The differential sensitivity of the hypothalamic-hypophysial-ovarian axis to 5-hydroxytryptophan alters the secretion of estradiol.

Serotonin [5-hydroxytryptamine (5-HT)] modulates ovarian function. The precursor of 5-HT, 5-hydroxytryptophan (5-HTP), has been used to treat depression. However, the effects of 5-HTP on ovarian and reproductive physiology remain unknown.

Neural activation associated with maternal and aversive interactions with pups in the Mongolian gerbil (Meriones unguiculatus).

According to approach-avoidance model, virgin female laboratory rats display maternal behaviour when the tendency to approach and interact with the pup is stronger than avoiding it. A positive neural mechanism that includes the medial preoptic area (mPOA)/bed nucleus of the stria terminalis (BNST) and a negative mechanism that involves the anterior hypothalamic nucleus (AHN)/ventromedial nucleus (VMN)/ periaqueductal grey (PAG) underlie to these behaviours. Unlike virgin rats, which avoid the pups, virgin females Mongolian gerbils (Meriones unguiculatus) can be immediately either maternal or aggressive with the pups.

Acute effects of -chloroamphetamine on testosterone and markers of apoptosis in seminiferous epithelium of prepubertal male rats.

Serotonin is a neurotransmitter that affects the secretion of gonadotropins and testosterone. In prepubertal male rats, serotonin has a stimulating role in testosterone secretion. Here, we used prepubertal male rats to study the effects of -chloroamphetamine (pCA) on circulating testosterone and gonadotropins and markers of apoptosis in germ cells from day 1 to day 5 post-treatment.

The content of gonadotropin-releasing hormone (GnRH), kisspeptin, and estrogen receptors (ERα/ERβ) in the anteromedial hypothalamus displays daily variations throughout the rat estrous cycle.

The content of gonadotropin-releasing hormone (GnRH), its mRNA, and estrogen receptor alpha (ERα) and beta (ERβ) in the hypothalamus varies throughout the estrous cycle. Furthermore, the abundance of these molecules displays asymmetry between the right and left side. In the present study, we investigated the changes in the content of ERα, ERβ, kisspeptin, and GnRH by western blot in the left and right anteromedial hypothalamus, at four different times during each stage of the rat estrous cycle.

Assessment of Renal Osteodystrophy via Computational Analysis of Label-free Raman Detection of Multiple Biomarkers.

Accurate clinical evaluation of renal osteodystrophy (ROD) is currently accomplished using invasive in vivo transiliac bone biopsy, followed by in vitro histomorphometry. In this study, we demonstrate that an alternative method for ROD assessment is through a fast, label-free Raman recording of multiple biomarkers combined with computational analysis for predicting the minimally required number of spectra for sample classification at defined accuracies. Four clinically relevant biomarkers: the mineral-to-matrix ratio, the carbonate-to-matrix ratio, phenylalanine, and calcium contents were experimentally determined and simultaneously considered as input to a linear discriminant analysis (LDA).

Estradiol and estrogen receptor α in the mPOA and MeA in dwarf hamster (Phodopus campbelli) fathers.

E and its alpha receptor (ERα) have an essential role in the regulation of maternal behavior. In dwarf hamster (Phodopus campbelli), E facilitates the display of paternal care, and it is possible that ERα is part of the neuroendocrine mechanisms that regulate this behavior. The aim of this study was to analyze the influence of copulation, cohabitation with the pregnant mate and the presence of the pups on paternal behavior, circulating E levels and the presence of ERα in the medial preoptic area (mPOA) and medial amygdala (MeA) in dwarf hamsters.

Estrogen Receptors Alpha and Beta in POA-AHA Region Regulate Asymmetrically Ovulation.

We examined the role of the estrogen receptors alpha (ERα) and beta (ERβ) in of the preoptic-anterior hypothalamic area (POA-AHA) in the regulation of ovulation in rats. The number of ERα- and ERβ-immunoreactive (-ir) cells was determined at 09:00, 13:00, and 17:00 h of each stage of the estrous cycle in intact rats. Additionally, the effects of blocking ERα and ERβ on ovulation rate at 09:00 h on diestrus-2 or proestrus day through the microinjection of methyl-piperidino-pyrazole (MPP) or cyclofenil in either side of POA-AHA were evaluated.

Paternal behavior in the Mongolian gerbil, and its regulation by social factors, T, ERα, and AR.

The present study evaluates the role of social factors in the transition from infanticidal to paternal male behavior and its association with T concentration, presence of estrogen receptor alpha (ERα) and androgen receptor (AR) in the olfactory bulb (OB), medial preoptic area (mPOA) and medial amygdala (MeA) of Mongolian gerbils (Meriones unguiculatus). This study included thirty-six sexually inexperienced males displaying aggressive behavior toward foreign pups. The selected animals were mated and organized into four groups.

