¹³³Xenon Clearance from Amniotic Fluid in Baboons During Administration of Oxytocin, Prostaglandin F_2α and A β- Mimetic Agent

Abstract

Amniotic fluid clearance of ¹³³xenon was measured in pregnant baboons near term during a control period of spontaneous uterine activity and during induction of contractions with oxytocin or PGF_2α and inhibition of activity by a β-adrenergic agent, berotec. There was no significant change in the clearance of ¹³³xenon from the amniotic fluid during moderate uterine activity induced by oxytocin or PGF_2α. The clearance rate decreased five-fold during infusion of berotec, compared with the control infusion periods, simultaneous with a decrease in uterine activity. When the berotec infusion was discontinued, the clearance of ¹³³xenon immediately returned to the previous level, while the return of uterine activity was more gradual.