|
| |
|
|
|
|
||||
| Home Help Feedback Subscriptions Archive Search Table of Contents | ||||
Journal of Experimental Biology, Vol 203, Issue 15 2365-2377, Copyright © 2000 by Company of Biologists
JOURNAL ARTICLES |
RD Handy, MM Musonda, C Phillips and SJ Falla
Department of Biological Sciences, The University of Plymouth, Drake Circus, Plymouth, Devon PL4 8AA, UK.R.Handy@plymouth.ac.uk
In mammals, copper (Cu) absorption occurs mostly in the small intestine, and some of the Cu transporters involved in its uptake have been characterised. In fish, however, the regions of the gut involved in Cu absorption and the membrane transport mechanisms responsible for gastrointestinal Cu uptake are unknown. Everted gut sacs and isolated perfused intestine of Clarias gariepinus were used to explore Cu absorption (at 22 degrees C). Gut sacs exposed to 100 micromol l(-1) mucosal solution Cu ([Cu](m)) showed that Cu was mostly (70 %) absorbed in the middle and hind intestine. Most of the accumulated Cu was located in the mucosa. In perfused intestines, cumulative Cu absorption from the mucosal solution to the serosal perfusate was greatest at 10 micromol l(-1) [Cu](m) and decreased at higher values of [Cu](m), while tissue accumulation of Cu showed a dose-dependent elevation. Absorption efficiency therefore declined with increasing Cu dose, and basolateral transport was the limiting factor in Cu uptake. Serosal applications of the P-type ATPase inhibitor vanadate (100 micromol l(-1)) or the anion transport inhibitor DIDS (100 micromol l(-1)) caused threefold increases in net Cu uptake (at [Cu](m)=10 micromol l(-1)). The vanadate effect was explained by a reduction in transepithelial potential rather than inhibition of Cu-ATPase, but the DIDS effect was not. Transepithelial potential, water transport and tissue [Cu] were not affected by DIDS, but tissue [K(+)] was elevated. Removal of Cl(-) simultaneously from both the mucosal and serosal solutions caused a 10-fold reduction in the rate of Cu uptake, while removal of Cl(-) from the mucosal solution only completely abolished Cu absorption to the serosal perfusate. Transepithelial potential effects are discussed. We conclude that Cu absorption occurs mostly in the intestine and is normally driven by a basolateral Cu/anion symport that prefers Cl(-).
This article has been cited by other articles:
|
|
 |
|
  J. Burke and R. D. Handy Sodium-sensitive and -insensitive copper accumulation by isolated intestinal cells of rainbow trout Oncorhynchus mykiss J. Exp. Biol., January 15, 2005; 208(2): 391 - 407. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. Carriquiriborde, R. D. Handy, and S. J. Davies Physiological modulation of iron metabolism in rainbow trout (Oncorhynchus mykiss) fed low and high iron diets J. Exp. Biol., January 1, 2004; 207(1): 75 - 86. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. R. Zerounian, C. Redekosky, R. Malpe, and M. C. Linder Regulation of copper absorption by copper availability in the Caco-2 cell intestinal model Am J Physiol Gastrointest Liver Physiol, May 1, 2003; 284(5): G739 - G747. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. R. Bury, P. A. Walker, and C. N. Glover Nutritive metal uptake in teleost fish J. Exp. Biol., January 1, 2003; 206(1): 11 - 23. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Kamunde, C. Clayton, and C. M. Wood Waterborne vs. dietary copper uptake in rainbow trout and the effects of previous waterborne copper exposure Am J Physiol Regulatory Integrative Comp Physiol, July 1, 2002; 283(1): R69 - R78. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. R. Bury, M. Grosell, C. M. Wood, C. Hogstrand, R. W. Wilson, J. C. Rankin, M. Busk, T. Lecklin, and F. B. Jensen Intestinal iron uptake in the European flounder (Platichthys flesus) J. Exp. Biol., January 11, 2001; 204(21): 3779 - 3787. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A Sacher, A Cohen, and N Nelson Properties of the mammalian and yeast metal-ion transporters DCT1 and Smf1p expressed in Xenopus laevis oocytes J. Exp. Biol., January 3, 2001; 204(6): 1053 - 1061. [Abstract] [PDF]
|
|
