Expression of SCC in ovarian granulosa cells and cultured cells, induced rapid structural changes in mitochondria.

In this study, the relation of P450scc expression and mitochondrial ultrastructure was examined in rat granulosa cells at the time of ovulation, and in the NIH/3T3 cells. Before ovulation in the ovary, granulosa cells of Graafian follicle which expressed only mRNA of P450scc had elongated mitochonria with lamellar cristae. After ovulation, granulosa lutein cells which expressed both P450scc mRNA and protein had oval and round mitochondria with tubular or vesicular cristae.

Intermembrane bridges within membrane organelles revealed by quick-freeze deep-etch electron microscopy.

Intracellular membrane-bounded organelles, such as the endoplasmic reticulum, Golgi apparatus, and mitochondrion, possess and maintain their shape and intrinsic relationship due to the nature of their membrane organization. To reveal the membranous attachments that support these shapes and relationships, we examined various kinds of cells by quick-freeze deep-etch electron microscopy. In the cisternae of the endoplasmic reticula, we found intermembrane bridges linking opposite membranes of the cisternae.

Steroidogenic activity and ultrastructural observation of atretic follicles in the cycling hamster ovary.

In mature hamster ovaries, many follicles undergo atresia and this atretic change occurs in any estrous day. In this study, the localization of enzymes involved in estrogen biosynthesis, Bromodeoxyuridine (BrdU) incorporation, and Proliferating Cell Nuclear Antigen (PCNA) were immunohistochemically examined in the atretic follicles always provided with an atrum variable in size. Moreover, the granulosa cells from the atretic follicle in various but parallel stages of development were examined by scanning and transmission electron microscopes.

Steroidogenic activity of atretic follicles in the cycling hamster ovary and relation to ultrastructural observations.

To evaluate the relation between the steroidogenic activity and cell proliferation of individual follicles in mature hamster ovaries during the estrous cycle, the localization of enzymes involved in estrogen biosynthesis and bromodeoxyuridine (BrdU) incorporation were examined immunohistochemically. Moreover, granulosa cells from the early atretic follicle were examined by scanning and transmission electron microscopy. Immunoreactivity for aromatase was localized in the granulosa cells of healthy developing follicles and Graafian follicles, as well as in newly formed granulosa lutein cells.

Electron microscopic immunocytochemistry on the colocalization of ATP synthase and cytochrome P-450 of side chain cleavage enzymes in mitochondria of rat and bovine adrenal cortical cells.

To clarify whether ATP synthase and side chain cleavage enzymes (SCC) can coexist in a mitochondrion of the adrenal cortical cell, and whether the functional heterogeneity of mitochondria can occur in an adrenal cortical cell, the immunostainability of these two enzymes in mitochondria was compared by electron microscope using pre- and post-embedding methods. In the pre-embedding method, the inner membrane of most mitochondria in the adrenal cortical cell was positively stained for SCC, 11 beta-hydroxylase, and ATP synthase, but among these immunopositive mitochondria we often observed negatively immunoreacted ones in the same adrenal cortical cell. In the positively stained mitochondria, immunoreaction products were evenly localized along the inner mitochondrial membrane.