dihydromorphine and Alcoholism

The dose-response curve for morphine-induced stimulation of striatal dopamine metabolism was shifted to the right in mice which had been withdrawn for 24 hours after chronic consumption of an ethanol-containing liquid diet. The apparent ED50 for morphine was increased by 33% in ethanol-treated mice. Concomitant with the shift in the dose-response curve, the affinity for dihydromorphine of the high-affinity caudate morphine receptor was decreased in ethanol-treated mice. The change in receptor properties after ethanol treatment included a decreased sensitivity of the receptor to the effects of sodium ion on morphine binding. The results suggest: 1) that the effect of morphine on dopamine metabolism in the mouse striatum is, at least in part, mediated by receptors that exhibit a high affinity for dihydromorphine: and 2) that ethanol treatment and withdrawal may induce specific changes in these particular opiate receptors.

Topics: 3,4-Dihydroxyphenylacetic Acid; Alcoholism; Animals; Caudate Nucleus; Corpus Striatum; Dihydromorphine; Dihydroxyphenylalanine; Dopamine; Humans; Male; Mice; Mice, Inbred C57BL; Morphine; Receptors, Opioid

Topics: Alcoholism; Animals; Brain; Dihydromorphine; Ethanol; Humans; Kinetics; Male; Rats; Rats, Inbred Strains; Receptors, Opioid; Receptors, Opioid, delta; Receptors, Opioid, mu