Renin, aldosterone, electrolyte, and cortisol responses to hypoxic decompression

Abstract

Responses of plasma renin activity, plasma aldosterone, plasma cortisol, and plasma electrolyte concentration and urinary electrolyte and aldosterone excretion were studied in four men during hypoxic decompression to a stimulated altitude of 4,760 m in a pressure chamber. Three of the four subjects developed significant acute mountain sickness. Plasma sodium and potassium concentrations were unchanged. No significant change in plasma renin activity was observed, but values tended to fall. Plasma aldosterone concentration was depressed while plasma cortisol was elevated and diurnal variation lost. Urinary sodium excretion was unchanged, but urinary potassium and aldosterone excretion were decreased. The decrease in plasma and urinary aldosterone and urinary potassium in the absence of change in plasma renin activity or plasma potassium is of uncertain origin. It is unlikely to be due to a decrease in adrenocorticotropin secretion since plasma cortisol rose during the same time. None of the changes could be causally implicated in the development of acute mountain sickness although the increase in plasma cortisol was greatest in the most ill.

Association of High Altitude Hypertension with Angiotensin Converting Enzyme (ACE) Gene Insertion/Deletion Polymorphism

“…Many studies have shown a significant ACE gene D allele with essential hypertension [25][26][27][28][29][30][31]. On the other hand, several researchers have shown no significant differences in the allele and genotype distribution of ACE gene polymorphism between low altitude normotensive control and high altitude hypertensive cases [32][33][34][35][36][37][38][39]. The increase in body size has seen to be positively associated with blood pressure.…”

“…On exposure to high altitude, systemic hypertension results from sympathetic stimulation and it may continue for many weeks. The involvement of the renin-angiotensin-aldosterone system (RAAS) in the control of the salt and water balance and thereby blood pressure is well known during hypoxia and high altitude exposure [35,36]. At high altitude renal secretion is stimulated by decreased renal blood flow [37], which in turn activates the RAAS [16].…”

Association of high-altitude systemic hypertension with the deletion allele-of the angiotensin-converting enzyme (ACE) gene

“…The involvement of the renin-angiotensin-aldosterone system in the control of the salt and water balance, and thereby blood pressure, is well known during hypoxia and high-altitude exposure (Keynes et al 1982;Sutton et al 1977). At high altitude renal renin secretion is stimulated by decreased renal blood flow (Pauli et al 1968), which in turn activates the renin-angiotensin-aldosterone system.…”

Pre-adaptation, adaptation and de-adaptation to high altitude in humans: hormonal and biochemical changes at sea level

“…Hormones of hydromineral metabolism during exposure to chronic hypoxia have previously been studied both at rest and during exercise (Slater et al 1969;Singh et al 1974;Sutton et al 1977;Hackett et al 1978;Milledge et al 1982Milledge et al , 1983aMilledge and Catley 1987;Maresch 1985;BaÈ rtsch et al 1991;Rock et al 1993;Anand et al 1993;Ponchia et al 1995). From these studies, it has generally been admitted that hypoxia initially depresses plasma aldosterone concentration which returns to control values after 12±20 days (Milledge et al 1983b).…”