Steroid synthesizing cellular sites in the ovary of catfish, Mystus cavasius: a histochemical study

Abstract

The distribution of Δ⁵-3β -hydroxysteroid dehydrogenase (Δ⁵-3β -HSDH), 17β-hydroxysteroid dehydrogenase (17β -HSDH), 11β -hydroxysteroid dehydrogenase (11 β -HSDH) and glucose-6-phosphate dehydrogenase (G-6-PDH) activities has been studied by histochemistry in the ovary of the catfish, Mystus cavasius. The enzyme activities occurred in the thecal cells of the ovary. In addition, a weak enzyme activity was observed in the hypertrophied granulosa cells of early atretic follicles. In later stages these phagocytic granulosa cells degenerated and only thecal cells remained in the connective tissue, surrounded by ovarian stroma. These thecal cells transformed into interstitial gland cells and an intense Δ⁵-3β -HSDH, 17β -HSDH, 11β -HSDH and G-6-PDH enzyme activity occurred in them. It is suggested that the thecal cells of mature follicles and the interstitial gland cells form important sites of steroidogenesis in the ovary of M. cavasius.