SERTOLI CELLS AS POTENTIAL TARGETS OF PROLACTIN ACTION IN THE TESTIS

Abstract Using primary cultures of porcine Sertoli cells as a model, the effects of ovine prolactin (oPRL) on Sertoli cell function were investigated through FSH binding. PRL treatment (0.3–5 ng/ml) induced a dose-dependent increase (ED 50 = 5.10 −11 M) of 125 I-FSH binding to Sertoli cells to a maximal stimulation (about 2.5-fold increase). This effect was time-dependent, being detected within 2 h ( P K d = 0.8 and 1.4 nM, respectively). Affinity labeling of these receptors by covalently binding to 125 I-oPRL and subsequent electrophoretic analysis of the labeled complexes revealed for the cell membranes, two major labeled bands of 74 and 64 kDa and three other faintly labeled bands of 190, 150 and 140 kDa. For the nuclear fractions, three major labeled bands with high molecular weights of 190, 150 and 140 kDa were observed. Taken together, the present findings suggest that Sertoli cells are potential targets for prolactin action in the porcine testis.