Neuronal activation associated with paternal and aversive interactions toward pups in the Mongolian gerbils (Meriones unguiculatus).

Approach/avoid model is used to analyze the neural regulation of maternal behavior in the laboratory rat. This model proposes that the medial preoptic area (mPOA) and bed nucleus of stria terminalis (BNST) are brain regions involved in facilitating mechanisms. By contrast, anterior hypothalamic nucleus (AHN), ventromedial hypothalamic nucleus (VMH), and periaqueductal gray participate in the inhibiting mechanisms of neural regulation of maternal behavior.

An increase in estradiol facilitates the onset of paternal behavior in the dwarf hamster (Phodopus campbelli).

In the dwarf hamster (Phodopus campbelli), activational effects of testosterone (T) and estradiol (E) in the regulation of paternal behavior have been repeatedly rejected because peripheral concentrations of E do not change across the reproductive cycle of males. Further, castration no affected paternal behavior despite that both T and E concentrations decreased significantly. However, the role of these hormones has not been evaluated in models of castration and hormonal replacement in virgin males.

The participation of the muscarinic receptors in the preoptic-anterior hypothalamic areas in the regulation of ovulation depends on the ovary.

Background: Muscarinic receptors (mAChRs) of the preoptic and anterior hypothalamus areas (POA-AHA) regulate ovulation in an asymmetric manner during the estrous cycle. The aims of the present study were to analyze the effects of a temporal blockade of mAChRs on either side of the POA-AHA performed in diestrus-2 rats on ovulation, the levels of estradiol, follicle stimulating hormone (FSH) and luteinizing hormone (LH) and the mechanisms involved in changes in ovulation.

Methods: Cyclic rats on diestrus-2 day were anesthetized and randomly assigned to the following groups: 1) microinjection of 1 μl of saline or atropine solution (62.

Unilaterally blocking the muscarinic receptors in the suprachiasmatic nucleus in proestrus rats prevents pre-ovulatory LH secretion and ovulation.

Background: The suprachiasmatic nucleus (SCN) and the cholinergic system of various regions of the hypothalamus participate in the regulation of gonadotropin-releasing hormone (GnRH) and gonadotropin secretion, which are necessary for the occurrence of ovulation. In the present study, our goal was to analyse the effects of unilaterally blocking the muscarinic receptors in the SCN on ovulation and steroid secretion.

Methods: Cyclic rats were randomly allotted to one of the experimental groups.

Inhibition of serotonin reuptake in the prepubertal rat ovary by fluoxetine and effects on ovarian functions.

Fluoxetine (FLX), a selective serotonin reuptake inhibitor is an antidepressant in the treatment of mood disorders. Its impact on reproductive processes is incompletely known. The present study analyzed the reproductive effects of FLX in prepubertal female rats.

Dorsal and medial raphe nuclei participate differentially in reproductive functions of the male rat.

Background: Innervation of the hypothalamus and median eminence arise from the dorsal and medial raphe nuclei (DRN and MRN, respectively). The hypothalamus regulates the secretion of gonadotropins, which in turn regulate the reproductive function of males and females. However, it is not known the role of raphe nuclei in male reproductive function.

Paternal behavior in the Mongolian gerbil (Meriones unguiculatus): Estrogenic and androgenic regulation.

Here, we analyzed the effects of testosterone (T) and its metabolites, estradiol (E2) and dihydrotestosterone (DHT), on the onset of paternal behavior in virgin male Mongolian gerbils (Meriones unguiculatus). We hypothesized that T and E2, but not DHT, would facilitate the onset of paternal behavior. Seventy males displaying aggression toward pups were selected through a paternal behavior screening test.

Effects of unilaterally microinjecting ethanol in the preoptic-anterior hypothalamic areas of rats on ovulation.

Background: Intragastric or intraperitoneal ethanol (EtOH) treatment inhibits reproductive functions in females and male rats. The area of the hypothalamus where these effects take place is unknown. As the participations of the preoptic-anterior hypothalamic area (POA-AHA) in regulating ovulation is asymmetric, this study aims to analyze the effects on 17β-estradiol(E2 ), progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH) serum levels, the messenger ribonucleic acid (mRNA) expression of estrogen receptor alpha (ERα) and beta (ERβ), and ovulation resulting from unilaterally microinjecting water or an EtOH solution into either side of the POA-AHA.

Unilateral or bilateral vagotomy induces ovulation in both ovaries of rats with polycystic ovarian syndrome.

