Polycystic ovary rat model exposure to 150 kHz intermediate frequency: hypothalamic-pituitary-ovarian axis at the receptor, cellular, tissue, and hormone levels.

INTRODUCTION: The hypothalamic-pituitary-ovarian (HPO) axis is the principal regulator of the reproductive system. The neurons in the arcuate nucleus of the hypothalamus signal the basophilic cells of the anterior pituitary to release luteinizing hormone (LH) and follicle stimulating hormone (FSH), which bind to the granulosa and theca cells of a follicle in the ovary to promote healthy follicular development. Disruption of this process at any time can lead to polycystic ovaries and, if left untreated, can lead to Polycystic Ovarian Syndrome (PCOS), one of the leading causes of infertility. A novel treatment option using 150 kHz Intermediate Frequency (IF) Electromagnetic Radiation (EMR) has been proposed to monitor the effect of this frequency during cystic development. METHODS: To prove this, an experiment was conducted to study the effect of whole-body exposure to 150 kHz EMR for 8 weeks at receptor, cellular, tissue and hormonal levels on the HPO axis of 25 young cyclic female rats. RESULTS: The results showed that 150 kHz EMR did not affect the histoarchitecture of neurons of arcuate nucleus of the hypothalamus of PCO-induced rats. It was also found that the number of basophilic cells of the pituitary gland was increased and the immunoreactivity of LH and FSH secretion increased. This EMR field also decreased the development of follicular cysts in the ovary and possibly increased the immunoreactivity of the LH and FSH receptors as well on the theca and granulosa cells of follicles in the ovary. CONCLUSION: There are still many limitations to this study. If properly evaluated, the results of this experiment could help develop a new non-invasive treatment option for women with PCOS in the near future.

Progesterone dose during synchronization treatment alters luteinizing hormone receptor and steroidogenic enzyme mRNA abundances in granulosa cells of Nellore heifers.

The objective was to investigate effects of progesterone (P4) dose on abundance of luteinizing hormone receptor (LHCGR), aromatase (CYP19A1), 3ß-hydroxysteroid dehydrogenase (HSD3B1), and other steroidogenic mRNA transcripts in granulosa cells from dominant follicles. Nellore heifers were assigned to one of six groups: new, first-use controlled internal drug release device (CIDR1) inserted for 5 days (Large-P4-dose-D5; n = 7) or 6 days (Large-P4-dose-D6; n = 8), prostaglandin (PG)F2α administered on D0 and 1 previously-used CIDR (CIDR3) inserted for 5 days (Small- P4-dose-D5; n = 8) or 6 days (Small-P4-dose-D6; n = 8), CIDR1 inserted on D0 and removed plus PGF2α on D5 (Large-P4-dose-proestrus (PE); n = 7), and CIDR3 and PGF2α on D0 and 1, CIDR3 removed plus PGF2α on D5 (Small-P4-dose-PE; n = 7). Duration of P4 treatment (D5 compared to D6) affected abundances of CYP19A1 mRNA transcripts, with there being greater abundances on D6 than D5 (P ≤ 0.05). Heifers treated with the large dose of P4 had a smaller dominant follicle, less serum and intra-follicular estradiol (E2) concentrations (P ≤ 0.05) and lesser LHCGR, CYP19A1, and HSD3B1 transcript abundances (P ≤ 0.05). Heifers treated to induce PE had a larger follicle diameter (P = 0.09), greater intra-follicular E2 concentrations and larger abundances of CYP19A1 mRNA transcript (P ≤ 0.05) than heifers of the D6 group. Overall, treatment with larger doses of P4 resulted in lesser abundances of LHCGR, HSD3B1, and CYP19A1 mRNA transcripts; thus, potentially leading to development of smaller dominant follicles and lesser E2 concentrations.

Nitrophenols suppress steroidogenesis in prehierarchical chicken ovarian follicles by targeting STAR, HSD3B1, and CYP19A1 and downregulating LH and estrogen receptor expression.

