Ultrastructural study on experimentally induced ovarian tumors in the rat.

Ovarian tumors induced by intrasplenic ovarian grafting were studied ultrastructurally to obtain the details with particular references to cytoplasmic organelles associated with steroid synthesis. The grafted cells were transformed ultrastructurally at around 7 months following intrasplenic ovarian grafting, in fact, intermediate type of cells were also seen in the grafts at this period. The grafted cells before the transformation showed fine structural evidence of steroid hormone secretions, as indicated by the presence of abundant smooth endoplasmic reticulum, lipid droplets and mitochondria with tubular or vesicular criste. After transformation, the cells, however, had no fine structural features associated with the production of steroid hormones.