The influence of l-methionine-d,l-sulfoximine on the labelling of acid soluble fraction and proteins of the brain cortex after intraperitoneal injection of 14c-leucine.

Methionine sulfoximine (MSO) inhibits the labelling of the acid soluble fraction and proteins of the brain cortex after the injection of 14C-leucine. The inhibition takes place even during the early stages after the injection of MSO, when no symptoms of paroxysms are observable. The action of MSO on the labelling of the acid soluble fraction and proteins in the brain cortex is obviously different from that in the kidney and liver. Whereas in the brain tissue MSO markedly influences the labelling of the free amino acid pool, in the kidney and liver it seems primarily affect the protein synthetic mechanisms. Also no decrease in labelling of the plasma acid soluble fraction was found on mice, treated with MSO. Experimental data support the idea, that the changes in the metabolism of proteins in the brain are not connected with the onset of the paroxysmal period.