Glucose dilates renal afferent arterioles via glucose transporter-1

Glomerular hyperfiltration often occurs during the early stage of diabetes. An acute glucose infusion increases glomerular filtration rate (GFR). The involvement of tubuloglomerular feedback response and direct effect of glucose on the afferent arterioles (Af-Arts) have been suggested. However, the signaling pathways to trigger Af-Art dilatation have not been fully identified. Therefore, in the present study we tested our hypothesis that an increase of glucose concentration enhances endothelial nitric oxide synthesis (NOS3) activity and dilates the Af-Arts via glucose transporter 1 (GLUT1) using isolated mouse Af-Arts with perfusion. We isolated and microperfused the Af-Arts from non-diabetic C57BL/6 mice. The Af-Arts were preconstricted with norepinephrine (NE, 1 µM). When we switched the D-glucose concentration from low (5 mM) to high (30 mM) in the perfusate, the preconstricted Af-Arts significantly dilated by 37.8{plus minus}7.1%, but L-glucose did not trigger the dilation. GLUT1 mRNA was identified i...