Regulation of an 8-kDa peptide involved in testosterone production by luteinizing hormone in rat Leydig cells

Results of Western blot analysis carried out with an interstitial cell extr act from male guinea pig and ovarian extract from immature female rats admi nistered equine chorionic gonadotropin (eCG) provide supportive evidence to our earlier suggestion that an 8-kDa peptide is involved in acquisition of steroidogenic capacity by the rat Leydig cells. It was found that though t he signal was observed in other tissues such as liver, kidney and lung whic h do not produce gonadal hormones, the peptide was modulated only by luteni zing hormone (LH) in the rat Leydig cells.