To assess the effects of 4-nitrophenol (PNP) and 3-methyl-4-nitrophenol (PNMC) on steroidogenesis in the chicken ovary, white (WF, 1-4 mm) and yellowish (YF, 4-8 mm) prehierarchical follicles were incubated in a medium supplemented with PNP or PNMC (10-8-10-4 M), ovine LH (oLH; 10 ng/mL), and combinations of oLH with PNP or PNMC (10-6 M). Testosterone (T) and estradiol (E2) concentrations in media and mRNA expression for steroidogenic proteins (STAR, HSD3B1, and CYP19A1), and LH receptors (LHR), estrogen receptor α (ESR1) and ß (ESR2) in follicles were determined by RIA and real-time qPCR, respectively. PNP and PNMC decreased T and E2 secretion by the WF and YF, and oLH-stimulated T secretion from these follicles. PNP decreased basal STAR and HSD3B1 mRNA levels both in the WF and YF, and CYP19A1 mRNAs in the WF. PNP reduced oLH-affected mRNA expression of these genes in the YF. PNMC inhibited basal STAR, HSD3B1, and CYP19A1 mRNA expression in the WF, but not in the YF. PNMC reduced oLH-stimulated STAR and CYP19A1 expression in the YF and WF, respectively. PNP decreased basal mRNA expression of LHR, ESR1, and ESR2 in the WF, but it increased ESR1 and ESR2 mRNA levels in the YF. PNMC reduced both basal and oLH-affected LHR, ESR1, and ESR2 mRNA expression in the WF; however, it did not influence expression of these genes in the YF. We suggest that nitrophenols by influencing sex steroid synthesis and transcription of LH and estrogen receptors in prehierarchical ovarian follicles may impair their development and selection to the preovulatory hierarchy.

Estrogenic properties of genistein acting on FSHR and LHR in rats with PCOS.

The purpose of the study was to study the activity of the phytoestrogen genistein (GEN) act- ing on FSHR and LHR in rat ovaries with polycystic ovary syndrome (PCOS). Sixty rats were di- vided into six groups. Rats in the dose group received genistein at a concentration of either 5 (low genistein dose group, L-gen), 10 (middle genistein dose group, M-Gen) or 20 (high genistein dose group, H-Gen) mg per kg of body weight per day. Estrogen group (EG, received 0.5 mg/kg Dieth- ylstilbestrol). Concentration of sex hormones in serum was quantified by enzyme-linked immuno- sorbent assay (ELISA). Expressions of follicle-stimulating hormone receptor (FSHR) and lutein- izing hormone receptor (LHR) protein were determined by immunohistochemistry. Treatment with genistein resulted in a strong stimulation of the concentration of sex hormone in serum. The concentration of progesterone and FSH was significantly higher in H-Gen when compared to the PCOS model control group (MG) (P ⟨ 0.01). In contrast, the concentration of testosterone, LH and the ratio of LH/FSH decreased in GEN treatment groups compared to MG, the effect was statistically significant, tested by the ANOVA test (p⟨0.01). For hormone receptor activity, treat- ment with genistein resulted in an improvement of ovarian function with LHR protein expression being enhanced and FSHR protein expression being suppressed. Our results demonstrate that Genistein played a significant role in regulating FSH and LH receptor expression to improve perimenopausal ovarian and uterine function.

Effect of melatonin on regulation of apoptosis and steroidogenesis in cultured buffalo granulosa cells.

