In vitro accumulation of triglyceride by perfused regenerating rat liver

1973 ◽  
Vol 142 (1) ◽  
pp. 319-322 ◽  
Author(s):  
Thomas J. Delahunty
Keyword(s):  
Rat Liver ◽  
Regenerating Rat Liver

EVIDENCE FOR THE INDUCTION OF URIDINE AND DEOXY-URIDINE PHOSPHORYLASES OF REGENERATING RAT LIVER IN VITRO

1965 ◽  
Vol 43 (1) ◽  
pp. 41-48 ◽  
Author(s):  
Esther W. Yamada
Keyword(s):  
Amino Acids ◽  
Tissue Culture ◽  
Rat Liver ◽  
Culture Medium ◽  
Specific Activity ◽  
Tissue Culture Medium ◽  
Uridine Phosphorylase ◽  
Regenerating Rat Liver ◽  
Specific Activities

Increases in the specific activities of undine and deoxyuridine phosphorylases of slices of regenerating rat liver were found 4 hours after incubation in tissue-culture medium containing uridine or 6-azauridine. These increases were not found when the tissue-culture medium contained either 8-azaguanine or puromycin, or when it lacked amino acids. Although both uridine and 6-azauridine were more effective in increasing the specific activity of uridine phosphorylase than that of deoxyuridine phosphorylase, azauridine was more effective than uridine in increasing the specific activities of both enzymes.In time studies, in which slices of regenerating rat liver were incubated in tissue-culture medium containing optimal concentrations of uridine, the specific activities of the two enzymes reached maximum levels at 3–4 hours. Puromycin prevented these increases.

scholarly journals Synthesis in Vitro of Glycosaminoglycans in Regenerating Rat Liver

1981 ◽  
Vol 19 (7) ◽  
Author(s):  
A. M. Gressner ◽  
J. E. Cadenbach ◽  
H. Greiling
Keyword(s):  
Rat Liver ◽  
Regenerating Rat Liver

scholarly journals Effect of methylglyoxal bis(guanylhydrazone) on polyamine metabolism in normal and regenerating rat liver and rat thymus

1973 ◽  
Vol 136 (3) ◽  
pp. 669-676 ◽  
Author(s):  
E. Hölttä ◽  
P. Hannonen ◽  
J. Pispa ◽  
J. Jänne
Keyword(s):  
Rat Liver ◽  
Diamine Oxidase ◽  
Competitive Inhibitor ◽  
Polyamine Metabolism ◽  
Adenosylmethionine Decarboxylase ◽  
Regenerating Rat Liver ◽  
Marked Accumulation ◽  
Sublethal Doses ◽  
Oxidase Reaction

1. Injections of sublethal doses of methylglyoxal bis(guanylhydrazone), a potent inhibitor of putrescine-activated S-adenosylmethionine decarboxylase in vitro, resulted after a few days in an immense increase in the activity of S-adenosylmethionine decarboxylase in normal and regenerating rat liver and in rat thymus. The increase in the activity of S-adenosylmethionine decarboxylase was at least partly due to a marked lengthening of the half-life of the enzyme. 2. In regenerating liver and thymus there was also a moderate stimulation of the activity of ornithine decarboxylase (EC 4.1.1.17) and a marked accumulation of tissue putrescine. 3. Injection of methylglyoxal bis(guanylhydrazone) into the rat also markedly decreased the activity of diamine oxidase (EC 1.4.3.6) in thymus. 4. In no cases where doses of methylglyoxal bis(guanylhydrazone) close to the LD50 dose for the rat were used was it possible to lower tissue spermidine content to any significant extent. 5. Methylglyoxal bis(guanylhydrazone) seemed to act as a competitive inhibitor for the substrate S-adenosylmethionine and as an uncompetitive inhibitor for the activator putrescine in the decarboxylation of S-adenosylmethionine in vitro. 6. In the diamine oxidase reaction, with putrescine as the substrate, methylglyoxal bis(guanylhydrazone) was a non-competitive inhibitor for putrescine.

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