Dataset Information

Methemoglobin determination by multi-component analysis in coho salmon (Oncorhynchus kisutch) possessing unstable hemoglobin.

ABSTRACT: Hemoglobin derivatives are often quantified in blood to establish cardio-respiratory status and possible causes of impaired oxygen transport. The derivative known as methemoglobin results from oxidation of hemoglobin and is pathologically relevant because it cannot transport oxygen. In species and individuals possessing unstable methemoglobin, methemoglobin formation leads to rapid hemichrome formation and precipitation. Oxidizing reagents in standard methemoglobin analysis techniques therefore prevent accurate quantification of hemoglobin oxidative degradation products in species possessing unstable hemoglobin. In this study, we demonstrated that individual coho salmon (Oncorhynchus kisutch) possess unstable methemoglobin. Because molar absorptivities of coho methemoglobin, hemichrome and carboxyhemoglobin were significantly different from humans, the use of previous standard methods leads to an overestimation of methemoglobin in coho. Spontaneous conversion of methemoglobin to hemichrome was also demonstrated in Chinook (O. tshawytscha), pink (O. gorbuscha) and chum salmon (O. keta), but not steelhead (O. mykiss), indicating there may be a frequent need to account for unstable hemoglobin when quantifying methemoglobin in salmonids.•Our method builds upon multi-component analysis (MCA) by using a multivariate modeling technique to derive the coho-specific molar absorptivities of major hemoglobin derivatives•This approach fills a current need for the accurate quantification of methemoglobin in fishes possessing unstable hemoglobin.

SUBMITTER: Blair S

PROVIDER: S-EPMC7115134 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Methemoglobin determination by multi-component analysis in coho salmon (<i>Oncorhynchus kisutch</i>) possessing unstable hemoglobin.

Blair Stephanie S Barlow Clyde C Martin Erin E Schumaker Ruth R McIntyre Jenifer J

MethodsX 20200222

Hemoglobin derivatives are often quantified in blood to establish cardio-respiratory status and possible causes of impaired oxygen transport. The derivative known as methemoglobin results from oxidation of hemoglobin and is pathologically relevant because it cannot transport oxygen. In species and individuals possessing unstable methemoglobin, methemoglobin formation leads to rapid hemichrome formation and precipitation. Oxidizing reagents in standard methemoglobin analysis techniques therefore ...[more]

PMID: 32257839

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Project description:The olfactory system of salmonids is sensitive to the adverse effects of metals such as copper and cadmium. In the current study, we analyzed olfactory-mediated alarm responses, epithelial injury and recovery, and a suite of olfactory molecular biomarkers encoding genes critical in maintaining olfactory function in juvenile coho salmon receiving acute exposures to cadmium (Cd). The molecular biomarkers analyzed included four G-protein coupled receptors (GPCRs) representing the two major classes of odorant receptors (salmon olfactory receptor sorb and vomeronasal receptors svra, svrb, and gpr27), as well as markers of neurite outgrowth (nrn1) and antioxidant responses to metals, including heme oxygenase 1 (hmox1), and peroxiredoxin 1 (prdx1). Coho received acute (8-168 h) exposures to 3.7 ppb and 347 ppb Cd, and a subset of fish was analyzed following a 16-day depuration. Coho exposed to 347 ppb Cd over 48 h exhibited a reduction in freeze responses, and an extensive loss of olfaction accompanied by histological injury to the olfactory epithelium. The olfactory injury in coho exposed to 347 ppb Cd was accompanied at the gene level by significant decreases in expression of the olfactory GPCRs and increased expression of hmox1. Persistent behavioral deficits, histological injury and altered expression of a subset of olfactory biomarkers were still evident in Cd-exposed coho following a 16-day depuration in clean water. Exposure to 3.7 ppb Cd also resulted in reduced freeze responses and histological changes to the olfactory epithelium within 48 h of Cd exposure, although the extent of olfactory injury was less severe than observed for fish in the high dose Cd group. Furthermore adverse behavioral effects were present in some coho receiving the low dose of Cd following a 16-day depuration. In summary, acute exposures to environmental levels of Cd can cause olfactory injury in coho salmon that may persist following depuration. Mechanism-based biomarkers of oxidative stress and olfactory structures can augment the evaluation of olfactory injury manifested at the physiological level.

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Dataset Information

Methemoglobin determination by multi-component analysis in coho salmon (Oncorhynchus kisutch) possessing unstable hemoglobin.

Publications

Methemoglobin determination by multi-component analysis in coho salmon (<i>Oncorhynchus kisutch</i>) possessing unstable hemoglobin.

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