Abstract | BACKGROUND: OBJECTIVE: To ascertain whether progressive exercise preconditioning induces HSP72 expression in the rat brain and prevents heat-stroke-induced cerebral ischaemia and injury. METHODS: Male Wistar rats were randomly assigned to either a sedentary group or an exercise group. Those in the exercise group progressively ran on a treadmill 5 days/week, for 30-60 min/day at an intensity of 20-30 m/min for 3 weeks. The effects of heat stroke on mean arterial pressure, cerebral blood flow, brain ischaemia markers ( glutamate, lactate/ pyruvate ratio and nitric oxide), a cerebral injury marker ( glycerol) and brain neuronal damage score in the preconditioned animals were compared with effects in unexercised controls. Heat stroke was induced by exposing urethane-anaesthetised animals to a temperature of 43 degrees C for 55 min, which caused the body temperature to reach 42 degrees C. RESULTS: Three weeks of progressive exercise pretreatment induced HSP72 preconditioning in the brain and conferred significant protection against heat-stroke- induced hyperthermia, arterial hypotension, cerebral ischaemia and neuronal damage; it also prolonged survival. CONCLUSIONS: Exercise for 3 weeks can improve heat tolerance as well as attenuate heat-stroke-induced cerebral ischaemia in rats. The maintenance of mean arterial pressure and cerebral blood flow at appropriate levels in the rat brain may be related to overexpression of HSP72.
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Authors | Yu-Wen Chen, Sheng-Hsien Chen, Willy Chou, Yi-Ming Lo, Ching-Hsia Hung, Mao-Tsun Lin |
Journal | British journal of sports medicine
(Br J Sports Med)
Vol. 41
Issue 9
Pg. 597-602
(Sep 2007)
ISSN: 1473-0480 [Electronic] England |
PMID | 17496074
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Chemical References |
- HSP72 Heat-Shock Proteins
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Topics |
- Animals
- Blotting, Western
- Body Temperature
(physiology)
- Brain Ischemia
(prevention & control)
- Cerebrovascular Circulation
(physiology)
- HSP72 Heat-Shock Proteins
(metabolism)
- Heart Rate
(physiology)
- Heat Stroke
(etiology, physiopathology)
- Male
- Neurons
(pathology)
- Physical Conditioning, Animal
(physiology)
- Random Allocation
- Rats
- Rats, Wistar
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