Angiotensin II receptor and myocardial remodeling in hypertension / 中国药理学通报

ABSTRACT

Angiotensin II (Ang II ) is an effector of rein-angiotensin system. Ang II receptors mediate its biological effects. An analysis of radioactive ligand demostrated that mammalian exists AT1 receptor and AT2 receptor subtype. AT1 receptor exists three isoforms, AT1A, AT1B and AT1c receptor subtype in rat and mouse. The AT3 and the AT4 subtype receptors had been cloned, but their structure and function were unknown. The AT1 receptor belongs to the superfamily of seven trans-membrane domain, G-protein-coupled receptors and was 20%~ 30% homologous to other G-protein-coupled receptors. The AT1 receptor mainly exists in vessel, heart and adrenal glands in adult animals. The AT2 receptor only has 32% amino acid sequences homologous to AT1 receptor and mainly exists in embronic tissue and intersti-tium. Recent studies have shown that the AT1 receptor may mediate most of the biological functionof Ang I . The AT1 receptor mediates promoting the expression of growth-related inducible transcription factors such as c-fos, c-jun and c-myc, and inducing myocardial cell hypertrophy, cardiac fibroblasts proliferation and interstitial collagen deposition. The AT1 receptor antagonist can reverse myocardial hypertrophy and collagen accumulation induced by hypertension, but the AT2 receptor antagonist can't. The biological function of the AT2 receptor is little known. The AT2 receptor may mediate inhibit on of growth factor-induced cell proliferation, oposite AT1 receptor-induced mi-togenic effect and induce apoptosis. The AT1 receptor and AT2 receptor subtype in myocardial tissue may regulate the genesis and development of myocardial remodeling in hypertension togather.