Effect of endotoxin on uterine cycle AMP in pregnant mice

The effect of endotoxin (LPS) on uterine cAMP was determined by measuring the levels of cAMP and cAMP phosphodiesterase after challenge. Two LPS preparations, isolated from wild type (WT) and Re chemotype mutant cells of Salmonella typhimurium were used. The pattern of termination differed with WT LPS resulting in expulsion of the fetuses, and Re LPS primarily causing the resorption of the fetuses. The animals challenged with WT LPS showed a decrease in uterine cAMP when the mice were starting to expel the fetuses while the Re LPS treated group maintained control levels of cAMP. Cyclic AMP phosphodiesterase also decreased in WT LPS and not the Re LPS group. These results suggest the possibility that uterine cAMP is involved in the expulsion of the fetuses.