Endocrine Abstracts

Previously, we have described an inhibitory role of melatonin (Mel) in the expression of StAR and key steroidogenic enzymes, as well as in the regulation of testosterone production in testes of Syrian hamsters. The goal of the present work was to further investigate the signaling pathway involves in the testicular action of Mel. Thus, Leydig cells were purified from reproductively active hamsters killed by asphyxia with carbon dioxide, and incubated in the presence of Mel and ...

The Syrian hamster is a seasonal breeder that undergoes a testicular regression when exposed to a short day photoperiod (SD, 6 h light per day) for 16 weeks, and a subsequent gonadal reactivation after longer times of permanence in SD. In this study, we investigated the role of melatonin (Mel) and prolactin (PRL), key players in the recrudescence phase, on testicular cyclooxygenase 2 (COX2) expression and prostaglandins (PGs) production during the photoperiodic regression&#150...