The effect of aminophylline on uterine smooth muscle contractility and prostaglandin production in the pregnant rat uterus in vitro

Abstract

The effect of aminophylline on contractility and prostaglandin production was investigated in a 20-day pregnant rat uterus preparation in vitro. A significant decrease was observed in frequency (24.4% of control, p less than 0.05) and contractile force (13.8% of control, p less than 0.001) in rat uterine segments treated with aminophylline. Treated segments produced more prostaglandin E2 (139.6% of control, p less than 0.001) and less prostaglandin F2 alpha (73.8% of control, p less than 0.001) during the 45-minute observation period. No significant difference in thromboxane B2 or 6-ketoprostaglandin F1 alpha production was noted. This is the first observation of prostaglandin levels in rat uterine segments treated with aminophylline. It could not be concluded from this study whether the observed changes in prostaglandin production are directly related to the relaxant effect of aminophylline.