Gene Expression Profile Revealed Different Effects of Angiotensin II Receptor Blockade and Angiotensin‐Converting Enzyme Inhibitor on Heart Failure

Summary: Although recent clinical studies have indicated that angiotensin II receptor blocker is as effective in treating heart failure as an angiotensin‐converting enzyme inhibitor, it is unknown whether their effects are different. Dahl salt‐sensitive rats were treated with an angiotensin‐converting enzyme inhibitor benazepril, and an angiotensin II receptor blocker candesartan from 11 weeks old. We examined cardiac geometry and function by echocardiography, and histology and gene expression by high‐density oligonucleotide arrays using Affymetrix U34 (Affymetrix, Santa Clara, CA, U.S.A.). Dahl salt‐sensitive rats fed a high salt diet showed a marked increase in blood pressure and developed concentric hypertrophy at 11 weeks, followed by left ventricle dilation and congestive heart failure by 20 weeks after birth. Although both medications had only a mild antihypertensive effect, they strongly suppressed the development of cardiac hypertrophy, fibrosis and heart failure to the same extent. Gene expression pattern examined by Affymetrix GeneChip (Affymetrix) is quite different between the two drug groups, indicating that angiotensin II receptor blocker and angiotensin‐converting enzyme inhibitor prevent heart failure by different mechanisms.