The Study of Synthesis, Accumulation and Release Processes of Atrial and Brain Natriuretic Peptides in Experimental Renovascular Hypertension

Abstract

The aim of the investigation was to study the dynamics of synthesis, accumulation and release processes of atrial (ANP) and brain (BNP) natriuretic peptides on day 60 of experimental renovascular hypertension.Materials and Methods. The experiments were carried put on white non-pedigree male rats. we studied renovascular hypertension using a two-kidney model with the left renal artery ligation. Arterial pressure (AP) was measured via caudal artery using an invasive technique. we analyzed left ventricular cardiac myocyte areas by light optics. Electron microscopic investigation was applied to study the left ventricular and right atrial tissue samples. ANP and BNP accumulation and release processes were assessed using a quantitative analysis of immunolabeled granules of atrial myocytes (А-type, "mature, storing", and B-type, "dissolving") under the transmission electron microscope. we performed a morphometric analysis of morphological types of the left ventricular and right atrial mitochondria.Results. The number of granules containing ANP and BNP in atrial myocytes on day 60 after the left renal artery ligation in rats was found to be no significantly different from that in the intact group. we revealed AP decrease up to the initial level. ANP and BNP content in atrial myocytes and AP recovered against the background of cardiac myocyte hypertrophy, mitochondrial de-energization and destructive changes in microcirculatory bloodstream.Conclusion. In a long-term period of experimental renovascular hypertension, ANP and BNP have a positive effect on AP level falling up to the initial one due to ANP and BNP release on day 30 of the experiment. The efficiency of natriuretic peptides acting as a regulatory component in primary hypertension formation depends on arterial hypertension genesis.

Possible Mechanisms for Normalization of the Level of Arterial Pressure with Unilateral Vasorenal Hypertension

“…В ряде исследований установлено, что в хронической фазе вазоренальной гипертензии концентрация в плазме ангиотензина II нормализуется [18,33]. В динамике развития вазоренальной гипертензии cнижение активности ренин-ангиотензиновой системы сопряжено с увеличением секреции натрийуретических пептидов (предсердного и мозгового), обладающих выраженным гипотензивным и кардиопротективным действием [5,9,10,18,27,34,35]. Кроме того, при деградации ангиотензина II образуются другие вещества и некоторые из них, например ангиотензин (1-7), обладают сосудорасширяющими свойствами и способны усиливать барорецепторный рефлекс [6,11].…”