Intrarenal angiotensin and bradykinin peptide levels in the remnant kidney model of renal insufficiency

Background. The remnant kidney model of renal failure is associated with normal or suppressed plasma renin and angiotensin (Ang) II levels when hypertension is established. However? the hypertension responds to angiotensin-converting enzyme (ACE) inhibition and Ang II receptor antagonism, suggesting a role for Ang II in the hypertensive process. Bradykinin (BK) is a potent vasoactive peptide that may also participate in this model. Methods. Ang IL and BK peptides were measured in the ischemic peri-infarct portion and the intact portion of the remnant kidney at two, five, and seven weeks after surgery. Plasma Ang II, renin, angiotensinogen, and aldosterone levels were also measured. Results. Ang II levels in the peri-infarct portion were higher than in the intact portion at ail time points and were higher than in sham-operated kidney at two weeks. Ang II levels in the intact portion were similar to the levels in kidneys of sham-operated rats at two and five weeks and were suppressed at seven weeks. BK levels were increased in the peri-infarct portion at all time points and in the intact portion at two and five weeks. Plasma Ang II and aldosterone levels were also elevated at two weeks. Conclusions Peri-infarct renal tissue Ang II levels and plasma Ang TT and aldosterone levels increase transiently during the evolution of hypertension in the remnant kidney model. Sustained hypertension is associated with an increase in intrarenal BK levels but not with persistent increases in intrarenal or circulating Ang II levels.