Age-related changes in the immune system \nof growing rats under acute \nand chronic stress conditions

Objectives : To examine whether or not excess pyruvate can provide the metabolic sub~trate to \nsupport the growth of early embryos in the presence of peritoneal fluid with endometriosis or interleukin- a . \nIntroduction : The adverse effect of peritoneal fluid with endometriosis on .early embryo growth has \npreviously been described (1). Recent studies suggest that interleukinsmay be the embryotoxic factor \nmediating the effect of endometriosis. This hypothesis is supported by the presence of interleukins in the \nperitoneal fluid obtained from women with endometriosis (unpublished observation). A common-metabolic \npathway mediating the effects. of endometriosis and interleukin could provide further support to the \nhypothesis. · \nMethodology : Two-cell mouse embryos were cultured in 1 ml Whitten's medium as previously described \n(1). The effects of excess pyruvate (1 mmol) on early embryo growth in the presence of peritoneal fluid \nwith endometriosis or interleukin-8 were examined. The embryos were cultured for 3 days. \nResults : Both peritoneal fluid with endometriosis and interlf:)ukin-8 were found to significantly inhibit \nthe development of early mouse embryos. The in vitro development from 2 cells to blastocysts was \nsuppressed in the presence of peritoneal fluid with mild, moderate or severe endometriosis (p<0.001 \nFisher's exact test). lnterleukin-8 (16 and 1000 pglml) however inhibited mainly the development of the \nlater stage embryo, from morulae to blastocysts (p<0.001 Fisher's exact test). Interestingly, pyruvate \nwas effective in reversing the embryotoxic effects of both the peritoneal fluid with endometriosis and \ninterleukin-8. \nConClusion : The ability of pyruvate to reverse the embryotoxic effects of both peritoneal fluid.with \nendometriosis and inter/eukin-8 suggests that a common pathway may be involved in their actions. This \nprovides further support to the hypothesis that interleukins mediate the embryotoxic effect of peritoneal \nfluid in endometriosis.