Manganese toxicity: free amino acids in the striatum and olfactory bulb of the mouse.

We studied the levels of twenty two free amino acids in the striatum and olfactory bulb of mice treated during nine weeks with daily intraperitoneal injections of manganese chloride at a concentration of 5.0 mg Mn+2/kg body weight. In the olfactory bulb the contents of alanine, alpha-amino-n-butyrate, arginine, asparagine, aspartate, citrulline, GABA, glutamate, glycine, isoleucine, leucine, methionine, phenylalanine, serine, threonine, tyrosine, and valine were diminished. No alterations were observed in the concentrations of free amino acids in the striatum of Mn-treated mice. The changes detected in the olfactory bulb merit a thorough evaluation in order to determine its importance on the pathophysiology of manganese poisoning.