Angiotensin and angiotensin converting enzyme tissue levels in two-kidney, one clip hypertensive rats.
Renal tissue angiotensin I (Ang I) and II (Ang II) content and angiotensin converting enzyme activity were assessed in both kidneys during initial (7 days) and maintenance (25 days) phases of two-kidney, one clip hypertension in rats. At 7 and 25 days, systolic arterial pressure was 146 +/- 2 and 170 +/- 7 mm Hg, respectively. After 7 days, Ang I content of clipped kidneys was 64% and 70% higher (p < 0.001) than in nonclipped and sham-operated kidneys, respectively, when compared with levels in kidneys from sham-operated rats. In kidneys harvested 25 days after clipping one renal artery, Ang I and Ang II contents in clipped kidneys were increased 102% and 24% (p < 0.01), respectively. Ang II content was also 32% higher in nonclipped kidneys. Angiotensin converting enzyme activity in nonclipped kidneys was greater (p < 0.05) than that in either clipped (46% higher) or sham-operated kidneys (57% higher). Plasma Ang I and Ang II levels were elevated at 7 days but were not different at 25 days in clipped rats. These results demonstrate a dissociation between intrarenal and circulating levels of Ang I and Ang II and suggest that qualitatively different mechanisms may be responsible for the elevated intrarenal Ang II levels during the initial and maintenance phases of renal hypertension.
Guan
S
S
Department of Physiology, Tulane University School of Medicine, New Orleans, La 70112.
Fox
J
J
Mitchell
K D
KD
Navar
L G
LG
D000803:Angiotensin I / Q000097:blood / Q000378:metabolism; D000804:Angiotensin II / Q000097:blood / Q000378:metabolism*; D000818:Animals; D006978:Hypertension, Renovascular / Q000378:metabolism*; D007668:Kidney / Q000378:metabolism; D008297:Male; D007703:Peptidyl-Dipeptidase A / Q000097:blood / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012016:Reference Values; D012083:Renin / Q000097:blood
D000804:Angiotensin II; D000803:Angiotensin I; D007703:Peptidyl-Dipeptidase A; D012083:Renin