Potentiation of the Depressant Action of Alcohol by Adrenalin

Abstract

The depression produced by alcohol closely parallels the concn. found in the brain and the amt. of alcohol in the blood always mirrors the concn. in the brain. The capillaries of the brain must, therefore, be completely permeable to alcohol. These facts form the basis of chemical tests for intoxication. Potentiation of the action of alcohol by previously administered adrenalin has been described by U. Friedemann, who explained it as increased permeability of brain capillaries and named it "auxoneuro-tropic" action. The expts. presented confirm such a poten-tiation but require a different interpretation. If Friedemann''s explanation be true, normal brain capillaries are incompletely permeable to alcohol, and it might be surmised that any unusual behavior after drinking resulted from release of adrenalin due to excitement. Therefore, the distribution of intraven. injd. alcohol was studied alone, and after adrenalin. For a short time, the muscles of rabbits, previously given adrenalin, contained almost no alcohol, while the concn. in their blood and brain remained high. In contrast to this, equilibrium was rapidly established be- tween blood, brain and muscle in the controls. The dose of adrenalin necessary to produce an "auxoneurotropic" effect was far greater than that released in the body. Furthermore, it has long been known that large doses of adrenalin will cause temporary vasoconstriction in skeletal muscle. Thus when distribution is correlated with the known actions of adrenalin, it is evident that the "auxoneurotropic" action of adrenalin can be explained by alterations in circulation.