Global REACH 2018: Volume regulation in high-altitude Andeans with and without chronic mountain sickness

Author(s):  
Andrew R. Steele ◽  
Michael M. Tymko ◽  
Victoria L. Meah ◽  
Lydia L Simpson ◽  
Christopher Gasho ◽  
...  

The high-altitude maladaptation syndrome known as chronic mountain sickness (CMS) is characterized by polycythemia and is associated with proteinuria despite unaltered glomerular filtration rate. However, it remains unclear if indigenous highlanders with CMS have altered volume regulatory hormones. We assessed N-terminal pro-B-type natriuretic peptide (NT pro-BNP), plasma aldosterone concentration, plasma renin activity, kidney function (urinary microalbumin, glomerular filtration rate), blood volume, and estimated pulmonary artery systolic pressure (ePASP), in Andean males without (n=14; age=39±11) and with (n=10; age=40±12) CMS at 4330 meters (Cerro de Pasco, Peru). Plasma renin activity (non-CMS: 15.8±7.9 vs. CMS: 8.7±5.4 ng/ml; p=0.025) and plasma aldosterone concentration (non-CMS: 77.5±35.5 vs. CMS: 54.2±28.9 pg/ml; p=0.018) were lower in highlanders with CMS compared to non-CMS, while NT pro-BNP was not different between groups (non-CMS: 1394.9±214.3 vs. CMS: 1451.1±327.8 pg/ml; p=0.15). Highlanders had similar total blood volume (non-CMS: 90±15 vs. CMS: 103±18 ml • kg-1; p=0.071), but Andeans with CMS had greater total red blood cell volume (non-CMS: 46±10 vs. CMS 66±14 ml • kg-1; p<0.01) and smaller plasma volume (non-CMS 43±7 vs. CMS 35±5 ml • kg-1; p=0.03) compared to non-CMS. There were no differences in ePASP between groups (non-CMS 32±9 vs. CMS 31±8 mmHg; p=0.6). A negative correlation was found between plasma renin activity and glomerular filtration rate in both groups (group: r=-0.66; p<0.01; non-CMS: r=-0.60; p=0.022; CMS: r=-0.63; p=0.049). A smaller plasma volume in Andeans with CMS may indicate an additional CMS maladaptation to high-altitude, causing potentially greater polycythemia and clinical symptoms.

1989 ◽  
Vol 257 (6) ◽  
pp. R1519-R1525 ◽  
Author(s):  
F. G. Smith ◽  
T. Sato ◽  
O. J. McWeeny ◽  
L. Torres ◽  
J. E. Robillard

The present study was designed to determine the influence of renal nerves in mediating the renal response to volume expansion in conscious newborn lambs. Bilateral renal denervation (n = 9) or sham surgery (n = 14) was carried out in newborn lambs 3 to 4 days before performing experiments. Lambs were between 6 and 12 days of age when studied. Chronic denervation did not alter basal neonatal renal function nor renal hemodynamics. Volume expansion with isotonic saline equal to 5% of body weight was associated with a fall in hematocrit and an increase in mean arterial blood pressure, glomerular filtration rate, urine flow rate, and Na+ excretion in intact and denervated lambs. In intact lambs, atrial natriuretic factor increased from 98 +/- 28 to 176 +/- 48 ng/ml during volume expansion and remained elevated for 1 h after volume expansion. In addition, plasma renin activity fell from 21 +/- 5 to 8 +/- 1 ng.ml-1.h-1 and aldosterone levels fell from 160 +/- 24 to 59 +/- 7 pg/ml by 150 min after the start of volume expansion. Similar changes in atrial natriuretic factor, plasma renin activity, and aldosterone were observed in denervated lambs. However, the increase in glomerular filtration rate, Na+ excretion, and fractional excretion of Na+ after volume expansion were significantly less in denervated than in intact lambs. Thus, in the newborn, the renal nerves do not appear to play a role in influencing basal renal hemodynamics and renal function but, as in the adult, the renal sympathetic nervous system does play a role in regulating fluid and electrolyte excretion during hypervolemia.


1978 ◽  
Vol 54 (6) ◽  
pp. 661-666
Author(s):  
T. Kahn ◽  
D. M. Kaji ◽  
G. Nicolis ◽  
L. R. Krakoff ◽  
R. M. Stein

1. The inter-relationships between plasma aldosterone, plasma renin activity, potassium excretion and plasma potassium were evaluated in subjects with normal and decreased glomerular filtration rate. 2. In seven studies of healthy control subjects and 12 studies of patients with renal disease, daily urine collections, plasma aldosterone and plasma renin activity were measured on a free diet for 5–10 days and subsequently during the addition of 50 mmol of potassium chloride daily for 5 days. Plasma aldosterone was also measured in 22 hospital patients with normal glomerular filtration rate and 24 patients with reduced glomerular filtration rate. 3. Plasma aldosterone was similar in base-line conditions in patients with or without renal disease and increased similarly during the administration of potassium chloride, suggesting that potassium excretion in patients with reduced glomerular filtration rate probably does not depend primarily upon increased aldosterone. 4. Plasma renin activity increased similarly in control subjects and patients with renal disease during the administration of 50 mmol of potassium chloride/day, but plasma renin activity did not increase when 100 mmol of potassium chloride/day was given to control subjects. 5. With the administration of 50 mmol of potassium chloride/day mean daily potassium excretion increased similarly in control subjects and patients with renal disease but plasma potassium increased significantly (4·7 to 5·4 mmol/l) only in patients with renal disease, suggesting that their uptake of potassium into cells was impaired.


