The effect of interleukin-1 and interleukin-2 on the adrenergic control of hormone-sensitive lipase in the human adipocyte.

The effect of interleukin-1 and interleukin-2 on lipolysis and the adrenergic control of lipolysis was studied. Biopsy specimens of human adipose tissue were incubated in media containing 3H-palmitate and 14C-glucose, and the ratio of these isotopes was used to determine adipocyte lipolysis. Isoproterenol, clonidine, and theophylline were used in the media to stimulate the beta 1- and alpha 2-receptors and the subreceptor mechanism, respectively. Interleukin-1 had no effect on basal lipolysis, and at maximal receptor stimulation, it had no effect on the adrenergic receptor control of lipolysis. Interleukin-2 had no effect on basal lipolysis or on the beta-adrenergic receptor. Interleukin-2 significantly (p less than 0.02) decreased the alpha 2-inhibition of lipolysis by 68%. The effect of interleukin-2 on the alpha-receptor was demonstrated to be a significant 45% decrease (p less than 0.03) in the receptor responsiveness (a measure of the postreceptor mechanism) with no alteration in receptor sensitivity (a measure of receptor number). This data suggest that interleukin-2 stimulates lipolysis by decreasing the alpha 2-adrenergic inhibition of hormone-sensitive lipase.