Diabetic cardiomyopathy: Role of renin angiotensin system

The renin angiotensin system (RAS) maintains the cardiovascular (CV) homeostasis and is involved in the pathogenesis of several disorders majorly related to heart and kidney. There are several peptides under RAS in which angiotensin (Ang) II is the major contributor. It was reported about the role of Ang II and its receptor Ang II type 1 (AT1) in mediating the CV remodeling during heart failure. Another receptor AT2 acts primarily opposite to that of AT1. Ang (1-7) is a peptide which can prevent the ventricular remodeling during cardiac complications acting via Mas receptor. Diabetes mellitus is characterized by multiple organ damage and also increases the prevalence and severity of CV diseases. Hyperglycemia activates the local RAS, resulting in the formation of Ang II and stimulation of the endogenous cell death pathway. Cardiac remodeling, including fibrosis and left ventricular hypertrophy, is found in the diabetic heart as a result of the activation of the RAS. Blockade of the AT1 receptor by Ang receptor blocker (ARB) can be effectively used to prevent the cardiac remodeling in the form of hypertrophy and fibrosis during diabetic conditions. By blocking the actions of Ang II on AT1 receptors, ARBs facilitate its action on AT2 receptors and also improves the conversion of Ang II to Ang (1-7), which upon acting on Mas receptor to counteract the activated RAS in diabetic cardiomyopathy.