Pathological changes in the occluded oviducts depend on the etiology and duration of trauma as well as on the hormonal condition of the patient. The same factors influence the outcome of surgical management. In this study we evaluated the influence of different estradiol (E2) levels on the morphology of oviducts with distal tubal occlusion. The oviducts of sexually mature female rabbits were surgically sutured at their abdominal ends. The animals were allocated into three groups: the first group was castrated; the second received estradiol (E2) (Oestradiol-depot - 0.2 mg/kg q. 7 days - Jenapharm, FRG); and the third remained without further treatment. E2 levels were checked every three weeks by means of the RIA method. Six and 12 weeks following the procedure we performed a salpingectomy. The oviducts were evaluated under light (HE, PAS and staining for reticular fibers), scanning electron and transmission electron microscopes. The castrated animals had an average E2 level of 21.2±6.1 pg/ml, those that received E2 - 845±432 pg/ml, and controls 42.1±12.5 pg/ml. Six weeks following oviduct closure, the castrated animals had wide oviducts with thin and low mucosal folds. Cells had few secretory granules and cilia. The animals receiving E2 had wide folds of tubal mucosa. Ciliated cells had few cilia. Non-castrated animals had secretory granules located in the apical parts of the cell. We also observed some areas deprived of cilia. Twelve months following oviduct closure the most pronounced morphological changes were seen in E2-receiving animals. The tubal lumen was distended, without mucosal folds. The epithelium was low, without cilia. We noted areas without epithelial cells. The oviducts of the castrated animals had a low epithelium, without ciliated cells and no discharge, however mucosal folds were abundant. This study revealed that the low level of E2 delays the onset of abnormalities in oviducts with distal occlusion. Elevated E2 levels amplify these changes.

Keywords: Tubal Occlusion, Infertility