Characteristics of the nitric oxide system indicators in the left ventricle myocardium in SHR

Abstract

The aim was to determine the morpho-functional parameters of the left ventricular myocardium NO system in the rats with essential hypertension (SHR line). Material and methods. We used a combination of modern highly informative methods, namely: research of NOS isoform profile (nNOS, iNOS eNOS) in the myocardial slices along with an assessment of their synthesis and expression of the corresponding mRNA; NO derived nitrites level determination directly in the myocardium homogenates and concentration of nitrotyrosine in blood plasma of rats. The results of the performed studies have shown that high blood pressure in the SHR was accompanied by a significant increase in the concentrations of all three NOS isoforms in the myocardium and increased expression of their mRNA. Higher concentration of nitrites by 18.8 % was detected in the SHR group compared with the control animals. The concentration of nitrotyrosine in blood plasma of rats with essential hypertension was also increased by 25 %. Conclusions. The predominance of IRM to constitutive isoforms of NOS with low IRM content to iNOS was noted in the myocardium of the control group rats while in SHR rats higher IRM values were marked for all NOS isoforms. The formation of hypertension is accompanied by high content of NO end metabolites and the development of systemic nitroso-oxidative stress with the increase of nitrotyrosine concentration.

The features of the nitric oxide system in the left ventricle myocardium in the rats with experimental intermittent hypoxia of different duration

“…Our previous studies of the NO system role in the pathologic myocardial remodeling caused by essential arterial hypertension in SHR rats have confirmed the assumption of the pathogenetic importance of this system as one of the possible conductors of cardiac muscle reconstruction [8]. However, the question of changes in the NO system under physiological effects, such as intermittent hypoxia, remains open.…”

“…The study of NOS mRNA isoforms expression in the left ventricular myocardium homogenates was carried out using a real-time polymerase chain reaction (RT-PCR) in the Department of Molecular Genetic Researches of the TMLC of ZSMU [8]. For RT-PCR in real time with the gene specific primers CFX96 ™ Real-Time PCR Detection Systems (Bio-Rad Laboratories Inc., USA) were used in accordance with the manufacturer's recommendations and Maxima SYBR Green/ROX qPCR Master Mix (2X) reagent kit (Thermo Fisher Scientific, Inc.).…”