Reproductive Homeostasis Research Articles

Oat Beta-Glucan Dietary Intervention on Antioxidant Defense Parameters, Inflammatory Response and Angiotensin Signaling in the Testes of Rats with TNBS-Induced Colitis.

Male infertility represents a significant public health concern. There is a negative impact of inflammatory bowel diseases (IBDs) on the male reproductive system. The aim of this study was to investigate whether oat beta-glucan (OBG) with different molar mass can modulate parameters of antioxidant defense and inflammatory response in the testes of adult Sprague-Dawley rats with TNBS-induced colitis and whether the OBG intervention can modulate the inflammatory response in association with the RAS system. Results: higher testicular superoxide dismutase (SOD), glutathione reductase (GR) activities and glutathione (GSH) concentration, and lower testosterone (T) level and glutathione peroxidase (GPx) activity, were observed in rats with colitis than in healthy control ones. TNBS-induced colitis resulted in decreased the angiotensin 1-7 (ANG 1-7) level in the testes of rats fed with low-molar mass OBG compared to control animals. Conclusions: although colitis induced moderate pro-oxidant changes in the gonads, it seems plausible that dietary intervention with different fractions of oat beta-glucans mass may support the maintenance of reproductive homeostasis via the stimulation of the local antioxidant defense system.

Roadmap for the expression of canonical and extended endocannabinoid system receptors and metabolic enzymes in peripheral organs of preclinical animal models.

The endocannabinoid system is widely expressed throughout the body and is comprised of receptors, ligands, and enzymes that maintain metabolic, immune, and reproductive homeostasis. Increasing interest in the endocannabinoid system has arisen due to these physiologic roles, policy changes leading to more widespread recreational use, and the therapeutic potential of Cannabis and phytocannabinoids. Rodents have been the primary preclinical model of focus due to their relative low cost, short gestational period, genetic manipulation strategies, and gold-standard behavioral tests. However, the potential for lack of clinical translation to non-human primates and humans is high as cross-species comparisons of the endocannabinoid system have not been evaluated. To bridge this gap in knowledge, we evaluate the relative gene expression of 14 canonical and extended endocannabinoid receptors in seven peripheral organs of C57/BL6 mice, Sprague-Dawley rats, and non-human primate rhesus macaques. Notably, we identify species- and organ-specific heterogeneity in endocannabinoid receptor distribution where there is surprisingly limited overlap among the preclinical models. Importantly, we determined there were no receptors with identical expression patterns among mice (three males and two females), rats (six females), and rhesus macaques (four males). Our findings demonstrate a critical, yet previously unappreciated, contributor to challenges of rigor and reproducibility in the cannabinoid field, which has implications in hampering progress in understanding the complexity of the endocannabinoid system and development of cannabinoid-based therapies.

Male Infertility in Diabetes Mellitus

Both diabetes mellitus (DM) and male infertility are widely prevalent, and their prevalence has increasing trends. Diabetes is known to have negative impacts on almost all aspects of male reproductive functions. Such pathophysiology is more widely studied in animal models, and in men with type 2 DM (T2DM), similar reproductive dysfunctions are also described in type 1 DM (T1DM). T1DM and T2DM may have different underlying mechanisms contributing to the changes seen in their sperm parameters. At the pretesticular level, DM causes hypogonadotropic hypogonadism. DM affects many aspects of testicular function. Increased oxidative stress and inflammation, increased reactive oxygen species, lipid peroxidation, advanced glycation end products, disrupted energy metabolism, and nuclear and mitochondrial deoxyribonucleic acid damage alter sperm count and quality. The structure and function of the epididymis, vas deferens, seminal vesicles, and prostate are also affected, changing sperm quality and viability. Genitourinary infections are common in DM and might alter reproductive homeostasis. Erectile and ejaculatory dysfunction frequently affects men with DM. Retrograde ejaculation and anejaculation may lead to infertility. Glucose-lowering drugs may also influence the male reproductive process; insulin, metformin, pioglitazone, sodium-glucose cotransporters, and glucagon-like peptide 1 agonist drugs may have favorable impacts. The pathophysiology of reproductive dysfunction and fertility in men with DM is yet to be completely elucidated. Many factors, including duration of diabetes, glycemic control, and associated comorbidities, may obscure the real impact of DM-related male infertility. The ongoing molecular studies generating new insights are expected to better clarify DM-induced alterations in male reproductive function.