This study was aimed to address melatonin receptor expression, mRNA level of hypothalamus and hypophysis hormone receptors (GnRHR, FSHR, and LHR), steroidogenesis, cell cycle, apoptosis, and their regulatory factors after addition of melatonin for 24 hr in cultured buffalo granulosa cells (GCs). The results revealed that direct addition of different concentrations of melatonin (100 pM, 1 nM, and 100 nM) resulted in significant upregulation (p < 0.05) of mRNA level of melatonin receptor 1a (MT1) without affecting melatonin receptor 1b (MT2). Melatonin treatment significantly downregulated (p < 0.05) mRNA level of FSH and GnRH receptors, whereas 100 nM dose of melatonin significantly increased mRNA level of LH receptor. Treatment with 100 nM of melatonin significantly decreased the basal progesterone production with significant decrease (p < 0.05) in mRNA levels of StAR and p450ssc, and lower mRNA level of genes (Insig1, Lipe, and Scrab1) that affect cholesterol availability. Melatonin supplementation suppressed apoptosis (100 nM, p < 0.05) and enhanced G2/M phase (1 nM, 100 nM, p < 0.05) of cell cycle progression which was further corroborated by decrease in protein expression of caspase-3, p21, and p27 and increase in bcl2. Our results demonstrate that melatonin regulates gonadotrophin receptors and ovarian steroidogenesis through MT1. Furthermore, the notion of its incorporation in apoptosis and proliferation of buffalo GCs extends its role in buffalo ovaries.

Impact of Cold Exposure on the Reproductive Function in Female Rats.

Female reproductive system diseases caused by exposure to a cold environment are widely considered as important human health challenges. Although the projection of female reproduction in cold temperature has been studied, a holistic view on the probable effects of cold exposure on the functions of the female reproductive system has not been achieved. Our aim was to evaluate the effects of cold exposure to the functions of the ovary and uterus in female rats. For this purpose, female rats were randomly grouped as follows: (1) the cold group was exposed to -10°C, 4 h per day for 2 weeks, and (2) the normal temperature (23 ± 1°C) group was used as control. Alterations were observed in different parameters, including body weight gain, organ coefficients, estrus cycle, and pathology of the cold-exposed female rats. Similarly, the serum reproductive hormones and mRNA expression were evaluated. Cold exposure induced estrus cycle irregularity and some alterations in the morphology of the ovary. Cold exposure impairs the function of the ovary probably by changing the level of serum LH and increasing LHR expression. Cold exposure induced a significant reduction of uterine epithelium height. Cold exposure causes alterations in the morphology of the uterus probably because of the effect of progesterone, the increase in the PR level, and the decrease in the ER level.

Systemic adiponectin treatment reverses polycystic ovary syndrome-like features in an animal model.

The present study examined the efficacy of adiponectin for regulating the reproductive, metabolic and fertility status of mice with polycystic ovary syndrome (PCOS). PCOS was induced in prepubertal (21- to 22-day-old) mice using dehydroepiandrosterone (6mg 100g-1day-1 for 25days), after which mice were administered either a low or high dose of adiponectin (5 or 15µgmL-1, s.c., respectively). PCOS mice exhibited typical features, including the presence of numerous cystic follicles, increased circulating androgens, increased body mass, altered steroidogenesis, decreased insulin receptor expression and increased serum triglycerides, serum glucose, Toll-like receptor (TLR)-4 (a marker of inflammation) and vascular endothelial growth factor (VEGF; a marker of angiogenesis). These parameters were significantly correlated with a reduction in adiponectin in PCOS mice compared with vehicle-treated control mice. Exogenous adiponectin treatment of PCOS mice restored body mass and circulating androgen, triglyceride and glucose levels. Adiponectin also restored ovarian expression of steroidogenic markers (LH receptors, steroidogenic acute regulatory protein and 3ß-hydroxysteroid dehydrogenase), insulin receptor, TLR-4 and VEGF levels in control mice. Adiponectin restored ovulation in PCOS mice, as indicated by the presence of a corpus luteum and attainment of pregnancy. These findings suggest that adiponectin effectively facilitates fertility in anovulatory PCOS. We hypothesise that systemic adiponectin treatment may be a promising therapeutic strategy for the management of PCOS.

Omega-3 polyunsaturated fatty acid docosahexaenoic acid and its role in exhaustive-exercise-induced changes in female rat ovulatory cycle.

