REGULATION OF GLYCOGEN-SYNTHASE ACTIVITY IN ISOLATED RAT ADIPOCYTES BY LEVAMISOLE

The effect of levamisole on glycogen synthase activity in isolated adi pocytes was studied. The addition of levamisole to these cells resulte d in an acute concentration-dependent increase ni glycogen synthase ac tivity. In contrast, epinephrine, dibutyryl cyclic AMP (DcAMP) and cys teamine decreased glycogen synthase activity. The stimulatory effect o f levamisole on the activity of the enzyme was not affected by the pre sence of epinephrine but was diminished when either DcAMP or cysteamin e was present. The results of this study suggest that levamisole incre ases adipocyte glycogen synthase activity by a mechanism that can be r eversed by the elevation of cAMP.