| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
|
|
|
|||||||
|
|||||||||
Laboratoire de Physiologie Cellulaire Respiratoire, Institut National de la Santé et de la Recherche Médicale (Equipe Mixte 9937), and Institut Fédératif de Recherche 4, Université Bordeaux 2, 33076 Bordeaux, France
The effect of chronic hypoxia
(CH; 1-4 wk) on the electromechanical properties of the rat main
pulmonary artery (MPA) was investigated. MPA rings obtained from rats
exposed for 14 days to hypobaric (50.5 kPa) CH exhibited spontaneous
and rhythmic contractions (SRCs) that were never observed in control
(normoxic) rats. SRCs were unaffected by tetrodotoxin, phentolamine,
BQ-123 and BQ-788, N-nitro-L-arginine methyl
ester, or endothelium removal. CH depolarized smooth muscle cells from
58.8 ± 9 to 38.6 ± 5.4 mV and increased the resting
cytosolic Ca2+ concentration from 67.3 ± 11.9 to
112.5 ± 16.4 nM. CH also induced spontaneous spikelike
depolarizations. All of these effects were inhibited by external
Ca2+ removal or nifedipine (1 µM). Moreover, depletion of
intracellular Ca2+ stores with ryanodine (1-5 µM) or
cyclopiazonic acid (3 µM) progressively attenuated SRCs. This study
demonstrates that CH switches the MPA from a quiescent to a
spontaneously active mechanical state. Finally, the fact that SRCs
precede the development of right ventricle hypertrophy and disappear
when this hypertrophy reaches a maximal value (after 3-4 wk of CH)
suggests that SRCs may play a role in the adaptive process of the
pulmonary circulation to CH.
calcium signaling; hypobaric hypoxia; pulmonary hypertension; smooth muscle; right ventricle hypertrophy
This article has been cited by other articles:
|
|
 |
|
  R. E. Haddock, T. H. Grayson, T. D. Brackenbury, K. R. Meaney, C. B. Neylon, S. L. Sandow, and C. E. Hill Endothelial coordination of cerebral vasomotion via myoendothelial gap junctions containing connexins 37 and 40 Am J Physiol Heart Circ Physiol, November 1, 2006; 291(5): H2047 - H2056. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 N. L. Jernigan, B. R. S. Broughton, B. R. Walker, and T. C. Resta Impaired NO-dependent inhibition of store- and receptor-operated calcium entry in pulmonary vascular smooth muscle after chronic hypoxia Am J Physiol Lung Cell Mol Physiol, March 1, 2006; 290(3): L517 - L525. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Nouette-Gaulain, M. Malgat, C. Rocher, J.-P. Savineau, R. Marthan, J.-P. Mazat, and F. Sztark Time course of differential mitochondrial energy metabolism adaptation to chronic hypoxia in right and left ventricles Cardiovasc Res, April 1, 2005; 66(1): 132 - 140. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
N. L. Jernigan, B. R. Walker, and T. C. Resta Endothelium-derived reactive oxygen species and endothelin-1 attenuate NO-dependent pulmonary vasodilation following chronic hypoxia Am J Physiol Lung Cell Mol Physiol, October 1, 2004; 287(4): L801 - L808. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
O. Pauvert, S. Bonnet, E. Rousseau, R. Marthan, and J.-P. Savineau Sildenafil alters calcium signaling and vascular tone in pulmonary arteries from chronically hypoxic rats Am J Physiol Lung Cell Mol Physiol, September 1, 2004; 287(3): L577 - L583. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
Y. Morio, E. P. Carter, M. Oka, and I. F. McMurtry EDHF-mediated vasodilation involves different mechanisms in normotensive and hypertensive rat lungs Am J Physiol Heart Circ Physiol, May 1, 2003; 284(5): H1762 - H1770. [Abstract] [Full Text] [PDF]
|
|
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |
