Biomedical Science and Engineering, 2015, Vol. 3, No. 2, 41-45 Available online at http://pubs.sciepub.com/bse/3/2/3 © Science and Education Publishing DOI:10.12691/bse-3-2-3 AT1 Receptor Antagonists: Pharmacological Treatment of Hypertension in Brazil Vanessa Pepeliascov 1 , Kleber de Magalhães Galvão 1 , Dones Cláudio Janz Jr 2 , Helen Dutra Leite 3 , Felipe de Lara Janz 3,* 1 Bandeirante University, Sao Paulo, Brazil 2 Ponta Grossa StateUniversity, Ponta Grossa Brazil 3 Universityof São Paulo, Sao Paulo, Brazil *Corresponding author: fljanz@usp.br Abstract High blood pressure (HBP) is a multifactorial disease that affects millions of people around the world and contributes to a large number of deaths due to acute myocardial infarction, stroke and chronic kidney disease. Its etiology remains inconclusive, but it is known that it arises of central and peripheral catecholaminergic dysfunction. Thus, cellular mechanisms are still under investigation. Its pathophysiology is characterized by an increase in systolic and diastolic blood pressure levels. The national and international guidelines for hypertension indicate that effective pharmacotherapy provides a control in blood pressure values and mortality⁄ morbidityreduction. Classes of antihypertensive drugs available for clinical use are diuretics, beta-blockers, alpha-blockers, sympatholytic, calcium channel antagonists, angiotensin converting enzyme inhibitors and angiotensin receptor antagonists of angiotensin II (ARBs). ARBs (i.e.: candesartan, irbesartan, losartan, olmesartan, telmisartan and valsartan)represent current and often used drug class in Brazil.They have different molecular configurations with independent action mechanismsin angiotensin II AT1 receptor. The objective of this paper is to discuss the pathophysiology and pharmacotherapy of hypertension, emphasizing the antagonists of angiotensin II used in Brazil, since they constitute a class of antihypertensive drugs that has fewer side effects and greater therapeutic efficacy. Keywords: high blood pressure, pharmacotherapy, angiotensin II antagonists Cite This Article: Vanessa Pepeliascov, Kleber de Magalhães Galvão, Dones Cláudio Janz Jr, Helen Dutra Leite, and Felipe de Lara Janz, “AT1 Receptor Antagonists: Pharmacological Treatment of Hypertension in Brazil.” Biomedical Science and Engineering, vol. 3, no. 2 (2015): 41-43. doi: 10.12691/bse-3-2-3. 1. Introduction 1.1. Blood Pressure and Control Mechanisms Peripheral vascular resistance (PVR) and cardiac output (CO) determine blood pressure (BP). Control of BP involves numerous substances and physiological mechanisms that interact to maintain the PA at appropriate levels in different situations. Control mechanisms result from the interaction of various physiological systems as cardiovascular, renal, neural and endocrine systems. The autonomic nervous system and its different hormonal types stand out in controlling blood pressure [1]. Dysfunctions in these control mechanisms, with consequent changes in the variables PVR and DC result in systemic hypertension (SH) [2]. Autonomic nervous system (ANS) plays an important role in controlling blood pressure. According to the VI Brazilian Guidelines on Arterial Hypertension (2010) in 2007, there were 1,157,509 cases for cardiovascular disease (CVD) in the National Health System. With regard to costs, in November 2009 there were 91,970 hospitalizations for CVD, resulting in a cost of R$ 165,461,644.33. End-stage renal disease, another condition often associated to hypertension, resulted in the inclusion of 94 282 individuals undergoing dialysis in SUS(Health UnicSystem and 9,486 deaths in 2007. We can classify this regulation in two ways: short- termneuro-humoral regulation and medium and long-term regulation through the activation or inhibition of hormone systems or for retention and excretion of sodium [3]. ANS influences tonic and reflex cardiovascular system. Largely the effects caused by the nervous system in the cardiovascular system are due tothe action of neurotransmitters noradrenaline (NA) and acetylcholine (Ach). However, catecholamines release in other postganglionic sympathetic and parasympathetic terminals potentiate or decrease the activity of NA and Ach [4]. According to Guyton and Hall, 2002, [5] there are reflex mechanisms from the autonomic nervous system, that control the BP, the main ones are the baroreceptors, arterial chemoreceptors and lung receptors. The blood pressure control by the baroreflex system (mediated by stimulation of baroreceptors aortic and carotid, called high-pressure receptors) acts in situations where it is required to keep track of blood pressure, such as physical exercise, postural changes or pathological situations like hemorrhage and hypothermia [6]. Arterial chemoreceptors are sensitive cells that monitor the amount of oxygen, carbon dioxide, and hydrogen ions in the blood. When BP falls below a critical level, chemoreceptors are