Plasminogen activators in the endometrium; a preliminary study in subfertile subjects

Abstract

Low or absent fibrinolytic activity in the mid-cycle endometrium is suggested as a prerequisite for the adhesion of fertilized ova. Plasminogen activator (PA) activity was evaluated in acid-treated endometrial curettings of subfertile females with 12 cases each in the proliferative and late secretory and 16 cases in the early secretory phase. PA activity varied widely with a mean of 70 ± 67.3 iu in the proliferative, 50.8 ± 38.5 iu in the late secretory and 25.9 ± 29.3 urokinase iu/0.5g tissue in the early secretory endometrium. Compared with proliferative endometrium, early secretory endometrium showed significantly lower activity (p < 0.01); the reduction in late secretory endometrium was not statistically significant. Unlike the normal patient, 12 out of 16 subfertile patients showed PA activity in the early secretory endometrium (4 to 85 urokinase iu/0.5g tissue). The presence of PA activity in early secretory endometrium may therefore be a possible factor related to the patients' continued infertility.