Cardiac mitochondrial metabolism may contribute to differences in thermal tolerance of red- and white-blooded Antarctic notothenioid fishes
| Autor: | Kristin M. O'Brien, Rebekah Woolsey, Anthony P. Farrell, Karen Schlauch, Elizabeth L. Crockett, Anna S. Rix, Stuart Egginton, Megan Hoffman, Sean Merriman |
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| Jazyk: | angličtina |
| Rok vydání: | 2018 |
| Předmět: |
030110 physiology
0301 basic medicine Hot Temperature Physiology Cellular respiration Antarctic Regions Citrate (si)-Synthase Aquatic Science Mitochondrion Chaenocephalus aceratus Mitochondria Heart 03 medical and health sciences Adenosine Triphosphate Respiration Animals Citrate synthase 14. Life underwater Critical thermal maximum Energy charge Molecular Biology Ecology Evolution Behavior and Systematics L-Lactate Dehydrogenase biology Chemistry Myocardium Metabolism biology.organism_classification Perciformes Biochemistry Insect Science biology.protein Animal Science and Zoology Research Article |
| ISSN: | 0022-0949 |
| Popis: | Studies in temperate fishes provide evidence that cardiac mitochondrial function and the capacity to fuel cardiac work contribute to thermal tolerance. Here, we tested the hypothesis that decreased cardiac aerobic metabolic capacity contributes to the lower thermal tolerance of the haemoglobinless Antarctic icefish, Chaenocephalus aceratus, compared with that of the red-blooded Antarctic species, Notothenia coriiceps. Maximal activities of citrate synthase (CS) and lactate dehydrogenase (LDH), respiration rates of isolated mitochondria, adenylate levels and changes in mitochondrial protein expression were quantified from hearts of animals held at ambient temperature or exposed to their critical thermal maximum (CT(max)). Compared with C. aceratus, activity of CS, ATP concentration and energy charge were higher in hearts of N. coriiceps at ambient temperature and CT(max). While state 3 mitochondrial respiration rates were not impaired by exposure to CT(max) in either species, state 4 rates, indicative of proton leakage, increased following exposure to CT(max) in C. aceratus but not N. coriiceps. The interactive effect of temperature and species resulted in an increase in antioxidants and aerobic metabolic enzymes in N. coriiceps but not in C. aceratus. Together, our results support the hypothesis that the lower aerobic metabolic capacity of C. aceratus hearts contributes to its low thermal tolerance. |
| Databáze: | OpenAIRE |
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