| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
|
|
|
|||||||
|
|||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1 Biological Sciences, University of Alberta, Edmonton, Canada; Bamfield Marine Sciences Centre, Bamfield, Canada
2 Biology, McMaster University, Hamilton, Canada; Bamfield Marine Sciences Centre, Bamfield, Canada
3 of Biological Sciences, University of Alberta, Biological Sciences, Edmonton, Canada; Bamfield Marine Sciences Centre, Bamfield, Canada
* To whom correspondence should be addressed. E-mail: martint{at}ualberta.ca.
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-1 at t=0 and 6 h) and infused with NaHCO3 for 12 h (1000 mequiv.kg-1.h-1) had significantly higher plasma [HCO3-] compared to fish that were infused with NaHCO3 alone (28.72 ± 0.41 vs. 6.57 ± 2.47 mmol l-1, N=3) while 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 post-feeding alkalosis ("alkaline tide"). Gill samples were taken 24-26 h after dogfish fed to satiety in a natural-like feeding regime. Immunolabeled gill sections revealed that V-H+-ATPase translocated to the basolateral membrane in the post-fed fish. Confirming this result, V-H+-ATPase abundance was 2-fold higher in gill cell membranes of the post-fed fish compared to fasted fish (n=4-5; p<0.05). These results indicate that: (1) intracellular H+ or HCO3- produced by CA (and not blood pH or HCO3-) 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 HCO3- secretion during a naturally ocurring post-feeding alkalosis.
This article has been cited by other articles:
|
|
 |
|
  C. Bucking and C. M. Wood The alkaline tide and ammonia excretion after voluntary feeding in freshwater rainbow trout J. Exp. Biol., August 1, 2008; 211(15): 2533 - 2541. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
C. A. Cooper and R. W. Wilson Post-prandial alkaline tide in freshwater rainbow trout: effects of meal anticipation on recovery from acid-base and ion regulatory disturbances J. Exp. Biol., August 1, 2008; 211(15): 2542 - 2550. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. B. Claiborne, K. P. Choe, A. I. Morrison-Shetlar, J. C. Weakley, J. Havird, A. Freiji, D. H. Evans, and S. L. Edwards Molecular detection and immunological localization of gill Na+/H+ exchanger in the dogfish (Squalus acanthias) Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2008; 294(3): R1092 - R1102. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. Tresguerres, S. K. Parks, S. E. Sabatini, G. G. Goss, and C. M. Luquet Regulation of ion transport by pH and [HCO3-] in isolated gills of the crab Neohelice (Chasmagnathus) granulata Am J Physiol Regulatory Integrative Comp Physiol, March 1, 2008; 294(3): R1033 - R1043. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH |
| Visit Other APS Journals Online |
