|
|
||||||||
1Kids Heart Research; 2Neurogenetics Research Unit and Institute for Neuromuscular Research, Childrens Hospital at Westmead; 3Discipline of Pediatrics and Child Health, Faculty of Medicine, University of Sydney, Sydney, New South Wales, Australia; 4Departments of Medicine and Physiology, Cardiovascular Research Institute, University of California, San Francisco, California; and 5Muscle Development Unit, Childrens Medical Research Institute, Sydney, New South Wales, Australia
Submitted 23 January 2006 ; accepted in final form 3 March 2006
Water accumulation in the heart is important in ischemia-reperfusion injury and operations performed by using cardiopulmonary bypass, with cardiac dysfunction associated with myocardial edema being the principal determinant of clinical outcome. As an initial step in determining the role of aquaporin (AQP) water channels in myocardial edema, we have assessed the myocardial expression of AQPs in humans, rats, and mice. RT-PCR revealed expression of AQP-1, -4, -6, -7, -8, and -11 transcripts in the mouse heart. AQP-1, -6, -7, and -11 mRNAs were found in the rat heart as well as low levels of AQP-4 and -9. Human hearts contained AQP-1, -3, -4, -5, -7, -9, -10, and -11 mRNAs. AQP-1 protein expression was confirmed by Western blot analysis in all three species. AQP-4 protein was detected in the mouse heart but not in the rat or human heart. To determine the potential functional consequences of myocardial AQP expression, water permeability was measured in plasma membrane vesicles from myocardial cells of wild-type versus various AQP knockout mice. Water permeability was reduced by AQP-1 knockout but not by AQP-4 or AQP-8 knockout. With the use of a model of isolated rat heart perfusion, it was found that osmotic and ischemic stresses are not associated with changes in AQP-1 or AQP-4 expression. These studies support a possible functional role of AQP-1 in myocardium but indicate that early adaptations to osmotic and ischemic stress do not involve transcriptional or posttranslational AQP-1 regulation.
aquaporin knockout; cardiac myocyte; cardiopulmonary bypass
This article has been cited by other articles:
![]() |
J. R. Egan, T. L. Butler, A. D. Cole, A. Aharonyan, D. Baines, N. Street, M. Navaratnam, O. Biecker, C. Zazulak, C. G. Au, et al. Myocardial ischemia is more important than the effects of cardiopulmonary bypass on myocardial water handling and postoperative dysfunction: A pediatric animal model. J. Thorac. Cardiovasc. Surg., November 1, 2008; 136(5): 1265 - 1273.e2. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. T. Skowronski, J. Lebeck, A. Rojek, J. Praetorius, E.-M. Fuchtbauer, J. Frokiaer, and S. Nielsen AQP7 is localized in capillaries of adipose tissue, cardiac and striated muscle: implications in glycerol metabolism Am J Physiol Renal Physiol, March 1, 2007; 292(3): F956 - F965. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |