title: Modulation of natriuresis by sympathetic nerves and angiotensin II in conscious dogs.
abstract: The effects of renal perfusion pressure and reflex sympathetic nerve stimulation on sodium excretion were studied in six conscious foxhounds on a normal sodium diet. This was done before, during common carotid occlusion (CCO), and during a recovery period following CCO. Three protocols were used 1) control (n = 6), 2) converting-enzyme inhibition (CEI, n = 6), and 3) CEI combined with a constant renal artery pressure (RAP, n = 5). In protocol 1, CCO increased RAP markedly (140.5 +/- 5.1 vs. 103.0 +/- 4.4 mmHg; P less than 0.001) along with a considerable natriuresis (128.4 +/- 20.1 vs. 86.3 +/- 15.1 mumol Na+/min; P less than 0.05). In protocol 2, CEI increased control sodium excretion but did not impair the natriuresis by CCO. Maintaining RAP at control levels in protocol 3 lead to an antinatriuresis (53.1 +/- 16.8 vs. 128.3 +/- 32.2 mumol Na+/min; P less than 0.05). Creatinine clearance was unaffected by all procedures. In conclusion, a change in ANG II formation shifts but does not impair the natriuretic response to CCO. A moderate sympathetic activation has a pronounced pressure-independent antinatriuretic effect, which is not mediated by angiotensin II.
authors.affiliation: I. Physiologisches Institut Heidelberg, Federal Republic of Germany.
authors.forename: P B
authors.initials: PB
authors.lastname: Persson
authors.forename: H
authors.initials: H
authors.lastname: Ehmke
authors.forename: U
authors.initials: U
authors.lastname: Kögler
authors.forename: H
authors.initials: H
authors.lastname: Kirchheim
mesh_terms: D000803:Angiotensin I / Q000494:pharmacology; D000804:Angiotensin II / Q000502:physiology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology*; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001643:Bridged Bicyclo Compounds / Q000494:pharmacology*; D001952:Bridged-Ring Compounds / Q000494:pharmacology*; D002339:Carotid Arteries / Q000502:physiology; D004285:Dogs; D005919:Glomerular Filtration Rate / Q000187:drug effects; D007668:Kidney / Q000187:drug effects / Q000294:innervation* / Q000502:physiology; D009318:Natriuresis / Q000187:drug effects; D017257:Ramipril; D012016:Reference Values; D012018:Reflex; D012077:Renal Artery / Q000502:physiology; D012083:Renin / Q000097:blood; D013564:Sympathetic Nervous System / Q000502:physiology*
chemical_list: D000806:Angiotensin-Converting Enzyme Inhibitors; D001643:Bridged Bicyclo Compounds; D001952:Bridged-Ring Compounds; D000804:Angiotensin II; D000803:Angiotensin I; D012083:Renin; D017257:Ramipril