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Bioaccumulation and subcellular partitioning of zinc in rainbow trout (Oncorhynchus mykiss): cross-talk between waterborne and dietary uptake.
Aquat Toxicol. 2009 Mar 09; 91(4):281-90.AT

Abstract

Zinc homeostasis was studied at the tissue and gill subcellular levels in rainbow trout (Oncorhynchus mykiss) following waterborne and dietary exposures, singly and in combination. Juvenile rainbow trout were exposed to 150 or 600microgl(-1) waterborne Zn, 1500 or 4500microgg(-1) dietary Zn, and a combination of 150microgl(-1) waterborne and 1500microgg(-1) dietary Zn for 40 days. Accumulation of Zn in tissues and gill subcellular fractions was measured. At the tissue level, the carcass acted as the main Zn depot containing 84-90% of whole body Zn burden whereas the gill held 4-6%. At the subcellular level, the majority of gill Zn was bioavailable with the estimated metabolically active pool being 81-90%. Interestingly, the nuclei-cellular debris fraction bound the highest amount (40%) of the gill Zn burden. There was low partitioning of Zn into the detoxified pool (10-19%) suggesting that sequestration and chelation are not major mechanisms of cellular Zn homeostasis in rainbow trout. Further, the subcellular partitioning of Zn did not conform to the spill-over model of metal toxicity because Zn binding was indiscriminate irrespective of exposure concentration and duration. The contribution of the branchial and gastrointestinal uptake pathways to Zn accumulation depended on the tissue. Specifically, in plasma, blood cells, and gill, uptake from water was dominant whereas both pathways appeared to contribute equally to Zn accumulation in the carcass. Subcellularly, additive uptake from the two pathways was observed in the heat-stable proteins (HSP) fraction. Toxicologically, Zn exposure caused minimal adverse effects manifested by a transitory inhibition of protein synthesis in gills in the waterborne exposure. Overall, subcellular fractionation appears to have value in the quest for a better understanding of Zn homeostasis and interactions between branchial and gastrointestinal uptake pathways.

Authors+Show Affiliations

Department of Biomedical Sciences, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, Canada.No affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

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

Language

eng

PubMed ID

19041145

Citation

Sappal, Ravinder, et al. "Bioaccumulation and Subcellular Partitioning of Zinc in Rainbow Trout (Oncorhynchus Mykiss): Cross-talk Between Waterborne and Dietary Uptake." Aquatic Toxicology (Amsterdam, Netherlands), vol. 91, no. 4, 2009, pp. 281-90.
Sappal R, Burka J, Dawson S, et al. Bioaccumulation and subcellular partitioning of zinc in rainbow trout (Oncorhynchus mykiss): cross-talk between waterborne and dietary uptake. Aquat Toxicol. 2009;91(4):281-90.
Sappal, R., Burka, J., Dawson, S., & Kamunde, C. (2009). Bioaccumulation and subcellular partitioning of zinc in rainbow trout (Oncorhynchus mykiss): cross-talk between waterborne and dietary uptake. Aquatic Toxicology (Amsterdam, Netherlands), 91(4), 281-90. https://doi.org/10.1016/j.aquatox.2008.10.007
Sappal R, et al. Bioaccumulation and Subcellular Partitioning of Zinc in Rainbow Trout (Oncorhynchus Mykiss): Cross-talk Between Waterborne and Dietary Uptake. Aquat Toxicol. 2009 Mar 9;91(4):281-90. PubMed PMID: 19041145.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Bioaccumulation and subcellular partitioning of zinc in rainbow trout (Oncorhynchus mykiss): cross-talk between waterborne and dietary uptake. AU - Sappal,Ravinder, AU - Burka,John, AU - Dawson,Susan, AU - Kamunde,Collins, Y1 - 2008/10/22/ PY - 2008/09/15/received PY - 2008/10/10/revised PY - 2008/10/14/accepted PY - 2008/12/2/pubmed PY - 2009/2/26/medline PY - 2008/12/2/entrez SP - 281 EP - 90 JF - Aquatic toxicology (Amsterdam, Netherlands) JO - Aquat Toxicol VL - 91 IS - 4 N2 - Zinc homeostasis was studied at the tissue and gill subcellular levels in rainbow trout (Oncorhynchus mykiss) following waterborne and dietary exposures, singly and in combination. Juvenile rainbow trout were exposed to 150 or 600microgl(-1) waterborne Zn, 1500 or 4500microgg(-1) dietary Zn, and a combination of 150microgl(-1) waterborne and 1500microgg(-1) dietary Zn for 40 days. Accumulation of Zn in tissues and gill subcellular fractions was measured. At the tissue level, the carcass acted as the main Zn depot containing 84-90% of whole body Zn burden whereas the gill held 4-6%. At the subcellular level, the majority of gill Zn was bioavailable with the estimated metabolically active pool being 81-90%. Interestingly, the nuclei-cellular debris fraction bound the highest amount (40%) of the gill Zn burden. There was low partitioning of Zn into the detoxified pool (10-19%) suggesting that sequestration and chelation are not major mechanisms of cellular Zn homeostasis in rainbow trout. Further, the subcellular partitioning of Zn did not conform to the spill-over model of metal toxicity because Zn binding was indiscriminate irrespective of exposure concentration and duration. The contribution of the branchial and gastrointestinal uptake pathways to Zn accumulation depended on the tissue. Specifically, in plasma, blood cells, and gill, uptake from water was dominant whereas both pathways appeared to contribute equally to Zn accumulation in the carcass. Subcellularly, additive uptake from the two pathways was observed in the heat-stable proteins (HSP) fraction. Toxicologically, Zn exposure caused minimal adverse effects manifested by a transitory inhibition of protein synthesis in gills in the waterborne exposure. Overall, subcellular fractionation appears to have value in the quest for a better understanding of Zn homeostasis and interactions between branchial and gastrointestinal uptake pathways. SN - 1879-1514 UR - https://www.unboundmedicine.com/medline/citation/19041145/Bioaccumulation_and_subcellular_partitioning_of_zinc_in_rainbow_trout__Oncorhynchus_mykiss_:_cross_talk_between_waterborne_and_dietary_uptake_ L2 - https://linkinghub.elsevier.com/retrieve/pii/S0166-445X(08)00345-7 DB - PRIME DP - Unbound Medicine ER -