Role of the cardiac renin-angiotensin system in human heart failure

The local effects of angiotensin II (ANG II) on the heart may play an important role for the pathophysiology of cardiovascular disease. Numerous in vitro studies have demonstrated that angiotensin II has distinctive cellular effects in the cardiovascular system which are independent from its effects on blood pressure. These have led to the hypothesis that activation of the angiotensin system in the heart could be of functional relevance for the adaptive processes in several cardiovascular disorders such as cardiac hypertrophy heart failure. This concept has been further supported by clinical studies showing the beneficial effects of angiotensin-converting enzyme inhibitors in these circumstances. In order to study the gene regulation of renin-angiotensin system components in cardiac disorders we investigated the gene expression of angiotensin converting enzyme in human heart failure. Results showed that the enzyme is activated locally in this condition, supporting previous studies in animals. Taken together with recent evidence from genetic studies linking the enzyme to myocardial infarction and cardiac hypertrophy, our findings are in support of the notion that angiotensin converting enzyme plays a central role in cardiovascular physiology and pathophysiology.