Aspectos morfofuncionais da zona glomerulosa adrenal de ratos com hipertensão renovascular: efeito do alisquireno

Abstract

Hypertension is one of the risk factors for developing cardiovascular diseases. This pathology is manifested not only as an elevation of blood pressure, but also implies structural and functional changes of target organs, causing, for example, left ventricular hypertrophy and development of kidney disease. Can be classified as primary (essential), no cause attributable, or secondary, which is a result of an identifiable cause. Renal artery stenosis is the most common cause of this type of hypertension. The model “two kidneys one clip” (2K1C) resembles the renovascular hypertension in humans, showing hyperactivity of the Renin angiotensin aldosterone (RAAS). The adrenal glands are one of the major homeostatic organs of mammals, as they regulate blood volume, electrolyte balance and blood pressure mainly by the action of aldosterone, a mineralocorticoid produced by cell in the glomerulosa zone of the adrenal cortical region. They are formed by two distinct histological regions: an external cortex and a medulla arranged internally. Both are surrounded by a connective tissue capsule. The Mineralocorticoid aldosterone is secreted by adrenal glands, governed by the RAAS and acts in target organs such as heart, blood vessels and kidneys in order to keep track of blood volume, electrolyte balance and blood pressure (BP). Recent studies enhance the action of aldosterone as key hormone in the development of the hypertension. The RAAS is a hormonal cascade that through its multiple interactions contributes to cardiovascular homeostasis, additionally also regulates the endothelium response to inflammation. Excessive or activation of this deregulation has been recognized as an element of importance in the pathogenesis of cardiovascular, renal diseases and hypertension. The aliskiren is a direct blocker of RAAS, decreasing the activity of Renin and plasma concentration of angiotensin II and aldosterone inhibition. Several studies are underway to assess the effectiveness of aliskiren on protection of target organs. In this work, we evaluated the effects of structural and ultrastructural alisquireno of the zone glomerulosa of the adrenal gland of rats 2K1C. AT1R expression was evaluated, as well as PGC-1α, Cytochrome C, Bax / Bcl-2, EEA1 e Rab7. It was observed that aliskiren was able to mitigate the deleterious effects caused by renovascular hypertension in the glomerulosa zone, reducing the expression of the AT1 receptor, Cytochrome C, Bax/Bcl-2 ratio, EEA1 and Rab 7. It was also observed that the aliskiren was not able to attenuate the mitochondrial biogenesis expressed by PGC-1α. Finally, was observed that the aliskiren was able to minimize ultrastructural damage in the glomerulosa zone.