COMPARISON OF 2 DOSAGES OF PROSTAGLANDIN-F2A ON CANINE UTERINE MOTILITY

The effect of 50 ug/kg prostaglandin F2a (PGF2a) was compared with 250 ug/kg PGF2a on uterine motility in the diestrous female. Microtipped pressure transducers were surgically implanted in the uteri of 6 femal es at 30 days diestrus and in 6 females at 60 days diestrus. Uterine r esponses to intravenous PGF2a (5 ug/kg), oxytocin (0.05 USP units/kg), and intramuscular PGF2a (50 ug/kg and 250 ug/kg) were measured in the awake females on Days 1 and 2 after implantation. There was no signif icant difference in the increase in intrauterine pressure produced by 50 ug/kg of PGF2a compared with 250 ug/kg of PGF2a. The longest durati on of the effect occurred when 250 ug/kg of PGF2a were given. Side eff ects were also documented. Significantly more vomiting occurred when 2 50 ug/kg PGF2a were given than when 50 ug/kg PGF2a were administered. The only advantage to using a higher dosage of PGF2a appears to be the longer duration of motility.