Exhaustive exercises can cause delayed menarche or menstrual cycle irregularities in females. Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) are incorporated into a wide range of benefits in many physiological systems. Our work aimed to assess the role of ω-3 PUFA docosahexaenoic acid (DHA) on the deleterious effects of exhaustive exercise on the female reproductive system in rats. Virgin female rats were randomly divided into 4 groups (12 rats in each): control group, omega-3 group treated with DHA, exhaustive exercise group, and exhaustive exercised rats treated with DHA. Omega-3 was given orally to the rats once daily for 4 estrous cycles. Exhaustive exercises revealed lower levels in progesterone and gonadotropins together with histopathological decrease in number of growing follicles and corpora lutea. Moreover, the exercised rats showed low levels of ovarian antioxidants with high level of caspase-3 and plasma cortisol level that lead to disruption of hypothalamic-pituitary-gonadal axis. ω-3 PUFA DHA has beneficial effects on the number of newly growing follicles in both sedentary and exercised rats with decreasing the level of caspase-3 and increasing the antioxidant activity in ovaries. Exhaustive exercises can cause ovulatory problems in female rats that can be improved by ω-3 supplementation.

Feeding hydroalcoholic extract powder of Lepidium meyenii (maca) enhances testicular gene expression of 3ß-hydroxysteroid dehydrogenase in rats.

Although feeding diets containing the extract powder of Lepidium meyenii (maca), a plant growing in Peru's Central Andes, increases serum testosterone concentration associated with enhanced ability of testosterone production by Leydig cells in male rats, changes in testicular steroidogenesis-related factors by the maca treatment are not known. This study examined the effects of maca on testicular gene expressions for luteinizing hormone receptor, steroidogenic acute regulatory protein and steroidogenic enzymes. Eight-week-old male rats were given the diets with or without (control) the maca extract powder (2%) for 6 weeks, and mRNA levels were determined by reverse transcription quantitative real-time PCR. The results showed that the testicular mRNA level of HSD3B1 (3ß-hydroxysteroid dehydrogenase; 3ß-HSD) increased by the treatment, whereas the levels of the other factors examined did not change. These results suggest that increased expression of 3ß-HSD gene may be involved in the enhanced steroidogenic ability by the maca treatment in rat testes.

Protein and mRNA expression of follicle-stimulating hormone receptor and luteinizing hormone receptor during the oestrus in the yak (Bos grunniens).

Follicle-stimulating hormone (FSH) and luteinizing hormone (LH) have a central role in follicle growth, maturation and oestrus, but no clear pathway in the seasonal oestrus of yak (Bos grunniens) has been found. To better understand the role of FSH and LH in seasonal oestrus in the yak, six yaks were slaughtered while in oestrus, and the pineal gland, hypothalamus, pituitary gland, and gonads were collected. Using real-time PCR and immunohistochemical assays, we determined the mRNA and protein expression of the FSH and LH receptors (FSHR and LHR) in these organs. The analysis showed that the FSHR mRNA expression level was higher in the pituitary gland tissue compared with LHR (p < .01) during oestrus. By contrast, there was low expression of FSHR and LHR mRNA in the pineal gland and hypothalamus. FSHR mRNA expression was higher than that of LHR (p < .05) in the ovary, whereas LHR mRNA expression was higher than that of FSHR (p < .01) in the uterus. FSHR and LHR proteins were located in the pinealocyte, synaptic ribbon and synaptic spherules of the pineal gland and that FSH and LH interact via nerve fibres. In the hypothalamus, FSHR and LHR proteins were located in the magnocellular neurons and parvocellular neurons. FSHR and LHR proteins were localized in acidophilic cells and basophilic cells in the pituitary gland, and in surface epithelium, stromal cell and gland epithelium in the uterus. In the ovary, FSHR and LHR protein were present in the ovarian follicle. Thus, we concluded that FSHR and LHR are located in the pineal gland, hypothalamus, pituitary and gonad during oestrus in the yak. However, FSHR was mainly expressed in the pituitary gland and ovaries, whereas LHR was mainly expressed in the pituitary gland and uterus.

