EFFECT OF DIETARY PROTEIN CONTENT ON VISUAL DISCRIMINATION LEARNING and BRAIN BIOCHEMISTRY IN THE ALBINO RAT

Effect of Protein Energy Deprivation on the Brain Enzymes of Glutamic Acid in Preweanling Rats

“…The differences could be due to greater reduc tion of brain protein content than the weight in undernourished rats. Rajalakshmi et al (1965Rajalakshmi et al ( , 1969 reported significant reduction in mean values of all the above-mentioned enzymes and in alanine, glutamic acid and GABA contents of the brain in postweanling young as well as adult rats on low protein diet. Rajalakshmi et al (1974) also reported decreased activity of GAD in undernourished preweanling rats.…”

“…Whether the neurological manifestations, in the form of apathy, mental dullness and lack of interest in surroundings encountered in patients with protein energy malnutrition are possibly due to increased concentration of GABA in the brain, is difficult to comment. However, Rajalakshmi et al (1965) had postulated that such changes are likely to be due to decreased concentration of glutamic acid and GABA in the brain. Present observations support the state ment by Baxter (1970) that elevated levels of GABA in the central nervous system are usually accompanied by sedated and depressed states while animals with low cerebral GABA levels are often hyperexcitable and prone to convul sions.…”

“…The enzymes studied included glutamine synthe tase, glutamine transferase, glutaminase 1, glutaminase II, glutamic acid decarboxylase (GAD), glutamic pyruvate transaminase (GPT) and glutamic oxaloacetic transaminase (GOT). The enzymes were estimated by the method described by Rajalakshmi et al (1965). Protein was estimated by the Biuret method described by Oser (1965).…”

“…and therefore it seems a possibility that these would be adverse- ly affected by undernutrition. Rajalakshmi et al (1965Rajalakshmi et al ( , 1969 demonstrated that the brain enzymes concerned with glutamic acid metabolism are altered during protein malnutrition. The present work was undertaken to study the glutamic acid metabolism in the whole brain of the undernourished preweanling rats.…”

Influence of Experimental Dietary Conditions on Hepatic Enzymes of Glutamic Acid Metabolism in Rats

“…Since glutamic acid can maintain the normal levels of leucocytic-and hepatic-free amino acids, some hepatic enzymes associated with glutamic acid metabolism were therefore studied under various experimental dietary conditions. Though Rajalakshmi et al (9) have reported that glutamate decarboxylase, glutamic pyruvic transaminase and glutaminases are lowered in brain of the protein deficient animals, such changes have not been observed in liver of rats given different levels of dietary protein. Fur thermore, the influence of starvation, dietary rehabilitation, feeding carbohy drate-free, protein-rich diet and of the dietary supplementation of non-protein nitrogen on some hepatic enzymes associated with glutamic acid metabolism has not as yet been studied.…”