Ammonia metabolism

Nitrogen donator in synthesis of purine bases, cytosine, GIcNAc, His, and Trp 

Koolman, Color Atlas of Biochemistry, 2nd edition 2005 Thieme All rights reserved. Usage subject to terms and conditions of license. 

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Lockwood, A. H., Yap, E. W. H. and Wong, W. H. Cerebral ammonia metabolism in patients with severe liver disease and minimal hepatic encephalopathy. /. Cereb. Blood Flow Metab. 11 337-341,1991. 

The North American phenotype is associated with the presence of CRM. Possibly as a result, the clinical presentation is less devastating in early infancy, although the outcome is almost invariably fatal in later infancy or early childhood. These patients do not have the associated abnormalities of ammonia metabolism, and the serum aspartic acid concentrations are not as severely depleted. Only one patient has been described with the North... 

Fig. 2. Effect of intravenous acetazoleamide on renal ammonia metabolism (dog).

B6. Bessman, S. P., Ammonia metabolism in animals. In Nitrogen Metabolism (W. McElroy and B. Glass, eds.), p. 433. Johns Hopkins, Baltimore, 1955. 

FI. Faloon, W. W., Auchincloss, J. H., Eich, R., and Gilbert, R., Ammonia metabolism in cirrhosis patients with portacaval shunt. Clin. Research Proc. 4, 18... 

K2. Kirk, E., Amino acid and ammonia metabolism in liver disease. Acta Med. Scand. Suppl. 78 (1936). 

In a study using rats, Schaerdel et al. (1983) exposed 4 groups of animals to ammonia at concentrations of 15, 32, 310, or 1,157 ppm for 24 h. Blood samples were taken 0, 8, 12, and 24 h after exposure. A significant increase in blood ammonia was found at the two highest concentrations after 8 h, but the increase was less marked at 12 or 24 h, suggesting an increase in ammonia metabolism. In another study, female rabbits were exposed to ammonia at concentrations of 50 or 100 ppm for 2.5-3 h (Mayan and Merilan 1972). No increase in blood pH was found, but there was a significant increase in blood urea nitrogen (BUN) in rabbits exposed to 100 ppm. In a study that exposed male Holstein calves to ammonia at concentrations of 50 and 100 ppm for 2.5 h, there was no increase in BUN or pH (Mayan and Merilan 1976). 

Duda, G.D., and P.Handler. 1958. Kinetics of ammonia metabolism in vivo. J. Biol. Chem. 232 303-314. 

Fig. 40.1 Reduction in the blood ammonia levels with a corresponding improvement in the detoxification functions of the liver as a result of multi factorial influence exerted by lactulose on ammonia metabolism...

Carbamoyl Phosphate Synthetase 11 (CPS-11) differs in several ways from its isoform (CPS-I), the enzyme which provides carbamoyl phosphate for the Urea cycle (see "Protein Turnover / Ammonia Metabolism"). 

Haussinger, D (1986). Regulation of hepatic ammonia metabolism The mtercellular glutamine cycle, fri "Advances in EnJtyme Regulation" (G. Weber, ed.), Vol. 25, pp. 159-180. Pergamon, Oxford. 

Souba, W. W. (1987), Interorgan ammonia metabolism in health and disease A surgeon s view. J. FareniernI Tnictai Mrtr II, 569-579-... 

The acquired causes of hyperammonemia are advanced liver disease and renal failure. Severe or chronic liver failure (as occurs in fiilminant hepatitis and cirrhosis, respectively) leads to a significant impairment of normal ammonia metabolism. Reye s syndrome, which is primarily a central nervous system disorder with minor hepatic dysfunction, is also associated with hyperammonemia. Hepatic en-... 

Bachmann C, Colombo JP. Acid-base status and plasma glutamine in patients with hereditary urea cycle disorders. In Soeters PB, Wilson )HP, Meijer AJ, eds. Advances in ammonia metabolism and hepatic encephalopathy, 1st ed. Amsterdam Elsevier, 1988 72-8. 

Seashore MR Yale University Sodium phenylbutyrate treatment of inborn errors of ammonia metabolism National Center for Research Resources... 

SummerskillWHJ, WolpertE. 1978. Ammonia metabolism in the gut. Am J Clin Nutr 23 633-639. 

Regulation of hepatic ammonia metabolism The intercellular glutamine cycle, D. Haussinger, 1986, Adv. Enzyme. Reg., 159180. 

Glutamine synthetase is an important enzyme both in synthesis of glutamine and in ammonia metabolism. It catalyzes the following reaction (see here also) ... 

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