Properties of rat anterior pituitary vasopressin receptors: relation to adenylate cyclase and the effect of corticotropin-releasing factor.

Abstract

Crude plasma membrane fractions were prepared from female Wistar rat anterior pituitaries. These fractions contained a single population of specific 3H-labeled [8- Corticotropin-releasing factor activated, and angiotensin inhibited, the adenylate cyclase activity of pituitary membranes. Under the same experimental conditions, vasopressin did not influence adenylate cyclase activity nor did it affect the corticotropin-releasing factor-induced activation. These data support the view that vasopressin is one component of the multifactorial regulation of corticotropin release and that it acts through a cAMP-independent pathway. The potentiation by vasopressin of corticotropin-releasing factor-induced cAMP accumulation in intact cells very likely proceeds through indirect mechanisms, which are not expressed in broken cell preparations.Despite abundant evidence (1-6) that the 41-residue peptide recently isolated from ovine hypothalami (7) is a physiological corticotropin-releasing factor (CRF), the hypothalamic factor responsible for the integrated release of corticotropin (ACTH) seems not to be a single peptide but a multifactorial complex (8, 9). Vasopressin has been proposed as a constituent of this complex (9, 10). There are several pieces of evidence in favor of this concept: the synergism observed between ovine CRF and vasopressin (10, 11); the coexistence of immunoreactive neurophysin/vasopressin and CRF in nerve terminals of the zona externa of the median eminence (12) and in cells of the paraventricular nucleus (13); and finally high levels of vasopressin in portal blood (14). Further support for the role of vasopressin in the CRF complex includes the potentiation of the Brattleboro rat CRF activity by addition of synthetic vasopressin (15) and recent chromatographic investigations (9,15 2907The publication costs of this article were defrayed in part by page charge payment. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. §1734 solely to indicate this fact.

Vasopressin V1a and V1b Receptors: From Molecules to Physiological Systems

“…Although CRH is the primary ACTH secretagogue (7,165,177), the influence of the AVP/V1b receptor on the HPA axis response becomes more significant under certain stress conditions (8,310,429). Blockade of the V1b receptor and CRH-R1 by the antagonists SSR149415 and CP-154,526, respectively, is effective for diminishing the ACTH response to stress.…”

“…For the control of ACTH secretion, CRH and AVP act synergistically on specialized cells, the corticotrophs, in the anterior pituitary gland (9,77,165,177,502). Although early studies proposed that AVP was the hypothalamic corticotrophin-releasing factor (331), after isolation of CRH from ovine hypothalami (515), this CRH peptide and its rodent and human counterparts proved to be a more powerful ACTH secretagogue than AVP, and it has since been shown to play a major role in the regulation of the HPA axis (7).…”

A Clinical Feature of Hyperlipidemia in Patients with Central Diabetes Insipidus.

“…Lipoprotein lipase after treatment and hepatic lipase before and is a disease caused by a lack of vasopressin, we suspected the mechanism of hypertriglyceridemia in this disease was somehow related to the function of this hormone. Three kinds of AVP receptors have been identified, namely Via [2], V 1 b [3] and V2 [4,5]. Via receptors, located in the liver, smooth muscle cells and kidney, mediate vasoconstrictor action.…”

“…Recently it was clarified that receptors for this hormone exist in various tissues other than the kidney such as smooth muscle cells, hepatocytes, adipocytes and cardiomyocytes [1][2][3][4][5], and that this hormone stimulates several metabolic processes, including glycogenolysis, gluconeogenesis, and fatty acid oxidation, and promotes lipolysis in rabbit and hamster suprarenal adipose tissues [6][7][8].…”

The physiology of corticotropin-releasing factor (CRF)

“…The cDNA of the oCRF precursor was cloned by Furutani et al, (1983) (Widmaier and Dallman, 1984), in culture (Buckingham, 1982), and in pituitary cells suspended in columns (Gaillard et al, 1984). Sensitivity varies but the in vitro effect appears to be specific for POMC derivatives (Wehrenberg et al, 1984).…”