The alterations of rat brain GABA and glutamine induced by the organophosphorus compound cyolane

Levels of the amino acids GABA and glutamine were determined in the whole brain of the white albino rat Rattus norvegicus after daily injection of 1/2, 1/4, 1/8, 1/16, 1/32 and 1/100 LD50 of cyolane. With 1/2 LD50 an increase in the level of both GABA and glutamine in the brain was recorded. Dose levels of 1/4 and 1/8 LD50 caused an increase in the level of GABA and a decrease in glutamine concentration followed by an increase from the 7th and 11th days for 1/4 and 1/8 LD50, respectively. The induced increase in GABA level started from the 2nd week for 1/16 and 1/32 LD50 and from the 3rd week for 1/100 LD50. Dose levels of 1/16, 1/32 and 1/100 LD50 caused a fluctuating increase in glutamine concentration starting from the 2nd, 3rd and 6th weeks, respectively, which was followed by a fluctuating decrease at the 9th week for 1/32 and 1/100 LD50. These findings support previous findings that the enhanced transformation of glutamic acid to GABA and glutamine is a result of a disturbance in the metabolism of the glutamic acid-GABA and the glutamic acid-glutamine systems in the rat brain.