Background: Injecting estradiol valerate (EV) to pre-pubertal or adult female rat results in effects similar to those observed in women with polycystic ovarian syndrome (PCOS). One of the mechanisms involved in PCOS development is the hyperactivity of the sympathetic nervous system. In EV-induced PCOS rats, the unilateral sectioning of the superior ovarian nerve (SON) restores ovulation of the innervated ovary.

Effects on steroid hormones secretion resulting from the acute stimulation of sectioning the superior ovarian nerve to pre-pubertal rats.

In the adult rat, neural signals arriving to the ovary via the superior ovarian nerve (SON) modulate progesterone (P4), testosterone (T) and estradiol (E2) secretion. The aims of the present study were to analyze if the SON in the pre-pubertal rat also modulates ovarian hormone secretion and the release of follicle stimulating hormone (FSH) and luteinizing (LH) hormone. P4, T, E2, FSH and LH serum levels were measured 30 or 60 minutes after sectioning the SON of pre-pubertal female rats.

Effects of acute unilateral ovariectomy to pre-pubertal rats on steroid hormones secretion and compensatory ovarian responses.

In the present study we analyzed the existence of asymmetry in the secretion of steroid hormones in pre-pubertal female rats treated with unilateral ovariectomy (ULO) or unilateral perforation of the abdominal wall (sham-surgery). Treated rats were sacrificed at different times after surgery. Since sham-surgery had an apparent effect on the age of first vaginal estrous (FVE) and serum levels hormone, the results of the sham surgery groups were used to assess the effects of their respective surgery treatment groups.

Unilateral sectioning of the superior ovarian nerve of rats with polycystic ovarian syndrome restores ovulation in the innervated ovary.

The present study tested the hypothesis that if polycystic ovary syndrome (PCOS) results from activating the noradrenergic outflow to the ovary, unilaterally sectioning the superior ovarian nerve (SON) will result in ovulation by the denervated ovary, and the restoration of progesterone (P4), testosterone (T) and estradiol (E2) normal serum level. A single 2 mg dose of estradiol valerate (EV) to adult rats results in the development of a syndrome similar to the human PCOS. Ten-day old rats were injected with EV or vehicle solution (Vh) and were submitted to sham surgery, unilateral or bilateral sectioning of the SON at 24-days of age.

Reproductive axis function and gonadotropin microheterogeneity in a male rat model of diet-induced obesity.

Obesity causes complex metabolic and endocrine changes that may lead to adverse outcomes, including hypogonadism. We herein studied the reproductive axis function in male rats under a high-fat diet and analyzed the impact of changes in glycosylation of pituitary LH on the bioactivity of this gonadotropin. Rats were fed with a diet enriched in saturated fat (20% of total calories) and euthanized on days 90 or 180 of diet.

Pituitary-testicular axis function, biological to immunological ratio and charge isoform distribution of pituitary LH in male rats with experimental diabetes.

Men with insulinopenic diabetes mellitus frequently present hypogonadism and exhibit circulating luteinizing hormone (LH) molecules with increased biological activity. To further study this latter issue, we analyzed the pattern of isoform distribution and the impact of changes in terminal glycosylation of pituitary LH on the bioactivity of this gonadotropin in experimental diabetes. Adult male rats were treated with streptozotocin or vehicle and euthanized on days 30, 60, or 90 posttreatment.

Seasonality of LH, testosterone and sperm parameters in spider monkey males (Ateles geoffroyi).

There are no reported data on hormonal fluctuations in black-handed spider monkey males. On previous research about the reproductive physiology of this monkey we have found that during the dry season females show ovulatory estrogen peaks and males present the best quality semen. As part of an ongoing research, in this study we assessed seasonal variations in the concentration of serum luteinizing hormone (LH) and testosterone (T) in three adult spider monkey males to corroborate the seasonal reproductive synchrony.

Steroidogenic impairment due to reduced ovarian transcription of cytochrome P450 side-chain-cleavage (P450scc) and steroidogenic acute regulatory protein (StAR) during experimental nephrotic syndrome.

The nephrotic syndrome is a renal disease characterized by proteinuria, hypoproteinemia, edema and hyperlipidemia. It has been reported that female nephrotic rats are characterized by loss of the oestrus cycle, follicle atresia, low gonadotropin and steroid concentrations; particularly, undetectable estradiol levels. Therefore, to determine the mechanisms involved in the ovarian steroidogenesis impairment, in this present study we evaluated the ovarian expression of the essential steroidogenesis components: cytochrome P450 side cholesterol chain cleavage enzyme (P450scc) and steroidogenic acute regulatory protein (StAR).