Abstract
Copper (Cu) is both a vital nutrient and a potent toxicant. The objective of this study was to analyze the mechanistic nature of intestinal Cu transport in rainbow trout using radiolabeled Cu (64Cu) and an in vitro gut sac technique. Reduction of mucosal NaCl levels inhibited Cu transport while increase caused stimulation; Na2SO4 had an identical effect, implicating Na+ rather than the anion. These responses were unrelated to solvent drag, osmotic pressure or changes in transepithelial potential. The presence of elevated luminal Ag stimulated Cu and Na+ uptake. Phenamil caused a partial inhibition of both Cu and Na+ uptake while hypercapnia stimulated Na+ and Cu transport. Cu uptake was sensitive to luminal pH and inhibited by a tenfold excess of Fe and Zn. These factors had no effect on Na+ uptake. On the basis of these results we propose a novel Na+-assisted mechanism of Cu uptake wherein the Na+ gradient stimulates an increase in the H+ concentration of the brushborder creating a suitable microenvironment for the effective transport of Cu via either DMT1 or Ctr1.
| Original language | English |
|---|---|
| Pages (from-to) | 433-446 |
| Number of pages | 14 |
| Journal | Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology |
| Volume | 177 |
| Issue number | 4 |
| DOIs | |
| State | Published - May 1 2007 |
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Keywords
- Ctr1
- DMT1
- Hypercapnia
- NHE
- pH
ASJC Scopus subject areas
- Animal Science and Zoology
- Environmental Science(all)
- Physiology
- Physiology (medical)
Cite this
Mechanisms of dietary Cu uptake in freshwater rainbow trout : Evidence for Na-assisted Cu transport and a specific metal carrier in the intestine. / Nadella, Sunita Rao; Grosell, Martin; Wood, Chris M.
In: Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology, Vol. 177, No. 4, 01.05.2007, p. 433-446.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Mechanisms of dietary Cu uptake in freshwater rainbow trout
T2 - Evidence for Na-assisted Cu transport and a specific metal carrier in the intestine
AU - Nadella, Sunita Rao
AU - Grosell, Martin
AU - Wood, Chris M.
PY - 2007/5/1
Y1 - 2007/5/1
N2 - Copper (Cu) is both a vital nutrient and a potent toxicant. The objective of this study was to analyze the mechanistic nature of intestinal Cu transport in rainbow trout using radiolabeled Cu (64Cu) and an in vitro gut sac technique. Reduction of mucosal NaCl levels inhibited Cu transport while increase caused stimulation; Na2SO4 had an identical effect, implicating Na+ rather than the anion. These responses were unrelated to solvent drag, osmotic pressure or changes in transepithelial potential. The presence of elevated luminal Ag stimulated Cu and Na+ uptake. Phenamil caused a partial inhibition of both Cu and Na+ uptake while hypercapnia stimulated Na+ and Cu transport. Cu uptake was sensitive to luminal pH and inhibited by a tenfold excess of Fe and Zn. These factors had no effect on Na+ uptake. On the basis of these results we propose a novel Na+-assisted mechanism of Cu uptake wherein the Na+ gradient stimulates an increase in the H+ concentration of the brushborder creating a suitable microenvironment for the effective transport of Cu via either DMT1 or Ctr1.
AB - Copper (Cu) is both a vital nutrient and a potent toxicant. The objective of this study was to analyze the mechanistic nature of intestinal Cu transport in rainbow trout using radiolabeled Cu (64Cu) and an in vitro gut sac technique. Reduction of mucosal NaCl levels inhibited Cu transport while increase caused stimulation; Na2SO4 had an identical effect, implicating Na+ rather than the anion. These responses were unrelated to solvent drag, osmotic pressure or changes in transepithelial potential. The presence of elevated luminal Ag stimulated Cu and Na+ uptake. Phenamil caused a partial inhibition of both Cu and Na+ uptake while hypercapnia stimulated Na+ and Cu transport. Cu uptake was sensitive to luminal pH and inhibited by a tenfold excess of Fe and Zn. These factors had no effect on Na+ uptake. On the basis of these results we propose a novel Na+-assisted mechanism of Cu uptake wherein the Na+ gradient stimulates an increase in the H+ concentration of the brushborder creating a suitable microenvironment for the effective transport of Cu via either DMT1 or Ctr1.
KW - Ctr1
KW - DMT1
KW - Hypercapnia
KW - NHE
KW - pH
UR - http://www.scopus.com/inward/record.url?scp=34247243596&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=34247243596&partnerID=8YFLogxK
U2 - 10.1007/s00360-006-0142-3
DO - 10.1007/s00360-006-0142-3
M3 - Article
VL - 177
SP - 433
EP - 446
JO - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
JF - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology
SN - 0174-1578
IS - 4
ER -