Regulation of inducible nitric oxide synthase expression in bovine ovarian granulosa cells |
| |
Authors: | Zamberlam Gustavo Portela Valério de Oliveira João Francisco C Gonçalves Paulo B D Price Christopher A |
| |
Institution: | 1. Laboratório de Biotecnologia e Reprodução Animal, Universidade Federal de Santa Maria, Santa Maria, RS, Brazil;2. Centre de Recherche en Reproduction Animale, Faculty of Veterinary Medicine, University of Montreal, C.P. 5000, St-Hyacinthe, J2S 7C6 QC, Canada |
| |
Abstract: | Nitric oxide (NO) is a potential regulator of ovarian follicle growth, and ovarian granulosa cells reportedly generate NO in response to gonadotrophins, suggesting that the regulated form of nitric oxide synthase (iNOS) is present. The objectives of the present study were to gain insight into the expression and role of iNOS in the follicle. Messenger RNA encoding iNOS was detected in granulosa cells, and abundance was higher in growing dominant follicles compared to subordinate follicles (P<0.01). FSH (P<0.05) and IGF1 (P<0.01) stimulated oestradiol secretion and iNOS mRNA abundance in granulosa cells in vitro, whereas FGF2 (P<0.05) and EGF (P<0.01) decreased oestradiol secretion and iNOS expression. The addition of an anti-oestrogen prevented FSH-induced iNOS mRNA accumulation. Inhibition of endogenous NO production did not affect steroidogenesis in granulosa cells, but increased FasL mRNA abundance, caspase-3 activation and the incidence of apoptotic cell death (P<0.05). These results demonstrate that iNOS is expressed in ruminant granulosa cells and is regulated by gonadotrophins and oestradiol. Physiological levels of NO may contribute to the survival of granulosa cells. |
| |
Keywords: | Ovary Nitric oxide Follicle Steroidogenesis Apoptosis |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|