Control of ion transport by mitochondrion-rich chloride cells of eurythermic teleost fish: Cold shock vs. cold acclimation
| Autor: | William S. Marshall, H.E.C. Buhariwalla, Regina R. F. Cozzi, E.M. Osmond, George N. Robertson, Katelyn R. Barnes |
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| Rok vydání: | 2012 |
| Předmět: |
Male
medicine.medical_specialty Physiology Acclimatization 030310 physiology Cell Count Biology Biochemistry Epithelium 03 medical and health sciences Chlorides Fundulidae Internal medicine medicine Membrane fluidity Cold acclimation Animals Phosphorylation Molecular Biology Ion transporter 030304 developmental biology 0303 health sciences Ion Transport Fatty Acids Fishes Homeoviscous adaptation Euryhaline Water-Electrolyte Balance Apical membrane Molecular biology Mitochondria Cold Temperature Electrophysiology Hypotonic Shock Endocrinology Hypotonic Solutions Focal Adhesion Protein-Tyrosine Kinases Tonicity Female |
| Zdroj: | Comparative Biochemistry and Physiology Part A: Molecular & Integrative Physiology. 162:234-244 |
| ISSN: | 1095-6433 |
| DOI: | 10.1016/j.cbpa.2012.03.010 |
| Popis: | Seawater-acclimated eurythermic mummichogs (Fundulus heteroclitus L.) were acclimated to cold and warm conditions (5 and 20 °C, 4 weeks). Opercular epithelia (OE) from 20 °C-acclimated animals, containing numerous mitochondrion-rich chloride cells were mounted in Ussing-style membrane chambers, cooled to 16, 13, 10, 5 and 2.5 °C, then subjected to hypotonic shock that normally inhibits Cl(-) secretion (as short-circuit current, I(sc)). Cold exposure to 10 °C slowed Cl(-) secretion (Q(10)=1.62 ± 0.204 95% CI) and OEs responded rapidly and reversibly to hypotonic shock, but below 8.0 °C a sharp decrease (Q(10)=5.63 ± 0.736) occurred and the tissue was unresponsive to hypotonicity. By immunocytochemistry, Focal Adhesion Kinase (FAK) phosphorylated at tyrosine-407 (pY(407)) colocalized with CFTR in apical membrane and dephosphorylated with hypotonic shock at 20 °C but failed to dephosphorylate at 5 °C, while opercular epithelia from cold-acclimated fish at 5 and 20 °C responded normally to hypotonic shock. Cold-shock of warm-acclimated OEs also stimulated covering over of mitochondrion- rich cell apical crypts, detected by SEM. Cold-acclimation increased C18:1 and decreased C18:0 fatty acids in liver, indicating homeoviscous adaptation. Eurythermic fish acclimate osmoregulatory systems to cold by maintaining membrane fluidity and preserving complex transport regulation pathways. |
| Databáze: | OpenAIRE |
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