Hypoxic preconditioning in an autohypoxic animal model
1 Medical School, Lishui University, Lishui 323000, China
2 Institute for Hypoxia Medicine, 3 School of Basic Medical Sciences, Department of Neurobiology, Capital Medical University, Beijing 100069, China
4 Biomedicine Research Center and Basic Medical College, Baotou Medical College, Baotou 014030, China
Abstract
Hypoxic preconditioning refers to the exposure of organisms, systems, organs, tissues or cells to moderate hypoxia/ischemia that results in increased resistance to a subsequent episode of severe hypoxia/ischemia. In this article, we review recent research based on a mouse model of repeated exposure to autohypoxia. Pre-exposure markedly increases the tolerance to or protection against hypoxic insult, and preserves the cellular structure of the brain. Furthermore, the hippocampal activity amplitude and frequency of electroencephalogram, latency of cortical somatosensory-evoked potential and spinal somatosensory-evoked potential progressively decrease, while spatial learning and memory improve. In the brain, detrimental neurochemicals such as free radicals are down-regulated, while beneficial ones such as adenosine are upregulated. Also, antihypoxia factor(s) and gene(s) are activated. We propose that the tolerance and protective effects depend on energy conservation and plasticity triggered by exposure to hypoxia via oxygen-sensing transduction pathways and hypoxia-inducible factor-initiated cascades. A potential path for further research is the development of devices and pharmaceuticals acting on antihypoxia factor(s) and gene(s) for the prevention and treatment of hypoxia and related syndromes.
Keywords
hypoxia; hypoxic preconditioning; adaptive medicine