Effects of tumour necrosis factor a (TNFa) on ovulation rate in the rat ovary

Abstract

The effects of tumour necrosis factor a (TNFa) on ovulation rate, ovarian secretion of steroids, and on tissue concentrations of the ovulatory mediators plasminogen activator (PA) and prostaglandins were examined in rat ovaries perfused in vitro for 20 h. Unstimuiated control ovaries did not ovulate whereas luteinizing hormone (LH; 100 ng mL-1) induced ovulations in all ovaries (2-6±0-7). TNFa (40 ng mL-1) induced ovulations in 3 of 5 ovaries (0-8±0-4). When TNFa was added concomitantly with LH, the LH-induced ovulation rate was increased four-fold (10-6±l-3). This effect was not seen when TNFa was added 5h after LH (3-2±0-6). More progesterone was released when TNFa was combined with LH by comparison with LH alone. Tissue concentrations of prostaglandin F2« (PGF^) and PGE were increased by the addition of TNFa when compared with the control group, but did not exceed those observed in the LH group, when TNFa was combined with LH. PA activity in the tissue was unaffected by TNFa and the LH-induced increase in PA activity was inhibited when TNFa was combined with LH. The results demonstrate that the proinflammatory cytokine TNFa promotes ovulations in the rat ovary. © CSIRO 1995.