Occurrence and Effect of PACAP in the Human Fetal Adrenal Gland

Abstract

A BSTRACT : In the study reported in this paper, we characterized PACAP in the human fetal adrenal gland and we investigated the effect of PACAP on steroid secretion from cultured fetal adrenal cells. The adrenal gland from 20week-old fetuses contained substantial concentrations of PACAP-immunoreactive material (88.6 ng/g wet tissue). HPLC analysis of adrenal extracts revealed the presence of both PACAP27 and PACAP38, the latter being the predominant form. Incubation of cultured fetal adrenal cells with PACAP38 (10 -7 M) significantly increased cortisol and DHEAS secretion. Administration of the ␤ -adrenoreceptor agonist isoproterenol mimicked the stimulatory effect of PACAP on both steroid secretion whereas preincubation of fetal cells with the ␤ -adrenoreceptor antagonist propranolol suppressed the steroidogenic effect of PACAP. These data, together with the observation that PACAP receptors are exclusively located on chromaffin cells, suggest that, in the fetal human adrenal gland, the effect of PACAP on steroid secretion is mediated via the local release of catecholamines.

Pituitary Adenylate Cyclase-Activating Polypeptide and Its Receptors: 20 Years after the Discovery

“…Exposure of human adrenal slices to the ␤-adrenergic receptor blocker l-alprenolol totally suppresses the steroidogenic effect of PACAP (Neri et al, 1996). Likewise, the action of PACAP on dehydroepiandrosterone and cortisol secretion by the fetal human adrenal gland is suppressed by the ␤-adrenoreceptor antagonist propranolol (Breault et al, 2000). Altogether, these observations indicate that, in several mammalian species, the effect of PACAP on corticosteroid secretion can be ascribed to the stimulatory action of the peptide on catecholamine secretion.…”

“…In newborn rat, PAC1-R mRNA is expressed in the adrenal medulla , and exposure of cultured neonatal rat chromaffin cells to PACAP stimulates neurite outgrowth (Wolf and Krieglstein, 1995). In 14-to 20-week-old human fetuses, PACAP binding sites are observed in the adrenal medulla Yon et al, 1998); in cultured human adrenochromaffin cells, PACAP stimulates AC activity, indicating that the binding sites found in the fetal human adrenal medulla actually correspond to functional receptors Breault et al, 2000). Because, during the second trimester of gestation, cells derived from the ectoderm migrate inside the fetal cortical zone to form the medulla (Cooper et al, 1990;Ehrhart-Bornstein et al, 1997), these observations suggest that PACAP may play a crucial role in the ontogenesis of the adrenal gland.…”

In vitro effects of crude extracts of Parkia biglobosa (Mimosaceae), Stereospermum kunthianum (Bignoniaceae) and Biophytum petersianum (Oxalidaceae) on corticosteroid secretion in rat

“…1 for other designations. stimulatory action of the peptide on catecholamine secretion [17][18][19]. Similarly, in the frog adrenal gland, tachykinininduced stimulation of corticosteroid production is mediated through activation of chromaffin cells [20].…”

A connection between extracellular matrix and hormonal signals during the development of the human fetal adrenal gland

“…2. dulla and the cortex (29)(30)(31). During fetal development, the adrenal medulla is mostly controlled by neuropeptides like the corticotrophin-releasing factor, arginin-vasopressin, vaso-active intestinal polypeptide, or the pituitary adenylate cyclase activating peptide (32,33), and these neuropeptides may directly regulate steroidogenic functions of the fetal cortex (34). However, the cortical development of the adrenal is mostly controlled by the major hormones Ang II and ACTH (35).…”