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Asprosin is an orexigenic adipokine that regulates appetite and glucose homeostasis in mammals. To date, only fragmentary findings are reported regarding its role in testicular activities. In the current investigation, immunolocalization and direct action of asprosin in adult mice testis was evaluated. Immunohistochemical and immunoblot studies were performed to analyse the testicular expression of asprosin. Intratesticular treatment of asprosin (0.1 μg and 1.0 μg per testis) was given to evaluate its direct action on testicular functions. Sertoli and Leydig cells were found to be immuno‐positive for asprosin. Intratesticular administration of asprosin resulted into a significant increase in glucose and lactate levels along with enhanced expression of asprosin receptor OLFR734, insulin receptor (IR), glucose transporter 8 (GLUT 8), lactate dehydrogenase (LDH) activity and monocorboxylate transporters (MCT2 and 4). In addition, asprosin administration increased the testicular expression of cell proliferation (proliferating cell nuclear antigen: PCNA), cell survival (B cell lymphoma 2: Bcl2) and decreased germ cell apoptosis (Cysteine aspartic acid protease 3: Caspase 3) leading to increased sperm counts. Further, asprosin treatment resulted into increased level of total cholesterol, testosterone and steroidogenic markers (steroidogenic acute regulatory protein: StAR; 3beta‐hydroxysteroid dehydrogenases: 3β HSD and 17beta‐hydroxysteroid dehydrogenases: 17β HSD). Asprosin treatment promotes testicular glucose uptake and lactate synthesis to provide energy for steroidogenesis and spermatogenesis. The significant correlation between the asprosin‐induced increased IR expression and increased testosterone, glucose and lactate levels suggests its role in increased survival and proliferation but decrease in germ cell apoptosis. This study proposed asprosin's role as an autocrine/paracrine regulator of testicular functions in adult mice. [ABSTRACT FROM AUTHOR]

Psychological stress is now widely recognized as one of the major risk factors for male fertility. Its impact on the dynamics of testicular germ cells, however, has yet to be fully investigated. Therefore, we used the rat restraint stress (RS) model as a psychological stressor to assess the impact of psychological stress on testicular germ cell dynamics. Adult male SD rats were exposed to sub‐chronic RS for 1.5 and 3 h per day for 30 days. The quality of cauda epididymis spermatozoa was adversely affected by RS exposure, and the frequency of spermatozoa with tail abnormalities was higher than that of spermatozoa with head abnormalities. RS exposure adversely affected testicular daily sperm production by disturbing the meiotic and post meiotic germ cell kinetics in the testis. The histomorphology of the testis was altered by loosening and vacuolization in the seminiferous epithelium, germ cell exfoliation and the presence of giant cells. Seminiferous tubules of stage I–VI and VII–VIII were severely affected in rats exposed to RS for 3 h. By interfering with steroidogenic enzymes, RS exposure disrupts testosterone biosynthesis. The testicular oxidative balance was also disturbed by RS exposure, which disrupted the levels/activities of lipid peroxidation, Nrf‐2, superoxide dismutase and catalase. There was also an increase in caspase‐3 activity and a decrease in the Bax‐Bcl2 ratio. In conclusion, our findings suggest that psychological stressors like RS impair testicular functions in rats by disrupting germ cell dynamics, downregulating testicular androgenesis and increasing oxidative stress and apoptosis. [ABSTRACT FROM AUTHOR]

In the present study, three aquatic macrophytes, Eichhornia crassipes, Salvinia molesta, and Pistia stratiotes were used to assess their relative efficacies in decontamination of a fish culture pond, regularly fed with coal mine effluent (CME). The level of metals like Fe, Mn, Ni, Zn, Cu, Pb, Cr, and Cd were much higher in CME-fed pond water than their recommended limits in drinking water set by the Bureau of Indian standards and in effluents by the Environmental Protection Agency. The levels of metal were lowered substantially in CME-fed pond water after exposure of the above plants to such water, however, metal levels in the plants increased tremendously. The increased metal levels in plants severely damaged their physiological and biochemical processes. The contents of chlorophyll a, b and carotenoid were reduced by 63.2, 64.2, and 46.3%, respectively, in E. crassipes, 41, 57.4, and 57.8% in S. molesta, and 42, 62, and 61% in P. stratiotes. The accumulating metals also generated oxidative stress in plants, as evident from the increased superoxide dismutase and catalase activities and enhanced malondialdehyde content. The E. crassipes was the most potent in absorbing the metals from the CME-fed pond water, followed by S. molesta and P. stratiotes. [ABSTRACT FROM AUTHOR]

