| Abstract: | The contractile response of the midpregnant human uterus to a new (PG) prostaglandin analogue, 15(S)-methyl-PGF2alpha (15-me-PGF2alpha), was investigated and compared to the effect of natural PGF2alpha. It was found that the threshold dose of 15-me-PGF2alpha was around 10 mcg when given as a single intravenous injection, which is approximately 1/10 of the corresponding dose of PGF2alpha. It was also found that higher intravenous doses of 15-me-PGFalpha resulted in a uterine response of longer duration than that following PGF2alpha. Intramuscular injection of the analogue at doses of 1.0-1.5 mg induced a marked uterine stimulation sustained for 5-7 hours without causing local reaction. Intravenous infusion of 5 mcg/min of 15-me-PGF2alpha stimulated a level of uterine activity equivalent to that of 75 mcg/min of PGF1alpha. The incidence of gastrointestinal side effects was the same in the 2 treatment groups. However, there seemed to be a tendency toward a significantly higher abortion rate with the analogue. |
