Abstract
Effects of pyrithioxine, a pyridoxine derivative, on the GOTM shuttle and on the activities of enzymes concerned with the metabolism of γ-aminobutyrate, glutamate, glutamine and cystathionine were investigated. The interconversions of glutamate into aspartate and of aspartate into glutamate with rat brain mitochondria were not affected by the presence of 10^<-4>M of pyrithioxine. Pyrithioxine in 10^<-4>M had no effects on the activities of rat brain glutamic decarboxylase, pig brain γ-aminobutyrate transaminase, rat brain glutaminase and glutamine synthetase. With partially purified preparation from rat brain, it was succeeded to detect the activity of cystathionase. The activity of the enzyme was not effected by pyrithioxine in various range of homoserine concentrations. Pyrithioxine did not effect in any concentration to the activities of pyridoxal phosphate as coenzyme for apoglutamic decarboxylase of rat brain and apocystathionase of rat liver.
