Norepinephrine transporter function and autonomic control of metabolism

Item Type:	Article
Title:	Norepinephrine transporter function and autonomic control of metabolism
Creators Name:	Boschmann, M. and Schroeder, C. and Christensen, N.J. and Tank, J. and Krupp, G. and Biaggioni, I. and Klaus, S. and Sharma, A.M. and Luft, F.C. and Jordan, J.
Abstract:	Genetic variability, numerous medications, and some illicit drugs influence norepinephrine transporter (NET) function; however, the metabolic consequences of NET inhibition are poorly understood. We performed a randomized, double-blind, cross-over trial in 15 healthy subjects who ingested 8 mg of the selective NET inhibitor reboxetine or placebo. Energy expenditure and substrate oxidation rates were determined by indirect calorimetry before and during iv infusion of 0.25, 0.5, 1, and 2 micro g isoproterenol/min. Adipose tissue metabolism was studied by microdialysis before and during local isoproterenol perfusion. At rest, energy expenditure and substrate oxidation rates did not differ between reboxetine and placebo treatment. At 1 micro g/min isoproterenol, energy expenditure was significantly increased in men (+15%) and women (+20%) with both reboxetine and placebo treatment. However, carbohydrate oxidation rate was significantly higher with reboxetine compared with placebo. Baseline and isoproterenol-stimulated adipose tissue blood flow was about 2-fold higher with reboxetine vs. placebo. Furthermore, glucose supply and metabolism was significantly increased and lipid mobilization much more stimulated in adipose tissue under reboxetine when compared with placebo at all isoproterenol concentrations used. We conclude that acute NET inhibition increases adipose tissue glucose uptake and metabolism. While lipid mobilization is increased, overall lipid oxidation is decreased during {beta}-adrenergic stimulation. This effect cannot be explained by increased systemic or adipose tissue norepinephrine concentrations. Instead, NET inhibition may sensitize adipose tissue to {beta}-adrenergic stimulation.
Keywords:	Adipose Tissue, Adrenergic {beta}-Agonists, Autonomic Nervous System, Blood Flow Velocity, Carbohydrate Metabolism, Cross-Over Studies, Double-Blind Method, Energy Metabolism, Glucose, Hemodynamics, Indirect Calorimetry, Isoproterenol, Lipid Peroxidation, Microdialysis, Morpholines, Norepinephrine, Norepinephrine Plasma Membrane Transport Proteins, Oxidation-Reduction, Placebos, Posture, Supination, Symporters
Source:	Journal of Clinical Endocrinology and Metabolism
ISSN:	0021-972X
Publisher:	Endocrine Society
Volume:	87
Number:	11
Page Range:	5130-5137
Date:	November 2002
Official Publication:	https://doi.org/10.1210/jc.2002-020533
PubMed:	View item in PubMed

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