Article
Lipid Mobilization with Physiological Atrial Natriuretic Peptide Concentrations in Humans
Lipidmobilisation mit physiologischen atrialen natriuretischen Peptid-Konzentrationen beim Menschen
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Published: | August 10, 2005 |
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Background: Natriuretic peptides regulate vascular tone and renal sodium excretion. In recent studies, atrial natriuretic peptide (ANP) in pharmacological concentrations stimulated lipid mobilization in humans.
Methods: We tested the metabolic response to ANP in physiologically relevant concentrations in 14 healthy normal weight men (31±1.2years). Microdialysis probes were placed into abdominal subcutaneous fat tissue and femoral skeletal muscle to determine metabolites of lipolysis. Indirect calorimetry monitored changes in substrate oxidation rates. ANP was infused at rates of 6.25, 12.5, and 25ng/Kg/min.
Results: Venous ANP concentrations increased from 42+-4pg/ml at baseline to 498+-26pg/ml (p<.001) at the highest infusion rate. The increase in serum non-esterified fatty acids and glycerol concentrations significantly correlated with the increase in plasma ANP concentrations (r2=0.86 and r2=0.76, respectively). In adipose tissue, glycerol increased from 53+-6 to 87+-13mmol/l (p<.001), although ANP increased regional blood flow. In contrast, in skeletal muscle, dialysate glycerol did not change with ANP infusion. Lipid oxidation rate increased with ANP infusion (p<.05) whereas carbohydrate oxidation rates decreased (p<.01).
Conclusion: ANP stimulates lipid mobilization from adipose tissue and lipid oxidation in concentrations that are encountered in heart failure patients. Natriuretic peptide induced lipid mobilization might contribute to cardiac cachexia. Drugs that interfere with the natriuretic peptide system should be evaluated for potential metabolic side effects.