Analysis of gene expression in granulosa cells post-maturation to evaluate oocyte culture systems in the domestic cat.

Maturation of oocytes is a prerequisite for successful embryo development. The fertilization competence of in vivo derived oocytes is significantly higher than that of oocytes matured in vitro. Commonly evaluated morphological criteria for oocyte maturation do not reflect the complexity and quality of maturation processes. Oocytes and granulosa cells are communicating closely in a bidirectional way during follicular growth and maturation. Assessing the mRNA expression of specific genes in granulosa cells could be a non-invasive way to evaluate the conditions of in vitro oocyte maturation. The objective of this study was to elucidate the influence of two different FSH additives on the in vitro maturation rate and gene expression of cumulus-oocytes complexes in domestic cat. Feline oocytes were matured in a medium, supplemented with LH and 0.02 IU/ml porcine FSH versus 0.02 IU or 1.06 IU/ml human FSH. Granulosa cells were separated from oocytes directly after 24 hr of maturation or after additional 12 hr of in vitro fertilization. Gene expression levels were analysed by quantitative PCR for aromatase, antimullerian hormone, follicle stimulating hormone receptor (FSHR), luteinizing hormone/choriogonadotropin receptor (LHCGR) and prostaglandin E synthase. Neither oocyte maturation rate nor gene expression levels differed after 24 or 36 hr in all three groups. However, variations were discovered in correlations of expression levels, for instance for FSHR and LHCG, indicating differences in the fine-tuning of in vitro maturation processes under varying FSH supplementations. We suppose that correlation between gene expressions of selected genes suggests a superior maturation quality of feline oocytes.

Assessing reproductive toxicity and antioxidant enzymes on beta asarone induced male Wistar albino rats: In vivo and computational analysis.

AIM: Beta asarone is the major constituent of oil obtained from Acorus calamus, the Indian traditional medicine plant. Several studies have shown that beta asarone causes liver and cardiac damages but the reproductive toxicity is not well understood. The present study was initiated to investigate whether beta asarone has the potential to cause reproductive toxicity by inducing oxidative stress in the testis of male Wistar albino rats. MATERIALS AND METHODS: For this study, the animals were divided into six groups: Group I was treated with saline (normal saline), Group II with DMSO (vehicle control) and Group III with cisplatin (10mg/kgb.wt.). Group IV, V and VI animals were administrated at three dose levels of beta asarone 12.5, 25 and 50mg/kgb.wt. The treatment was carried out for 14days and animals were sacrificed on 29th day and processed for sperm analysis, hormone assay, histopathological, and antioxidant enzymatic assays. We also used molecular docking studies to predict the binding nature of beta asarone with luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR). KEY FINDINGS: Beta asarone administered at a dose of 50mg/kgb.wt. was responsible for inducing certain noticeable degenerative changes in histopathological analysis of the tissue. This was supported by altered sperm morphology and hormonal variations when compared to the control groups. Antioxidant enzyme levels were also found to be decreased. This was further validated by molecular docking studies. SIGNIFICANCE: The present study provides evidence that beta asarone administered at a dose of 50mg/kg b.wt. is capable enough in bringing about moderate amount of degenerative changes in rat testis and altered antioxidant status. Therefore provides a suitable evidence to prove that beta asarone causes reproductive toxicity.

Evaluation of luteinizing hormone regulation of maturation and apoptosis, expression of LHR and FSHR in cumulus-oocyte complexes in Lanzhou fat-tailed sheep.

