Atrial natriuretic peptide levels and plasma volume contraction in acute alveolar hypoxia

• Published in: Journal of applied physiology (1985) 1997-01, Vol.82 (1), p.102-110
• Main Authors: Albert, T. S. E, Tucker, V. L, Renkin, E. M
• Format: Article
• Language: English
• Subjects: Animals; Apud cells. Peptide and protein hormones. Growth factors; Atrial Natriuretic Factor - metabolism; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Hypoxia - metabolism; Male; Oxygen - physiology; Plasma Volume - physiology; Pulmonary Alveoli - physiopathology; Radioimmunoassay; Rats; Rats, Wistar; Vertebrates: endocrinology
• ISSN: 8750-7587; 1522-1601
• DOI: 10.1152/jappl.1997.82.1.102

T. S. E. Albert, V. L. Tucker, and E. M. Renkin Department of Human Physiology, University of California, Davis, California 95616 Received 1 February 1996; accepted in final form 4 September 1996. Albert, T. S. E., V. L. Tucker, and E. M. Renkin. Atrial natriuretic peptide levels and plasma volume contraction in acute alveolar hypoxia. J. Appl. Physiol. 82(1): 102-110, 1997. Arterial oxygen tensions (Pa O 2 ), atrial natriuretic peptide (ANP) concentrations, and circulating plasma volumes (PV) were measured in anesthetized rats ventilated with room air or 15, 10, or 8% O 2 ( n  = 5-7). After 10 min of ventilation, Pa O 2 values were 80 ± 3, 46 ± 1, 32 ± 1, and 35 ± 1 Torr and plasma immunoreactive ANP (irANP) levels were 211 ± 29, 229 ± 28, 911 ± 205, and 4,374 ± 961 pg/ml, respectively. At Pa O 2 40 Torr, irANP responses were more closely related to inspired O 2 ( P  = 0.014) than to Pa O 2 ( P  = 0.168). PV was 36.3 ± 0.5 µl/g in controls but 8.5 and 9.9% lower ( P    0.05) for 10 and 8% O 2 , respectively. Proportional increases in hematocrit were observed in animals with reduced PV; however, plasma protein concentrations were not different from control. Between 10 and 50 min of hypoxia, small increases (+40%) in irANP occurred in 15% O 2 ; however, there was no further change in PV, hematocrit, plasma protein, or irANP levels in the lower O 2 groups. Urine output tended to fall during hypoxia but was not significantly different among groups. These findings are compatible with a role for ANP in mediating PV contraction during acute alveolar hypoxia. fluid balance; cardiac output; arterial hypoxemia; blood gases; plasma protein concentration 0161-7567/97 $5.00 Copyright © 1997 the American Physiological Society