The Role of Dietary Phosphate in Hypertension, Vascular Function and Inflammation.

Abstract

Endothelial dysfunction is a hallmark of hypertension and other vascular diseases. Endothelial nitric oxide synthase (eNOS) is essential for endothelial function and homeostasis, and eNOS dysregulation is a key common pathophysiologic step in several cardiovascular disease states. In this study, we examined the vascular function in response to dietary phosphate, which has been reported to regulate hypertension. C57bL/6 male mice were subcutaneously implanted with either saline or Ang II Infusion mini-osmot ic pumps (0.25 uL/hour for 28 days) before the diet protocol and underwent the 2-week control diet of 0.3% and 2-week phosphate diet (0.15%, 0.3%, 1.5%P). After that, the mice were sacrificed, and flow cytometry for the analysis of immune cells was performed on the aorta of control and Ang II-infused mice receiving the corresponding P-rich diet (0.15%,0.3%,1.5%P).Vascular reactivity studies by Wire myography for thoracic aortas were performed. To further assess vascular function, eNOS protein and superoxide are to be measured in aorta samples. Our data showed that high phosphate diet (1.5% P) reduced blood pressure following hypertensive stimuli. However, high phosphate diet exhibited a deleterious effect on the endothelial function and vascular inflammation especially in the hypertensive Ang II-infused mice. Thus, the role of phosphate in hypertension requires additional studies to dissect the mechanisms involved in mediating its effect on the vasculature.