Corticotropin-Releasing Hormone as Adrenal Androgen Secretagogue

The regulation of adrenarche is one of the enigmas of pediatric endocrinology. Adrenarche is thought to be governed by a dual control mechanism in which an adrenal androgen secretagogue acts upon a zona reticularis primed by ACTH. We hypothesized that corticotropin-releasing hormone (CRH) may serve as adrenal androgen secretagogue. We tested the concept by infusing either saline or human (h) CRH (1 µg/kg/h in saline) over 3 h, after overnight dexamethasone pretreatment, into eight young men within a randomized, cross-over study design. Serum ACTH and dehydroepiandrosterone-sulfate were measured once hourly; DHEA, androstenedione and 17-hydroxy-progesterone were determined at baseline and after 3 h of saline/hCRH infusion. ACTH levels remained unaltered during saline infusion and average ACTH responses amounted to 13 pg/mL (3.3 pmol/L) during hCRH infusion. Neither saline nor hCRH infusion altered 17-hydroxy-progesterone levels. Serum dehydroepi-androsterone-sulfate rose swiftly within 3 h of hCRH infusion and remained unchanged after saline (mean increase 37 versus 1%; p < 0.01). On average, serum DHEA doubled and androstenedione tripled during hCRH infusion, although no changes were observed during saline infusion (p < 0.01). In conclusion, CRH appears to have the capacity to act as adrenal androgen secretagogue. We suggest that the enigma of adrenarche may have an elegant solution, with CRH and ACTH coupled in sequence at the hypothalamic-pituitary level, and in parallel within the zona reticularis, just as they presumably are within the fetal adrenal, which is exposed to CRH of placental origin.