Effects of citrulline administration on enzymes of liver and brain in rats.

Intraperitoneal administration of citrulline (30 mg/kg body weight) for three days to rats brought about an increase in the activity of hepatic ornithine-aminotransferase without any change in glutamine-synthetase activity. In the brain of the same animals, the activity of the glutamine synthetase in cerebellum and brain stem increased significantly. In cerebral hemispheres the activity of ornithine aminotransferase was increased without a change in glutamine-synthetase activity. Under these conditions, there is a rise in the content of glutamine, citrulline, arginine and ornithine in all the three regions of the brain.