Differing modes of growth performance induced by hypoxia and effects on oxidative defense and glycolysis metabolism in two marine Brachionus rotifer species

Hypoxia is often a concern in closed, recirculating aquaculture facilities. Here, we examined the effects of hypoxia (0.3–1.0 mg O2/L; two days of continuous exposure) on growth and metabolism in two marine rotifers, Brachionus plicatilis and Brachionus rotundiformis, having differing sizes and environmental acclimation abilities. The obtained results revealed that the super-small (SS)-type rotifer B. rotundiformis possesses higher tolerance to hypoxia during reproduction than the large (L)-type B. plicatilis. Exposure to hypoxia significantly inhibited the growth of B. plicatilis, whereas it had no influence on B. rotundiformis. While adaptive strategies, such as smaller body size and enhanced swimming speed, were detected in B. rotundiformis. To identify the underlying mechanisms of the phenomena, the activity of key biomarkers and enzymes involved in oxidative defense and glycolysis (energy) was examined. In B. plicatilis, although the level of antioxidants increased, hypoxia still induced the production of high levels of reactive oxygen species (ROS) and hypoxia-inducible factors (single-minded homolog 1 and aryl hydrocarbon receptor nuclear translocator). However, in B. rotundiformis, enhanced defensive responses (increment of manganese superoxide dismutase and glutathione S-transferase levels) successfully maintained the balance of ROS during hypoxia. Regarding energy metabolism, the expression of six key biomarkers involved in the glycolytic pathway was all significantly upregulated in B. plicatilis. Both B. plicatilis and B. rotundiformis increased ATP production, by 1.9- and 1.2-fold, respectively. Unlike B. plicatilis, B. rotundiformis may have used the produced ATP to swim faster and maintain reproductive homeostasis. The difference in resistance and growth/molecular responses to hypoxic exposure between B. plicatilis and B. rotundiformis may be attributed to their disparate mass-specific metabolic rates and habitat-evolutionary adaptations. The greater tolerance for hypoxia is beneficial to the rapid and high-density cultivation of B. rotundiformis in aquaculture facilities.

CLINICAL PROFILES AND CHARACTERISTICS OF MENSTRUAL DYSFUNCTION IN WOMEN AFTER SUFFERING FROM COVID-19 OR VACCINATION.

The aim: To investigate changes in the characteristics of menstrual function in women after suffering from Covid-19 or vaccination against SARS-CoV-2. Materials and methods: After the retrospective analysis of 378 medical records patients were divided into: Group 1 (177 women) with menstrual function disorders (MFD) after COVID-19, Group 2 (121 women) with MFD after SARS-CoV-2 vaccination, Group C (80 women) without MFD after COVID-19 or vaccination (controls). The study focused on the clinical and hormonal menstrual cycle characteristics and factors influencing MFD. Results: Dyshormonal thyroid disorders were observed in 63.0% of Group 1 and 45.7% of Group 2 patients; hyperprolactinemia - in 31.0% and 39.4%, hyper¬estrogenia - in 50% and 21%, and hyperandrogenism - in 39% and 20%. MFD was associated with hyperandrogenism with concurrent hyperprolactinemia, in the context of thyroid dysfunction; and with changes of gonadotropin production, along with normal and elevated estrogen concentrations and worsening of mental health that suggest disruption of central regulatory and feedback mechanisms in the pituitary-thyroid-ovarian system under the stressors influence. Conclusions: There are changes in the menstrual cycle associated with disruption of the hypothalamus-pituitary-ovary system and thyroid function in women after suffering from Covid-19 or vaccination. To reestablish reproductive homeostasis, employing a personalized diagnostic strategy is recommended, encompassing the evaluation of thyroid gland status, hormonal profiling, and the consideration of psychosocial facets.

