Catecholamine effects on lipolysis and blood flow in human abdominal and femoral adipose tissue

With the use ofthe microdialysis method, the present study, performed on young,healthy, nonobese subjects of both genders, compares the effects oflocally infused catecholamines on glycerol concentration and blood flowin abdominal (Abd) and femoral (Fem) adipose tissue. Physiologicalactivation of the sympathetic nervous system through active tilt wasalso investigated. In both genders, extracellular glycerolconcentration was higher in Fem than in Abd adipose tissue. Local bloodflow was lower in Fem than in Abd adipose tissue. Isoproterenolperfusion increased extracellular glycerol levels, but no differenceswere found by gender or fat-deposit site. Isoproterenolinduced a greater increase in local blood flow in Fem adipose tissue inboth genders. Epinephrine and norepinephrine perfusion increasedextracellular glycerol and reduced blood flow. No major differenceswere found according to gender and fat-deposit site. Active tiltincreased plasma glycerol, free fatty acid, norepinephrine levels, andextracellular glycerol concentration to the same extent whatever thegender and fat deposit. Thus, Fem adipose tissue is characterized by ahigher extracellular glycerol concentration and a lower blood flow thanis Abd tissue in men and women. In these tissues, in situ lipolysis andlocal blood flow were similar in response to adrenergic stimulation.