Effects of Chronic D-Amphetamine and Phenylethylamine on the Concentrations of Neurotransmitter Amino Acids in the Rat Brain

Abstract

Rats were treated acutely and chronically with D-amphetamine or phenylethylamine. Following the treatments, the concentrations of amino acids in the hypothalamus and caudate nucleus were measured from prederivatized tissue extracts using reversed phase high pressure liquid chromatography with fluorescence detection. Acute amphetamine slightly decreased the caudate glutamine concentration, and chronic treatment for 10 days increased caudate aspartate content. Chronic phenylethylamine enhanced the taurine content, both in caudate and hypothalamus. No significant changes were observed in the concentrations of glutamate, GABA or alanine. The results indicate that these two stimulants can modify the brain metabolism of certain neuroactive amino acids in addition to the metabolism of catecholamines. The specific effect of chronic phenylethylamine on taurine concentration suggests an adaptive response of taurine-containing cells to repeated administrations of phenylethylamine.