Steroidogenic cellular sites in the cat ovary: a histochemical study.

The distribution of lipids, NADH, NADPH diaphorase, glucose 6-phospate, the isocitrate dehydrogenases, Δ⁵-3β- and 17β-hydroxysteroid dehydrogenases, and acid phosphatase in immature, cycling, and pregnant cat ovaries has been histochemically studied. Corpora lutea were found only in pregnant cats. Acid phosphatase was present in the degenerating follicles and only in trace amounts in the corpora lutea and was absent in the interstitial gland cells, germinal epithelium, and the normal developing follicles. Lipids and the various enzymes studied were localized in the theca interna of preantral and antral follicles, interstitial gland cells, and in the corpora lutea. Germinal epithelium lacked lipids, diaphorases, and all the enzymes investigated. It is suggested that theca interna and the interstitial gland cells form principal sites of steroid synthesis in the ovaries of immature as well as cycling cats while corpora lutea form additional sites of steroidogenesis during pregnancy.