EFFECTS OF MORPHINE, ALCOHOL AND COCAINE ON CELLULAR PROTEIN-SYNTHESIS, ACCUMULATION AND PROTEOLYSIS

Drug addicts have been reported to develop malnutrition as well as imm une dysfunction. Because cultured mesangial cells have many properties similar to both muscle cells and mononuclear cells, we studied the ef fects of commonly used drugs (heroin, cocaine and alcohol) on protein synthesis, accumulation and intracellular proteolysis. In the basal st ate, morphine (active metabolite of heroin, 10(-6) M) showed a lower ( p < 0.05) incorporation of C-14-tyrosine into TCA insoluble cellular a s well as supernatant precipitates when compared with the control. In contrast, cocaine increased (10(-6) M, p < 0.05 and 10(-8) M, p < 0.01 ) incorporation of C-14-tyrosine into cellular TCA insouble precipitat es. Morphine (10(-10)M to 10(-8) M) significantly decreased (p < 0.02) degradation of cellular protein. On the contrary, cocaine (10(-8) M) increased (p < 0.05) intracellular protein degradation. These results indicate that the use of drugs may significantly alter intracellular p roteolysis as well as synthesis. Drug-induced altered protein metaboli sm may be playing a role in the development of malnutrition as well as in immune dysfunction.