Ultrastructure of the Vaginal Tissue of Rabbits Treated With Collagen Sponge Alone and Medicated with Zinc and Copper Salts and Copper Wire

We tested the reaction of rabbit vaginal epithelium to inserted collagen sponges which have been proposed for human use as intravaginal contraceptive barriers. Some collagen sponges were medicated with zinc and copper sulfate and oher (untreated) sponges were wrapped loosely with copper wire. Scanning and transmission electron microscopy was performed on vaginal tissue after 10days of intravaginal contact with the sponges. The characteristic longitudinal rugate arrangement of polygonal, flat epithelial cells with a dense, even covering of microvilli seen in intact vaginas was not changed by the presence of a collagen sponge for 10days. In the presence of zinc sulfate in the sponge, the microvilli were in general shorter; however, the cells remained flat and continuous, forming visible, longitudinally oriented folds. Sponges containing copper sulfate induced marked changes in the epithelial lining of the rabbit vagina. Cells of differing sizes protruded above the plane of the surface. These cells had a hypertrophic appearance with narrow neck and widening at the top. Microvilli in these cells were very short and widely spaced, in contrast to the profuse microvillous projections in other vaginal samples. Copper wire induced definite abnormalities which were classified into three categories: (1) altered appearance similar to that caused by copper sulfate; (2) localized complete denudation of cells; (3) necrotic changes with penetration of the continuity of epithelial lining and excessive leukocytic infiltration of the lesion at the site of direct contact of the vaginal mucosa with the wire.