ALCOHOL INDUCES FORMATION OF MORPHINE PRECURSORS IN THE STRIATUM OF RATS

Dopamine-derived alkaloids, the tetrahydroisoquinolines (TIQs), are su spected to play a role in the pathogenesis of alcoholism. The present study describes the alcohol induced formation of the S-enantiomer of T etrahydropapaveroline and Norcoclaurine in the rat brain. These compou nds are of special interest since both were found as being intermediat es in the biosynthesis of morphine in the opium poppy. The concentrati on of both TIQs were determined in different brain regions of Wistar r ats after 6 and 18 months alcohol consumption nd libitum. Gas chromato graphy/mass spectrometry was used for the detection and quantification of the enantiomers. Tetrahydropapaveroline and norcoclaurine were det ected only in the striatum of those rats which had consumed alcohol fo r 18 month, neither in other brain regions nor in any brain regions of the controls or the short term (6 month) alcohol treated rats. These findings and the fact that those tetrahydroisoquinolines were only det ected in the striatum of the alcohol fed rats and were present only as the S-enantiomers suggest that an alcohol induced biosynthetic pathwa y exists in the mammalian brain.