mice. In parallel, while leptin induced endothelial dysfunction in intact ECMR female mice (P&lt;0.05), specific deletion of MR in endothelial cells protected female mice from leptin-induced endothelial dysfunction. These data indicate that progesterone drives the sex-difference in the levels of ECMR expression and predisposes female mice to leptin-induced endothelial dysfunction. In addition, these data provide a rational for the higher efficacy of MR blockade in obese and diabetic women suffering from cardiovascular disease.

Abstract P6-07-09: Attenuation of progesterone driven mammary stem cell expansion by telapristone acetate

Abstract Purpose: The interplay of the ovarian hormones estradiol (E2) and progesterone (P4) contributes to the development of breast cancer, potentially aided by P4-induced expansion in mammary stem cells as observed in diestrous phase in mice, as well as the luteal phase and during pregnancy in women. Telapristone Acetate (TPA), a selective progesterone receptor modulator (SPRM), exhibits a protective effect against mammary carcinogenesis in rodents. TPA has been shown to display a more specific PR blockade and less toxicity when compared to RU486. We have examined the mammary stem cell pool expansion upon exposure to E2+P4 in mice and compared its attenuation by both TPA and RU486. Methods: 8 week old female ovariectomized FVB mice weighing above 20g, were randomized into 4 treatment groups: sham (skin incision only, no pellets), E2+P4, E2+P4+Telapristone Acetate (TPA), E2P4+ Mifepristone (RU486). Eight experimental replicates were performed. At age 10 weeks, the mice were implanted with subcutaneous 30-day release pellets of E2 and P4 (0.3 mg E2 &amp; 30.0 mg P4), E2P4+TPA (30.0 mg) and E2P4+RU486 (30.3 mg) in either flank. The mice were euthanized at day 15 of treatment. Single cell suspensions of the 4th inguinal mammary gland pair and one thoracic gland were prepared and labeled with cell surface markers. Lineage negative mammary gland cells were sorted into luminal and basal population subsets. The basal cell niche was identified as CD24+CD49fhi, the mammary stem cells (MaSC) within this niche are identified by CD61+CD49fhi. The cells were sorted on BD FACSAria 5-Laser and the data was analyzed using BD FACSDIVA.The D'Agostino-Pearson test was performed to determine the normal distribution and once normal distribution was confirmed one-way ANOVA (repeated measures) was performed to examine differences in percent cell populations with Tukey test for post-hoc analysis. Results: The mammary stem cells (MaSC, CD61+CD49fhi) within the basal cell (CD24+CD49fhi) niche showed significant expansion at day 15 in mice implanted with Estrogen and Progesterone 30-day release pellet compared to sham (64.2%, 45.07% respectively; p=0.0392). This expansion was significantly attenuated in both TPA (-38.21%, p=0.011) and RU486 (-34.30%, p=0.002) treated mice compared to MaSC in mice treated with E2+P4 alone (+45.07%). Simultaneously, luminal progenitor cells (CD61+CD49flo) show a marked reduction in E2+P4 treated mice compared to sham (17.77%, 45.54%, respectively; p=0.0375). Luminal mature cells (CD61-CD49flo) show an expansion in E2+P4 treated mice compared to sham (82.23%, 54.41% respectively; %, p=0.0371). TPA significantly (58.40 %, p=0.061) suppresses LM cells expansion observed in the E2+P4 group. TPA and RU486 show significant suppression of the MaSC population in mouse mammary gland compared to the EP-treated mice. Conclusion: TPA and RU486 alter the P4 driven changes in mammary gland cellular composition and in a manner consistent with the hypothesis that they will inhibit hormone-induced tumorigenesis in the mammary gland. To gain a better insight into this phenomenon, a high throughput transcriptomic profiling (RNASeq) of mammary stem cells isolated from the treatment groups is being performed. Citation Format: Ranjan M, Lee O, Sun L, Karavites L, Clare S, Khan SA. Attenuation of progesterone driven mammary stem cell expansion by telapristone acetate [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-07-09.

