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 - Kober, Lars
AU - Torp-Pedersen, Christian
PY - 2005/3/15
Y1 - 2005/3/15
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.
KW - Aged
KW - Endothelium, Vascular/drug effects
KW - Female
KW - Forearm/physiology
KW - Glucose/metabolism
KW - Humans
KW - Hyperinsulinism/metabolism
KW - Insulin/blood
KW - Male
KW - Middle Aged
KW - Nitric Oxide/metabolism
KW - Nitroprusside/pharmacology
KW - Serotonin/pharmacology
KW - Vasodilation/drug effects
KW - Vasodilator Agents/pharmacology
KW - omega-N-Methylarginine/pharmacology
U2 - 10.1080/10623320490904098
DO - 10.1080/10623320490904098
M3 - Journal article
C2 - 15763942
VL - 11
SP - 231
EP - 239
JO - Endothelium: Journal of Endothelial Cell Research
JF - Endothelium: Journal of Endothelial Cell Research
SN - 1062-3329
IS - 5-6
ER -