Modulatory effects of adrenergic agonists on testosterone secretion from rat dispersed testicular cells or Percoll-purified Leydig cells

Freshly dispersed testicular interstitial cells as well as Percoll-purified Leydig cells were studied in vitro in order to evaluate the effect of adrenergic agonists on testosterone (T) secretion. Epinephrine and phenylephrine did not change the rate of T release under basal conditions in freshly dispersed interstitial cells, but enhanced it during human chorionic gonadotropin (hCG) stimulation. Norepinephrine and clonidine had no effect on T secretion. In contrast, in Percoll-purified Leydig cells epinephrine increased T release both under basal and hCG-stimulated conditions. These data demonstrate that neurotransmitters may participate in T secretion from isolated Leydig cells

Characterization of adrenergic control of the Leydig cell steroidogenesis: identification of both stimulatory and inhibitory components

Percoll-purified Leydig cells were studied in vitro in order to evaluate the effect of adrenaline on testosterone (T) secretion. Adrenaline enhanced the basal and potentiated the hCG-induced T release. A similar effect was also obtained with the ß2-agonist, salbutamol. Although phenyleprine, an alfa1-agonist, did not alter the basal T secretion, it enhanced hCG-mediated T secretion. Para-aminoclonidine, an alfa2-agonist, decreased the basal T release without altering the HCG-stimulated T release. These data demonstrate that either inhibitory or stimulatory effects on T release can be obtained and that they depend on the adrenoreceptor subtype involved