Effect of PH changes on the action of PG E1 and PG E2 on the pregnant uterus in mice

The effect of pH changes on the action of Dinoprostone [PG E2] and Misoprostol [PG E1] was studied using the pregnant uterus of mice. Both drugs were capable of stimulating uterine activity and increasing resting uterine muscle tone in their original solution. A decrease in either drug's pH was associated with diminution of the response to both prostaglandins. Rise of pH mildly affected Misoprostol, while it had no ill effect on Dinoprostone. This indicated that when either one of the 2 prostaglandins needs to be inserted vaginally, local infections are better treated first in order to obtain a maximal response