Differential Role of Renal Alpha 1 Adreno Receptors Subtypes in Renal Vasculature in Normotensive and Hypertensive Conditions Subjected to High Dietary Salt Load

Abstract

Chronic high salt intake is well known to be linked to cause an increase in the blood pressure and one of the pathogenic effects of high salt on blood pressure is vascular functional impairment. The effect of sodium on vasculature involves an increase in the vascular resistance that could triggers a rise in the blood pressure. Sodium-induced increase in vascular resistance is primarily independent of any change in blood pressure; however, it could be an initiating factor for increase in the blood pressure. Salt induced increase in the vascular resistance involves alterations in several vasoregulatory mechanisms as evidenced in various vascular beds. A mechanism exhibiting a substantial effect on vascular function is the alpha (α1)-adrenergic system that significantly influences vascular resistance, thereby affecting peripheral vascular resistance and blood pressure. This review focused on the effects of increase dietary sodium intake on the α1-adrenergic system in renal vascular beds under normotensive and hypertensive conditions. Because the α1-adrenergic regulations of renal vascular function and renal hemodynamics affect blood pressure to a great extent, renal vascular assessment was performed. Study reports enhanced renal vascular sensitivity to α1-adrenergic agonist in high sodium normotensive and hypertensive condition, this could be due to functional alterations in the renal α1-adrenoreceptor density. This provide additional evidence on the underlying vascular pathology in salt-induced hypertension.