Vasopressin: A potent autocrine/paracrine regulator of mammal adrenal functions.

Abstract

The control of adrenal functions by locally secreted neuropeptides or neutotransmitters is of great physiological importance. Vasopressin (VP) is one of these autocrine/paracrine regulators. We demonstrated by RT-PCR and perifusion experiments that rat and human adrenal medulla expressed and released vasopressin under basal conditions and under stimulation by acetylcholine. Intra-adrenal concentrations of VP may be sufficient to activate adrenal VP receptors. In the cortex, only the Vla receptor subtype has been detected. It triggered both steroid secretion and cortical growth. In the medulla, both Vla and Vlb receptor subtypes were expressed. Vlb receptors were mainly present on chromaffin ceils and stimulated catecholamine secretion. The role of the V la receptor remains unclear. Pathophysiological studies also revealed that human pheochromocytoma did not overexpress vasopressin receptors but might oversecrete vasopressin causing high plasma VP concentrations and elevated blood pressure.Endocr Res Downloaded from informahealthcare.com by Universitat Autonoma Barcelona on 11/04/14For personal use only.

Vasopressin V1a and V1b Receptors: From Molecules to Physiological Systems

“…Both V1a and V1b receptors are found in chromaffin cells of the adrenal medulla, where AVP stimulates catecholamine secretion (184,195). AVP peptide is found in the adrenal medulla and is believed to stimulate the secretion of adrenocortical and medullar hormones as a paracrine/autocrine hormone (195). In V1aR-KO mice, the secretion of glucocorticoids, corticosterone in rodents, and mineralocorticoid (mainly aldosterone) upon AVP stimulation was significantly attenuated (27,53,278).…”

“…The V1a receptor is expressed in the normal adrenal cortex and in hypertrophic and cancer states (53,196,258,474). Both V1a and V1b receptors are found in chromaffin cells of the adrenal medulla, where AVP stimulates catecholamine secretion (184,195). AVP peptide is found in the adrenal medulla and is believed to stimulate the secretion of adrenocortical and medullar hormones as a paracrine/autocrine hormone (195).…”

“…In the adrenal medulla, synthesis and secretion of AVP is stimulated by neurotransmitters (acetylcholine) or neuropeptides such as CRH (379), and the resulting AVP then stimulates catecholamine release (166,195,261). Both V1a and V1b receptors are expressed in the adrenal medulla.…”

“…Thus it appears that AVP participates in the regulation of adrenocortical and medullar functions through an autocrine/paracrine mechanism in the adrenal gland (166,183,195), although the production of AVP in the peripheral tissues should be carefully examined via mRNA and protein levels.…”

MECHANISMS IN ENDOCRINOLOGY: Autocrine/paracrine regulatory mechanisms in adrenocortical neoplasms responsible for primary adrenal hypercorticism

“…Arginine vasopressin (AVP) AVP produced by chromaffin cells in normal adrenal glands may exert a positive control on aldosterone and cortisol secretion via activation of type 1a receptors (V1a) positively coupled to phospholipase C (113,114). Intra-adrenal AVP secretion by pheochromocytomas has been evidenced by hormone measurement in preoperative adrenal vein sampling (115,116) and confirmed by in vitro experiments (117).…”