Differential response of the ampullary and isthmic cells to ovariectomy and estrogen treatment: an ultrastructural study.

Ultrastructural response of the ciliated and secretory cells from the ampullary and isthmic parts of the oviduct was studied in ovariectomized and ovariectomized plus estradiol dipropionate (EDP) treated rabbits. Ovariectomy did not significantly affect the cilia in the ampullary epithelium; degenerative signs, however, appeared overtly in the isthmic cilia. EDP at either 1 microng/kg or 5 microng/kg doses raised the number of cilia/cell in either tubal segments. For comparable change isthmic cilia seemed to require a higher dosage of the estrogen. Ovariectomy led to the depletion of the secretory granules (SGs) from the secretory cells of either tubal segments. EDP at both the doses induced formation of the SGs; this is more remarkable in the isthmic cells. Merocrine type of secretions were observed from the secretory cells of either segments but only at the high dose of estrogen. The findings are discussed in the backdrop of current knowledge.