The present study aimed to assess LH effects on in vitro maturation (IVM) and apoptosis and also to explore the gene expressions of LHR and FSHR in cumulus-oocyte complexes (COCs) of the sheep. COCs were in vitro matured 24h in the IVM medium supplemented with varying concentrations of LH (0, 5, 10, 20 and 30 µg/mL). They were allocated into LH-1 (control group), LH-2, LH-3, LH-4 and LH-5 groups, respectively. FSH (10 IU/mL) addition was as a positive control (FSH group). COCs apoptosis was assessed by TUNEL. The qPCR and Western blotting were utilized to detect mRNA and protein expressions of FSHR and LHR, respectively. The results showed maturation rates of oocytes improved as LH concentration increased from 0 to 10 µg/mL (IU/mL), reaching a peak value of 44.3% in the LH-3 group. Maturation rate of LH-5 group was lower than that of LH-3 and FSH-treated groups. The lowest apoptosis rate was found in LH-3 group. The germinal vesicle break down (GVBD) rates of LH-2, LH-3 and LH-4 groups were also increased in comparison with that found in LH-1 group (control group). GVBD rate of LH-5 was lower than that in LH-3 group. The germinal vesicle (GV) rates in LH-3 and LH-4 groups were lower than those in LH-1 and LH-5 groups (p<0.05, or p<0.01). The lowest GV rate was found in LH-3 group. GV rates in LH-2, LH-4 and LH-5 groups were higher than that in FSH group (p<0.05). At hours 20, 22 and 24 after oocytes IVM, caspase-3 concentrations in four LH-treated groups were decreased in comparison with that in LH-1 group. At 24h, caspase-3 concentrations of LH-2 and LH-3 groups were lower than that in LH-1 group (p<0.05). Expression levels of FSHR and LHR mRNAs rose when LH concentrations in IVM medium increased. The greatest expressions of FSHR and LHR mRNAs were found in LH-5 and LH-3 groups (p<0.01) in comparison with those in the control group (LH-1). Meanwhile, FSHR mRNA expressions in LH-2, LH-3 and LH-4 groups were lower than that in FSH group (p<0.01 or p<0.05). Expression levels of FSHR proteins revealed no significant differences among all groups. Expression levels in LHR proteins were increased. LHR protein level in LH-2 group was higher than that in LH-1 group. In conclusion, LH treatment could promote the maturation rate and GVBD rate. LH reduced apoptosis rate, GV rate of sheep oocytes, and caspase-3 concentrations in IVM medium fluids and additionally enhanced expressions of FSHR and LHR mRNAs of sheep COCs.

Aging-related premature luteinization of granulosa cells is avoided by early oocyte retrieval.

Why IVF pregnancy rates decline sharply after age 43 is unknown. In this study, we compared granulosa cell (GC) function in young oocyte donors (n=31, ages 21-29), middle-aged (n=64, ages 30-37) and older infertile patients (n=41, ages 43-47). Gene expressions related to gonadotropin activity, steroidogenesis, apoptosis and luteinization were examined by real-time PCR and western blot in GCs collected from follicular fluid. FSH receptor (FSHR), aromatase (CYP19A1) and 17ß-hydroxysteroid dehydrogenase (HSD17B) expression were found down regulated with advancing age, while LH receptor (LHCGR), P450scc (CYP11A1) and progesterone receptor (PGR) were up regulated. Upon in vitro culture, GCs were found to exhibit lower proliferation and increased apoptosis with aging. While FSH supplementation stimulated GCs growth and prevented luteinization in vitro. These observations demonstrate age-related functional declines in GCs, consistent with premature luteinization. To avoid premature luteinization in women above age 43, we advanced oocyte retrieval by administering human chorionic gonadotropin at maximal leading follicle size of 16  mm (routine 19-21  mm). Compared to normal cycles in women of similar age, earlier retrieved patients demonstrated only a marginal increase in oocyte prematurity, yet exhibited improved embryo numbers as well as quality and respectable clinical pregnancy rates. Premature follicular luteinization appears to contribute to rapidly declining IVF pregnancy chances after age 43, and can be avoided by earlier oocyte retrieval.

Molecular regulation of hypothalamus-pituitary-gonads axis in males.

