P0147the Effect of High Sodium Chloride Content in the Diet on the Cardiovascular System of Macacus Fascicularis

Abstract

Background and Aims It is traditionally believed that high consumption of sodium chloride leads to the development of arterial hypertension, which, in turn, will cause heart remodeling. However, more and more evidence is accumulating that a high sodium chloride content in the diet can cause heart damage without increasing blood pressure (BP). This is confirmed in experiments on rats. In addition, in animals of this species, supplementing a high-salt diet with soy proteins can prevent cardiovascular damage. Whether such mechanisms operate in primates remains unclear. Method The study was performed on male Macacus fascicularis. Monkeys were included in the experiment at the age of 4.6 -7.0 years and had a body weight of 5,5-7,5kg. Animals were divided into 3 groups. The first (control) included 5 animals, received standard ration; the second – 5 animals, received diet with high sodium chloride content (8 g NaCl/1 kg of the feed); the third – 6 animals, who were on a diet with high salt contents supplemented by soya isolated proteins (200 g/kg of the feed). In anesthetized animals measured blood pressure and performed an echocardiographic investigation. Follow up period lasted four month. Results Initially, in all groups of animals, blood pressure levels (Mean(SEM)) and echocardiographic parameters did not significantly differ. During the observation period, the studied parameters did not change much. For example, in the first group, an ejection fraction (EF) increased from 61.7(1.67) to 71.6(4.74), %; P=0.045. In the same group, a tendency toward a decrease in the left ventricle end-systolic dimension (1.50(0.056)vs 1.29(0.118), mm; P=0.079) was noted. Whereas the level of systolic and diastolic blood pressures in this group (for example, systolic BP: 115.4(3.95)vs 126.0(5.39), mm Hg; P=0.134) as well as in other groups of monkeys did not change significantly. Nevertheless, after four months of observation, the level of systolic blood pressure in the second group (126.0(5.39) mm Hg) of animals was significantly higher than in the first (103.0(5.54), P=0.0118) and nonsignificantly - in the third (104.0(8.39), mm Hg; P=0.065). EF in the end of follow up period in second group (71.6(4.74%) was significantly higher than in control (58.1(2.72),%; P=0.039) but not in the third group (60.9(5.03),%; P=0.162). Tricuspid annular plane systolic excursion in second group (1.02(0.08), mm) had an insignificant tendency to increase in comparison to the first (0.782(0.096), mm; P=0.094) or third (0.818(0.049), mm; P=0.052) groups. Conclusion Our data do not exclude the possibility that a high salt content in the food of lower primates can contribute to an increase in blood pressure and a change in heart function. However, to resolve the issues of the relationship between changes in heart function and the level of blood pressure and the presence of the cardioprotective effect of soy proteins under these conditions, longer observations are needed.

Comparative study of blood pressure and echocardiographic values of male cynomolgus macaques (Macaca fascicularis)

“…It is impossible to imagine modern clinical cardiology without echocardiographic examination, which combines such an advantage as non‐invasiveness with wide possibilities for the assessment of cardiac structure, functional parameters of the heart and central haemodynamics. Echocardiography is increasingly used for experimental studies of the effects of different pathological and therapeutic factors on the cardiovascular system 3,4 . Besides, a significant obstacle in assessing the structural and functional parameters of the cardiovascular system of various animal species is the lack of reference values, both in terms of their quality and the possible completeness of data presentation 5 .…”