Effect of D1-like receptor on α-adrenergic receptor mediated proliferation of vascular smooth muscle cells

Abstract

Objective To determine the effect of D1-like receptor on α-adrenergic receptor-mediated proliferation of vascular smooth muscle (VSM) cells. Methods The primary cultured VSM cells were treated by norepinephrine (NE) with or without the presence of D1-like receptor agonist, fenoldopam. The proliferation of VSM cells was determined by 3H-TdR incorporation. Result NE dose-dependently increased proliferation of primary cultured VSM cells from aorta of Sprague–Dawley rats, this effect was via α-adrenergic receptor, because α-adrenergic receptor blocker, phentolamine, blocked the stimulatory effect of NE on VSM cell proliferation. D1-like receptor agonist, fenoldopam, by itself had no effect, but reduced the stimulatory effect of NE on VSM cell proliferation. The above-mentioned effects were also confirmed in primary cultured VSM cells from human mesenteric arteries. Conclusion Activation of D1-like receptor reduces the stimulatory effect of NE on VSM cell proliferation, which may take part into the pathogenesis of essential hypertension.