|
|
||||||||
| ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
TOPICAL REVIEW |
1 Department of Physiological Sciences, Stellenbosch University, Stellenbosch, South Africa
Since a constant supply of oxygen is essential to sustain life, organisms have evolved multiple defence mechanisms to ensure maintenance of the delicate balance between oxygen supply and demand. However, this homeostatic balance is perturbed in response to a severe impairment of oxygen supply, thereby activating maladaptive signalling cascades that result in cardiac damage. Past research efforts have largely focused on determining the pathophysiological effects of severe lack of oxygen. By contrast, and as reviewed here, exposure to moderate chronic hypoxia may induce cardioprotective properties. The hypothesis put forward is that chronic hypoxia triggers regulatory pathways that mediate long-term cardiac metabolic remodelling, particularly at the transcriptional level. The novel proposal is that exposure to chronic hypoxia triggers (a) oxygen-sensitive transcriptional modulators that induce a switch to increased carbohydrate metabolism (fetal gene programme) and (b) enhanced mitochondrial respiratory capacity to sustain and increase efficiency of mitochondrial energy production. These compensatory protective mechanisms preserve contractile function despite hypoxia.
(Received 20 August 2007;
accepted after revision 24 August 2007;
first published online 30 August 2007)
Corresponding author M. F. Essop: Department of Physiological Sciences, Stellenbosch University, Room 2009, Mike De Vries Building, Merriman Avenue, Stellenbosch, South Africa. Email: mfessop{at}sun.ac.za
This article has been cited by other articles:
![]() |
H. M. Prentice Key contributions of the Na+/H+ exchanger subunit 1 and HCO3- transporters in regulating neuronal cell fate in prolonged hypoxia Am J Physiol Regulatory Integrative Comp Physiol, February 1, 2008; 294(2): R448 - R450. [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |