Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.6.1.2 (alanine aminotransferase)
 26,722 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Crocodilians such as caimans and alligators are uricotelic and ammoniotelic animals. They are carnivorous but they excrete ammonium ions in an alkaline urine. The metabolic organization of the kidney of the Mississippi alligator was studied by measuring the renal metabolite profile, the activities of enzymes, and the behavior of kidney tubules in vitro. The liver and tail muscle were also studied. Both awake and anesthetized animals were in a state of low plasma bicarbonate and low blood pH with high plasma lactate concentration. This did not prevent the excretion of an alkaline urine (pH 7.76). alpha-Ketoglutarate was low in all three tissues and lactate was high. Glutamate concentration and glutamate dehydrogenase activity were highest in the kidney with a low equilibrium constant for alanine aminotransferase (KGPT). Glutaminase I was found only in the kidney. It could not be detected in liver or muscle. Glutamine synthetase was found only in the liver. Phosphoenolpyruvate carboxykinase (PEPCK) was present in both liver and kidney. Alanine aminotransferase and malic enzyme showed high activity in the kidney but were inconspicuous in liver and muscle. Malate dehydrogenase and lactate dehydrogenase were present in all three tissues. Renal tubules incubated with glutamine and alanine were ammoniagenic and gluconeogenic. Lactate was gluconeogenic. Enzyme activities were measured at both 30 and 37 degrees C. The studies on renal tubules were also performed at these two temperatures. Temperature had little effect on the data including acid-base values in the blood. Our findings demonstrate that the kidney of the alligator is perfectly equipped for various metabolic functions and especially for ammoniagenesis and gluconeogenesis.
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PMID:Metabolic machinery of the alligator kidney. 649 95

Renal adaptation to chronic metabolic acidosis was studies in Arbor Acre hens receiving ammonium chloride by stomach tube 0.75 g/kg/day during 6 days. During a 14-day study, it was shown that the animals could excrete as much as 60% of the acid load during ammonium chloride administration. At the same time urate excretion fell markedly but the renal contribution to urate excretion (14%) did not change. During acidosis, blood glutamine increased twofold and the tissue concentration of glutamine rose in both liver and kidney. Infusion of L-glutamine led to increased ammonia excretion and more so in acidotic animals. Glutaminase I, glutamate dehydrogenase, alanine aminotransferase (GPT), and malic enzyme activities increased in the kidney during acidosis but phosphoenolpyruvate carboxykinase (PEPCK) activity did not change. Glutaminase I was not found in the liver, but hepatic glutamine synthetase rose markedly during acidosis. Glutamine synthetase was not found in the kidney. Renal tubules incubated with glutamine and alanine were ammoniagenic and gluconeogenic to the same degree as rat tubules with the same increments in acidosis. Lactate was gluconeogenic without increment during acidosis. The present study indicates that the avian kidney adapts to chronic metabolic acidosis with similarities and differences when compared to dog and rat. Glutamine originating from the liver appears to be the major ammoniagenic substrate. Our data also support the hypothesis that hepatic urate synthesis is decreased during acidosis.
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PMID:The kidney of chicken adapts to chronic metabolic acidosis: in vivo and in vitro studies. 681 56

100 mg of taurine per kg body weight had been administered intraperitoneally and 30 min after the administration the animals were sacrificed. Glutamate dehydrogenase, aspartate aminotransferase, alanine aminotransferase, glutaminase, glutamine synthetase, glutamate decarboxylase and GABA aminotransferase along with the content of glutamate and GABA in cerebral cortex, cerebellum and brain stem were studied and compared with the same obtained in the rats treated with normal saline in place of taurine. The results indicated a significant decrease in the activity of glutamate dehydrogenase in cerebral cortex and cerebellum and a significant increase in brain stem. Glutaminase and glutamine synthetase were found to increase significantly both in cerebral cortex and cerebellum. The activities of glutamate decarboxylase was found to increase in all the three regions along with a significant decrease in GABA aminotransferase while the content of glutamate showed a decrease in all the three brain regions, the content of GABA was observed to increase significantly. The above effects of taurine on the metabolism of glutamate and GABA are discussed in relation to the functional role of GABA and glutamate. The results indicate that taurine administration would result in a state of inhibition in brain.
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PMID:Acute metabolic effects of taurine on the enzymes metabolizing glutamate and gaba. 2049 55