Blockade of spinal nerves attenuates myocardial apoptosis in acute myocardial ischaemia/infarction in rats.
OBJECTIVE
Evidence showed involvement of neural activity in acute myocardial ischaemia but the knowledge about the role in the pathology is still limited. The objective of this study was to examine whether low cervical and upper thoracic epidural anaesthesia could reduce apoptosis of the myocardium induced by 3-h and 6-h permanent coronary artery occlusion (CAO) in rats.


METHODS
The left anterior descending branch of coronary artery was ligated in anaesthetized Sprague-Dawley rats with and without precondition of epidural anaesthesia at the level of upper thoracic segments. Apoptosis of the myocardium insulted by acute myocardial ischaemia and infarction was assessed using terminal deoxynucleotidyl transferase-mediated dUTP nick endlabelling and caspase assay.


RESULTS
The apoptotic rates of the myocytes were 16.90 +/- 1.38 and 19.75 +/- 1.47% in the groups of CAO 3 h and CAO 6 h, respectively, whereas in the epidural groups, 10.25 +/- 1.07 and 13.05 +/- 1.19% of the apoptotic rates were detected at 3 and 6 h of CAO, significantly lower than that in the time-matched CAO animals without epidural anaesthesia (P < 0.01). Lower caspase-3 activity was observed in epidural anaesthesia group, 1.41 +/- 0.11 folds of the sham (versus 1.86 +/- 0.14 folds in CAO-3 h group) and 2.0 +/- 0.18 folds (versus 2.87 +/- 0.20 folds in CAO-6 h group) at 3 and 6 h of CAO, respectively, which were statistically significant (P < 0.05).


CONCLUSIONS
The findings may indicate blockade of spinal nerves could reduce apoptosis of myocardium in acute myocardial ischaemia and infarction.
Guo
Zheng
Z
Department of Anesthesiology, Shanxi Medical University and Second Hospital of Shanxi Medical University, 56 Xinjian Nan Road, Taiyuan 030001, Shanxi, PR China. guozheng713@yahoo.com
Wang
Jin-Ping
JP
D000577:Amides / Q000008:administration & dosage / Q000494:pharmacology*; D000767:Anesthesia, Epidural / Q000379:methods; D000779:Anesthetics, Local / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D053148:Caspase 3 / Q000378:metabolism; D004195:Disease Models, Animal; D020287:In Situ Nick-End Labeling; D008297:Male; D009203:Myocardial Infarction / Q000188:drug therapy* / Q000503:physiopathology; D017202:Myocardial Ischemia / Q000188:drug therapy* / Q000503:physiopathology; D032383:Myocytes, Cardiac / Q000187:drug effects / Q000378:metabolism; D009407:Nerve Block / Q000379:methods; D051381:Rats; D017207:Rats, Sprague-Dawley; D000077212:Ropivacaine; D013997:Time Factors
D000577:Amides; D000779:Anesthetics, Local; D000077212:Ropivacaine; D053148:Caspase 3