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Gastrointestinal uptake and fate of cadmium in rainbow trout acclimated to sublethal dietary cadmium.
Aquat Toxicol. 2004 Aug 10; 69(2):149-63.AT

Abstract

Adult rainbow trout were pre-exposed to a sublethal concentration of dietary Cd (500 mg/kg dry wt.) for 30 days to induce acclimation. A gastrointestinal dose of radiolabeled Cd (276 microg/kg wet wt.) was infused into the stomach of non-acclimated and Cd-acclimated trout through a stomach catheter. Repetitive blood samples over 24 h and terminal tissue samples were taken to investigate the gastrointestinal uptake, plasma clearance kinetics, and tissue distribution of Cd. Only a small fraction of the infused dose (non-acclimated: 2.4%; Cd-acclimated: 6.6%) was internalized across the gut wall, while most was bound in the gut tissues (10-24%) or remained in the lumen (16-33%) or lost from the fish (approximately 50%) over 24 h. Cadmium loading during pre-exposure produced a profound increase of total Cd in the blood plasma (approximately 28-fold) and red blood cells (RBC; approximately 20-fold). The plasma Cd-time profiles consisted of an apparent rising (uptake) phase and a declining (clearance) phase with a maximum value of uptake in 4 h, suggesting that uptake of gastrointestinally infused Cd was very rapid. Acclimation to dietary Cd did not affect plasma Cd clearance (approximately 0.5 ml/min), but enhanced new Cd levels in the plasma (but not in the RBC), and resulted in a longer half-life for plasma Cd. Tissue total and new Cd levels varied in different regions of the gastrointestinal tract, and overall levels in gut tissues were much greater than in non-gut tissues, reflecting the Cd exposure route. Dietary Cd, but not the infused Cd, greatly increased total Cd levels of all gut tissues in the order posterior-intestine (640-fold) > cecae (180-fold) > mid-intestine (94-fold) > stomach (53-fold) in Cd-acclimated fish relative to naïve fish. Among non-gut tissues in the Cd-acclimated fish, the great increases of total Cd levels were observed in the liver (73-fold), kidney (39-fold), carcass (35-fold), and gills (30-fold). The results provide some clear conclusions that may be useful for environmental risk assessment of dietary Cd exposure in fish.

Authors+Show Affiliations

Chowdhury MJ
Department of Biology, McMaster University, 1280 Main Street West, Hamilton, Ont., L8S 4K1, Canada. chowdhury.mohammed@epamail.epa.gov
McDonald DG
No affiliation info available
Wood CM
No affiliation info available

MeSH

AcclimatizationAnalysis of VarianceAnimalsBiological TransportCadmiumCadmium RadioisotopesCatheterizationDietErythrocytesGastrointestinal TractGillsLiverModels, BiologicalOncorhynchus mykiss

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

15261451

Citation

Chowdhury, M J., et al. "Gastrointestinal Uptake and Fate of Cadmium in Rainbow Trout Acclimated to Sublethal Dietary Cadmium." Aquatic Toxicology (Amsterdam, Netherlands), vol. 69, no. 2, 2004, pp. 149-63.
Chowdhury MJ, McDonald DG, Wood CM. Gastrointestinal uptake and fate of cadmium in rainbow trout acclimated to sublethal dietary cadmium. Aquat Toxicol. 2004;69(2):149-63.
Chowdhury, M. J., McDonald, D. G., & Wood, C. M. (2004). Gastrointestinal uptake and fate of cadmium in rainbow trout acclimated to sublethal dietary cadmium. Aquatic Toxicology (Amsterdam, Netherlands), 69(2), 149-63.
Chowdhury MJ, McDonald DG, Wood CM. Gastrointestinal Uptake and Fate of Cadmium in Rainbow Trout Acclimated to Sublethal Dietary Cadmium. Aquat Toxicol. 2004 Aug 10;69(2):149-63. PubMed PMID: 15261451.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Gastrointestinal uptake and fate of cadmium in rainbow trout acclimated to sublethal dietary cadmium. AU - Chowdhury,M J, AU - McDonald,D G, AU - Wood,C M, PY - 2003/11/21/received PY - 2004/05/12/revised PY - 2004/05/13/accepted PY - 2004/7/21/pubmed PY - 2004/9/17/medline PY - 2004/7/21/entrez SP - 149 EP - 63 JF - Aquatic toxicology (Amsterdam, Netherlands) JO - Aquat Toxicol VL - 69 IS - 2 N2 - Adult rainbow trout were pre-exposed to a sublethal concentration of dietary Cd (500 mg/kg dry wt.) for 30 days to induce acclimation. A gastrointestinal dose of radiolabeled Cd (276 microg/kg wet wt.) was infused into the stomach of non-acclimated and Cd-acclimated trout through a stomach catheter. Repetitive blood samples over 24 h and terminal tissue samples were taken to investigate the gastrointestinal uptake, plasma clearance kinetics, and tissue distribution of Cd. Only a small fraction of the infused dose (non-acclimated: 2.4%; Cd-acclimated: 6.6%) was internalized across the gut wall, while most was bound in the gut tissues (10-24%) or remained in the lumen (16-33%) or lost from the fish (approximately 50%) over 24 h. Cadmium loading during pre-exposure produced a profound increase of total Cd in the blood plasma (approximately 28-fold) and red blood cells (RBC; approximately 20-fold). The plasma Cd-time profiles consisted of an apparent rising (uptake) phase and a declining (clearance) phase with a maximum value of uptake in 4 h, suggesting that uptake of gastrointestinally infused Cd was very rapid. Acclimation to dietary Cd did not affect plasma Cd clearance (approximately 0.5 ml/min), but enhanced new Cd levels in the plasma (but not in the RBC), and resulted in a longer half-life for plasma Cd. Tissue total and new Cd levels varied in different regions of the gastrointestinal tract, and overall levels in gut tissues were much greater than in non-gut tissues, reflecting the Cd exposure route. Dietary Cd, but not the infused Cd, greatly increased total Cd levels of all gut tissues in the order posterior-intestine (640-fold) > cecae (180-fold) > mid-intestine (94-fold) > stomach (53-fold) in Cd-acclimated fish relative to naïve fish. Among non-gut tissues in the Cd-acclimated fish, the great increases of total Cd levels were observed in the liver (73-fold), kidney (39-fold), carcass (35-fold), and gills (30-fold). The results provide some clear conclusions that may be useful for environmental risk assessment of dietary Cd exposure in fish. SN - 0166-445X UR - https://www.unboundmedicine.com/medline/citation/15261451/Gastrointestinal_uptake_and_fate_of_cadmium_in_rainbow_trout_acclimated_to_sublethal_dietary_cadmium_ DB - PRIME DP - Unbound Medicine ER -