A cell line designated as HFB-ES was established from blastula stage embryos of H. fossilis (Singhi). The embryonic cells were harvested and maintained in Leibovitz's medium supplemented with 15% fetal bovine serum. The cell line had been subcultured for more than 90 passages in a period of 24 months. HFB-ES cells were able to grow at temperatures between 25 and 35℃ with an optimum temperature of 28℃. The growth rate of HFB-ES was proportional to FBS concentration, with optimum growth seen at 15% FBS concentration. The originality of the cell line was confirmed by sequencing of cytochrome oxidase c subunit I (COI), cytochrome b gene, and microsatellite DNA profile. Results of chromosome complements of HFB showed normal karyomorphology with 56 (2«) diploid number of chromosomes after 40 passages which indicated that the developed cell line is chromosomally stable. The pluripotency of HFB was demonstrated by alkaline phosphatase activity and Oct-4 gene expression. Expression of GFP reporter gene was successful in HFB-ES. These results indicated that HFB-ES could be utilized for future gene expression studies. [ABSTRACT FROM AUTHOR]

The plasma profile of growth hormone (GH) was monitored in the freshwater catfish, Clarias batrachus over a single 24-h transverse timescale in the middle of each month starting from March to August. This period included different physiological status of the fish and also varying environmental photoperiod and ambient temperature. Statistically significant ultradian rhythm in GH was detected in all the months of study. Of the two ultradian peaks, one was located invariably in the early photophase with the other one in the early scotophase. During the period of intense reproductive activity (June and July), circadian rhythm in GH was also recorded in addition to ultradian rhythm. The 24-h average (Mesor) and amplitude of ultradian rhythm of GH were high in March and April coinciding with the increase in photoperiod, temperature and feeding activity. Mesor increased further in May, reaching the maximum in June with a further rise in the water temperature and intense gonadal activity, but the amplitude declined during these months. In the breeding month of July, Mesor declined moderately and amplitude declined further. In August, Mesor and amplitude both attained minimum levels. In July and August one of the ultradian peaks overlapped with the circadian peak of the GH rhythm and the circadian peaks appeared in the night, while in other months it appeared in the early morning or at midday. Synchronization of one of the ultradian peaks with that of the circadian peak in GH in the night of July and August might provide physiological advantage for the execution of breeding at the coolest part of the day. The rhythmic patterns of GH secretion might have a strong correlation with the changing photoperiod, temperature, and feeding and reproductive activity. The observed temporal organization in GH in C. batrachus may have physiological consequences that might provide suitable milieu for the regulation of its somatic and gonadal growth, and execution of reproductive activity. [ABSTRACT FROM AUTHOR]

Analysis of changes in the plasma levels of GTH II over a 24-h day/nightcycle revealed statistically significant circadian or ultradian variationor both in its circulating level during the gonadally active months of thereproductive cycle. The 24-h average and amplitude of circadian or ultradianrhythm in GTH II increased with the advancement of ovarian development andmaturation. In April, a single peak in GTH II level was noticed in the nightat 20.6 h. In contrast, in May, June and July a biphasic pattern (ultradianrhythm) was noticed with two characteristic peaks, one in the photophase andthe other in the scotophase. In addition, in May a statistically significantcircadian rhythm in plasma GTH II was validated with a peak located at 20.1h. These rhythms seem to have physiological significance. The ultradian rhythmwith two peaks during the reproductively active phase appears to provide asuitable physiological milieu for the temporally different yet synchronouspopulation of oocytes for the secretion of steroids. Thus, the observed temporalorganization in GTH II may have physiological consequences leading to accomplishmentof reproductive process at appropriate time of the year. [ABSTRACT FROM AUTHOR]

