EFFECT OF ADMINISTRATION OF LUTEINIZING-HORMONE (LH) AND DEPRIVATION OF LH ON THE PROTEINS OF SMOOTH ENDOPLASMIC-RETICULUM OF IMMATURE AND ADULT-RAT LEYDIG-CELLS

Analysis of proteins of smooth endoplasmic reticulum (SER) of Leydig c ells from immature and admit rats by two-dimensional polyacrylamide ge l electrophoresis (SDS-PAGE) revealed the presence of several new prot eins in the adult rats. Administration of human chorionic gonadotropin to immature rats for ten days also resulted in a significant increase as well as the appearance of several new proteins. The general patter n of SDS-PAGE analysis of the SER proteins of Leydig cells resembled t hat of the adult rat. SDS-PAGE analysis of the SER proteins of Leydig cells from adult rats following deprivation of endogenous luteinizing hormone by administration of antiserum to ovine luteinizing hormone re sulted in a pattern which to certain extent resembled that of an immat ure I at. Western Blot analysis of luteinizing hormone antiserum treat ed rat Leydig cell proteins revealed a decrease in the 17-alpha-hydrox ylase compared to the control. These results provide biochemical evide nce for the suggestion that one of the main functions of luteinizing h ormone is the control of biogenesis and/or turnover SER of Leydig cell s in the rat.