ROLE OF ALDOSTERONE IN THE REMNANT KIDNEY MODEL IN THE RAT

The renin-angiotensin-aldosterone system (RAAS) participates in the in jury sustained by the remnant kidney, Our studies assessed the importa nce of aldosterone in that model and the response of aldosterone to dr ugs interfering with the RAAS, Initially, four groups of rats were stu died: SHAM-operated rats, untreated remnant rats (REM), REM rats treat ed with losartan and enalapril (REM AIIA), and REM AIIA rats infused w ith exogenous aldosterone (REM AIIA + ALDO), The last group was mainta ined with aldosterone levels comparable to those in untreated REM rats by constant infusion of exogenous aldosterone. REM rats had larger ad renal glands and a > 10-fold elevation in plasma aldosterone compared to SHAM, REM. AIIA rats demonstrated significant suppression of the hy peraldosteronism as well as marked attenuation of proteinuria, hyperte nsion, and glomerulosclerosis compared to REM, REM AIIA + ALDO rats ma nifested greater proteinuria, hypertension, and glomerulosclerosis tha n REM AIIA rats, Indeed, by 4 wk of observation all of these features of the experimental disease were similar in magnitude in REM AIIA + AL DO and untreated REM, In separate REM rats spironolactone administrati on did not reduce glomerular sclerosis but did transiently reduce prot einuria, lowered arterial pressure, and lessened cardiac hypertrophy, In summary, aldosterone contributes to hypertension and renal injury i n the remnant kidney model.