Action of the hydroethanolic extract of the flowers of Acmella oleracea (L.) R.K. Jansen on the reproductive performance of Wistar females rats: A popular female aphrodisiac from the Amazon

Ethnopharmacological relevanceThe species Acmella oleracea (L.) R.K. Jansen (Asteraceae), popularly known as jambú, is marketed in fairs as a female aphrodisiac and has several pharmacological activities already confirmed, among them the sexual stimulant action. The objective of this study was to evaluate the effects of the oral administration of the hydroethanolic extract of A. oleracea flowers (EHAo) on wistar rats during the pre-mating, mating, and pre-implantation period. Material and methodsDuring the treatment period, measurements of feed intake, water intake, weight, estrous cycle, behavior, reproductive parameters, biochemical parameters, hematological parameters, and histopathology of ovaries were performed daily. ResultsIn the gas chromatography analysis – mass spectrometry characterization, the compound (2E, 6Z, 8E)-N-isobutyldeca-2,6,8-trienamide (spilanthol) was detected as the majority compound at the 84% concentration. In the conditions of this study, EHAo did not cause maternal toxicity. However, in the estrous cycle, the frequency of the Proestrous (P) and Estrous (E) phase was significantly increased with the doses of 88.91 and 444.57mg/kg of the EHAo in relation to the control. On the other hand, the metaestrous (M) and diestrous (D) phases showed a significant reduction in their frequency in the groups treated with EHAo. Water intake increased significantly (p < 0.01), as well as the triglyceride levels, the total cholesterol and fractions (p < 0.05), and the percentage of neutrophils (p < 0.05). ConclusionIt is concluded, therefore, that the treatment with EHAo, which is one of the forms popularly used, is safe in the concentrations and time of treatment studied as it is able to influence the estrous cycle without altering folliculogenesis and fertility.

Effects of non-contingent cocaine on 3 alpha-androstanediol. II. Disruption of lordosis of proestrous rats

Drug use influences sexual behavior, performance, and can be associated with increased sexual risk-taking. Our prior results using an animal model indicate that progestogens contribute to hormonally-mediated changes in sexual behavior of female rodents during acute cocaine exposure. Androgens, such as testosterone, and its metabolite 3ɑ-androstanediol (3α-diol), and estradiol, are known to influence male sexual behavior, but can also alter the expression of sexual behavior of female rodents. As such, we investigated the influence of endogenous androgen and estradiol fluctuations on cocaine-mediated changes in motor behavior and sexual receptivity of rats during diestrous or proestrous phases of the estrous cycle. Female rats were administered saline or cocaine (5, 10, or 20mg/kg, i.p.). Motor behavior was observed in the first 30min following drug administration, and then sexual responding was assessed for 15min. Cocaine decreased aggressive behavior in response to attempted mounts by a male among non-receptive (diestrous) rats and inhibited sexual behavior among sexually receptive (proestrous) rats. Cocaine dose-dependently altered concentrations of testosterone metabolites (estradiol and 3α-diol), but not testosterone, which correlated to motor and sexual behaviors of diestrous and proestrous rats, respectively. These data suggest that actions of 3α-diol may be involved in female sexual and motor behavior in response to cocaine, in a cycle-dependent manner.

Estrogenic suppression of binge-like eating elicited by cyclic food restriction and frustrative-nonreward stress in female rats.

Because binge eating and emotional eating vary through the menstrual cycle in human females, we investigated cyclic changes in binge-like eating in female rats and their control by estrogens. Binge-like eating was elicited by three cycles of 4 days of food restriction and 4 days of free feeding followed by a single frustrative nonreward-stress episode (15 min visual and olfactory exposure to a familiar palatable food) immediately before presentation of the palatable food. Intact rats showed binge-like eating during the diestrous and proestrous phases of the ovarian cycle, but not during the estrous (periovulatory) phase. Ovariectomized (OVX) rats not treated with estradiol (E2) displayed binge-like eating, whereas E2-treated OVX rats did not. The procedure did not increase signs of anxiety in an open-field test. OVX rats not treated with E2 that were subjected to food restriction and sacrificed immediately after frustrative nonreward had increased numbers of cells expressing phosphorylated extracellular signal-regulated kinases (ERK) in the central nucleus of the amygdala (CeA), paraventricular nucleus of hypothalamus (PVN), and dorsal and ventral bed nuclei of the stria terminalis (BNST) compared with nonrestricted or E2-treated rats. These data suggest that this female rat model is appropriate for mechanistic studies of some aspects of menstrual-cycle effects on emotional and binge eating in human females, that anxiety is not a sufficient cause of binge-like eating, and that the PVN, CeA, and BNST may contribute to information processing underlying binge-like eating.