Extracellular vesicles in seminal plasma: A safe and relevant tool to improve fertility in livestock?

Seminal plasma (SP) is not a pre-requisite for pregnancy. Yet, this heterogeneous, composite SP has proven relevant for fertility, as mediator for cell-to-cell communication between producing cells, spermatozoa and the female internal genital tract, regulating complex reproductive processes. Bearing hormones, proteins, cytokines as well as nuclei acids in nano-sized lipid bilayer seminal extracellular vesicles (sEVs), the SP concerts signaling to the female. Signals influence timing of ovulation, sperm transport and, particularly, enable the female immune system to balance her cryptic choice to engage into pregnancy or reject an eventual fertilization. This essay, focusing on livestock in general and pigs in particular, discusses the intrinsic roles of sEVs with regards to reproductive homeostasis, while binding and internalizing their cargo in spermatozoa and female tract epithelia to regulate their functional activity. Since prior studies had inconclusive results using bulk SP or single SP-contained free molecules, argumentation is hereby provided to increase the current incipient research on livestock sEVs, where fragile molecules relevant for fertility are shielded from degradation during handling. Seminal EVs isolated from SP can be used for andrological diagnosis and perhaps to select breeders with optimal fertility. Moreover, sEVs can be laboratory-uploaded with specific molecules or even engineered as lipid nanodroplets used as additives for extenders to improve fertility after artificial insemination (AI) or reproductive biotechnologies.

Role-Playing Between Environmental Pollutants and Human Gut Microbiota: A Complex Bidirectional Interaction.

There is a growing interest in the characterization of the involvement of toxicant and pollutant exposures in the development and the progression of several diseases such as obesity, diabetes, cancer, as well as in the disruption of the immune and reproductive homeostasis. The gut microbiota is considered a pivotal player against the toxic properties of chemicals with the establishment of a dynamic bidirectional relationship, underlining the toxicological significance of this mutual interplay. In fact, several environmental chemicals have been demonstrated to affect the composition, the biodiversity of the intestinal microbiota together with the underlining modulated metabolic pathways, which may play an important role in tailoring the microbiotype of an individual. In this review, we aimed to discuss the latest updates concerning the environmental chemicals–microbiota dual interaction, toward the identification of a distinctiveness of the gut microbial community, which, in turn, may allow to adopt personalized preventive strategies to improve risk assessment for more susceptible workers.

Infection with endosymbiotic Spiroplasma disrupts tsetse (Glossina fuscipes fuscipes) metabolic and reproductive homeostasis.

Tsetse flies (Glossina spp.) house a population-dependent assortment of microorganisms that can include pathogenic African trypanosomes and maternally transmitted endosymbiotic bacteria, the latter of which mediate numerous aspects of their host's metabolic, reproductive, and immune physiologies. One of these endosymbionts, Spiroplasma, was recently discovered to reside within multiple tissues of field captured and laboratory colonized tsetse flies grouped in the Palpalis subgenera. In various arthropods, Spiroplasma induces reproductive abnormalities and pathogen protective phenotypes. In tsetse, Spiroplasma infections also induce a protective phenotype by enhancing the fly's resistance to infection with trypanosomes. However, the potential impact of Spiroplasma on tsetse's viviparous reproductive physiology remains unknown. Herein we employed high-throughput RNA sequencing and laboratory-based functional assays to better characterize the association between Spiroplasma and the metabolic and reproductive physiologies of G. fuscipes fuscipes (Gff), a prominent vector of human disease. Using field-captured Gff, we discovered that Spiroplasma infection induces changes of sex-biased gene expression in reproductive tissues that may be critical for tsetse's reproductive fitness. Using a Gff lab line composed of individuals heterogeneously infected with Spiroplasma, we observed that the bacterium and tsetse host compete for finite nutrients, which negatively impact female fecundity by increasing the length of intrauterine larval development. Additionally, we found that when males are infected with Spiroplasma, the motility of their sperm is compromised following transfer to the female spermatheca. As such, Spiroplasma infections appear to adversely impact male reproductive fitness by decreasing the competitiveness of their sperm. Finally, we determined that the bacterium is maternally transmitted to intrauterine larva at a high frequency, while paternal transmission was also noted in a small number of matings. Taken together, our findings indicate that Spiroplasma exerts a negative impact on tsetse fecundity, an outcome that could be exploited for reducing tsetse population size and thus disease transmission.

