Protease activity in fibromyoma and normal human myometrium.

The potential involvement of intracellular proteases in the pathophysiology of fibromyoma was studied by assay of activity of two proteolytic enzymes in fibromyoma and adjacent normal myometrium. Protease I, a soluble acid protease and protease II, a particulate protease optimally active at the neutral pH range are present in fibromyoma as well as in normal myometrial tissue. No consistent difference was observed between the specific activities of these enzymes in the fibromyoma and the surrounding myometrium. The large variation in the specific activity of the protease noted among normal and fibroid tissue samples from different patients cannot be ascribed to differences in cellularity. This variance might suggest differences in rate of processing of steroid hormones or different degrees of vascularization. The present findings do not support a major role for modulation of intracellular protease activities in the development of fibromyoma.