IN VITRO OXIDATION OF MORPHINE BY RAT TISSUE HOMOGENATES

¹ Dept. of Pharmacology, University of Michigan Medical School, Ann Arbor

Morphine, in the presence of cytochrome c, is oxidized by rat tissue homogenates to a compound which is indistinguishable from pseudomorphine by chromatographic analysis. The addition of cytochrome c to these homogenates causes a concomitant fall in glucuronide synthesis. The capacity to oxidize morphine is intimately associated with the cytochrome enzymes. Nalorphine, heterocodeine and dihydromorphinone, compounds having free phenolic hydroxyl groups, are oxidized under similar conditions, codeine is not transformed in this manner. The pharmacological implications of these findings are discussed.