Intratesticular secretion of a factor(s) with major stimulatory effects on Leydig cell testosterone secretion in vitro

The interaction of hCG, hydroxysteroids and interstitial fluid on rat Leydig cell steroidogenesis in vitro

“…The rate of cholesterol sidechain cleavage (as well as the transport of cholesterol to the mitochondria) is also increased by the trophic stimulus of LH (or hCG) which is the principal hormone regulating Leydig cell testosterone synthesis. However, the stimulatory activity in testicular interstitial fluid is not due to the presence of pituitary LH (Sharpe & Cooper, 1984). Nevertheless, it …”

“…Rat Leydig cells were prepared from adult male Sprague-Dawley rats and purified and cultured for 20 h as described by Sharpe & Cooper (1984) and Risbridger et al (1986). Briefly, purified Leydig cells were obtained using discontinuous gradients of Percoli (Pharmacia Ltd, Uppsala, Sweden).…”

“…However, there is increasing evidence to suggest that intratesticular concentrations of testosterone are regulated by local factors which may emanate from the seminiferous tubules and be transferred across the basement membrane into interstitial fluid to affect the Leydig cells (see reviews by de Kretser, 1982;Parvinen, 1982;Sharpe, 1983). In accordance with this proposal it has been demonstrated that rat testicular interstitial fluid (which bathes the Leydig cells in vivo) contains a proteinaceous factor(s), which is not LH, and can stimulate testosterone production in vitro by isolated Leydig cells from adult male rats (Sharpe & Cooper, 1984;Risbridger et ai, 1986).…”

Heterodimers and homodimers of inhibin subunits have different paracrine action in the modulation of luteinizing hormone-stimulated androgen biosynthesis.

“…Because uncharacterized Sertoli cell factors have been shown to either enhance or suppress Leydig cell functions (22)(23)(24)(25)(26), we tested the hypothesis that inhibin and related proteins may exert paracrine actions by modulating Leydig cell androgen production. We further tested the hypothesis that inhibin and related proteins regulate androgen production by ovarian theca interna cells.…”

Ultrastructural analysis of a local regulation of Leydig cells in the adult monkey (Macaca fascicularis) and rat

“…Sertoli\p=n-\Leydig cell communications have been demonstrated (Sharpe & Cooper, 1984;Tabone et al, 1984;Benhamed et al, 1985;Janecki et al, 1985;Verhoeven & Cailleau, 1985) but the chemical nature of the active substance(s) remains uncertain. In the rat and the stump-tailed macaque, Sertoli cell secretions contain an LHRH-like factor which influences Leydig cell steroidogenesis (Sharpe, 1983(Sharpe, , 1984.…”