Menstruation Research Today is a free monthly online journal that collates and summarizes the latest research about Menstruation, including details on menstrual cycle, pregnancy, pain, irregular menstruation.

Methoxychlor inhibits growth and induces atresia of antral follicles through an oxidative stress pathway.

Gupta RK, Miller KP, Babus JK, Flaws JA

Program in Toxicology, Department of Epidemiology and Preventive Medicine, University of Maryland School of Medicine, 660 West Redwood Street, Howard Hall 133B, Baltimore, Maryland 21201, USA.

The mammalian ovary contains antral follicles, which are responsible for the synthesis and secretion of hormones that regulate estrous cyclicity and fertility. The organochlorine pesticide methoxychlor (MXC) causes atresia (follicle death via apoptosis) of antral follicles, but little is known about the mechanisms by which MXC does so. Oxidative stress is known to cause apoptosis in nonreproductive and reproductive tissues. Thus, we tested the hypothesis that MXC inhibits growth and induces atresia of antral follicles through an oxidative stress pathway. To test this hypothesis, antral follicles isolated from 39-day-old CD-1 mice were cultured with vehicle control (dimethylsulfoxide [DMSO]), MXC (1-100 microg/ml), or MXC + the antioxidant N-acetyl cysteine (NAC) (0.1-10 mM). During culture, growth was monitored daily. At the end of culture, follicles were processed for quantitative real-time polymerase chain reaction of Cu/Zn superoxide dismutase (SOD1), glutathione peroxidase (GPX), and catalase (CAT) mRNA expression or for histological evaluation of atresia. The results indicate that exposure to MXC (1-100 microg/ml) inhibited growth of follicles compared to DMSO controls and that NAC (1-10 mM) blocked the ability of MXC to inhibit growth. MXC induced follicular atresia, whereas NAC (1-10 mM) blocked the ability of MXC to induce atresia. In addition, MXC reduced the expression of SOD1, GPX, and CAT, whereas NAC reduced the effects of MXC on their expression. Collectively, these data indicate MXC causes slow growth and increased atresia by inducing oxidative stress.

Published 14 September 2006 in Toxicol Sci, 93(2): 382-9.
Full-text of this article is available online (may require subscription).

© 2004-2008 Menstruation Research Today. All Rights Reserved.