Abstract
Morphological changes of the oviductal epithelium of the rat treated with hormones ($17{\beta}$-estradiol ${\mu}g$/day and progesterone 2.5mg/day) for ten days were observed transmission and scanning electron microscopically. The results obtained were as follows: 1. The cilia formation of ciliary cell(CC) was more accelerated by the treatment of estradiol than progesterone, but the balance of estrogen and progesterone was required for the maintenance of CC. The effect of hormone was different between the segments for the maintenance of CC. 2. The short secretory cell(SSC) was severely inhibited in the formation of secretory granules with single hormonal treatment but the activity of secretion was more inhibited by progesterone than by estradiol. 3. The long secretory cell(LSC) had not a great difference between estradiol and progesterone treatments as compared with the normal sexual cycle, but the formation of secretory granules was somewhat accelerated by progesterone treatment. 4. The formation of secretory granules of junctional cell (JC) was severely accelerated by estradiol treatment as compared with the normal sexual cycle. The formation of secretory granules during progesterone treatment, on the other hand, was inhibited completely, but the numbers of pinocytotic vesicles appeared at the cytoplasmic apical portion. 5. Three types of secretory cells, SSC, LSC and JC, on the rat oviductal epithelium could be suggested to have different cell tapes respectively from the morphological changes by hormone treatment.