[Monolayer culture of human ovarian thecal cells. A study on morphological and functional characteristics].

The aim of this study was to establish a monolayer culture system for human ovarian thecal cells and to investigate their morphological and functional characteristics. Theca layers were isolated and digested with collagenase-hyaluronidase solution, and dispersed thecal cells were cultured for 10 days in plastic dishes. Histological examination indicated that there were no contaminating granulosa cells in isolated theca layers. Various histochemical studies revealed abundant lipid droplets and 3 beta-hydroxysteroid dehydrogenase activity in cultured cells. The major steroids secreted were delta 4-androstenedione (delta 4) and progesterone(P). delta 4 secretion was very high during the first 2 days (31.6 +/- 1.9 ng/1 X 10(5) cells/2 days) and declined thereafter. P was secreted in moderate amounts throughout the 10 day culture period (9.0-21.3 ng/1 X 10(5) cells/2 days), while estradiol secretion was very low. Subsequently, the responsiveness of cultured thecal cells to gonadotropins and dibutyryl cyclic AMP (Bu2cAMP) was investigated. LH/HCG and Bu2cAMP stimulated delta 4 and P secretion in a dose-related manner. The maximal effective doses of LH and HCG were both 10 ng/ml, and that of Bu2cAMP was 10(-3)M. In conclusion, it was evident that these monolayer-cultured human thecal cells could maintain their morpho-functional characteristics during culture. Therefore, this culture system will provide an excellent model for further studies on the functional properties of thecal cells.