Photo-pollution disrupts reproductive homeostasis in female rats: The duration-dependent role of selenium administrations.

Although selenium is known to be essential for reproductive function, studies have indicated the adverse effect with its prolonged use. The present study investigated the duration-related effect of selenium administrations on reproductive hormones and estrous cycle indices in adult female Wistar rats exposed to a model of light pollution using altered photoperiod (AP). Ninety-six cyclic female Wistar rats displaying 4-5 days' estrous cycle length (ECL) and weighing 148-152 g were randomly divided into short and long experimental cohorts consisting of six groups each and spanning for 1 and 8 weeks, respectively. Each consisted of control, high selenium dose (HSE), low selenium dose (LSE), AP, AP + HSE, and AP + LSE. The rats were orally administered high dose (150 μg/kg) and low dose (100 μg/kg) of sodium selenite once per day. The estrous cycle indices were monitored. Plasma levels of follicle-stimulating hormone, luteinizing hormone (LH), estradiol (E), progesterone (P), prolactin, E/P ratio, and histology of ovary and uterine horn were evaluated. The statistical analysis was performed using Statistical Package for the Social Sciences. In AP rats, HSE and LSE caused no significant effect on LH, E, P, and E/P ratio, ECL, estrus interval (EI), and estrous cycle ratio (ECR). The effect of HSE and LSE on LH, E, P, E/P ratio, and ECL showed no duration-dependent increase, but there was a duration-dependent increase in EI and ECR at low dose. The study indicated that administration of HSE of selenium improved reproductive function in photo-pollution-exposed rats irrespective of the duration of treatment.

Orexin A-Mediated Modulation of Reproductive Activities in Testis of Normal and Cryptorchid Dogs: Possible Model for Studying Relationships Between Energy Metabolism and Reproductive Control.

Orexin A (OxA) is a neuropeptide produced in the lateral hypothalamus that performs pleiotropic functions in different tissues, including involvement in energy homeostasis and reproductive neuroendocrine functions. The role of OxA is particularly important given the well-studied relationships between physiological mechanisms controlling energy balance and reproduction. The enzyme P450 aromatase (ARO) helps convert androgens to estrogens and has roles in steroidogenesis, spermatogenesis, and energy metabolism in several organs. The goal of this study was thus to investigate the role of OxA in ARO activity and the effects of this regulation on reproductive homeostasis in male gonads from healthy and cryptorchid dogs. The cryptorchidism is a specific condition characterized by altered reproductive and metabolic activities, the latter of which emerge from impaired glycolysis. OxA helps to stimulate testosterone (T) synthesis in the dog testis. We aimed to investigate OxA-mediated modulation of 17β-estradiol (17β-E) synthesis, ARO expression and metabolic indicators in testis of normal and cryptorchid dogs. Our results indicate putative effects of OxA on estrogen biosynthesis and ARO activity based on western blotting analysis and immunohistochemistry for ARO detection and in vitro tests. OxA triggered decrease in estrogen production and ARO activity inhibition; reduced ARO activity thus prevented the conversion of T to estrogens and increasing OxA-mediated synthesis of T. Furthermore, we characterized some metabolic and oxidative modulations in normal and cryptorchid dog's testis. The steroidogenic regulation by OxA and its modulation of ARO activity led us to hypothesize that OxA is a potential therapeutic target in pathological conditions associated with steroidogenic alterations and OxA possible involvement in metabolic processes in the male gonad.

