Changes of cardiovascular system in rats associated with high intake of sodium chloride
Objective. The aim of the research was to study the influence of diet with different contents of NaCl on the level of arterial blood pressure (BP), processes of myocardial remodeling in response to changes in nuclear transcription factor кB (NFкB) expression in the myocardium in rats. Design and methods. Two groups of male Wistar rats have received a diet with normal (0,34 %; n = 8) and high (8,0 %; n = 8) content of NaCl for 2 months. BP was measured; urea, creatinine and sodium levels in blood serum and creatinine, protein and sodium levels in the urine were determined. The cardiac left ventricular mass index (LVMI) was calculated, morphological study of myocardium (lightoptical microscopy), including quantitative morphometry was carried out. The relative expression level of the NfкB gene was assessed in heart. Results. The high-salt diet resulted in a significant increase of diuresis and sodium concentration in the urine. High diet levels of NaCl did not affect significantly BP and LVMI. However, there were changes in the myocardium structure in the high-salt diet group, including myocardium hypertrophy and hyperplasia of cardiomyocytes, perivascular fibrosis, angiospasm, increased thickness of the artery walls due to smooth muscle cells hypertrophy, their vacuolization, and vascular sclerosis. There was a 3,4-fold increase in NFкB gene expression level in myocardium in the high-salt group compared to the low-salt group. Conclusions. Our findings suggest that the high consumption of sodium chloride can cause myocardial remodeling regardless of changes in BP.