The hypothalamic-pituitary-gonadal axis (HPG) plays vital roles in reproduction and steroid hormone production in both sexes. The focus of this review is upon gene structures, receptor structures and the signaling pathways of gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The hormones' functions in reproduction as well as consequences resulting from mutations are also summarized. Specific characteristics of hormones such as the pulsatile secretions of GnRH are also covered. The different regulators of the HPG axis are introduced including kisspeptin, activin, inhibin, follistatin, androgens and estrogen. This review includes not only their basic information, but also their unique function in the HPG axis. Here we view the HPG axis as a whole, so relations between ligands and receptors are well described crossing different levels of the HPG axis. Hormone interactions and transformations are also considered. The major information of this article is depicted in three figures summarizing the current discoveries on the HPG axis. This article systematically introduces the basic knowledge of the HPG axis and provides information of the current advances relating to reproductive hormones.

Effects of icariin on reproductive functions in male rats.

The present study investigated the effects and potential mechanism(s) of action of icariin on the reproductive functions of male rats. Adult rats were treated orally with icariin at doses of 0 (control), 50, 100, or 200 mg/kg body weight for 35 consecutive days. The results show that icariin had virtually no effect on the body weight or organ coefficients of the testes or epididymides. However, 100 mg/kg icariin significantly increased epididymal sperm counts. In addition, 50 and 100 mg/kg icariin significantly increased testosterone levels. Real-time PCR suggests icariin may be involved in testosterone production via mRNA expression regulation of genes such as peripheral type benzodiazepine receptor (PBR) and steroidogenic acute regulatory protein (StAR). Furthermore, 100 mg/kg icariin treatment also affected follicle stimulating hormone receptor (FSHR) and claudin-11 mRNA expression in Sertoli cells. Superoxide dismutase (SOD) activity and malondialdehyde (MDA) levels were measured in the testes; 50 and 100 mg/kg icariin treatment improved antioxidative capacity, while 200 mg/kg icariin treatment upregulated oxidative stress. These results collectively suggest that icariin within a certain dose range is beneficial to male reproductive functions; meanwhile, higher doses of icariin may damage reproductive functions by increasing oxidative stress in the testes.

Effects of sub-chronic aluminum chloride exposure on rat ovaries.

AIMS: This experiment investigated the effects of sub-chronic aluminum chloride (AlCl3) exposure on rat ovaries. MAIN METHODS: Eighty female Wistar (5weeks old) rats, weighed 110-120g, were randomly divided into four treatment groups: control group (CG), low-dose group (LG, 64mg/kg BW AlCl3), mid-dose group (MG, 128mg/kg BW AlCl3) and high-dose group (HG, 256mg/kg BW AlCl3). The AlCl3 was administered in drinking water for 120days. The ovarian ultrastructure was observed. The activities of acid phosphatase (ACP), alkaline phosphatase (ALP), succinate dehydrogenase (SDH), Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase, the contents of Fe, Cu and Zn, and the protein expression of follicle-stimulating hormone receptor (FSHR) and luteinizing hormone receptor (LHR) in the ovary were determined. KEY FINDINGS: The results showed that the structure of the ovary was disrupted, the activities of ALP, ACP, SDH, Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase, the contents of Zn, Fe and the protein expression of FSHR and LHR were lowered, and the content of Cu was increased in AlCl3-treated rats than those in control. SIGNIFICANCE: The results indicate that sub-chronic AlCl3 exposure caused the damage of the ovarian structure, the disturbed metabolism of Fe, Zn and Cu and the decreased activities of Na(+)-K(+)-ATPase, Mg(2+)-ATPase and Ca(2+)-ATPase in the ovary, which could result in suppressed energy supply in the ovary. A combination of suppression of energy supply and reduction of expression of FSHR and LHR could inhibit ovulation and corpus luteum development, leading to infertility in female rats.

Examining sources of variation in HPG axis function among individuals and populations of the dark-eyed junco.

