title: The effects of angiotensin-converting enzyme inhibition on sodium handling in patients with advanced chronic obstructive pulmonary disease.
abstract: Ten clinically stable, hypercapneic patients with advanced chronic obstructive pulmonary disease were studied to assess the effect of angiotensin-converting enzyme blockade on their inability to excrete a sodium load. Renal, hormonal, and cardiovascular responses to sodium loading were determined during two 5.5-h studies: control day, placebo; and experimental day, captopril. At baseline, compared with control subjects, patients displayed a decrease in urinary sodium associated with low effective renal plasma flow and high plasma level of aldosterone. Captopril, given before sodium loading, produced a significant increase in urinary sodium without increasing effective renal plasma flow and without suppressing plasma aldosterone more than sodium loading alone. Thus, the mechanism by which angiotensin-converting enzyme inhibition induces an acute sodium diuresis in these patients remains to be elucidated. The blockade of angiotensin with captopril also affected the osmotic regulation of vasopressin: for a given increase in plasma osmolality, the increase in plasma vasopressin was subnormal, a finding consistent with the hypothesis that angiotensin II contributes to the regulation of vasopressin secretion.
authors.affiliation: Department of Medicine, Indiana University School of Medicine, Indianapolis.
authors.forename: M O
authors.initials: MO
authors.lastname: Farber
authors.forename: M H
authors.initials: MH
authors.lastname: Weinberger
authors.forename: G L
authors.initials: GL
authors.lastname: Robertson
authors.forename: N S
authors.initials: NS
authors.lastname: Fineberg
mesh_terms: D000806:Angiotensin-Converting Enzyme Inhibitors / Q000627:therapeutic use*; D002216:Captopril / Q000627:therapeutic use; D002986:Clinical Trials as Topic; D006801:Humans; D006935:Hypercapnia / Q000188:drug therapy / Q000503:physiopathology; D008173:Lung Diseases, Obstructive / Q000188:drug therapy* / Q000503:physiopathology; D008297:Male; D009318:Natriuresis / Q000187:drug effects*; D009994:Osmolar Concentration; D010919:Placebos; D011897:Random Allocation; D012462:Saline Solution, Hypertonic; D012964:Sodium / Q000378:metabolism; D013997:Time Factors; D014667:Vasopressins / Q000097:blood
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D010919:Placebos; D012462:Saline Solution, Hypertonic; D014667:Vasopressins; D002216:Captopril; D012964:Sodium