Reproductive Homeostasis and Senescence in Drosophila melanogaster.

The homeostatic properties of reproduction in aging female Drosophila melanogaster are investigated. Classic studies based on cohort analysis suggest that homeostatic capacity declines gradually as daily oviposition rates decline in aging flies. Analysis at the level of individuals gives a very different picture: reproductive homeostasis remains relatively constant for most of adult life until a critical point when oviposition either ceases entirely or continues in dysregulated fashion. The collapse of homeostatic capacity is abrupt. Enhanced homeostasis is associated with increased lifetime fecundity and improved prospects for survival. The fractal concept of lacunarity can be used to parameterize the "roughness" of individual fecundity trajectories and is inversely related to homeostatic capacity.

Inhibin B in seminiferous tubules of human testes in normal spermatogenesis and in idiopathic infertility

ABSTRACTInhibin B is one of the most significant serum markers of spermatogenesis, but its testicular expression has been poorly studied. Inhibin B sensitivity as well as the ability to reflect the level and condition of spermatogenesis and forecast certain changes in reproductive homeostasis in males is still a subject of active discussion. The purpose of this study is to examine the level of expression of inhibin B in cells of human seminiferous tubules in normal and in pathological spermatogenesis (idiopathic infertility) by revealing the proportion of immunostaining cells for inhibin B. The research conducted included analysis of testicular tissue samples taken from 82 males diagnosed with infertility and nonobstructive azoospermia. The influence of inhibin on the germ cells of men aged 22–35 been analyzed using the immunohistochemical method. According to the obtained results, high expression of inhibin can be detected both in Sertoli (98.0 ± 2.66) and Leydig (94.0 ± 1.55) cells in patients suffering from focal spermatogenesis disorders (mixed atrophy), in comparison with the men in the control group (65.9 ± 0.44 and 12.0 ± 0.44, respectively). The level of inhibin expression in the cytoplasm of spermatogonia was 4.0 ± 0.22 in control group of fertile men, while it was significantly increased in patients with Sertoli cell-only syndrome with focal spermatogenesis (45.0 ± 0.44). In the case of severe lesion to the seminiferous tubules (e.g., tubular hyalinization), the lowest level of inhibin expression in Sertoli cells is detected, whereas the immunostaining in Leydig cells showed only slight changes. Further histological research of Sertoli cells and inhibin B expression is necessary because, according to our data, the degree of inhibin B expression may be a useful marker of Sertoli cells function which can lead to new findings in the concept of local reproductive homeostasis in testis that may be impaired in some forms of idiopathic infertility in males.Abbreviations: β-TGF: β-transforming growth factor family; GCA: germ cell abnormalities/atypia; JS: Johnsen score; FSH: follicle stimulating hormone; TESE: testicular sperm extraction; LH: luteinizing hormone; F-Testo: free testosterone; ELISA: the enzyme-linked immunosorbent assay; CV: coefficient of variance; DR: range of definitions; AZF: azoospermia factorI; HC: immunohistochemical; HIER: heat induction of epitope retrieval; H&E: hematoxylin and eosin

Dual Actions of Mammalian and Piscine Gonadotropin-Inhibitory Hormones, RFamide-Related Peptides and LPXRFamide Peptides, in the Hypothalamic-Pituitary-Gonadal Axis.

