Effects of salsolinol on smooth muscle responses to various biogenic amines.

Isolated smooth muscle tissues from rats, guinea pigs and rabbits were used to investigate pharmacological effects of salsolinol (1-methyl-6,7-dihydroxy-1,2,3,4-tetrahydroisoquinoline). By itself, salsolinol did not produce any profound or sustained sympathomimetic or 5-hydroxytryptamine-like activity in the concentrations used in these experiments (7.7 and 77 muM). Salsolinol was found to antagonize the contraction of the rabbit aorta induced by noradrenaline but did not affect the adrenaline-induced relaxation of the guinea pig tracheal chain. On both the rat fundus and oestrus rat uterus, salsolinol exhibited significant anti-5-hydroxytryptamine activity but responses of these tissues to acetylcholine and histamine remained unaffected, indicating that the action was not non-specific. These results suggest that in vivo formation of salsolinol after ethanol ingestion could produce significant pharmacological effects.