Influence of morphine on protein synthesis in discrete subcellular fractions of the rat brain

Extensive time course (15 min to 24 hr) measurements were made of the effects of acute and chronic morphine treatment on the incorporation of 3H-lysine into rat brain proteins. Acute and chronic morphine treatment inhibited cortical protein synthesis in the microsomal (Mc), mitochondrial (Mw) and soluble fractions (Sol.). In the subcortex, acute morphine stimulated labelled protein accumulation in the Mc and Mw fractions, Chronic morphine treatment decreased 3H-lys-protein accumulation in these fractions.