PRODUCTION OF PROSTAGLANDINS BY THE EARLY PREGNANT GUINEA-PIG UTERUS IN VITRO

Abstract

SUMMARY The amounts of prostaglandins F2α (PGF2α) and E2 (PGE2) produced by homogenized, incubated, pregnant and non-pregnant guinea-pig uteri were compared. The sizes of the corpora lutea from these animals were considered in relation to the amounts of prostaglandins produced by their uteri. The amount of PGF2α produced by the uteri from day-15 bilaterally pregnant guinea-pigs was significantly less than that produced by uteri from guinea-pigs on day 15 of the oestrous cycle. Corpora lutea from the pregnant animals were maintained but those from the day 15 non-pregnant animals had regressed. There was no significant difference between the results obtained for PGE2. Results from day 15 unilaterally pregnant animals and day 25 bilaterally pregnant animals are also presented and their implications discussed. The findings reported here may well explain how, in the guinea-pig, the conceptus is able to neutralize the luteolytic effects of the uterus.