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.
Experimental and Clinical Research Center, Charité and HELIOS Klinikum, Berlin, Germany.
Andreas L
AL
Birkenfeld
Petra
P
Budziarek
Michael
M
Boschmann
Cedric
C
Moro
Frauke
F
Adams
Gabriele
G
Franke
Michel
M
Berlan
Marie A
MA
Marques
Fred C G J
FC
Sweep
Friedrich C
FC
Luft
Max
M
Lafontan
Jens
J
Jordan
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