Gonadotropin-inhibitory hormone (GnIH) is a hypothalamic neuropeptide that decreases gonadotropin synthesis and release by directly acting on the gonadotrope or by decreasing the activity of gonadotropin-releasing hormone (GnRH) neurons. GnIH is also called RFamide-related peptide in mammals or LPXRFamide peptide in fishes due to its characteristic C-terminal structure. The primary receptor for GnIH is GPR147 that inhibits cAMP production in target cells. Although most of the studies in mammals, birds, and fish have shown the inhibitory action of GnIH in the hypothalamic–pituitary–gonadal (HPG) axis, several in vivo studies in mammals and many in vivo and in vitro studies in fish have shown its stimulatory action. In mouse, although the firing rate of the majority of GnRH neurons is decreased, a small population of GnRH neurons is stimulated by GnIH. In hamsters, GnIH inhibits luteinizing hormone (LH) release in the breeding season when their endogenous LH level is high but stimulates LH release in non-breeding season when their LH level is basal. Besides different effects of GnIH on the HPG axis depending on the reproductive stages in fish, higher concentration or longer duration of GnIH administration can stimulate their HPG axis. These results suggest that GnIH action in the HPG axis is modulated by sex-steroid concentration, the action of neuroestrogen synthesized by the activity of aromatase stimulated by GnIH, estrogen membrane receptor, heteromerization and internalization of GnIH, GnRH, and estrogen membrane receptors. The inhibitory and stimulatory action of GnIH in the HPG axis may have a physiological role to maintain reproductive homeostasis according to developmental and reproductive stages.

Sodium fluoride adversely affects ovarian development and reproduction in Drosophila melanogaster

The study demonstrates the effects of chronic sub-lethal exposure of sodium fluoride (NaF) on reproductive structure and function of female Drosophila melanogaster. As a part of treatment, flies were maintained in food supplemented with sub-lethal concentrations of NaF (10–100 μg/mL). Fecundity, ovarian morphology, presence and profusion of viable cells from ovary and fat body were taken into consideration for evaluating changes in reproductive homeostasis. Wing length (a factor demonstrating body size and reproductive fitness) was also monitored after NaF exposure. Significant reduction in fecundity, alteration in ovarian morphology along with an increase in apoptosis was observed in treated females. Simultaneous decline in viable cell number and larval weight validates the result of MTT assay. Furthermore, altered ovarian Glucose-6-phosphate dehydrogenase and catalase activities together with increased rate of lipid peroxidation after 20 and 40 μg/mL NaF exposure confirmed the changes in reproduction related metabolism. Enhanced lipid peroxidation known for ROS generation might have induced genotoxicity which is confirmed through Comet assay. The enzyme activities were not dose dependent, rather manifested a bimodal response, which suggests a well-knit interaction among the players inducing stress and the ones that help establish physiological homeostasis.

Effect of Rhodopsin Phosphorylation on Dark Adaptation in Mouse Rods.

Rhodopsin is a prototypical G-protein-coupled receptor (GPCR) that is activated when its 11-cis-retinal moiety is photoisomerized to all-trans retinal. This step initiates a cascade of reactions by which rods signal changes in light intensity. Like other GPCRs, rhodopsin is deactivated through receptor phosphorylation and arrestin binding. Full recovery of receptor sensitivity is then achieved when rhodopsin is regenerated through a series of steps that return the receptor to its ground state. Here, we show that dephosphorylation of the opsin moiety of rhodopsin is an extremely slow but requisite step in the restoration of the visual pigment to its ground state. We make use of a novel observation: isolated mouse retinae kept in standard media for routine physiologic recordings display blunted dephosphorylation of rhodopsin. Isoelectric focusing followed by Western blot analysis of bleached isolated retinae showed little dephosphorylation of rhodopsin for up to 4 h in darkness, even under conditions when rhodopsin was completely regenerated. Microspectrophotometeric determinations of rhodopsin spectra show that regenerated phospho-rhodopsin has the same molecular photosensitivity as unphosphorylated rhodopsin and that flash responses measured by trans-retinal electroretinogram or single-cell suction electrode recording displayed dark-adapted kinetics. Single quantal responses displayed normal dark-adapted kinetics, but rods were only half as sensitive as those containing exclusively unphosphorylated rhodopsin. We propose a model in which light-exposed retinae contain a mixed population of phosphorylated and unphosphorylated rhodopsin. Moreover, complete dark adaptation can only occur when all rhodopsin has been dephosphorylated, a process that requires >3 h in complete darkness. G-protein-coupled receptors (GPCRs) constitute the largest superfamily of proteins that compose ∼4% of the mammalian genome whose members share a common membrane topology. Signaling by GPCRs regulate a wide variety of physiological processes, including taste, smell, hearing, vision, and cardiovascular, endocrine, and reproductive homeostasis. An important feature of GPCR signaling is its timely termination. This normally occurs when, after their activation, GPCRs are rapidly phosphorylated by specific receptor kinases and subsequently bound by cognate arrestins. Recovery of receptor sensitivity to the ground state then requires dephosphorylation of the receptor and unbinding of arrestin, processes that are poorly understood. Here we investigate in mouse rod photoreceptors the relationship between rhodopsin dephosphorylation and recovery of visual sensitivity.

