part of part of endothelial cell endothelial cell of arteriole kidney afferent arteriole cell kidney afferent arteriole endothelial cell An endothelial cell that lines the interior surface of the afferent arteriole and maintains vascular tone. This cell responds to changing ion concentrations and blood pressure by releasing vasoactive substances, in order to regulate blood flow into the glomeruli, which is essential for glomerular filtration. KUPO:0001039 renal afferent arteriole