Fig. 6.

Steroidogenic activities of fetal Leydig, adult Leydig, and fetal Sertoli cells. A, Synthetic pathway from pregnenolone to testosterone is shown. 3β-HSD, CYP17A1, and 17β-hydroxysteroid dehydrogenase type III (17βHSD3) are involved in the pathway. T, Testosterone; Adione, androstenedione; P4, progesterone; 17OHP4, 17α-hydroxyprogesterone; P5, pregnenolone; DHEA, dehydroepiandrosterone ((3S,8R,9S,10R,13S,14S)-3-hydroxy-10,13-dimethyl-1,2,3,4,7,8,9,11,12,14,15,16-dodecahydrocyclopenta[a]phenanthren-17-one). B, Indicated numbers of fetal Leydig (FLCs), adult Leydig (ALCs), and fetal Sertoli cells (FSCs) were incubated in the presence of ³H-pregnenolone (³H-P5) or ³H-androstenedione (³H-Adione). Steroids extracted from whole medium and cells were subjected to HPLC analysis. Arrows show the peaks of the steroids. The study was performed three times with different cell preparations, and representative HPLC chromatograms are indicated. The horizontal line indicates elution time (minutes), whereas the vertical line indicates ³H count.