Ascorbic acid feeding of rats reduces copper absorption, causing impaired copper status and depressed biliary copper excretion

1994 ◽  
Vol 41 (1-2) ◽  
pp. 47-58 ◽  
Author(s):  
Gerrit J. Van den Berg ◽  
Shiguang Yu ◽  
Arnoldina G. Lemmens ◽  
Anton C. Beynen
Keyword(s):  
Ascorbic Acid ◽  
Copper Excretion ◽  
Copper Absorption ◽  
Copper Status

scholarly journals Regulation of murine copper homeostasis by members of the COMMD protein family

2020 ◽  
Vol 14 (1) ◽  
pp. dmm045963
Author(s):  
Amika Singla ◽  
Qing Chen ◽  
Kohei Suzuki ◽  
Jie Song ◽  
Alina Fedoseienko ◽  
...  
Keyword(s):  
Copper Homeostasis ◽  
Copper Accumulation ◽  
Copper Transporter ◽  
Copper Excretion ◽  
Copper Absorption ◽  
Hepatic Copper ◽  
High Copper ◽  
Molecular Machinery ◽  
And Function

ABSTRACTCopper is an essential transition metal for all eukaryotes. In mammals, intestinal copper absorption is mediated by the ATP7A copper transporter, whereas copper excretion occurs predominantly through the biliary route and is mediated by the paralog ATP7B. Both transporters have been shown to be recycled actively between the endosomal network and the plasma membrane by a molecular machinery known as the COMMD/CCDC22/CCDC93 or CCC complex. In fact, mutations in COMMD1 can lead to impaired biliary copper excretion and liver pathology in dogs and in mice with liver-specific Commd1 deficiency, recapitulating aspects of this phenotype. Nonetheless, the role of the CCC complex in intestinal copper absorption in vivo has not been studied, and the potential redundancy of various COMMD family members has not been tested. In this study, we examined copper homeostasis in enterocyte-specific and hepatocyte-specific COMMD gene-deficient mice. We found that, in contrast to effects in cell lines in culture, COMMD protein deficiency induced minimal changes in ATP7A in enterocytes and did not lead to altered copper levels under low- or high-copper diets, suggesting that regulation of ATP7A in enterocytes is not of physiological consequence. By contrast, deficiency of any of three COMMD genes (Commd1, Commd6 or Commd9) resulted in hepatic copper accumulation under high-copper diets. We found that each of these deficiencies caused destabilization of the entire CCC complex and suggest that this might explain their shared phenotype. Overall, we conclude that the CCC complex plays an important role in ATP7B endosomal recycling and function.

scholarly journals High tin intake reduces copper status in rats through inhibition of copper absorption

1995 ◽  
Vol 73 (6) ◽  
pp. 863-869 ◽  
Author(s):  
Shiguang Yu ◽  
Anton C. Beynen
Keyword(s):  
Body Weight ◽  
Weight Gain ◽  
Feed Intake ◽  
Body Weight Gain ◽  
Male Rats ◽  
Copper Absorption ◽  
Copper Status ◽  
Demineralized Water ◽  
Liver And Kidney

The mechanism underlying the reduced Cu status in rats fed on a high-Sn diet was investigated. Male rats aged 4 weeks were fed ad lib. on purified diets containing either 1 or 100 mg Sn/kg and demineralized water for a period of 4 weeks. The high-Sn diet had no effect on feed intake, body-weight gain or weight of liver and kidney but significantly reduced Cu concentrations in plasma, liver and kidney. Biliary Cu excretion was decreased significantly in rats fed on the high-Sn diet. Apparent Cu absorption (Cu intake−faecal Cu) was not affected by the high-Sn diet, but the estimate of true Cu absorption (Cu intake−(faecal Cu−biliary Cu)) was significantly reduced. We conclude that high Sn intake reduces Cu status in rats through inhibition of Cu absorption. The decreased biliary Cu excretion observed on the high-Sn diet is a result of the reduced Cu absorption.

