engleski

The Effects of High Salt Intake on Cerebral Circulation

A high salt (HS) diet has harmful effects on organ systems in the human body. High doses of salt lead to impaired microcirculation, increase the level of reactive oxygen species (ROS) and activates the immune system. Such a diet suppresses the renin-angiotensin system (RAS) and is a known risk factor for the development of cardiovascular disease. Studies have shown that angiotensin II (ANG II) is a key link between high salt intake and the development of endothelial dysfunction. Numerous studies have shown that 3-7 days of high salt diet do not changed significantly blood pressure, but lead to endothelial dysfunction and impaired vascular reactivity even in normotensive animal and human models due to increased oxidative stress. With the knowledge that stroke is one of the leading causes of mortality and that the potential impact of high salt dietary intake in these cases was not investigated, we have based our research on the influence of this parameter on cerebral resistance vessels which are crucial for control of brain blood flow and tissue perfusion. Studies demonstrate that acute HS intake leads to impaired vasodilation and change the mechanisms of middle cerebral arteries (MCAs) vasodilation in response to flow without significant changes in blood pressure. This impaired vasodilation occurs, most likely, because of decreased serum ANG II concentrations and a consequent increase in systemic and vascular oxidative stress level. Also, HS diet leads to changes in the expression of the transcription factor hypoxia- inducible factor-1 α (HIF-α) and vascular endothelial growth factor (VEGF) which are obviously involved in increased oxidative stress in the vasculature. In contrast to the above, angiotensin II supplementation under conditions of high salt intake, preserved level of FID, decreased incurred oxidative stress and showed that mechanisms in MCAs are same like in low salt conditions. These results are very important for the understanding of the necessity to decrease kitchen salt even in the case of normotension in order to decrease the risk of stroke and other cardiovascular diseases.

high salt diet ; cerebral circulation

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