Effects of cyclic AMP altering drugs on endotoxin-induced termination of pregnancy

The effects of dibutyryl-cyclic AMP (DBcAMP), propranolol, and theophylline on endotoxin (LPS) challenged pregnant mice was determined by comparing the patterns of termination and times of fetal expulsion. Endotoxin isolated from wild type (WT) and Re chemotype mutant cells of Salmonella typhimurium was used. Wild type LPS caused the expulsion of the fetuses, while Re LPS primarily caused the resorption of the fetuses. The major change in pattern occurred in the propranolol treated Re LPS challenged group with a trend toward more expulsions and a decrease in uterine cyclic AMP (cAMP) levels to that approaching the group challenged with wild type LPS. The time of expulsion was also affected in the wild type LPS treated group, with propranolol hastening and DBcAMP and theophylline delaying the expulsion. These results support the hypothesis that uterine cAMP is involved in the expulsion of the fetuses.