Zheng Guo1, Jin-Ping Wang. 1. 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
Abstract
BACKGROUND AND OBJECTIVES: 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). CONCLUSION: The findings may indicate blockade of spinal nerves could reduce apoptosis of myocardium in acute myocardial ischaemia and infarction.
BACKGROUND AND OBJECTIVES: 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). CONCLUSION: The findings may indicate blockade of spinal nerves could reduce apoptosis of myocardium in acute myocardial ischaemia and infarction.