TY - JOUR
T1 - Waterborne vs. dietary copper uptake in rainbow trout and the effects of previous waterborne copper exposure
AU - Kamunde, Collins
AU - Clayton, Cheryl
AU - Wood, Chris M.
PY - 2002/8/20
Y1 - 2002/8/20
N2 - Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to waterborne Cu (22 μg/l) in moderately hard water for up to 28 days. Relative to control fish kept at background Cu levels (2 μg/l), Cu-preexposed fish displayed decreased uptake rates of waterborne Cu via the gills but not of dietary Cu via the gut during 48-h exposures to 64Cu-radiolabeled water and diet, respectively. At normal dietary and waterborne Cu levels, the uptake rates of dietary Cu into the whole body without the gut were 0.40-0.90 ng·g-1·h-1, >10-fold higher than uptake rates of waterborne Cu into the whole body without the gills, which were 0.02-0.07 ng·g-1·h-1. Previously Cu-exposed fish showed decreased new Cu accumulation in the gills, liver, and carcass during waterborne 64Cu exposures and in the liver during dietary 64Cu exposures. A 3-h gill Cu-binding assay showed downregulation of the putative high-affinity, low-capacity Cu transporters and upregulation of the low-affinity, high-capacity Cu transporters at the gills in Cu-preexposed fish. Exchangeable Cu pools in all the tissues were higher during dietary than during waterborne 64Cu exposures, and previous Cu exposure reduced waterborne exchangeable Cu pools in gill, liver, and carcass. Overall, these results suggest a quantitatively greater role for the dietary than for the waterborne route of Cu uptake, a key role for the gill in Cu homeostasis, and important roles for the liver and gut in the normal metabolism of Cu in fish.
AB - Juvenile rainbow trout (Oncorhynchus mykiss) were exposed to waterborne Cu (22 μg/l) in moderately hard water for up to 28 days. Relative to control fish kept at background Cu levels (2 μg/l), Cu-preexposed fish displayed decreased uptake rates of waterborne Cu via the gills but not of dietary Cu via the gut during 48-h exposures to 64Cu-radiolabeled water and diet, respectively. At normal dietary and waterborne Cu levels, the uptake rates of dietary Cu into the whole body without the gut were 0.40-0.90 ng·g-1·h-1, >10-fold higher than uptake rates of waterborne Cu into the whole body without the gills, which were 0.02-0.07 ng·g-1·h-1. Previously Cu-exposed fish showed decreased new Cu accumulation in the gills, liver, and carcass during waterborne 64Cu exposures and in the liver during dietary 64Cu exposures. A 3-h gill Cu-binding assay showed downregulation of the putative high-affinity, low-capacity Cu transporters and upregulation of the low-affinity, high-capacity Cu transporters at the gills in Cu-preexposed fish. Exchangeable Cu pools in all the tissues were higher during dietary than during waterborne 64Cu exposures, and previous Cu exposure reduced waterborne exchangeable Cu pools in gill, liver, and carcass. Overall, these results suggest a quantitatively greater role for the dietary than for the waterborne route of Cu uptake, a key role for the gill in Cu homeostasis, and important roles for the liver and gut in the normal metabolism of Cu in fish.
KW - Copper metabolism
KW - Copper preexposure
KW - Diet
KW - Water
UR - http://www.scopus.com/inward/record.url?scp=0036340405&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0036340405&partnerID=8YFLogxK
M3 - Article
C2 - 12069932
AN - SCOPUS:0036340405
VL - 283
SP - R69-R78
JO - American Journal of Physiology - Cell Physiology
JF - American Journal of Physiology - Cell Physiology
SN - 0363-6143
IS - 1 52-1
ER -