Matrix metalloproteinase-1 and -3 and mast cells are present in the endometrium of women using progestin-only contraceptives

Abstract

Progestin-only contraceptives are associated with menstrual bleeding disturbances; a major reason why these agents are discontinued. The pathogenesis of such abnormal uterine bleeding associated with progestin-only contraceptives remains ill-defined. Matrix metalloproteinases (MMP)s and mast cells (MC)s are postulated to be involved in endometrial breakdown observed in normal menstruation. In this study comparisons were made of the immunolocalization of MMP-1 and -3 and MC in endometrium from women using Norplant or depot medroxyprogesterone acetate (DMPA) with normal controls. Positive MMP immunostaining was observed focally in stromal cells and adjacent extracellular matrix. Quantitative a..