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V-H+ -ATPase translocation during blood alkalosis in dogfish gills: interaction with carbonic anhydrase and involvement in the postfeeding alkaline tide.
- Source :
-
American journal of physiology. Regulatory, integrative and comparative physiology [Am J Physiol Regul Integr Comp Physiol] 2007 May; Vol. 292 (5), pp. R2012-9. Date of Electronic Publication: 2007 Jan 04. - Publication Year :
- 2007
-
Abstract
- We investigated the involvement of carbonic anhydrase (CA) in mediating V-H(+)-ATPase translocation into the basolateral membrane in gills of alkalotic Squalus acanthias. Immunolabeling revealed that CA is localized in the same cells as V-H(+)-ATPase. Blood plasma from dogfish injected with acetazolamide [30 mg/kg at time (t) = 0 and 6 h] and infused with NaHCO(3) for 12 h (1,000 microeq.kg(-1).h(-1)) had significantly higher plasma HCO(3)(-) concentration than fish that were infused with NaHCO(3) alone (28.72 +/- 0.41 vs. 6.57 +/- 2.47 mmol/l, n = 3), whereas blood pH was similar in both treatments (8.03 +/- 0.11 vs. 8.04 +/- 0.11 pH units at t = 12 h). CA inhibition impaired V-H(+)-ATPase translocation into the basolateral membrane, as estimated from immunolabeled gill sections and Western blotting on gill cell membranes (0.24 +/- 0.08 vs. 1.00 +/- 0.28 arbitrary units, n = 3; P < 0.05). We investigated V-H(+)-ATPase translocation during a postfeeding alkalosis ("alkaline tide"). Gill samples were taken 24-26 h after dogfish were fed to satiety in a natural-like feeding regime. Immunolabeled gill sections revealed that V-H(+)-ATPase translocated to the basolateral membrane in the postfed fish. Confirming this result, V-H(+)-ATPase abundance was twofold higher in gill cell membranes of the postfed fish than in fasted fish (n = 4-5; P < 0.05). These results indicate that 1) intracellular H(+) or HCO(3)(-) produced by CA (and not blood pH or HCO(3)(-)) is likely the stimulus that triggers the V-H(+)-ATPase translocation into the basolateral membrane in alkalotic fish and 2) V-H(+)-ATPase translocation is important for enhanced HCO(3)(-) secretion during a naturally occurring postfeeding alkalosis.
- Subjects :
- Animals
Dogfish blood
Feeding Behavior physiology
Hydrogen-Ion Concentration
Protein Transport
Sodium Bicarbonate pharmacology
Time Factors
Alkalosis blood
Carbonic Anhydrases metabolism
Dogfish metabolism
Gills enzymology
Postprandial Period physiology
Vacuolar Proton-Translocating ATPases metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0363-6119
- Volume :
- 292
- Issue :
- 5
- Database :
- MEDLINE
- Journal :
- American journal of physiology. Regulatory, integrative and comparative physiology
- Publication Type :
- Academic Journal
- Accession number :
- 17204588
- Full Text :
- https://doi.org/10.1152/ajpregu.00814.2006