Pharmacological Activation of Brown Adipose Tissue Metabolism

50mg of Mirabegron will be administered orally at time 0 in protocol A.

Acute cold exposure protocol using a water-conditioned cooling suit will be applied from time 120 to 300 min in protocol B

I.v. injection of 18-fluorodeoxyglucose (18FDG) will be performed at time 270 min, followed by 30 min dynamic PET/CT scanning

i.v. injection of 11C-acetate will be performed, followed by 20 min dynamic PET/CT scanning

i.v. administration of 1.5 uCi/min of \[3-3H\]-glucose

i.v. administration of 0.08 umol/kg/min of \[U-13C\]-palmitate

i.v. administration of 0.05 µmol/kg/min of 2H-glycerol