Studies on plasma vasopressin and the renin-angiotensin-aldosterone system in chronic obstructive lung disease
Farber, M.O.; Kiblawi, S.S.; Strawbridge, R.A.; Robertson, G.L.; Weinberger, M.H.; Manfredi, F.
Journal of Laboratory and Clinical Medicine 90(2): 373-380
1977
ISSN/ISBN: 0022-2143 PMID: 886222 Document Number: 111290
Possible mechanisms involved in the impaired water and Na handling of stable, nonedematous hypoxic patients with chronic obstructive lung disease (COLD).sbd.group A, normacapnic; group B, hypercapnic.sbd.were evaluated. Basal glomerular filtration rate (GFR); effective renal plasma flow (ERPF); water, NA and solute excretion; plasma and urine osmolality (Posm and Uosm); and plasma arginine vasopressin (AVP) were measured serially for 4 h following an oral water load of 20 ml/kg. In the same patients, AVP and Posm were measured serially following 3% NaCl infusion. Plasma renin (PRA) and plasma aldosterone (PA) were also determined before and after i.v. 3% saline. Results were compared with those previously obtained in normal subjects. Group B patients showed low ERPF, impaired water and impaired Na excretion when compared with group A patients or with normal subjects. The AVP response of COLD patients, whether hypercapnic of not, was the same as observed in normal subjects over a wide range of Posm values induced by water loading and by hypertonic saline. COLD patients, particularly those in group B, tended to have higher than normal baseline levels of PRA and PA which were suppressed less completely than in normal subjects following saline infusion. In COLD patients AVP response is normal over a wide range of plasma osmolalities (270-310 mOsm/kg and the defect in Na and water excretion observed in hypercapnic COLD patients may be related to increased levels of PRA and PA.