In the present investigation, daily variations in plasma levels of melatonin,testosterone and estradiol-17β were analysed in the tropical freshwatercatfish, Clarias batrachus during early and late-preparatory, pre-spawning,late-spawning and post-spawning phases of its annual reproductive cycle. Plasmamelatonin levels exhibited a significant circadian rhythm during all the reproductivephases but peaks were invariably at night. The amplitude of melatonin washigh during the early-preparatory phase and low in the pre-spawning phase.Testosterone also displayed significant rhythm during all the studied phasesexcept post spawning phase. Estradiol-17β revealed diurnal rhythm onlyduring preparatory and pre-spawning phases. The peak in the levels of plasmatestosterone and estradiol-17β were recorded during the photophase. Duringthe late-preparatory phase, the rhythm of testosterone coincided with therhythm of estradiol-17β. [ABSTRACT FROM AUTHOR]

Growth hormone (GH), in the recent past, has been recognized as a potent steroid stimulating hormone independent of gonadotropin (GtH). However, the mode and mechanism of its steroidogenic action in the testis is not yet elucidated, particularly in fish. The present study was designed to understand the mode and mechanism of steroidogenic action of growth hormone in testis of the catfish, Clarias batrachus through in vivo and in vitro Leydig cell culture studies using the signaling molecule inhibitors. Exogenous administration of GtH, GH and insulin to the male catfish increased testicular and circulating testosterone level. In vitro treatment of Leydig cells with these hormones also increased testosterone production. The steroidogenic action of GH appeared to be indirect and mediated through Leydig cell produced insulin-like growth factor I (IGF-I), as the treatments with actinomycin D, cycloheximide and anti-IGF-I abolished the GH-induced testosterone production by Leydig cells. The GH-induced stimulation in IGF-I production by the isolated Leydig cells further substantiates this notion. GH appears to employ cAMP/PKA and tyrosine kinase signaling pathways to induce IGF-I production, as the adenylyl cyclase inhibitor (SQ 22,536), cAMP-dependent protein kinase (PKA) blocker (H-89) and tyrosine kinase inhibitor (lavendustin A) abolished the GH-induced IGF-I production and in turn testosterone by the Leydig cells. This study suggests that GH exerts independent androgenic effect in the catfish testis indirectly through augmenting the Leydig cell production of IGF-I. [ABSTRACT FROM AUTHOR]

Abstract: The presence of neuronal nitric oxide synthase (nNOS), inducible NOS (iNOS) and nitric oxide (NO) in the testis of seasonally breeding catfish has previously been demonstrated. The present study was aimed to investigate the presence of NO in fish gametes and its role in sperm physiology and strengthen the previous findings. NO, a biological signalling molecule is synthesized during the conversion of l-arginine to l-citrulline by nitric oxide synthases (NOS) in the presence of NADPH and oxygen. In the present study, a considerable amount of NO content was detected in the fresh sperm suspension of fish. A drastic reduction in NO content of the sperm suspension was observed after cryopreservation. Ovarian fluid collected from freshly stripped eggs also contained a substantial amount of NO. Further, effects of a NO donor, sodium nitroprusside (SNP), and NOS inhibitor, N-(G)-nitro-l-arginine-methyl ester (l-NAME) were evaluated on motility and fertilizing ability of fresh and cryopreserved sperm. The percentage of motile fresh sperm (66.2±3.7%) was enhanced (P <0.05) by SNP at the dose of 10−3 M, whereas the greater and lesser concentrations of SNP did not influence the percentage of motility as compared to the control. However, a significant reduction in the percentage of motile fresh sperm was observed at the tested doses of 10−3 M and 10−4 M of l-NAME. The maximum reduction (23.0±3.4%) was evoked at the greatest concentration (10−3 M); while at the smallest dose of 10−5 M, reduction was insignificant. Ovarian fluid also enhanced sperm motility. Altogether, findings of the present study suggest that NO plays an important role in sperm performance of fish. [Copyright &y& Elsevier]