Impact of Sexual Deprivation on Sexual Behavior and Some Reproductive-Endocrinal Functions in Albino Rats

Objective: To study the effect of stress on the sexual behavior and its pathophysiological effects on some reproductive and endocrine functions in albino rats.Methods: One hundred and twenty albino rats were included and divided into a control groupand three experimental sub-groups, which were subjected to sexual stress. Female rats were investigated for the cytological changes in the phases of the estrous cycle. All rats were observed for behavioral changes throughout the experiment. Histopathological examination of the thyroid, testes and ovaries and the assessment of thyroid and gonadal hormones in the sera of control and experimental rats were performed.Results: Cytological examination revealed stopped estrous cycle in the diestrous phase in all female rats. Thyroid hormones revealed a decrease in the levels of triiodothyronine and thyroxin; however, non-significant changes were detected in the thyroid-stimulating hormone level in experimental rats compared to the controls. Gonadal hormones revealed a great discrepancy in their levels among both sexes.Conclusions: The results of the present study show that sexual excitation is one of the stressful factors affecting sexual behavior, hypothalamic-pituitary-thyroid and hypothalamic-pituitary-gonadal axes as well as sex organs with secretory functions. Therefore, it is considered as a socio-pathological factor that needs more specific studies to further clarify its effects.

Prenatal Exposure of Kisspeptin Antagonist on the GonadotropinReleasing Hormone (GnRH) Expression in Rat Model of Polycystic Ovary Syndrome

Introduction: Polycystic ovary syndrome (PCOS) is one of the most common endocrine disorders in women of reproductive age. Increased GnRH/luteinizing hormone (LH) pulse frequency is a characteristic of endocrine abnormalities in PCOS. Kisspeptin antagonists reduce LH pulse frequency and amplitude and are hence supposed to slow GnRH neuron activity that may adjust GnRH/LH levels in PCOS conditions.Objective: To investigate the impact of kisspeptin antagonist P271 administration during prenatal life to reduce GnRH expression in adulthood in prenatally androgenized (PNA) rats as a model of PCOS.Materials and methods: PNA rats (n=9) and controls (n=9) received P271 on day 20 of their prenatal life, and they were examined in adulthood (110-120 days). The ability of P271 to alter GnRH mRNA expression, and plasma levels of gonadotropins and steroid hormones were tested using reverse transcription q-Real-time PCR and ELISA methods, respectively.Results: In this study, based on the result of Generalized Estimating Equation (GEE) model, we found that GnRH expression in PCOS+P271 rats decreased compared to PCOS rats in the diestrous phase. In addition, P271 administration reduced gonadal steroid and gonadotropin levels in both PCOS and non-PCOS rats.Conclusion: In conclusion prenatal administration of kisspeptin antagonists can reduce GnRH expression and LH, FSH, T, P4 and E2 levels in PCOS rats in later life.

Soy isoflavones exert beneficial effects on letrozole-induced rat polycystic ovary syndrome (PCOS) model through anti-androgenic mechanism

Context: Soy is the main source of phytoestrogens, which has long been used as traditional food. One major subtype of phytoestrogens includes isoflavones and they are scientifically validated for their beneficial actions on many hormone-dependent conditions. Objective: The present study examines the effect of soy isoflavones on letrozole-induced polycystic ovary syndrome (PCOS) rat model. Materials and methods: PCOS was induced in Sprague–Dawley rats with of 1 mg/kg letrozole, p.o. once daily for 21 consecutive days. Soy isoflavones (50 and 100 mg/kg) was administered for 14 days after PCOS induction. Physical parameters (body weight, oestrous cycle determination, ovary and uterus weight) metabolic parameters (oral glucose tolerance test, total cholesterol), steroidal hormone profile (testosterone and 17β-oestradiol), steroidogenic enzymes (3β-hydroxy steroid dehydrogenase (HSD) and 17β-HSD), oxidative stress and histopathology of ovary were studied. Results: Soy isoflavones (100 mg/kg) treatment significantly altered the letrozole-induced PCOS symptoms as observed by decreased body weight gain (p < 0.05), percentage diestrous phase (p < 0.001), testosterone (p < 0.001), 3β-HSD (p < 0.01) and 17β-HSD (p < 0.001) enzyme activity and oxidative stress. Histological results reveal that soy isoflavones treatment in PCOS rats resulted in well-developed antral follicles and normal granulosa cell layer in rat ovary. Discussion: Treatment with soy isoflavones exerts beneficial effects in PCOS rats (with decreased aromatase activity) which might be due to their ability to decrease testosterone concentration in the peripheral blood. Conclusion: Analysis of physical, biochemical and histological evidences shows that soy isoflavones may be beneficial in PCOS.