Gonadal steroids are important mediators of traits relevant to fitness, and thus may be targets of selection. However, more knowledge is needed about sources of variation along the endocrine axes that may contribute to functional variation in steroid levels. In a controlled captive environment, we studied males of two closely related subspecies of the dark-eyed junco (Junco hyemalis) that differ in testosterone-related phenotype, asking whether they also differ in testosterone (T), and assessing the contribution of the sequential links of the hypothalamic-pituitary-gonadal axis. When males of both subspecies were challenged with gonadotropin-releasing hormone (GnRH), they were similar in circulating luteinizing hormone (LH) and T responses. When challenged with exogenous LH, they again produced levels of T similar to one another, and to the levels produced in response to GnRH. However, the smaller, less ornamented, and less aggressive subspecies had greater abundance of mRNA for LH receptor in the testes and for androgen receptor in the rostral hypothalamus, suggesting potential differences in regulatory feedback. We suggest that circulating hormone levels may be less prone to evolutionary change than the responsiveness of individual hormone targets. Among individuals, T titers were highly repeatable whether males were challenged with GnRH or with LH, but LH produced in response to GnRH did not covary with T produced in response to LH. Testis mass, but not LH receptor transcript abundance, predicted individual variation in T responses. These data implicate the gonad, but not the pituitary, as an important source of individual variation in T production.

Ascorbic acid supplementation enhances recovery from ethanol induced inhibition of Leydig cell steroidogenesis than abstention in male guinea pigs.

The impact of ascorbic acid supplementation against ethanol induced Leydig cell toxicity was studied in guinea pigs. Male guinea pigs were exposed to ethanol (4g/kgb.wt.) for 90 days. After 90 days, ethanol administration was completely stopped and animals in the ethanol group were divided into abstention group and ascorbic acid supplemented group (25mg/100gb.wt.) and those in control group were maintained as control and control+ascorbic acid group. Ethanol administration reduced the serum testosterone and LH (luteinising hormone) levels and elevated estradiol levels. Cholesterol levels in Leydig cell were increased whereas the mRNA and protein expressions of StAR (steroidogenic acute regulatory) protein, cytochrome P450scc (cytochrome p450side chain cleavage enzyme), 3ß-HSD (3ß-hydroxysteroid dehydrogenase), 17ß-HSD (17ß-hydroxysteroid dehydrogenase) and LH receptor were drastically reduced. Administration of ascorbic acid resulted in alteration of all these parameters indicating enhanced recovery from ethanol induced inhibition of Leydig cell steroidogenesis. Although abstention could also reduce the inhibition of steroidogenesis, this was lesser in comparison with ascorbic acid supplemented group.

Manganese-induced effects on testicular trace element levels and crucial hormonal parameters of Hyline cocks.

Manganese (Mn) is an essential element required for normal development and reproduction. However, little is known about the reproductive toxicity of Mn in birds. To investigate the Mn-induced toxicity on testicular trace element levels and crucial hormonal parameters on male reproduction in birds, 50-day-old male Hyline cocks were fed either a commercial diet or a Mn-supplemented diet. The changes in contents of copper (Cu), iron (Fe), zinc (Zn), and calcium (Ca) in testis were detected. Hormonal parameters were evaluated including the levels of testosterone (T), luteinizing hormone (LH), follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), triiodothyronine (T3), and thyroxine (T4) in the serum. The mRNA levels of luteinizing hormone receptor (LHR) and follicle-stimulating hormone receptor (FSHR) were determined in this study. The results showed that Mn was accumulated in testis, and the content of Cu, Fe, Zn, and Ca decreased. Exposure to Mn significantly lowered the content of T, LH, FSH, and the mRNA expression levels of LHR and FSHR. Levels of T3 and T4 appeared with a decreased tendency, and TSH presented no obvious regularity. It indicated that Mn exposure resulted in the disbalance of testicular trace elements and influenced hormone levels in the molecular level, which may be possible underlying reproductive toxicity mechanism induced by Mn.