1977 ◽  
Vol 43 (3) ◽  
pp. 421-424 ◽  
Author(s):  
J. R. Sutton ◽  
G. W. Viol ◽  
G. W. Gray ◽  
M. McFadden ◽  
P. M. Keane

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.


1965 ◽  
Vol 20 (5) ◽  
pp. 1026-1027 ◽  
Author(s):  
Rodolfo Lozano ◽  
Carlos Monge C.

When compared with sea-level residents, the healthy natives living at an altitude of 4,540 m show a 12% reduction in the glomerular filtration rate, a 37% reduction in effective renal plasma flow, a 12% reduction in effective renal blood flow, and an increase of 39% in the filtration fraction. The corresponding values in patients with chronic mountain sickness living at 4,300 m above sea level are: glomerular filtration rate, 32% reduction; effective renal plasma flow, 57% reduction; effective renal blood flow, 9% increase; and filtration fraction, 56% increase. The mean hematocrit values of the healthy and sick natives investigated were 59 and 79%, respectively. The possible relationships between cardiac output, hematocrit values, and renal hemodynamics are discussed. altitude stress; blood flow, kidney; glomerular filtration Submitted on October 5, 1964


1982 ◽  
Vol 93 (1) ◽  
pp. 65-70 ◽  
Author(s):  
Stephen Ball ◽  
E. J. Johns

The renal nerves of the left kidney of sodium-replete anaesthetized rats were stimulated for 30-min periods at 2–3 Hz (15 V, 0·2 ms). Renal blood flow was reduced by 22% and glomerular filtration rate by 14% which resulted in a rise in filtration fraction of 12%. Circulating plasma renin activity was increased by 30% during such nerve stimulation. In rats treated for 3–4 weeks with deoxycorticosterone acetate (DOCA) and saline (150 mm-NaCl) basal values of arterial blood pressure, renal blood flow, glomerular filtration rate and filtration fraction were not significantly different from those observed in sodium-replete rats. However, plasma renin activity was lower, being approximately one-third of that observed in sodium-replete animals. Stimulation of the renal nerves in rats treated with DOCA and saline resulted in a fall in renal blood flow of 32% and a much larger fall in glomerular filtration rate of 33% which resulted in no change in filtration fraction. Plasma renin activity was not changed by renal nerve stimulation in the animals treated with DOCA and saline. It is suggested that these renal responses provide evidence in the rat for a role of locally generated angiotensin II in regulating glomerular filtration rate during electrical activation of the renal nerves by causing preferential vasoconstriction of the efferent arteriole.


1988 ◽  
Vol 74 (1) ◽  
pp. 63-69 ◽  
Author(s):  
S. B. Harrap ◽  
A. E. Doyle

1. To determine the relevance of renal circulatory abnormalities found in the immature spontaneously hypertensive rat (SHR) to the genetic hypertensive process, glomerular filtration rate and renal blood flow were measured in conscious F2 rats, derived from crossbreeding SHR and normotensive Wistar–Kyoto rats (WKY), at 4, 11 and 16 weeks of age by determining the renal clearances of 51Cr-ethylenediaminetetra-acetate and 125I-hippuran respectively. Plasma renin activity was measured at 11 and 16 weeks of age. 2. Mean arterial pressure, glomerular filtration rate and renal blood flow increased between 4 and 11 weeks of age. Between 11 and 16 weeks the mean glomerular filtration rate and renal blood flow did not alter, although the mean arterial pressure rose significantly. At 11 weeks of age, during the developmental phase of hypertension, a significant negative correlation between mean arterial pressure and both glomerular filtration rate and renal blood flow was noted. However, by 16 weeks when the manifestations of genetic hypertension were more fully expressed, no correlation between mean arterial pressure and renal blood flow or glomerular filtration rate was observed. Plasma renin activity was negatively correlated with both glomerular filtration rate and renal blood flow, but the relationship was stronger at 11 than at 16 weeks of age. 3. These results suggest that the reduction in renal blood flow and glomerular filtration rate, found in immature SHR, is genetically linked to the hypertension and may be of primary pathogenetic importance. It is proposed that the increased renal vascular resistance in these young animals stimulates the rise of systemic arterial pressure which returns renal blood flow and glomerular filtration rate to normal.


Sign in / Sign up

Export Citation Format

Share Document