Immunohistochemical study of endometrial microvascular basement membrane components in women using Norplant

Abstract

The mechanisms responsible for progestogen-induced breakthrough bleeding remain unexplained. The aim of the present study was to examine the expression of three basement membrane components, collagen IV (CIV), laminin and heparan sulphate proteoglycan (HSPG), by immunohistochemistry in sections of endometrium from women receiving the subdermal levonorgestrel implant (Norplant®) and normally cycling women. Control biopsies were obtained from 20 normal subjects from Melbourne, Australia, and pre- and post-Norplant-insertion biopsies were obtained from 11 women from Sydney, Australia, with between 3 and 6 months Norplant exposure. It was postulated that in Norplant users a decrease in the amoun..