Relationship between individual ventilatory response and acute renal water excretion at high altitude

2008 ◽  
Vol 162 (2) ◽  
pp. 103-108 ◽  
Author(s):  
Gabriele Valli ◽  
Daniela Bonardi ◽  
Federica Campigotto ◽  
Valter Fasano ◽  
Alessandra Gennari ◽  
...  
Keyword(s):  
High Altitude ◽  
Ventilatory Response ◽  
Water Excretion ◽  
Renal Water Excretion

Blunted hypoxic ventilatory drive in subjects susceptible to high-altitude pulmonary edema

1989 ◽  
Vol 66 (3) ◽  
pp. 1152-1157 ◽  
Author(s):  
Y. Matsuzawa ◽  
K. Fujimoto ◽  
T. Kobayashi ◽  
N. R. Namushi ◽  
K. Harada ◽  
...  
Keyword(s):  
Pulmonary Function ◽  
Pulmonary Edema ◽  
High Altitude ◽  
Pulmonary Function Test ◽  
Ventilatory Response ◽  
Hypoxic Ventilatory Response ◽  
High Altitude Pulmonary Edema ◽  
Function Test ◽  
History Of ◽  
Low Altitude

It has been proposed that subjects susceptible to high-altitude pulmonary edema (HAPE) show exaggerated hypoxemia with relative hypoventilation during the early period of high-altitude exposure. Some previous studies suggest the relationship between the blunted hypoxic ventilatory response (HVR) and HAPE. To examine whether all the HAPE-susceptible subjects consistently show blunted HVR at low altitude, we evaluated the conventional pulmonary function test, hypoxic ventilatory response (HVR), and hypercapnic ventilatory response (HCVR) in ten lowlanders who had a previous history of HAPE and compared these results with those of eight control lowlanders who had no history of HAPE. HVR was measured by the progressive isocapnic hypoxic method and was evaluated by the slope relating minute ventilation to arterial O2 saturation (delta VE/delta SaO2). HCVR was measured by the rebreathing method of Read. All measurements were done at Matsumoto, Japan (610 m). All the HAPE-susceptible subjects showed normal values in the pulmonary function test. In HCVR, HAPE-susceptible subjects showed relatively lower S value, but there was no significant difference between the two groups (1.74 +/- 1.16 vs. 2.19 +/- 0.4, P = NS). On the other hand, HAPE-susceptible subjects showed significantly lower HVR than control subjects (-0.42 +/- 0.23 vs. -0.87 +/- 0.29, P less than 0.01). These results suggest that HAPE-susceptible subjects more frequently show low HVR at low altitude. However, values for HVR were within the normal range in 2 of 10 HAPE-susceptible subjects. It would seem therefore that low HVR alone need not be a critical factor for HAPE. This could be one of several contributing factors.

Effect of a selective octapeptide analogue of somatostatin on renal water excretion in the dog

Metabolism ◽  
1985 ◽  
Vol 34 (5) ◽  
pp. 408-409 ◽  
Author(s):  
Theodore Mountokalakis ◽  
Mortimer Levy
Keyword(s):  
Water Excretion ◽  
Renal Water Excretion

Contributions of glomerular and tubular mechanisms to antidiuresis in conscious domestic fowl

1985 ◽  
Vol 249 (6) ◽  
pp. F842-F850 ◽  
Author(s):  
J. N. Stallone ◽  
E. J. Braun
Keyword(s):  
Water Conservation ◽  
Domestic Fowl ◽  
Arginine Vasotocin ◽  
Quantitative Investigation ◽  
Secondary Importance ◽  
Water Excretion ◽  
Avian Kidney ◽  
Combined Actions ◽  
A Minor ◽  
Renal Water Excretion

Recently developed radioimmunoassay (RIA) techniques were employed in a quantitative investigation of the renal actions of the avian antidiuretic hormone arginine vasotocin (AVT) in the conscious domestic fowl. Constant intravenous infusion of AVT at doses of 0.125-1.00 ng X kg-1 X min-1 was used to produce plasma AVT (PAVT) concentrations (verified by RIA) over the entire range of physiological PAVT levels in the domestic fowl. Comparison of the dose-response relationships between PAVT and glomerular and tubular mechanisms of antidiuresis revealed that tubular mechanisms are of primary importance and glomerular mechanisms of secondary importance in the conservation of water by the avian kidney. The greatest proportion of the total AVT-induced reduction in renal water excretion occurred at low physiological PAVT levels (less than 5 microU/ml), prior to any significant reduction in glomerular filtration rate (GFR), and appeared to be the exclusive result of tubular mechanisms of antidiuresis. At high PAVT levels (5-16 microU/ml), glomerular and tubular mechanisms overlapped, and their effects on water conservation could not be separated. Although GFR was reduced by nearly 30% at the highest dose of AVT, only minor additional amounts of water were conserved by the combined actions of glomerular and tubular mechanisms. Thus glomerular mechanisms appear to have only a minor secondary effect on water-conserving ability of the avian kidney.

Hypocapnia and sustained hypoxia blunt ventilation on arrival at high altitude

1984 ◽  
Vol 56 (3) ◽  
pp. 602-606 ◽  
Author(s):  
S. Y. Huang ◽  
J. K. Alexander ◽  
R. F. Grover ◽  
J. T. Maher ◽  
R. E. McCullough ◽  
...  
Keyword(s):  
High Altitude ◽  
Ventilatory Response ◽  
Minute Ventilation ◽  
Ventilatory Responses ◽  
Low Altitude ◽  
Arterial O2 Saturation ◽  
Sustained Hypoxia

Hypoxia at high altitude stimulates ventilation, but inhibitory influences in the first days after arrival limit the ventilatory response. Possible inhibitory influences include hypocapnia and depression of ventilation during sustained hypoxia. Our approach was to compare hypoxic ventilatory responses at low altitude with ventilation at high altitude. In 12 subjects we compared responses both to isocapnic hypoxia and poikilocapnic (no CO2 added) hypoxia during acute (less than 10 min) and sustained (30 min) hypoxia in Denver (1,600 m) with ventilations measured on each of 5 days on Pikes Peak (4,300 m). On Pikes Peak, day 1 ventilation [minute ventilation = 10.0 1/min, BTPS; arterial O2 saturation (Sao2) = 82%] was less than predicted by either acute isocapnic or poikilocapnic tests. However, sustained poikilocapnic hypoxia (Sao2 approximately = 82%) in Denver yielded ventilation similar to that on Pikes Peak on day 1. By Pikes Peak days 4 and 5, endtidal PCO2, pHa, and Sao2 approached plateaus, and ventilation (12.4 1/min, BTPS) on these days was as predicted by the acute isocapnic test. Thus the combination of hypocapnia and sustained hypoxia may have blunted the ventilatory increase on Pikes Peak day 1 but apparently not after 4 or 5 days of acclimatization.

scholarly journals Effect of alpha- and beta-adrenergic stimulation on renal water excretion in man

1974 ◽  
Vol 6 (4) ◽  
pp. 247-253 ◽  
Author(s):  
Tomas Berl ◽  
Judith A. Harbottle ◽  
Robert W. Schrier
Keyword(s):  
Adrenergic Stimulation ◽  
Beta Adrenergic ◽  
Water Excretion ◽  
Renal Water Excretion
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