ABSTRACT
Proteins, as enzymes or structural proteins, control the reactions taking place within the cell. The possible functions of nucleic acids and proteins in the phenomena of dependence on and tolerance to narcotic analgesic drugs have received some attention. There have been very few reported studies of the effects of morphine treatment on nucleic acid metabolism in higher’ animals. Two drugs which inhibit protein synthesis directly, namely cycloheximide and puromycin, have been used in studies of morphine tolerance and dependence. Studies of the effect of morphine treatment on the rate of protein synthesis in vivo are complicated by the effects of morphine on the rate of decline of radioactivity in the free amino acid pool. The effect of morphine on amino acid efflux was not confined to the naturally occurring l-isomer, since the efflux of d-leucine was also reduced by morphine.
