Endometrial prostaglandins in women with abnormal menstrual bleeding.

Endogenous prostaglandin (PG) concentrations (6oxo PGF1 alpha, PGE, PGF2 alpha) have been measured by radioimmunoassay in the endometrium of women with objectively assessed menstrual blood loss (MBL). The concentration of PGE and "total" PG (6oxo PGF1 alpha + PGE + PGF2 alpha) was greater in the endometrium of those women with heavy menses (median MBL 152 ml (range 86,432) n = 16) than in those individuals with a normal menstrual loss (MBL 59 ml (18,78) n = 18). The concentrations of PGE and PGF2 alpha were similar in each group, but the concentration of 6oxo PGF1 alpha was significantly less than that of both PGE and PGF2 alpha. In 19 individuals, specimens of endometrium were incubated for 1 and 2 hours in modified 199 medium to assess PG release. There was a direct correlation between endogenous PG content and the production of 6oxo PGF1 alpha, PGE, PGF2 alpha and "total" PG in the first hour, which persisted for the second hour with PGF2 alpha and "total" PG. Endometrial PGs may play a role in the mechanism underlying menstruation; however the observed relationship between the prostanoids and MBL will vary with different experimental methods.