The antagonizing effect of aspartic acid on the brain levels of monoamines and free amino acids during the development of tolerance to and physical dependence on morphine

Abstract

Since it has been shown in a previous study that aspartic acid prevents the development of physical dependence on and tolerance to morphine and antagonizes the abstinence syndrom signs, the biochemical bases of that prevention were investigated in the present study. The brain contents of serotonin, DA, NA, and free amino acids of the rats given aspartic acid and morphine separately and in combination were determined. It has been observed that most of the morphine-induced changes in the brain were normalized in the group given aspartic acid and morphine together. The relative ineffectiveness of aspartic acid in normalizing some amino acid levels decreased by morphine was discussed and some logical explanations were found.