The inducibility of tyrosine aminotransferase (EC 2.6.1.5) by corticosteroid hormones in rat-human hybrid clones was studied. The presence of human X chromosome activity in the cells was always associated with the suppression of tyrosine aminotransferase inducibility in all the clones examined. Negative correlation between the human X chromosome and inducibility of the enzyme was clearly establ...

1. A vitamin &-deficient diet was fed to an adult male subject to confirm previously described changes in tryptophan metabolism and urinary 4-pyridoxic acid excretion, and erythrocyte alanine and aspartate aminotransferase activities. 2. The results were compared with those obtained in women taking oestrogencontaining oral contraceptives. 3. The development of dietary vitamin B, deficiency was ...

Rat liver tyrosine aminotransferase was purified 200-fold and an antiserum raised against it in rabbits. 2. Hepatic tyrosine aminotransferase activity was increased fourfold by tyrosine, twofold by tetracycline, 2.5-fold by cortisone 21-acetate and ninefold by a combination of tyrosine and cortisol administered intraperitoneally to rats. 3. Radioimmunoassay with 14C-labelled tyrosine aminotrans...

1. Plasma aspartate transaminase and alkaline phosphatase activities were measured weekly for approximately 30 weeks in a group of healthy males and females. 2. The magnitude of variation of the enzyme activities within any individual was studied with respect to four criteria: (a) the individual’s normal range, (b) the normal range calculated for each sex separately, (c) the clinically accepted...

Eleven variants able to grow without proline (provided arginine was absent) were obtained by spontaneous mutation from Salmonella typhimurium LT7 proA and proAB deletion mutants. Suppression resulted from mutation at argG, which specifies N(alpha)-acetylornithine delta-transaminase. In the absence of exogenous arginine, deficiency of this enzyme would cause derepression of the arginine pathway ...

The effect of Picibanil, a streptococcal agent, on the development of liver injury after operations for urogenital cancer was studied retrospectively in the light of serum alanine aminotransferase (ALT) activity. The series comprised 32 cases receiving Picibanil and 33 controls with otherwise comparable clinical backgrounds. Picibanil reduced the incidence of postoperative ALT rise over 50 U/l ...

We evaluated serial enzyme and bilirubin determinations as aids to diagnosis of Epstein-Barr virus-induced infectious mononucleosis (121 cases) and the heterophil-negative mononucleosis-like illness due to cytomegalovirus (33 cases). Laboratory evidence for either type of mononucleosis includes mild to moderate hepatic dysfunction, with aspartate aminotransferase activity increased, but lower t...

In livers of fetuses of 220--340 g body wt, total cytosolic tyrosine aminotransferase activity was 1.0 nmol of product/mg of protein per min, and the corresponding values for autopsy livers of newborns of 740--1,475 g and 2,600--3,650 g were 1.5 and 5.7, respectively, as compared with the adult value of 12.7. On the other hand, para-hydroxyphenylpyruvate dioxygenase activity is at adult level a...

Clinical laboratories estimating enzyme activity in serum are using commercial lyophilized sera for four major purposes. These uses-as a standard and for intermethod, intramethod, and precision control-are segregated, and specifications for each deployment are examined in terms of requirements for the enzyme material: freedom from interfering or indicator enzymes and chromogens; high specific a...

objectives: liver is one of the most sensitive tissues to oxidant damage. hence, the present study was conducted to compare the effects of melissa officinalis (mo) extract and atorvastatin on the activity of liver enzymes in rats. materials and methods: in this experimental study, 60 male wistar rats were selected and allocated to six groups (n=10). the control group received a normal diet, sha...