Histochemical Analysis of the Thecal Interstitial Gland in the Ovaries of the Microchiropteran Bat, Hipposideros speoris (Schneider) during the Reproductive Cycle

Abstract

A study of ovaries during a complete reproductive cycle in mature females of Hipposideros speoris showed the presence of thecal type interstitial gland tissue during the late-recrudescence and breeding phases. Luteal-like transformation of fibroblasts of theca of multilaminar atretic follicles results in the formation of thecal interstitial gland tissue. This interstitial tissue undergoes a variety of cellular alterations till its complete differentiation. After persisting for a short while in the wall of degenerating follicles it reverts back as stromal cells and thus is very transient. Cyclical variations in the histochemical localization of lipids, 3β-hydroxysteroid dehydrogenase (3β-HSDH), 17β-hydroxysteroid dehydrogenase (17β-HSDH), succinic dehydrogenase (SDH) and Glucose-6-phosphate dehydrogenase (G-6-PDH) were observed. The histochemical shift in the enzyme activities and substrates during the reproductive cycle, corresponding to changes in the metabolic requirements as well as steroidogenesis suggests role for this tissue in ovarian physiology.