Dehydrogenations by brain tissue. The effects of narcotics

IT has recently been shown The narcotics exert a profound inhibitory action on the oxidation of substances important in carbohydrate metabolism, viz. glucose and lactic and pyruvic acids, this action being accom- plished at concentrations of narcotics which are of the same order as those required to produce deep narcosis in animals. The narcotics, however, at these concentrations, do not interfere with the oxidation by the brain of sodium succinate or p-phenylenediamine. This indicates that their behaviour is not due to a disturbance of the brain-cell whereby its mechanisms for accomplishing oxidations as a whole are affected. Their behaviour appears to be due to an effect, possibly at cell interfaces, whereby the mechanisms which result in an activation of the molecules of lactic and pyruvic acids are greatly disturbed. It has also been shown that among narcotics belonging to the same chemical type those with the greater hypnotic activity have the greater inhibitory action on the oxidation by brain of glucose or lactic acid. The conclusion was drawn that an adsorption of the narcotic took place at a specific area or centre of the nervous system. This resulted in an inhibition of the oxidation of glucose, and of lactic and pyruvic acids by the cells constituting this nervous centre. The access or activation of oxygen was un- impaired, but the diminished ability of the cells to oxidise glucose or lactic acid resulted in a lowering of the amount of energy available for the cells to accomplish their functional activities. Narcosis-or a depression of the normal functional activity of the nervous centre in question-might then ensue.