Copper status and ascorbic acid concentrations in rats

1996 ◽  
Vol 16 (2) ◽  
pp. 237-243 ◽  
Author(s):  
Wade D. Kubat ◽  
Joseph R. Prohaska
Keyword(s):  
Ascorbic Acid ◽  
Copper Status

A defect of biliary excretion of copper in copper-laden Bedlington terriers

1982 ◽  
Vol 243 (3) ◽  
pp. G231-G236 ◽  
Author(s):  
Le-Chu Su ◽  
Charles A. Owen ◽  
Paul E. Zollman ◽  
Robert M. Hardy
Keyword(s):  
Biliary Excretion ◽  
Biliary Obstruction ◽  
Autosomal Recessive ◽  
Wilson’S Disease ◽  
Wilson's Disease ◽  
Copper Excretion ◽  
Copper Absorption ◽  
Excessive Accumulation

Copper-laden Bedlington terriers were found to absorb copper normally, based on the ratio of 64Cu in bile and in plasma ceruloplasmin after oral and intravenous doses of the radionuclide. The excessive accumulation of the copper in Bedlington terriers was due to impaired biliary excretion of the metal, The abnormal Bedlington pattern was simulated in normal dogs by biliary obstruction. Although the Bedlington terriers excreted more copper in their urine than normal, the amount was far less than that accumulated secondary to inadequate biliary excretion. These abnormalities are shared by patients with Wilson's disease, both conditions being inherited on an autosomal recessive basis. copper absorption; copper excretion; radiocopper; Wilson's disease Submitted on May 5, 1981 Accepted on March 30, 1982

Enzymic diagnosis of copper deficiency in subterranean clover. II. A simple field test

1982 ◽  
Vol 33 (6) ◽  
pp. 981 ◽  
Author(s):  
E Delhaize ◽  
JF Loneragan ◽  
J Webb
Keyword(s):  
Ascorbic Acid ◽  
Oxygen Uptake ◽  
Field Test ◽  
Oxidase Activity ◽  
Room Temperature ◽  
Copper Deficiency ◽  
Subterranean Clover ◽  
Ascorbate Oxidase ◽  
Copper Status ◽  
Dark Blue

A rapid, simple and robust field test is described for diagnosing copper deficiency in subterranean clover plants by measuring ascorbate oxidase activity in young folded leaf blades (YFL) homogenized in phosphate buffer. The test measures activity by counting the drops of iodine required to titrate, to a dark blue end-point, excess ascorbic acid added to and incubated for 20 min with a YFL homogenate. When reagent control titrations had titres of 11 drops of iodine, YFL homogenates from copper-adequate plants had titres of 2-3 drops, from copper-deficient plants 6-11, and from plants with marginal copper supply 4-5 drops. The test was standardized against the measurement of ascorbate oxidase activity in YFL by oxygen uptake. Ascorbate oxidase activity was remarkably insensitive to assay temperature, decreasing by only one-third with decreasing temperature from 30 to 10�C. It was also very stable in both homogenates and whole leaves. At room temperature, activity dropped by only 25% in homogenates after 6 h and in whole leaf blades after 48 h. When stored in ice, leaf blades retained full activity for at least 5 days. Diagnosis of copper deficiency by the new test agreed closely with diagnosis based on copper analysis of young open leaves taken from the same subterranean clover plants in field pastures. The test should allow extension workers to give on-the-spot advice about the copper status of pastures containing subterranean clover.

Ascorbic acid supplementation and copper status in rats

1989 ◽  
Vol 23 (1) ◽  
pp. 165-172 ◽  
Author(s):  
G. J. Van den Berg ◽  
J. P. Van Wouwe ◽  
A. C. Beynen
Keyword(s):  
Ascorbic Acid ◽  
Acid Supplementation ◽  
Copper Status ◽  
Ascorbic Acid Supplementation ◽  
And Copper Status

Effect of Varying Ascorbic Acid Intakes on Copper Absorption and Ceruloplasmin Levels of Young Men

1987 ◽  
Vol 117 (12) ◽  
pp. 2109-2115 ◽  
Author(s):  
Robert A. Jacob ◽  
James H. Skala ◽  
Stanley T. Omaye ◽  
Judith R. Turnlund
Keyword(s):  
Ascorbic Acid ◽  
Young Men ◽  
Copper Absorption
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