Abstract
Ethanol, 2.4 g/kg, or saline was given intraperitoneally to mice separately or 3 h after α-methyltyrosine, a tyrosine hydroxylase inhibitor. Some animals also received l-Dopa in various doses 2 h before ethanol or saline. All animals received an inhibitor of peripheral Dopa decarboxylase 30 min before l-Dopa. Immediately after the last injection the locomotor activity was recorded every 5 min for 1 h. The ethanol-induced stimulation of locomotor activity was suppressed by α-methyltyrosine. This suppression was partially reversed by l-Dopa. The reversal appeared to be optimal at a low dose of l-Dopa, 5–20 mg/kg, which by itself did not appear to influence the locomotor activity. These results support the view that central catecholamines are involved in the stimulatory action of ethanol on locomotor activity.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Ahlenius, S., Andén, N. E., Engel, J.: Restoration of locomotor activity in mice by low l-Dopa doses after suppression by α-methyltyrosine but not by reserpine. Brain Res. 62, 189–199 (1973)
Ahlenius, S., Brown, R., Engel, J., Svensson, T. H., Waldeok, B.: Antagonism by nialamide of the ethanol-induced locomotor stimulation in mice. J. Neural Transmission (in press) (1974)
Ahlenius, S., Carlsson, A., Engel, J., Svensson, T. H., Södersten, P.: Antagonism by alpha methyltyrosine of the ethanol-induced stimulation and euphoria in man. Clin. Pharmacol. Ther. 14, 586–591 (1973)
Boissier, J. T., Simon, P.: De la potentialisation des effets de la Dopa par les inhibiteurs de la monoamineoxydase. Psychopharmacologia (Berl.) 8, 428–436 (1966)
Butcher, L. L., Engel, J.: Behavioural and biochemical effects of l-Dopa after peripheral decarboxylase inhibition. Brain Res. 15, 233–242 (1969)
Carlsson, A.: Amphetamine and brain catecholamines. Proceedings of the Mario Negri Institute for Pharmacological Research, Milan, Italy. E. Costa and S. Garattini, Eds., pp. 289–300. New York: Raven Press 1970
Carlsson, A., Engel, J., Svensson, T. H.: Inhibition of ethanol-induced excitation in mice and rats by α-methyl-p-tyrosine. Psychopharmacologia (Berl.) 26, 307–312 (1972)
Carlsson, A., Lindqvist, M.: Effect of ethanol on the hydroxylation of tyrosine and tryptophan in rat brain in vivo. J. Pharm. Pharmacol. 25, 437–440 (1973)
Carlsson, A., Magnusson, T., Svensson, T. H., Waldeck, B.: Effect of ethanol on the metabolism of brain catecholamines. Psychopharmacologia (Berl.) 30, 27–36 (1973)
Hansson, L. C. F.: Evidence that the central action of amphetamine is mediated via cateoholamines. Psychopharmacologia (Berl.) 9, 78–80 (1966)
Randrup, A., Munkvad, J.: Role of catecholamines in the amphetamine excitatory response. Nature (Lond.) 211, 540 (1966)
Read, G. W., Cutting, W., Furst, A.: Comparison of excited phases after sedatives and tranquillizers. Psychopharmacologia (Berl.) 1, 346–350 (1960)
Reynolds, G. S., van Sommers, P.: Effects of ethyl alcohol on avoidance behaviour. Science 132, 42–43 (1960)
van Rossum, J. M.: Mode of action of psychomotor stimulant drugs. Int. Rev. Neurobiol. 12, 307–383 (1970)
Smith, C. B.: Enhancement by reserpine and α-methyl Dopa of the effects of l-amphetamine upon locomotor activity in mice. J. Pharmacol. exp. Ther. 142, 343–350 (1963)
Strömberg, U.: Dopa effects on motility in mice: potentiation by MK 485 and dexchlorpheniramine. Psychopharmacologia (Berl.) 18, 58–67 (1970)
Weissman, A., Koe, B. K., Tenen, S.: Antiamphetamine effects following inhibition of tyrosine hydroxylase. J. Pharmacol. exp. Ther. 151, 339–352 (1966)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Engel, J., Strömbom, U., Svensson, T.H. et al. Suppression by α-methyltyrosine of ethanol-induced locomotor stimulation: Partial reversal by l-Dopa. Psychopharmacologia 37, 275–279 (1974). https://doi.org/10.1007/BF00421541
Received:
Issue Date:
DOI: https://doi.org/10.1007/BF00421541