Prolonged local forearm hyperinsulinemia induces sustained enhancement of nitric oxide-dependent vasodilation in healthy subjects

TY - JOUR

T1 - Prolonged local forearm hyperinsulinemia induces sustained enhancement of nitric oxide-dependent vasodilation in healthy subjects

AU - Hermann, Thomas S

AU - Ihlemann, Nikolaj

AU - Dominguez, Helena

AU - Rask-Madsen, Christian

AU - Køber, Lars Valeur

AU - Torp-Pedersen, Christian

N1 - Keywords: Aged; Endothelium, Vascular; Female; Forearm; Glucose; Humans; Hyperinsulinism; Insulin; Male; Middle Aged; Nitric Oxide; Nitroprusside; Serotonin; Vasodilation; Vasodilator Agents; omega-N-Methylarginine

PY - 2005

Y1 - 2005

N2 - Systemic hyperinsulinemia induces enhancement of endothelium-dependent vasodilation of healthy subjects. During systemic infusion of insulin, endothelium-dependent vasodilation may be improved through a decrease in the concentration of free fatty acids. To explore the direct effect of continued insulin on the vascular endothelium, the authors infused insulin in the brachial artery for 4 h and measured the effect on endothelium-dependent vasodilation in the human forearm. Thirty-six experiments were performed in healthy subjects, mean age 47.7 +/- 1.1 years. Endothelium-dependent and -independent vasodilatation was studied during intra-arterial infusion of serotonin and sodium nitroprusside (SNP), respectively. Forearm blood flow was measured by plethysmography. Intra-arterial insulin was infused for 240 min at a constant rate and blood flow was measured hourly during stimulation of endothelium-dependent and -independent vasodilation.N(G)-monomethyl-L-arginine (L-NMMA) was coinfused to test the degree of nitric oxide (NO)-mediated vasodilation. Insulin infusion for 60 min enhanced serotonin-induced vasodilation by 37% compared to vehicle, p = .016. This increase was maintained for 4 h and was blocked by L-NMMA. The SNP response was increased by insulin but the increment was inhibited by L-NMMA. Four hours of local forearm hyperinsulinemia causes a sustained increase in endothelium dependent vasodilation in resistance vessels, which is mediated by NO.

AB - Systemic hyperinsulinemia induces enhancement of endothelium-dependent vasodilation of healthy subjects. During systemic infusion of insulin, endothelium-dependent vasodilation may be improved through a decrease in the concentration of free fatty acids. To explore the direct effect of continued insulin on the vascular endothelium, the authors infused insulin in the brachial artery for 4 h and measured the effect on endothelium-dependent vasodilation in the human forearm. Thirty-six experiments were performed in healthy subjects, mean age 47.7 +/- 1.1 years. Endothelium-dependent and -independent vasodilatation was studied during intra-arterial infusion of serotonin and sodium nitroprusside (SNP), respectively. Forearm blood flow was measured by plethysmography. Intra-arterial insulin was infused for 240 min at a constant rate and blood flow was measured hourly during stimulation of endothelium-dependent and -independent vasodilation.N(G)-monomethyl-L-arginine (L-NMMA) was coinfused to test the degree of nitric oxide (NO)-mediated vasodilation. Insulin infusion for 60 min enhanced serotonin-induced vasodilation by 37% compared to vehicle, p = .016. This increase was maintained for 4 h and was blocked by L-NMMA. The SNP response was increased by insulin but the increment was inhibited by L-NMMA. Four hours of local forearm hyperinsulinemia causes a sustained increase in endothelium dependent vasodilation in resistance vessels, which is mediated by NO.

U2 - 10.1080/10623320490904098

DO - 10.1080/10623320490904098

M3 - Journal article

C2 - 15763942

SN - 1062-3329

VL - 11

SP - 231

EP - 239

JO - Endothelium

JF - Endothelium

IS - 5-6

ER -