TY - JOUR
T1 - Chronic hyperinsulinemia enhances adrenergic vasoconstriction and decreases calcitonin gene-related peptide-containing nerve-mediated vasodilation in pithed rats
AU - Takotori, Shingo
AU - Zamami, Yoshito
AU - Mio, Mitsunobu
AU - Kurosaki, Yuji
AU - Kawasaki, Hiromu
N1 - Copyright:
Copyright 2008 Elsevier B.V., All rights reserved.
PY - 2006/5
Y1 - 2006/5
N2 - The present study investigated the influence of chronic hyperinsulinemia on vascular responsiveness induced by adrenergic nerves and calcitonin gene-related peptide-containing (CGRPergic) nerves in pithed rats with insulin resistance. Male Wistar rats (6 weeks old) received 15% fructose solution in drinking fluid for 10 weeks (fructose-drinking rats: FDR), which resulted in significant increases in plasma levels of insulin, total cholesterol and triglyceride, and systolic blood pressure, as compared with control rats. Pithed FDR showed greater adrenergic nerve-mediated pressor response to spinal cord stimulation (SCS) at the lower thoracic vertebra (Th 9-12) and pressor response to exogenous noradrenaline than control rats. In pithed FDR with blood pressure artificially increased by continuous infusion of methoxamine and blockade of autonomic ganglia by hexamethonium, CGRPergic nerve-mediated depressor responses to SCS were significantly smaller than those in control rats, but depressor responses to other vasodilators such as acetylcholine, CGRP and sodium nitroprusside were similar to those in control rats. These results suggest that chronic hyperinsulinemia in FDR facilitates adrenergic nerve-mediated vasoconstriction, which is associated with attenuated CGRPergic nerve-mediated vasodilation.
AB - The present study investigated the influence of chronic hyperinsulinemia on vascular responsiveness induced by adrenergic nerves and calcitonin gene-related peptide-containing (CGRPergic) nerves in pithed rats with insulin resistance. Male Wistar rats (6 weeks old) received 15% fructose solution in drinking fluid for 10 weeks (fructose-drinking rats: FDR), which resulted in significant increases in plasma levels of insulin, total cholesterol and triglyceride, and systolic blood pressure, as compared with control rats. Pithed FDR showed greater adrenergic nerve-mediated pressor response to spinal cord stimulation (SCS) at the lower thoracic vertebra (Th 9-12) and pressor response to exogenous noradrenaline than control rats. In pithed FDR with blood pressure artificially increased by continuous infusion of methoxamine and blockade of autonomic ganglia by hexamethonium, CGRPergic nerve-mediated depressor responses to SCS were significantly smaller than those in control rats, but depressor responses to other vasodilators such as acetylcholine, CGRP and sodium nitroprusside were similar to those in control rats. These results suggest that chronic hyperinsulinemia in FDR facilitates adrenergic nerve-mediated vasoconstriction, which is associated with attenuated CGRPergic nerve-mediated vasodilation.
KW - Adrenergic pressor
KW - Calcitonin gene-related peptide-nerve depressor
KW - Hyperinsulinemia
KW - Pethed rat
KW - Spinal cord stimulation
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U2 - 10.1291/hypres.29.361
DO - 10.1291/hypres.29.361
M3 - Article
C2 - 16832157
AN - SCOPUS:33745659837
VL - 29
SP - 361
EP - 368
JO - Hypertension Research
JF - Hypertension Research
SN - 0916-9636
IS - 5
ER -