Preconditioned somatothermal stimulation on median nerve territory increases myocardial heat shock protein 70 and protects rat hearts against ischemia-reperfusion injury.
OBJECTIVE
This study was designed to test the hypotheses that local somatothermal stimulation on the left median nerve territory increases myocardial heat shock protein 70 and that preconditioning of rats with local somatothermal stimulation protects the hearts against subsequent ischemia-reperfusion injury.


METHODS
Local somatothermal stimulation was brought about by means of application of a heating rod over and above the left median nerve territory (1.5 cm proximal to the palm crease) in male Sprague-Dawley rats. After rats were treated with local somatothermal stimulation, the gene expression of heat shock protein 70 in regional muscle, heart, and liver was assessed by means of Western blotting and reverse transcription-polymerase chain reaction. In addition, durations of arrhythmia, mortality rates, and mitochondrial functions were compared between groups preconditioned with or without local somatothermal stimulation followed by subsequent myocardial ischemia-reperfusion injury.


RESULTS
The results showed that the gene expression of heat shock protein 70 was upregulated in the muscle beneath the area of local somatothermal stimulation, as well as in the heart, although not in the liver. When animals were preconditioned with local somatothermal stimulation on the left median nerve territory followed by subsequent ischemia-reperfusion injury of the heart, there were significant decreases of creatine kinase level from the heart, duration of arrhythmia, mortality rate, and improved mitochondrial respiratory function compared with that seen in those without local somatothermal stimulation preconditioning.


CONCLUSIONS
We conclude that local heat stress preconditioning on the left median nerve territory has a potential cardioprotective effect against subsequent ischemia-reperfusion injury.
Chiu
Jen-Hwey
JH
Institute of Traditional Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan. chiujh@mailsrv.ym.edu.tw
Tsou
Meng-Ting
MT
Tung
Hwa-Hsung
HH
Tai
Chih-Ho
CH
Tsai
Shen-Kou
SK
Chih
Chun-Lien
CL
Lin
Jaung-Geng
JG
Wu
Chew-Wun
CW
D000818:Animals; D001145:Arrhythmias, Cardiac / Q000378:metabolism* / Q000401:mortality / Q000517:prevention & control*; D015153:Blotting, Western; D004195:Disease Models, Animal; D015870:Gene Expression; D018840:HSP70 Heat-Shock Proteins / Q000032:analysis* / Q000502:physiology; D006358:Hot Temperature / Q000627:therapeutic use*; D006979:Hyperthermia, Induced / Q000379:methods*; D019194:Ischemic Preconditioning / Q000379:methods*; D008099:Liver / Q000737:chemistry; D008297:Male; D008475:Median Nerve / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry; D015428:Myocardial Reperfusion Injury / Q000378:metabolism* / Q000401:mortality / Q000517:prevention & control*; D009206:Myocardium / Q000737:chemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation
D018840:HSP70 Heat-Shock Proteins