Inhibition of protein synthesis on homologous and heterologous desensitization in the rat adipocyte

Desensitization of lipolysis was induced in isolated rat adipocytes by incubation with isoproterenol 10^?5M or ACTH 250 mU/ml for two and three hours, respectively. Those cells desensitized with isoproterenol were restimulated with either isoproterenol 10^?7M or ACTH 6 mU/ml and those cells desensitized with ACTH were restimulated with isoproterenol 10^?7M. Lipolysis was quantitated by the release of cyclic AMP and glycerol. No effect on either homologous or heterologous desensitization was observed when either cycloheximide 2 μg/ml or puromycin 10^?4M was included in the incubation media during the induction of desensitization. These findings support the conclusion that protein synthesis plays no role in the desensitization of lipolysis in the isolated rat adipocyte.