TY - JOUR
T1 - Differential uptake and oxidative stress response in zebrafish fed a single dose of the principal copper and zinc enriched sub-cellular fractions of Gammarus pulex
AU - Khan, Farhan R.
AU - Bury, Nicolas R.
AU - Hogstrand, Christer
PY - 2010/9/15
Y1 - 2010/9/15
N2 - The sub-cellular compartmentalisation of trace metals and its effect on trophic transfer and toxicity in the aquatic food chain has been a subject of growing interest. In the present study, the crustacean Gammarus pulex was exposed to either 11 mu g Cu l(-1), added solely as the enriched stable isotope Cu-65, or 660 mu g Zn l(-1), radiolabeled with 2MBq Zn-65, for 16 days. Post-exposure the heat stable cytosol containing metallothionein-like proteins (MTLP) and a combined granular and exoskeletal (MRG + exo) fractions were isolated by differential centrifugation, incorporated into gelatin and fed to zebrafish as a single meal. Assimilation efficiency (AE) and intestinal lipid peroxidation, as malondialdehyde (MDA) were measured. There was a significant difference (p <0.05) between the retention of the MTLP-Zn (39.0 +/- 6.4%) and MRG + exo-Zn (17.2 +/- 3.7%) and of this zinc retained by the zebrafish a significantly greater proportion of the MTLP-Zn feed had been transported away from the site of uptake. For Cu-65, although the results pointed towards greater bioavailability of the MTLP fraction compared to MRG + exo during the slow elimination phase (24-72h) these results were not significant (p = 0.155). Neither zinc feed provoked a lipid peroxidation response in the intestinal tissue of zebrafish compared to control fish (gelatin fed), but both Cu-65 labeled feeds did. The greater effect was exerted by the MRG + exo (2.96 +/- 0.29 nmol MDA mg protein(-1)) feed which three-fold greater than control (p <0.01) and almost twice the MDA concentration of the MTLP feed (1.76 +/- 0.21 nmol MDA mg protein(-1), p
AB - The sub-cellular compartmentalisation of trace metals and its effect on trophic transfer and toxicity in the aquatic food chain has been a subject of growing interest. In the present study, the crustacean Gammarus pulex was exposed to either 11 mu g Cu l(-1), added solely as the enriched stable isotope Cu-65, or 660 mu g Zn l(-1), radiolabeled with 2MBq Zn-65, for 16 days. Post-exposure the heat stable cytosol containing metallothionein-like proteins (MTLP) and a combined granular and exoskeletal (MRG + exo) fractions were isolated by differential centrifugation, incorporated into gelatin and fed to zebrafish as a single meal. Assimilation efficiency (AE) and intestinal lipid peroxidation, as malondialdehyde (MDA) were measured. There was a significant difference (p <0.05) between the retention of the MTLP-Zn (39.0 +/- 6.4%) and MRG + exo-Zn (17.2 +/- 3.7%) and of this zinc retained by the zebrafish a significantly greater proportion of the MTLP-Zn feed had been transported away from the site of uptake. For Cu-65, although the results pointed towards greater bioavailability of the MTLP fraction compared to MRG + exo during the slow elimination phase (24-72h) these results were not significant (p = 0.155). Neither zinc feed provoked a lipid peroxidation response in the intestinal tissue of zebrafish compared to control fish (gelatin fed), but both Cu-65 labeled feeds did. The greater effect was exerted by the MRG + exo (2.96 +/- 0.29 nmol MDA mg protein(-1)) feed which three-fold greater than control (p <0.01) and almost twice the MDA concentration of the MTLP feed (1.76 +/- 0.21 nmol MDA mg protein(-1), p
U2 - 10.1016/j.aquatox.2010.06.007
DO - 10.1016/j.aquatox.2010.06.007
M3 - Article
VL - 99
SP - 466
EP - 472
JO - AQUATIC TOXICOLOGY
JF - AQUATIC TOXICOLOGY
IS - 4
ER -