Effect of vagus nerve stimulation on thermal injury in rats.
OBJECTIVE
To investigate the effects of vagus nerve stimulation on haemodynamics, pulmonary histopathology, arterial blood gas and pro-inflammatory responses to thermal injury.


METHODS
Forty-eight male Sprague-Dawley (SD) rats were randomly divided into six equal groups: normal control (NC) group; thermal injury (TEM) group subjected to 40% total body surface area (%TBSA) third-degree thermal injury; vagotomy (VGX) group subjected to bilateral cervical vagotomy after thermal injury; electrical stimulation (STM) group subjected to bilateral cervical vagotomy plus the left vagus nerve trunk electrical stimulation (5 V, 2 ms and 1 Hz) after thermal injury; the antagonist of muscarinic acetylcholine receptor (MRA) group administrated with atropine (0.1 mg kg(-1)) before electrical stimulation and the antagonist of nicotinic acetylcholine receptor (NRA) group administrated with hexamethonium (10 mg kg(-1)) before electrical stimulation.


RESULTS
The haemodynamics, histopathology of lung tissue, arterial blood gas, lactic acid, tumour necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels were measured. Vagus nerve electrical stimulation not only significantly increased the mean arterial pressure (MAP) and heart rate (HR), but also decreased the infiltration of inflammatory cells into interstitial and alveolar spaces after thermal challenge and attenuated TNF-alpha and IL-6 production. Hexamethonium pre-treatment significantly reversed the effects of vagal electrical stimulation, but atropine administration before electrical stimulation had no such effects.


CONCLUSIONS
Direct electrical stimulation of the vagus nerve might produce therapeutic effect on thermal injury. The effect may be realised by limiting the inflammatory response via nicotinic acetylcholine receptors in rats.
Song
Xue-Min
XM
The Research Centre of Anesthesiology and Critical Care Medicine, Zhongnan Hospital, Wuhan University, Wuhan 430071, Hubei Province, China.
Li
Jian-Guo
JG
Wang
Yan-Lin
YL
Liang
Hui
H
Huang
Yue
Y
Yuan
Xiang
X
Zhou
Qing
Q
Zhang
Zong-Ze
ZZ
D000818:Animals; D001794:Blood Pressure; D002056:Burns / Q000473:pathology / Q000503:physiopathology / Q000628:therapy*; D002245:Carbon Dioxide / Q000097:blood; D004195:Disease Models, Animal; D006339:Heart Rate; D015850:Interleukin-6 / Q000378:metabolism; D019344:Lactic Acid / Q000097:blood; D008168:Lung / Q000378:metabolism / Q000648:ultrastructure; D008297:Male; D008854:Microscopy, Electron; D010100:Oxygen / Q000097:blood; D010313:Partial Pressure; D051381:Rats; D017207:Rats, Sprague-Dawley; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D055536:Vagus Nerve Stimulation / Q000379:methods*
D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha; D002245:Carbon Dioxide; D019344:Lactic Acid; D010100:Oxygen