Testicular peritubular cells secrete a protein under androgen control that modulates Sertoli cell functions.
Peritubular cells of the seminiferous tubule synthesize component(s) that stimulate Sertoli cells in culture to increase the production of androgen-binding protein and testicular transferrin. The active peritubular cell component(s) are trypsin-sensitive, heat-sensitive, acid-stable molecule(s) having a molecular weight between 50,000 and 100,000. These specific factors(s) are referred to as P Mod-S to designate protein(s), produced by peritubular cells (P), that modulate the functions of Sertoli cells (S). The degree of stimulation by P Mod-S is comparable to that obtained by maximal hormonal stimulation of the synthesis of ABP and transferrin by Sertoli cells. Levels of P Mod-S secreted into the medium by primary cultures of peritubular cells are increased in the presence of testosterone. Comparable concentrations of 17 beta-estradiol do not stimulate peritubular cells to synthesize P Mod-S. Data are interpreted to indicate that androgens act on testicular peritubular cells to increase the formation of P Mod-S and that P Mod-S may modulate the properties of adjacent Sertoli cells. Findings are discussed in relation to the nature of mesenchymal-epithelial cell interactions in the seminiferous tubule and to the possible role of P Mod-S as a mediator of androgen actions of Sertoli cells.
D000727:Androgen-Binding Protein / Q000096:biosynthesis*; D000728:Androgens / Q000502:physiology*; D000818:Animals; D002352:Carrier Proteins / Q000096:biosynthesis*; D002478:Cells, Cultured; D003470:Culture Media; D004958:Estradiol / Q000494:pharmacology; D008297:Male; D008970:Molecular Weight; D011506:Proteins / Q000502:physiology; D051381:Rats; D012708:Sertoli Cells / Q000502:physiology*; D013737:Testis / Q000166:cytology / Q000378:metabolism / Q000502:physiology*; D013739:Testosterone / Q000494:pharmacology; D014168:Transferrin / Q000096:biosynthesis*
D000727:Androgen-Binding Protein; D000728:Androgens; D002352:Carrier Proteins; D003470:Culture Media; D011506:Proteins; D014168:Transferrin; D013739:Testosterone; D004958:Estradiol