spacer gif spacer gif spacer gif spacer gif spacer gif
QUICK SEARCH:   [advanced]


spacer gif
     Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents    

First published online June 15, 2007
Journal of Experimental Biology 210, 2290-2299 (2007)
Published by The Company of Biologists 2007
doi: 10.1242/jeb.002824
This Article
Right arrow Summary Freely available
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Right arrow reprints & permissions
Citing Articles
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Kristensen, K.
Right arrow Articles by Wang, T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Kristensen, K.
Right arrow Articles by Wang, T.

Oxygen-sensitive regulatory volume increase and Na transport in red blood cells from the cane toad, Bufo marinus

Karina Kristensen1, Pia Koldkjær2,*, Michael Berenbrink2 and Tobias Wang1

1 Department of Zoophysiology, Aarhus University, Denmark
2 School of Biological Sciences, The Biosciences Building, Crown Street, Liverpool L69 7ZB, UK


Figure 1
View larger version (14K):
[in this window]
[in a new window]

  		Fig. 1. Na influx in washed red blood cells (RBCs) equilibrated to a range of oxygen partial pressure (PO2) values in the presence of 10–4 mol l-1 ouabain. The influx was measured in unstimulated cells to get basal influx ({circ}) and in cells stimulated by a calculated 25% osmotic shrinkage alone ({square}) or in the presence of 10–4 mol l-1 EIPA (•). The cell suspensions were exposed to the experimental gas mixture 10 min before shrinkage (time zero in the figures). (A) 5–15 min, (B) 15–30 min, (C) 30–45 min and (D) 45–60 min. * indicates statistical difference from basal influx within the same PO2 and time interval; {dagger} indicates statistical difference from air-equilibrated RBCs within the same treatment and time interval; {ddagger} indicates statistical difference from the same treatment and PO2 level in the 5–15 min time interval. N=4, P<0.05.

 

Figure 2
View larger version (5K):
[in this window]
[in a new window]

  		Fig. 2. Effect of EIPA on fractional Na influx induced by 25% shrinkage of N2-equilibrated cells. The Na influx was measured between 15 and 30 min, where maximal shrinkage-induced influxes were found. A curve was fitted using non-linear regression (SigmaPlot 8.0). N=4.

 

Figure 3
View larger version (19K):
[in this window]
[in a new window]

  		Fig. 3. Changes in mean cellular haemoglobin concentration (MCHC) as a function of time in washed red blood cells (RBCs) in the presence of 10–4 mol l-1 ouabain. The dotted line indicates osmotic shrinkage of the RBCs following addition of sucrose (calculated to yield 25% shrinkage). (A) Oxygenated control ({square}) and shrunken ({blacksquare}) as well as deoxygenated control ({circ}) and shrunken (•) RBCs. (B) Difference in MCHC between shrunken and control cells under oxygenated ({blacksquare}) or deoxygenated (•) conditions. The dashed and the dash-dot-dashed lines indicate 50% recovery from initial change in MCHC upon shrinkage in oxygenated and deoxygenated RBCs, respectively. (C) Deoxygenated control and shrunken RBCs with and without transport inhibitors. Control cells ({circ}), shrunken cells (•), shrunken cells treated with 10–4 mol l-1 amiloride (Figure 3) or with 10–5 mol l-1 bumetanide (Figure 3). * indicates mean values that are statistically different from the respective time zero value; {dagger} indicates mean values that are statistically different from shrinkage under deoxygenated conditions; {ddagger} indicates values for deoxygenated control RBCs that are statistically different from values for oxygenated control RBCs. N=5, P<0.05.

 

Figure 4
View larger version (23K):
[in this window]
[in a new window]

  		Fig. 4. Changes in mean cellular haemoglobin concentration (MCHC) as a function of time in air-equilibrated whole blood at 1% CO2 (A) or 3% CO2 (B) or air-equilibrated washed red blood cells (RBCs) in the presence of 10–4 mol l-1 ouabain (C). The dotted lines indicate osmotic shrinkage by addition of sucrose (calculated to yield 25% shrinkage). Control cells ({square}; N=9, 4 and 11 in A, B and C, respectively), shrunken cells ({blacksquare}; N=9, 4 and 11 in A, B and C, respectively), shrunken cells treated with 10–4 mol l-1 amiloride (Figure 4; N=9, 4 and 11 for A, B and C, respectively) or with 10–5 mol l-1 bumetanide (Figure 4; N=4, 4 and 6 in A, B and C, respectively). * indicates mean values that are statistically different from the respective control value at time zero; {dagger} indicates mean values that are statistically different from shrinkage alone; {ddagger} indicates values that are not statistically different from corresponding values in control blood samples. P<0.05.

 

Figure 5
View larger version (15K):
[in this window]
[in a new window]

  		Fig. 5. Na influx as a function of time in washed red blood cells (RBCs) in the presence of 10–4 mol l-1 ouabain in (A) deoxygenated cells (equilibrated to humidified N2 for 10 min prior to treatments) or (B) air-equilibrated cells. The Na influx was measured in unstimulated cells to get the basal influx and in cells stimulated by 10–5 mol l-1 isoproterenol at time zero either alone or in the presence of transport inhibitors. * indicates statistical difference from basal influx within same time interval; {dagger} indicates statistical difference from influx in isoproterenol stimulated cells within same time interval; {ddagger} indicates statistical difference from same treatment in the 5–15 min time interval. P<0.05. (A) N=4 and (B) N=6.

 




© The Company of Biologists Ltd 2007