Abstract

The effect of amphetamine-like compounds on the adenine nucleotide, inorganic phosphate and creatine phosphate content of the rat brain, frozen in situ, has been studied. Four hours after treatment with l-methylamphetamine, d- and l-amphetamine, l-ephedrine, dl-phenmetrazine and d-phendimetrazine there was an increase in the ratio ATP/ADP as a result of an increase in the ATP level and decrease in the ADP level. The dose required to produce this effect appears to be correlated with the potency of the drugs as central nervous system stimulants. The increased ratio ATP/ADP was demonstrated ½, 1½ and 3 hours after treatment with l-methylamphetamine, d-amphetamine and dl-phenmetrazine so that a relationship between this effect and the onset and duration of action of these drugs was indicated. It is suggested that the increase in the ratio ATP/ADP indicates a net increase in the resynthesis of ATP and that the increased energy thus made available may be a factor in the central stimulant action of these drugs.