Ripening of the cervix with sodium nitroprusside in nonpregnant women.

Few clinical trials have examined the effects of nitric oxide donors on the human cervix. We address the question of the ultrastructural and clinical effects of topical NO donor on the nonpregnant human cervix.Twenty patients admitted to the hospital for hysterectomy were randomly assigned to receive either placebo gel or 1\% nitroprusside-based gel into the cervical canal. After surgery, a small biopsy of the cervical canal was taken and analyzed by electron microscopy. Vital parameters were monitored after application.In the placebo group, the connective tissue was normal. In the experimental group, the collagen fibers were widely spaced, and no longitudinal collagen bundles were visible. Macrophages, leukocytes, and activated fibroblasts in treated tissues demonstrated a proinflammatory reaction. Adverse effects were reported in a minority of subjects. No significant changes in blood pressure or in nitrite and nitrate levels were reported.In both fertile and postmenopausal women, cervical sodium nitroprusside induced morphologic changes similar to those reported for the ripening process.