In vivo renal angiotensin converting enzyme activity decreases in glycerol-induced acute renal failure.
We previously demonstrated that intrarenal angiotensin II generation during glycerol-induced acute renal failure was attenuated, which may have resulted from the inability of intrarenal converting enzyme to convert renal angiotensin I to angiotensin II. In order to test this hypothesis in vivo, we determined the ability of the kidney to convert angiotensin I to angiotensin II by measuring the decrease in renal cortical blood flow (RCBF) in response to exogenous angiotensin I administration. Changes in RCBF were monitored by laser-Doppler velocimetry. Three groups of rats were studied: Group I, controls (N = 7); 24 hours prior to study Group II animals were injected with 50% glycerol, 8 ml/kg i.m. (N = 4); and Group III rats were injected with mercuric chloride, 3 mg/kg s.c. (N = 5). All experimental animals had a three- to sixfold rise in serum creatinine. Mean glomerular filtration rate (GFR) of the left and right kidney in control rats was 0.7 and 0.7 ml/min, respectively. Twenty-four hours after glycerol, GFR was 0.2 ml/min in the left kidney and 0.2 ml/min in the right kidney. In HgCl2 treated rats GFR was 0.1 ml/min in the left kidney and 0.1 ml/min in the right kidney. Each of the following maneuvers elicited a similar rise in blood pressure in Groups I through III. Specifically, when first angiotensin I (4 micrograms/kg/min) was infused for three minutes; second, when 10 minutes later angiotensin I (5 micrograms) was directly applied on the left kidney; and third, when angiotensin II (5 micrograms) was topically administered.(ABSTRACT TRUNCATED AT 250 WORDS)
Baranowski
R L
RL
Section of Nephrology, Veterans AdministrationMedical Center, Salt Lake City, Utah.
Westenfelder
C
C
D058186:Acute Kidney Injury / Q000139:chemically induced* / Q000201:enzymology; D000803:Angiotensin I / Q000378:metabolism; D000804:Angiotensin II / Q000378:metabolism; D000818:Animals; D005919:Glomerular Filtration Rate; D005990:Glycerol / Q000633:toxicity; D007668:Kidney / Q000201:enzymology*; D008297:Male; D008627:Mercuric Chloride / Q000633:toxicity; D007703:Peptidyl-Dipeptidase A / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D012079:Renal Circulation
D000804:Angiotensin II; D008627:Mercuric Chloride; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; D005990:Glycerol