Effect of sparteine sulfate on uterine prostaglandin F in the rat.

Indomethacin, an inhibitor of prostaglandin synthetase, added to an in vitro bath in a concentration of 1, 5, and 10 X 10(-6) g/ml reduced sparteine-induced contractions of isolated uterine segments from pregnant rats. Contractions induced by prostaglandin F2alpha and acetylcholine were not reduced. Sparteine increased the prostaglandin F content of the blood and uterine tissue in the pregnant but not in the nonpregnant rat. This increase was significantly reduced by the administration of indomethacin (10 mg/kg). The present study suggests that the mechanism of sparteine action is mediated through a prostaglandin F system.