The effect of various 1,2,3,4-tetrahydroisoquinoline derivatives on 3H-dopamine and 3H-serotonin uptake in rat brain structures — In vitro studies

Abstract

Although its oxidation to acetate overwhelmingly predominates, acetaldehyde (ACH) formed during ethanol metabolism can be “trapped” by condensation with catecholamines (CAs) or DOPA. The condensation products, tetrahydroisoquinolines (TIQs), have been detected in the brains of mice chronically exposed to ethanol [1] and in the urine of alcoholics during detoxification [2].Catecholic TIQs are not without physiological effects. Several TIQs derived from dopamine or DOPA have been shown to promote ethanol consumption when infused centrally into alcohol-avoiding rats [3]. The TIQ derived from ACH and DOPA (3-carboxysalsolinol) has an analgesic action in mice [4]. The neurochemical aspects underlying these recently described effects of TIQs have not been clarified. Since alterations in serotonin (5-HT) have been implicated in ethanol preference [5] and in drug-induced analgesia (antinociception) [6], we decided to examine the effects of certain TIQs on the serotonergic system. In this communication, we report that intraperitoneal (i.p.) administration of Is, 3s(cis)-3-carboxysalsolinol (cSAL) results in significant changes in brain 5-HT levels and/or metabolism.