Distribution of amino acids and amino-acid enzymes in whole kidney and renal cortex. Effect of 24-h starvation.
The levels of activity of amino-acid enzymes (alanine-, aspartate- and tyrosine transaminases, serine dehydratase, glutamate dehydrogenase, glutamine synthetase, arginase and adenylate deaminase) in the kidney cortex and whole kidney of control and 24-h starved adult rats have been determined from crude homogenates. The individual amino-acid content of the two kidney fractions indicated has also been studied. Serine dehydratase was found mainly in the cortex, whilst glutamine synthetase presence was mainly limited to the medulla. The distribution of adenylate deaminase and glutamate dehydrogenase is remarkably uniform along the kidney. Starvation induced decreases in arginase and adenylate deaminase activities as well as a decrease in cortical serine dehydratase. Analysis of the variance of the enzyme data showed no significant overall changes with respect to distribution and starvation. The same analysis applied to aminograms indicated only significant changes when the distribution was studied on starved samples as a whole, with changes mainly in the urea cycle and some essential amino acids. The results suggested a remarkable degree of uniformity in kidney composition both with respect to amino acid and enzyme distribution. This uniformity is not markedly affected by starvation despite the important rôle of kidney in the overall amino-acid economy of the Mammal.
D000659:AMP Deaminase / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism*; D000818:Animals; D001119:Arginase / Q000378:metabolism; D005260:Female; D005969:Glutamate Dehydrogenase / Q000378:metabolism; D005974:Glutamate-Ammonia Ligase / Q000378:metabolism; D007668:Kidney / Q000378:metabolism*; D007672:Kidney Cortex / Q000378:metabolism; D012695:L-Serine Dehydratase / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D013217:Starvation / Q000378:metabolism*; D000637:Transaminases / Q000378:metabolism
D000596:Amino Acids; D005969:Glutamate Dehydrogenase; D000637:Transaminases; D001119:Arginase; D000659:AMP Deaminase; D012695:L-Serine Dehydratase; D005974:Glutamate-Ammonia Ligase