Impact of Sexual Deprivation on Sexual Behavior and Some Reproductive-Endocrinal Functions in Albino Rats

Objective: To study the effect of stress on the sexual behavior and its pathophysiological effects on some reproductive and endocrine functions in albino rats.Methods: One hundred and twenty albino rats were included and divided into a control groupand three experimental sub-groups, which were subjected to sexual stress. Female rats were investigated for the cytological changes in the phases of the estrous cycle. All rats were observed for behavioral changes throughout the experiment. Histopathological examination of the thyroid, testes and ovaries and the assessment of thyroid and gonadal hormones in the sera of control and experimental rats were performed.Results: Cytological examination revealed stopped estrous cycle in the diestrous phase in all female rats. Thyroid hormones revealed a decrease in the levels of triiodothyronine and thyroxin; however, non-significant changes were detected in the thyroid-stimulating hormone level in experimental rats compared to the controls. Gonadal hormones revealed a great discrepancy in their levels among both sexes.Conclusions: The results of the present study show that sexual excitation is one of the stressful factors affecting sexual behavior, hypothalamic-pituitary-thyroid and hypothalamic-pituitary-gonadal axes as well as sex organs with secretory functions. Therefore, it is considered as a socio-pathological factor that needs more specific studies to further clarify its effects.

AMPKα2 in Kiss1 Neurons Is Required for Reproductive Adaptations to Acute Metabolic Challenges in Adult Female Mice.

A temporary and reversible inhibition of the hypothalamo-pituitary-gonadal axis is adaptive when energy reserves are diminished, allowing individual survival and energy accumulation for eventual reproduction. The AMP-activated protein kinase (AMPK) works as a cellular sensor of the AMP to ATP ratio and ultimately of energy availability. Activation of AMPK suppresses ATP-consuming processes and stimulates ATP-producing pathways. The AMPK α2 catalytic subunit is expressed in multiple hypothalamic nuclei including those associated with reproductive control, ie, the anteroventral periventricular nucleus and the arcuate nucleus. Subsets of kisspeptin neurons in the anteroventral periventricular nucleus (20% in females) and arcuate nucleus (45% in males and 65% in females) coexpress AMPKα2 mRNA. Using the Cre-loxP approach, we assessed whether AMPKα2 in Kiss1 cells is required for body weight and reproductive function. The AMPKα2-deleted mice show no difference in body weight and time for sexual maturation compared with controls. Males and females are fertile and have normal litter size. The AMPKα2-deleted and control females have similar estradiol feedback responses and show no difference in Kiss1 mRNA expression after ovariectomy or ovariectomy plus estradiol replacement. In males, acute fasting decreased Kiss1 mRNA expression in both groups, but no effect was observed in females. However, after an acute fasting, control mice displayed prolonged diestrous phase, but AMPKα2-deleted females showed no disruption of estrous cycles. Our findings demonstrate that the AMPKα2 catalytic subunit in Kiss1 cells is dispensable for body weight and reproductive function in mice but is necessary for the reproductive adaptations to conditions of acute metabolic distress.

EFFECT OF MUSIC AND NOISE ON GROWTH AND MATURATION IN FEMALE ALBINO RAT

Background:Noise stress is implicated in various illnesses of human, and it is responsible for increased morbidity associated with modern life style. Music induces emotions which are often accompanied by physiological reactions. Objective:Investigating the effect of light music and noise on growth and maturation from weaning to puberty in female rat with studying the histological structuresof pituitary, thyroid and ovaries. Material and Methods:Fifty animals were used in this work and divided into five equal groups: ● Control group. ● Rats exposed to noise for 60 days (over 90db, 1h/day). ● Rats exposed to music for 60 days (1h/day). ● Rats exposed to music then noise for 60days (2h/ day). ● Rats exposed to noise then music for 60days (2h/ day). At the end of experiment, serum was obtained from the rats during the di-estrous phase for determination of: 1. Growth hormone. 2. TSH level. 3. Gonadotrophic hormones (FSH, LH). 4. Prolactin hormone. 5. Leptin hormone. Histopathological study for pituitary, thyroid and ovaries were done. Results: This study revealed that noise caused significant decrease in gonadotrophic hormones (LH, FSH) and TSH, with significant increase in serum leptin without any changes in both growth and prolactin hormones. In addition, it produced significant pathological changes in pituitary, thyroid, ovaries and uterus. These changes included congested dilated blood sinusoids and loss of normal cellular arrangement. On the other hand, music caused insignificant changes in gonadotrophic hormones (LH, FSH) and TSH levels, with significant increase in leptin hormone without any changes in both growth and prolactin hormones levels. In addition, it produced insignificant pathological changes in pituitary, thyroid and ovaries as compared with the control group. Conclusions: Exposure to noise stress could affect the process of reproduction but does not affect the process of growth. In addition, listening to light music does not disturb the process of reproduction or growth. Where there was an equilibrium in biochemical and histological results.