Photoperiod modulates oestrogen status, insulin interposed glucose uptake and connexin-43 in testes of golden hamster, Mesocricetus auratus

Abstract

ABSTRACT The environmental photoperiod plays an important role in regulation of seasonal reproductive events. However, with reference tooestrogen status the exact mechanism involved in testicular seasonality is still unclear in general and especially in long-day breeder golden hamster, Mesocricetus auratus. Therefore, in the present study we explored the effect of day length (long day, LD and short day, SD) in modulation of oestrogen level, metabolic and gap junction markers expressionin testes. Our results suggest that LD exposureinduced normal testicular activity as evident by histoarchitectural analyses showing different stages of spermatogenesis, spermatozoa filled lumen and normal Leydig cells. Furthermore, LD upregulated testicular metabolic parameters such as IR, GLUT-8, glucose leveland LDH activity along with predominant testicular gap junction protein (Connexin-43) expression as compared to SD. On the other hand, the expressions of ER-α, aromatase and caspase-3 were reduced under LD condition as compared to SD. Thus, it can be inferred that photoperiod modulates the circulatoryoestrogen level, along with gap junction protein and apoptosis markers expression in testes and harmonizes the energy homeostasis involved in reproductive maintenance for seasonality of golden hamster. Therefore, we may conclude that day-length-mediatedoestrogen is a prominent modulator of male reproductive health. Abbreviations Insulin receptor (IR); Glucose uptake transporter-8 (GLUT-8); Estrogen receptor-alpha (ER-α); Connexin-43 (Cxn-43); Lactate dehydrogenase (LDH)