Ultrastructural Correlates of in vitro Inhibition of Luteinization of Mature Porcine Ovarian Granulosa Cells by Fluid from Immature Porcine Follicles1

Abstract

A comparison was made of the ultrastructure of preovulatory porcine granulosa cells after 2 days of culture in media which were either inhibitory of luteinization (supplemented with fluid from immature porcine antral follicles) or permissive of luteinization (supplemented with fluid from mature porcine antral follicles or adult female porcine serum). Electron micrographs were analyzed using standard morphometric techniques and the resulting data subjected to statistical analysis. The percentage of the total cell volume occupied by lipid bodies, mitochondria and lysosome-appearing bodies was significantly less in cells cultured in media containing the luteinization inhibitory fluid from immature follicles than in cells cultured in either of the 2 luteinization permissive media. The area of smooth endoplasmic reticulum and mitochondrial membranes was also markedly reduced in the inhibited cells. The luteinization inhibitory follicular fluid thus appears to suppress the development of cytoplasmic organelles and structures associated with progesterone synthesis.