Early Neuroendocrine Disruption in Hypothalamus and Hippocampus: Developmental Effects Including Female Sexual Maturation and Implications for Endocrine Disrupting Chemical Screening

The timing of puberty has been mainly studied in females for several reasons, including the possible evaluation of a precise timer (i.e. menarcheal age) and concerns with respect to the high prevalence of precocity in females as opposed to males. Human evidence of altered female pubertal timing after exposure to endocrine disrupting chemicals (EDCs) is equivocal. Among the limiting factors, most studies evaluate exposure to single EDCs at the time of puberty and hardly assess the impact of lifelong exposure to mixtures of EDCs. Some rodent and ovine studies indicate a possible role of foetal and neonatal exposure to EDCs, in accordance with the concept of an early origin of health and disease. Such effects possibly involve neuroendocrine mechanisms because the hypothalamus is a site where homeostasis of reproduction, as well as control of energy balance, is programmed and regulated. In our previous studies, pulsatile gonadotrophin-releasing hormone (GnRH) secretion control via oestrogen, glutamate and aryl hydrocarbon receptors was shown to be involved in the mechanism of sexual precocity after early postnatal exposure to the insecticide dichlorodiphenyltrichloroethane. Very recently, we have shown that neonatal exposure to the potent synthetic oestrogen diethylstilbestrol (DES) is followed by early or delayed puberty depending on the dose, with consistent changes in developmental increase of GnRH pulse frequency. Moreover, DES results in reduced leptin stimulation of GnRH secretion in vitro, an effect that is additive with prenatal food restriction. Thus, using puberty as an endpoint of the effects of EDC, it appears necessary to consider pre- and perinatal exposure to low doses and to pay attention to the other conditions of prenatal life, such as energy availability, keeping in mind the possibility that puberty could not only be advanced, but also delayed through neuroendocrine mechanisms.

Diabetes induced testicular dysfunction amelioration by ethyl acetate fraction of hydromethanolic extract of root of Musa paradisiaca L. in streptozotocin-induced diabetic rat

