Table 12-1.

Sertoli cell–Leydig cell regulatory interactions

Paracrine factor	Origin	Receptor	Action
Androgens	Leydig cell	Sertoli cell	Regulate/maintain function and differentiation
Pro-opiomelanocortin peptides	Leydig cell	Sertoli cell	Decrease FSH actions
β-endorphin	Leydig cell	Sertoli cell	Decrease steroidogenesis
GnRH-like factor	Sertoli cell	Leydig cell	Decrease steroidogenesis
Estrogens	Sertoli cell	Leydig cell	Decrease steroidogenesis
TGF-α	Sertoli cell	Leydig cell	Decrease steroidogenesis
IL-1	Sertoli cell	Leydig cell	Decrease steroidogenesis
IGF-1	Sertoli cell	Leydig cell	Increase steroidogenesis