Search

The presence of prostaglandins (PGs) E1 and F2 alpha in extracts of endometrial, myometrial and placental samples from 19 pregnant women at term, was investigated. The tissue samples were obtained from the following group of patients: untreated, A) with onset of labor, B) without onset of labor; pre-treated (without onset of labor); C) with betamethasone, D) with estradiol-17 beta. Thin-layer chromatography determinations demonstrated PGE1 presence in all tissue samples from the four groups. On the other hand, PGF2 alpha was consistently found in placenta and endometrial samples from groups A, C, and D, but it was absent in those from group B. The results suggest a physiological role of PGF2 alpha in human parturition, and a possible influence of estrogens and corticosteroids on the appearance of this prostaglandin.

The purpose of this study was investigate the effect of depolarizing (high K+, procaine 5 mM, high K+-Ca2+ free) or hyperpolarizing (K+ free) solutions on the generation and release of prostaglandins (PGs) E and F from the rat uterus. The output of PGs in the bathing solution was measured by bioassay. Results are expressed as ng/g dry weight/min. Under basal conditions in Krebs Ringer Bicarbonate medium, the total output of PGs (E + F) was 12.8 +/- 0.9, 20.5 +/- 2.5 and 39.1 +/- 4.3 ng/dw/min at 0-60, 60-80, 80-100 min intervals respectively, the major proportion being PGF like material in all cases. When the strips were bathed in depolarizing solution the total output increased significantly PGE being the most augmented. However, when K+ free solution was used there was a marked reduction in prostaglandins release as compared with basal conditions or depolarizing media. These results can not be attributed to osmotic effect, muscular work or neurotransmitter release from nerve endings. A close relationship between the variations in membrane potential and prostaglandins release seems to indicate that both parameters might correlate well.