Fibrinolytic activity of human uterine fluid

Normal biochemical composition of uterine fluid is essential for survival and successful implantation of the blastocyst. Fibrinolytic enzymes are involved in the implantation process. The variation of the fibrinolytic activity of uterine fluid with the phase of the normal menstrual cycle was investigated with the aid of radial enzyme diffusion on fibrin plates. The lytic activity increased during the proliferative phase, reached a maximum in midcycle and then fell to its lowest level during the luteal phase. It increased again in the premenstruum.