[Age-dependence of catecholamine effect in man. III. Influence of alpha- and beta-adrenergic agents on the lipolysis in the adipose tissue in vitro].

With the help of subcutaneous adipose tissue performed on 0,1- to 10-, 20- to 40- and 60- to 75-year-old test persons the effect of isoprenalin, adrenalin and noradrenalin on the release of glycerol or the unesterified fatty acids was investigated. Independent on age the quantity of the isoprenalin-stimulated lipolysis increases with the size of the fatty acids of the incubated tissues. The specimens of adipose tissue used do not show any differences in the size of the adipocytes between the individual age groups. Amaximum release of glycerol is achieved in a concentration of the medium of 10(-5) mol/l (isopernalin) to 10(-4) mol/l (adrenalin). Isopernalin effects an altogether larger increase of lipolysis in the adipose tissue of the human being of old age in already smaller concentrations compared with other age groups. These findings refer to a higher affinity of adrenergic beta-receptors of the adipocytes in this age period, but also to possible age differences in the chain of lipolysis mediated by cAMP.