ObjectiveTo investigate the diabetic therapeutic potentiality and antioxidative efficacy of ethyl acetate fraction of hydro-methanol (40:60) extract of root of Musa paradisiaca Lam. (Musaceae) in streptozotocin-induced diabetic rat. MethodsStreptozotocin-induced diabetic state was confirmed by decreased serum insulin level and carbohydrate metabolomics i.e. increased fasting blood glucose level, glycated hemoglobin level and diminished glycogen contents in liver and skeletal muscle. Reproductive homeostasis alteration in diabetes was evaluated by reproductive organo-somatic indices, sperm count, motility and histological analysis of testicular seminiferous tubule along with levels of serum testosterone, testicular cholesterol and seminal vesicular fructose assessment. Oxidative stress in primary and accessory sex organs, and in sperm pellet was assessed by measuring antioxidant enzyme activities along with quantification of free radicals products. Testicular pro-apoptotic Bax-α mRNA expression pattern was studied semi-quantitatively by PCR technique. Reverse phase HPLC fingerprinting was performed using methanol and acetonitrile as mobile phase. ResultsOral administration of ethyl acetate fraction at a dose of 20 mg/0.5 mL of distilled water/100 gm body weight twice daily to the diabetic rats for 28 days significantly recovered organo-somatic indices, protected reproductive activities, corrected oxidative stress markers and pro-apoptotic mRNA expression pattern, which were deviated in diabetes mellitus from control level without any type of toxicity. HPLC fingerprinting shows five completely resolved peaks at γ max 254 nm and 342 nm. ConclusionsIt has a promising antihyperglycaemic and antioxidative activity for curing diabetes induced reproductive disorders in streptozotocin-induced diabetic rat.

Population Differentiation and Plastic Responses to Drought Stress in the Generalist AnnualPolygonum persicaria

We tested the generalist annual plant Polygonum persicaria (Polygonaceae) for adaptive differentiation in drought responses. Populations from one consistently moist and two variably dry sites were grown in moist and drought conditions in a greenhouse. Physiological, morphological, and reproductive data were collected. All three populations maintained similar levels of fitness in both drought and moist conditions, indicating that these populations may be equally drought tolerant. Also, the three populations had similar water use efficiency and root biomass responses to soil moisture, indicating that substantial phenotypic plasticity is present in all the populations, including a population from a consistently moist site. The magnitude of plastic responses for specific traits varied among the populations; i.e., the physiological and morphological means by which these plants maintained reproductive homeostasis across moisture conditions was population dependent. In particular, the moist‐site population had t...

Field physiology: physiological insights from animals in nature.

Whereas comparative physiology documents the range of physiological variation across a range of organisms, field physiology provides insight into the actual mechanisms an organism employs to maintain homeostasis in its everyday life. This requires an understanding of an organism's natural history and is prerequisite to developing hypotheses about physiological mechanisms. This review focuses on a few areas of field physiology that exemplify how the underlying physiology could not have been understood without appropriate field measurements. The examples we have chosen highlight the methods and inference afforded by an application of this physiological analysis to organismal function in nature, often in extreme environments. The specific areas examined are diving physiology, the thermal physiology of large endothermic fishes, reproductive physiology of air breathing vertebrates, and endocrine physiology of reproductive homeostasis. These areas form a bridge from physiological ecology to evolutionary ecology. All our examples revolve around the central issue of physiological limits as they apply to organismal homeostasis. We view this theme as the cornerstone of physiological analysis and supply a number of paradigms on homeostasis that have been tested in the context of field physiology.

Recombinant perciform GnRH-R activates different signaling pathways in fish and mammalian heterologous cell lines

Perciforms have three forms of gonadotropin-releasing hormone (GnRH) in their brain. All three GnRHs are potent secretogogues for luteinizing hormone (LH) from the pituitary. The pivotal role of GnRH-R–GnRH interactions in reproductive homeostasis is well established; however, there is a paucity of information on how a GnRH-R responds to the three endogenous GnRH forms in a perciform species. In this study, a recombinant pituitary GnRH-R from striped bass (stb) was expressed in a mammalian cell line (COS-7) and a fish cell line (CHSE–214). Activation of the signaling pathways was monitored by reporter gene (luciferase) based assays, which were specific for cAMP-PKA or Ca 2+/calmodulin kinase (activated via c-fos promoter) signaling pathways. The stbGnRH-R expressed in two different cell lines triggered different downstream signaling in response to the treatments with chicken (c) GnRH II. Interestingly, when endogenous GnRHs were used in combinations, the luciferase activity was significantly attenuated in transfected CHSE-214 cells.