Plasma immunoreactive gamma melanotropin in patients with idiopathic hyperaldosteronism, aldosterone-producing adenomas, and essential hypertension.

Abstract

A non-ACTH aldosterone-stimulating factor(s) has been implicated in the pathogenesis of idiopathic hyperaldosteronism (IHA). Although this factor has not been fully characterized, some evidence suggests that it may be related to a pro-gamma-melanotropin (pro-gamma-MSH), derived from the NH2-terminal region of pro-opiomelanocortin. In the present study, plasma immunoreactive (IR-) gamma-MSH levels at 0800 h in patients with IHA were evaluated (90 +/- 17 fmol/ml; range: 13-173 fmol/ml) and found to be significantly higher (P less than 0.05) than those in subjects with aldosterone-producing adenomas (33 +/- 8 fmol/ml), essential hypertension (33 +/- 6 fmol/ml), and normotensive controls (19 +/- 2 fmol/ml). Seven of nine IHA subjects had circulating IR-gamma-MSH levels above the normal range (greater than 35 fmol/ml). In plasmas sampled at 1200 h, IR-gamma-MSH was significantly higher in patients with IHA (95 +/- 26 fmol/ml) and adenomas (63 +/- 23 fmol/ml), as compared with essential hypertensives (31 +/- 6 fmol/ml) and normotensives (19 +/- 3 fmol/ml). Mean plasma IR-ACTH, plasma cortisol, and urinary cortisol levels did not differ significantly between any of these groups. In order to evaluate the effect of a pro-gamma-MSH in vitro, adrenal adenoma tissue was obtained from two patients, one with elevated IR-gamma-MSH (61 fmol/ml) and a second with low IR-gamma-MSH (12 fmol/ml). Aldosterone secretion by dispersed adenoma cells from the former, but not the latter, underwent a fourfold dose-dependent (10(-14)-10(-9) M) increase in response to human Lys-gamma 3-MSH. These data suggest that a pro-gamma-MSH may be implicated as a pathogenic factor in a subset of patients with primary aldosteronism, particularly among those differentially diagnosed as having IHA.

• Authors: G T Griffing, B Berelowitz, M Hudson, R Salzman, J A Manson, S Aurrechia, J C Melby, R C Pedersen, A C Brownie
• Journal: The Journal of clinical investigation (J Clin Invest) Vol. 76 Issue 1 Pg. 163-9 (Jul 1985) ISSN: 0021-9738 [Print] United States
• PMID: 4019776 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Aldosterone
• Melanocyte-Stimulating Hormones

Topics

• Adenoma (blood)
• Adult
• Aldosterone (metabolism)
• Female
• Humans
• Hyperaldosteronism (blood)
• Hypertension (blood)
• Male
• Melanocyte-Stimulating Hormones (blood)
• Middle Aged
• Pituitary Neoplasms (blood)
• Pituitary-Adrenal System (physiopathology)