REN and endothelial dysfunction: Possible adverse effects of uric acid on the vasculature have been linked to increased chemokine and cytokine expression [88], induction of renal vasoconstriction mediated by endothelial dysfunction, activation of the renin-angiotensin system [87], and stimulation of oxidative stress in vascular smooth muscle cell (VSMC) proliferation, mediated by the mitogen-activated protein (MAP) kinase pathway [89] and increased vascular C-reactive protein (CRP) expression [88].