Acute and chronic temperature dependence of Na+/H+ exchange activity of Pimephales promelas gills
| Autor: | Jill M. Patel, Randall K. Packer, William Ye, Jeffrey L. Garvin, Katrina Thede, Matthew L Garvin, Simon Wentworth, Varsha Aravindabose, Ian Monroe |
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| Rok vydání: | 2021 |
| Předmět: |
0301 basic medicine
Gill biology Physiology Chemistry Vesicle ATPase 030204 cardiovascular system & hematology Biochemistry Molecular biology Acclimatization 03 medical and health sciences chemistry.chemical_compound 030104 developmental biology 0302 clinical medicine biology.protein Atpase activity Ammonium Pimephales promelas Molecular Biology Homeostasis |
| Zdroj: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 257:110975 |
| ISSN: | 1095-6433 |
| DOI: | 10.1016/j.cbpa.2021.110975 |
| Popis: | Na+/H+ exchangers (NHE) mediate at least part of Na+ entry into gill epithelia via Na+/NH4+ exchange. For homeostasis, Na+ entry into and exit via Na+/K+ ATPase from gill epithelia must balance. Na+/K+ ATPase activity is reduced in cold- compared to warm-acclimated freshwater temperate fish. We hypothesized gill NHE activity is greater in warm- than cold-acclimated fish when measured at acclimation temperatures, and NHE activity displays a temperature dependence similar to Na+/K+ ATPase. Since NHE mRNA expression does not differ, we measured the Na+-dependence of pH-induced Na+ fluxes in gill vesicles from warm- and cold-acclimated fathead minnows at 20o and 7 °C, and calculated maximum transport rates (Vmax) and Na+ K1/2s. We also measured NH4+-induced Na+ fluxes and Na+-induced H+ fluxes. In vesicles from warm-acclimated fish, NHE Vmaxs were 278 ± 33 and 149 ± 23 arbitrary unit/s (au/s) and Na+ K1/2s were 12 ± 4 and 6 ± 4 mmol/l when assayed at 20o and 7 °C (p |
| Databáze: | OpenAIRE |
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