Production of prostaglandins E and Falpha by corpora lutea, corpora albicantes and stroma from the human ovary.

This study has shown that corpora lutea, stromal tissue and corpora albicantes from human ovaries contain prostaglandin E (PGE) and PGFalpha, and that the two former tissues can synthesize these prostaglandins during incubation. Enhanced syntheses, especially of PGE, occurred on adding arachidonic acid to the incubation medium, and the presence of prostaglandin synthetase activity was conclusively demonstrated. In corpora lutea obtained during the early and mid-luteal phase, the mean concentrations of PGE and PGFalpha were 34.3 and 9l9 ng/g respectively (mean ratio PGE:PGFalpha = 3.7); similar values were found in three corpora lutea from women at 10-12 weeks of pregnancy. All these corpora lutea contained appreciable amounts of progesterone and oestradiol-17beta. Prostaglandin levels were generally lower in corpora lutea obtained during the late luteal phase, although the PGE:PGFalpha ratio had increased to a mean value of 8.4. In corpora albicantes, the concentrations of both PGE and PGFalpha were significantly higher than the levels found in corpora lutea (P less than 0.01), whilst the mean ratio of PGE:PGFalpha had fallen significantly to 1.8 (P less than 0.01). Prostaglandin levels in stromal tissue varied considerably between individuals. The mean values were significantly lower than those of the corpora albicantes (P less than 0.01) but not significantly different to corpora lutea at any stage. These findings are discussed in relation to the possible role of prostaglandins in ovarian steroidogenesis and corpus luteum regression in man.