Abstract
Most cirrhotics have tyrosinemia and subnormal tyrosine tolerance; in some the ability to metabolizep-hydroxyphenylpyruvic and homogentisic acids is impaired. In previous studies, the initial transamination appeared to be the rate-limiting step. In this study, hepatic tyrosine transaminase activity was compared in liver biopsies from eight noncirrhotic and ten cirrhotic subjects to determine whether the subnormal tyrosine tolerance was related to decreased maximal activity of this enzyme. Fasting plasma tyrosine in the cirrhotics (133±43 μmol/liter) was significantly higher (P<0.005) than in the noncirrhotic subjects (64±25 μmol/liter). Tyrosine transaminase activity in the cirrhotic livers (42±11 μmol PHPA/g liver/hr, or 0.47±0.1 μmol PHPA/mg protein/hr) was not significantly different from the enzyme activity in the noncirrhotic liver (43±7 μmol PHPA/g liver/hr, or 0.39±.12 μmol PHPA/mg protein/hr.) Thus elevated tyrosine levels in cirrhotics cannot be explained by decreased tyrosine transaminase activity in the liver, and other explanations must be sought.
This is a preview of subscription content, log in via an institution to check access.
Similar content being viewed by others
References
Levine RJ, Conn HO: Tyrosine metabolism in patients with liver disease. J Clin Invest 46:2012–2020, 1867
Nordlinger BM, Fulenwider JT, Ivey GL, Faraj BA, Ali FM, Kutner M, Henderson JM, Rudman D: Tyrosine metabolism in cirrhosis. J Lab Clin Med 94:833–840, 1979
Galambos JT: Major Problems in Internal Medicine. Cirrhosis. W.B. Saunders Co., Philadelphia, 1979, p 198
Campbell DP, Parker DE, Anagnostopoulos CE: Survival prediction in portocaval shunts: A computerized statistical analysis. Am J Surg 126:748–751, 1973
Gerron GG, Ansley JD, Isaacs JW, Kutner MH, Rudman D: Technical pitfalls in measurement of venous plasma NH3 concentration. Clin Chem 22:663–666, 1976
Viamonte M, Warren WD, Foman JJ: Liver angiography in the assessment of portal hypertension in liver cirrhosis. Radiol Clin North Am 8:147–157, 1970
Heymsfield SB, Fulenwider JT, Nordlinger EM, Barlow R, Sones P, Kutner M: Accurate maeasurement of liver, kidney, and spleen volume and mass by computerized axial tomography. Ann Intern Med 90:185–187, 1979
Wheelan DT, Zannoni VG: Micro-assay of tyrosine aminotransferase andp-hydroxyphenylpyruvic acid oxidase in mammalian liver and patients with hereditary tyrosinemia. Biochem Med 9:19–31, 1974
Fellman JG, Vanbellinghen PJ, Jones RT, Koler RD: Soluble and mitochondrial forms of tyrosine amino transferase. Biochemistry 8:615–622, 1969
Lowry OH, Rosebrough NJ, Farr AL, Randall RJ: Protein measurement with the Folin phenol reagent. J Biol Chem 193:265–275, 1951
Medes G: A new error of tyrosine metabolism: Tyrosinosis. The intermediary metabolism of tyrosine and pheylalanine. Biochem J 26:917–940, 1932
Ansley JD, Isaacs JW, Rikkers LF, Kutner MH, Nordlinger BM, Rudman D: Quantitative tests of nitrogen metabolism in cirrhosis: Relationship to other manifestations of liver disease. Gastroenterology 75:570–579, 1978
Lumeng L, Li T-K: Vitamin B6 metabolism in chronic alcohol abuse. Pyridoxal phosphate levels in plasma and effect of acetaldehyde on pyridoxal phosphate synthesis and degradation in human erythrocytes. J Clin Invest 53:693–704, 1974
Mitchell D, Wagner C, Stone WJ, Wilkinson GR, Schenker S: Abnormal regulation of plasma pyridoxal 5-phosphate in patients with liver disease. Gastroenterology 71:1043–1049, 1976
Williamson DH, Lund P, Krebs HA: The redox state of free nicotinamideadenine dinucleotide in the cytoplasm and mitochondria of rat liver. Biochem J 103:514–527, 1967
Fisher JE: False neurotransmitters and hepatic coma. Res Publ Assoc Nerv Ment Dis 53:53–73, 1974
Faraj BA, Bowen PA, Isaacs JW, Rudman D: Hypertyraminemia in cirrhotic patients. N Engl J Med 294:1360–1364, 1976
Faraj BA, Fulenwider JT, Rypins EB, Nordlinger BM, Ivey GL, Jansen RD, Ali FM, Camp VM, Kutner M, Schmidt F, Rudman D: Tyramine kinetics and metabolism in cirrhosis. J Clin Invest 64:413–419, 1979
Author information
Authors and Affiliations
Additional information
Supported in part by Public Health Service Research Grants AM15736 and AM21646-02, and by General Clinical Research Center Public Health Service Research Grant 5M01RR00039.
Rights and permissions
About this article
Cite this article
Henderson, J.M., Faraj, B.A., Ali, F.M. et al. Tyrosine transaminase activity in normal and cirrhotic liver. Digest Dis Sci 26, 124–128 (1981). https://doi.org/10.1007/BF01312228
Received:
Revised:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF01312228