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O2 consumption, aerobic glycolysis and tissue phosphagen content during activation of the Na+/K+ pump in rat portal vein

Hellstrand, Per LU ; Jorup, Carin and Lydrup, Marie-Louise (1984) In Pflügers Archiv 401(2). p.119-124
Abstract
Oxygen consumption, lactate production and tissue contents of ATP, phosphocreatine (PCr) and lactate were measured following readdition of K+ to K+-depleted rat portal veins, in order to study the energy turnover associated with Na+/K+ pumping. During incubation in K+-free medium at 37 degrees C spontaneous contractions disappeared in 10-20 min. Readdition of K+ (5.9 mM) after 40 min K+-free incubation caused hyperpolarization of the cell membrane for the first 5-10 min and then gradual depolarization with return of spontaneous action potentials and contractions by 10-20 min. During the first 4-6 min after K+ readdition aerobic lactate production was about doubled and then gradually returned to the original level (0.17 mumol/min g) at... (More)
Oxygen consumption, lactate production and tissue contents of ATP, phosphocreatine (PCr) and lactate were measured following readdition of K+ to K+-depleted rat portal veins, in order to study the energy turnover associated with Na+/K+ pumping. During incubation in K+-free medium at 37 degrees C spontaneous contractions disappeared in 10-20 min. Readdition of K+ (5.9 mM) after 40 min K+-free incubation caused hyperpolarization of the cell membrane for the first 5-10 min and then gradual depolarization with return of spontaneous action potentials and contractions by 10-20 min. During the first 4-6 min after K+ readdition aerobic lactate production was about doubled and then gradually returned to the original level (0.17 mumol/min g) at about 20 min. The increase in glycolytic rate was prevented by 1 mM ouabain. In contrast, O2 consumption (in K+-free medium, 0.38 mumol/min g) rose by about 10% when K+ was added and this increase lasted about 5 min. By 8 min after K+ addition the increased glycolysis and oxidative phosphorylation had accounted for each about the same amount of extra ATP generation over that extrapolated from the steady rate before K+ addition. The average total increase in ATP turnover in the first 8 min was 15%. During this period there was no change in the cellular content of ATP, PCr, or extractable ADP. The results indicate that Na+/K+ pumping utilizes a relatively small share of the total energy turnover in the vascular smooth muscle but is to a large extent dependent on aerobic glycolysis and therefore a major site of carbohydrate usage. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
Vascular smooth muscle, Na+/K+ pump- O2 consumption, Glycolysis, Membrane potential
in
Pflügers Archiv
volume
401
issue
2
pages
119 - 124
publisher
Springer
external identifiers
  • pmid:6089095
  • scopus:0021445273
ISSN
0031-6768
DOI
10.1007/BF00583871
language
English
LU publication?
yes
id
39f7096f-3f57-43ec-8f70-6ff3f49d19a7 (old id 1103286)
date added to LUP
2008-08-12 15:57:09
date last changed
2017-04-23 04:25:14
@article{39f7096f-3f57-43ec-8f70-6ff3f49d19a7,
  abstract     = {Oxygen consumption, lactate production and tissue contents of ATP, phosphocreatine (PCr) and lactate were measured following readdition of K+ to K+-depleted rat portal veins, in order to study the energy turnover associated with Na+/K+ pumping. During incubation in K+-free medium at 37 degrees C spontaneous contractions disappeared in 10-20 min. Readdition of K+ (5.9 mM) after 40 min K+-free incubation caused hyperpolarization of the cell membrane for the first 5-10 min and then gradual depolarization with return of spontaneous action potentials and contractions by 10-20 min. During the first 4-6 min after K+ readdition aerobic lactate production was about doubled and then gradually returned to the original level (0.17 mumol/min g) at about 20 min. The increase in glycolytic rate was prevented by 1 mM ouabain. In contrast, O2 consumption (in K+-free medium, 0.38 mumol/min g) rose by about 10% when K+ was added and this increase lasted about 5 min. By 8 min after K+ addition the increased glycolysis and oxidative phosphorylation had accounted for each about the same amount of extra ATP generation over that extrapolated from the steady rate before K+ addition. The average total increase in ATP turnover in the first 8 min was 15%. During this period there was no change in the cellular content of ATP, PCr, or extractable ADP. The results indicate that Na+/K+ pumping utilizes a relatively small share of the total energy turnover in the vascular smooth muscle but is to a large extent dependent on aerobic glycolysis and therefore a major site of carbohydrate usage.},
  author       = {Hellstrand, Per and Jorup, Carin and Lydrup, Marie-Louise},
  issn         = {0031-6768},
  keyword      = {Vascular smooth muscle,Na+/K+ pump- O2 consumption,Glycolysis,Membrane potential},
  language     = {eng},
  number       = {2},
  pages        = {119--124},
  publisher    = {Springer},
  series       = {Pflügers Archiv},
  title        = {O2 consumption, aerobic glycolysis and tissue phosphagen content during activation of the Na+/K+ pump in rat portal vein},
  url          = {http://dx.doi.org/10.1007/BF00583871},
  volume       = {401},
  year         = {1984},
}