Zinc supplementation reduces blood ammonia and increases liver ornithine transcarbamylase activity in experimental cirrhosis

  title={Zinc supplementation reduces blood ammonia and increases liver ornithine transcarbamylase activity in experimental cirrhosis},
  author={Oliviero Riggio and Manuela Merli and Livio Capocaccia and Massimo Caschera and Angelo Zullo and Giorgio Pinto and Eugenio Gaudio and Antonio Franchitto and Roberta Spagnoli and Elvira D'aquilino and Siro Seri and R. Moretti and Alfredo Cantafora},
Zinc deficiency is common in cirrhosis and may be involved in the alteration of ammonia metabolism. Rats with carbon tetrachloride–induced cirrhosis have high plasma ammonia and low serum and tissue zinc levels. We used this model to examine the effects of oral zinc supplementation on activities of plasma ammonia and liver ornithine transcarbamylase (a key enzyme in the urea cycle). These parameters were examined in two consecutive experiments. Each experiment included two groups of rats… 
Zinc supplementation and amino acid‐nitrogen metabolism in patients with advanced cirrhosis
The data indicate that long‐term oral zinc speeds up the kinetics of urea formation from amino acids and ammonia, whereas the beneficial effects on encephalopathy might stem from decreased ammonia.
Orotic acid level, in addition to other liver function parameters such as AST, ALT, ALP, LDH may be routinely determined so that more useful and meaningful results can be obtained about pathogenesis of liver diseases especially cirrhosis.
Zinc and protein metabolism in chronic liver diseases.
The role of zinc in liver cirrhosis.
The present review summarizes the emerging evidence on the pitoval role of zinc in the pathogenesis of liver cirrhosis and suggests zinc deficiency may alter hepatocyte functions and also immune responses in inflammatory liver diseases.
Zinc supplementation in experimental liver cirrhosis: a morphological, structural and ultrastructural study.
Zinc treatment influences biochemical parameters, but not the morphology of liver cirrhosis, in cirrhotic rats treated by intragastric administration of CCl4.
Hepatic Encephalopathy and Helicobacter pylori: A Critical Reappraisal
Data indicate that ammonia production in the stomach by H. pylori urease appears to be inadequate to clinically affect ammonia disposal in the majority of cirrhotic patients, and further studies are warranted in this field.
Effects of oral branched-chain amino acids on hepatic encephalopathy and outcome in patients with liver cirrhosis.
  • T. Kawaguchi, E. Taniguchi, M. Sata
  • Biology, Medicine
    Nutrition in clinical practice : official publication of the American Society for Parenteral and Enteral Nutrition
  • 2013
The clinical impacts of BCAA supplementation on Hepatic encephalopathy and possible mechanisms for a BCAA-induced improvement of HE/MHE are summarized and some modifications of oral BCAA therapy for improvement of efficacy in HE treatment are presented.


Plasma ammonia and liver ornithine transcarbamoylase activity in zinc-deficient rats.
It is concluded that an increase in plasma ammonia may occur as a result of deficiency of zinc.
Correlations between zinc, amino acids and ammonia in liver cirrhosis.
While confirming known data (reduced zinc levels, imbalance of plasma amino acids, hyperammonaemia in chronic liver diseases the findings also revealed correlations between the above substances, a negative correlations existed between zinc and ammonia.
Carbon tetrachloride-induced experimental cirrhosis in the rat: a reappraisal of the model.
  • F. Ariosto, O. Riggio, L. Capocaccia
  • Medicine, Biology
    European surgical research. Europaische chirurgische Forschung. Recherches chirurgicales europeennes
  • 1989
The goal of this study was to evaluate the presence of extrahepatic damage and the uniformity and reversibility of the histological findings in CCl4-induced liver cirrhosis in the rat, and a number of functional alterations usually observed in man were obtained.
The influence of portosystemic shunting on zinc and vitamin A metabolism in liver cirrhosis.
A study on 37 hospitalized patients with liver cirrhosis was performed and an influence of portosystemic shunting on zinc deficiency and subsequent vitamin A deficiency by decreased RBP release is concluded.
Tissue zinc status and drug elimination in patients with chronic liver disease.
It is suggested that tissue zinc depletion in some patients with hepatic cirrhosis may explain in part the impaired capacity to metabolize drugs.
Urea cycle enzyme activities are normal and inducible by a high‐protein diet in CCl4 cirrhosis of rats
This example of CCl4‐induced Cirrhosis in the rat does not serve as a good model for human cirrhosis, in which the urea cycle enzymes are reported to be decreased in activity.
On the protective action of zinc against experimental liver damage due to choline free diet or carbon tetrachloride
  • T. Saldeen
  • Chemistry, Medicine
    Zeitschrift fur die gesamte experimentelle Medizin einschliesslich experimentelle Chirurgie
  • 1969
Moderate zinc doses had a more favourable effect on the liver damage when the injections were given during the second half than during the first half of the experimental period, which may indicate that the zinc effct sets in at the regenerative phase.
Activities of Krebs-Henseleit enzymes in normal and cirrhotic human liver.
Observations indicated that in cirrhotic patients, the pathway NH, + urea is restricted and reduced activities of one or more hepatic enzymes of the Krebs-Henseleit (KH) cycle are measured.