Atrial natriuretic peptide induces postprandial lipid oxidation in humans.
OBJECTIVE
Atrial natriuretic peptide (ANP) regulates arterial blood pressure. In addition, ANP has recently been shown to promote human adipose tissue lipolysis through cGMP-mediated hormone-sensitive lipase activation. We hypothesized that ANP increases postprandial free fatty acid (FFA) availability and energy expenditure while decreasing arterial blood pressure.


METHODS
We infused human ANP (25 ng . kg(-1) . min(-1)) in 12 men (age 32 +/- 0.8 years, BMI 23.3 +/- 0.4 kg/m(2)) before, during, and 2 h after ingestion of a standardized high-fat test meal in a randomized, double-blind, cross-over fashion. Cardiovascular changes were monitored by continuous electrocardiogram and beat-by-beat blood pressure recordings. Metabolism was monitored through venous blood sampling, intramuscular and subcutaneous abdominal adipose tissue microdialysis, and indirect calorimetry.


RESULTS
ANP infusion decreased mean arterial blood pressure by 4 mmHg during the postprandial phase (P < 0.01 vs. placebo). At the same time, ANP induced lipolysis systemically (P < 0.05 vs. placebo) and locally in subcutaneous abdominal adipose tissue (P < 0.0001 vs. placebo), leading to a 50% increase in venous glycerol (P < 0.01) and FFA (P < 0.05) concentrations compared with placebo. The increase in FFA availability with ANP was paralleled by a 15% increase in lipid oxidation rates (P < 0.05 vs. placebo), driving a substantial increase in postprandial energy expenditure (P < 0.05 vs. placebo).


CONCLUSIONS
Our data identify the ANP system as a novel pathway regulating postprandial lipid oxidation, energy expenditure, and concomitantly arterial blood pressure. The findings could have therapeutic implications.
Birkenfeld
Andreas L
AL
Experimental and Clinical Research Center, Charité and HELIOS Klinikum, Berlin, Germany.
Budziarek
Petra
P
Boschmann
Michael
M
Moro
Cedric
C
Adams
Frauke
F
Franke
Gabriele
G
Berlan
Michel
M
Marques
Marie A
MA
Sweep
Fred C G J
FC
Luft
Friedrich C
FC
Lafontan
Max
M
Jordan
Jens
J
D000273:Adipose Tissue / Q000187:drug effects / Q000502:physiology; D000328:Adult; D009320:Atrial Natriuretic Factor / Q000008:administration & dosage / Q000494:pharmacology*; D001783:Blood Flow Velocity / Q000187:drug effects; D001794:Blood Pressure / Q000187:drug effects; D004734:Energy Metabolism / Q000187:drug effects; D006801:Humans; D007262:Infusions, Intravenous; D008055:Lipids / Q000502:physiology*; D008066:Lipolysis / Q000187:drug effects; D008297:Male; D017551:Microdialysis; D010084:Oxidation-Reduction; D019518:Postprandial Period / Q000187:drug effects*; D012016:Reference Values
D008055:Lipids; D009320:Atrial Natriuretic Factor