Studies of the fine structure of ovarian interstitial tissue

Summary The fine structure of ovarian steroid-producing cells of the domestic fowl as seen after administration of steroids is described. Diaethylstilboestrol, estradiol and hydroxyprogesterone were given as intramuscular injections for a 28-days period. The main cytoplasmic changes of the steroid-producing cells were an increase in the number and the size of lipid droplets due to a possible expansion of the endoplasmic reticulum and a confluence of the smooth endoplasmic reticulum and the lipid droplets. The mitochondria became paler, markedly reduced in size and number, and contained less cristae. The Golgi apparatus became smaller and tended to disappear. The most prominent nuclear changes were irregular outline of the nuclear membrane, shrinkage of the nucleus, formation of pseudo-inclusions, decreased number of nuclear bodies with a tendency to vacuolization and small nucleoli. These alterations have never been demonstrated in ovarian steroid-producing cells before, and they are consistent with atrophic changes observed in steroid-producing cells in other organs. The present study substantiates the view that the thecal gland must be concerned with endocrine function. The possible functions of the different cell types of the thecal gland are discussed.