Studies on IUD-induced menorrhagia and increased synthesis of prostacyclin in endometrium

Abstract

43 samples of endometrium from IUD-users with excessive uterine bleeding (MBL>80 ml), normal menstrual blood loss (MBL< 80 ml) and non-IUD-users with normal menstrual blood loss (< 80 ml) have been studied. Concentration of 6-keto-PGF_1α, a metabolite of prostacyclin (PGI₂), was determined by radioimmunoassay. It was found that the concentration of 6-keto-PGF_1α of patients with IUD-induced excessive uterine bleeding was significantly higher than that of IUD-users with MBL less than 80 ml (P<0.05) and of non-IUD-users (P<0.01). But the difference between IUD-users with normal menstruation and the control was of no statistical significance (P>0.05). The results also indicated a positive correlation between the amount of MBL and 6-keto-PGF_1α concentration in endometrium of IUD-users (r = 0.439;P<0.05). The measurements of both tissue plasminogen. activator (t-PA) and 6-keto-PGI_1α concentrations from samples of 28 cases showed a weak positive correlation between t-PA and 6-keto-PGF_1α (r = 0.459;P<0.05). Further study is necessary to evaluate the significance of this result. In summary, our studies prove that the increased 6-keto-PGF_1α is an important factor contributing to excessive uterine bleeding in IUD-users.

Keywords

IUD / menorrhagia / endometrium / 6-keto-PGFi_1α / prostacyclin / tissue plasminogen activator

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