The influence of simvastatin combined with the accessory hemiazygos vein retrograde on IL-1 、BDNF and GDNF in swines' ischemia/reperfusion injury

Objective Inspired by the simvastatin' s brain protective effect,we seek to investigate its protective effect and mechanism of the spinal cord ischemia/reperfusion injury.Methods 24 healthy adult tibet mini-pigs of either sex,weighted 20-30 kg,were randomly divided into 3 groups,8 pigs in each group.Group A,Sham operation group.Group B,Control group,i.e.the simple Ischemia/Reperfusion group.Group C,simvastatin experimental group.Creating the models of spinal cord Ischemia/Reperfusion by thoracic aorta occlusion (70 min).Isolating the accessory hemiazygos vein and ligating the distal end.1000 ml lactated ringer solution were pumped into the vein and the rate is 860 ml/h and pumping time 70 minutes.Proximal blood pressure,distal blood pressure,heart rate and the nasopharyngeal temperature were recorded every 10 minutes during the operation.After the operation,pigs were kept free access to food and water.Pigs of the simvastatin experimental group were fed with simvastatin tablets 80 mg/day,orally for 30 days.Recording the motor function score at 6,24,48 h after reperfusion (see Taylor motor function scoring system).All 8 pigs of each group were killed at 30 days after reperfusion and take the L2-L5 and sacral spinal cord as quickly as possible to observe the express changes of IL-1、BDNF and GDNF applying immunochemistry,electron microscope and Elisa method.Results In the simvastatin experimental group,the 24,48 h motor function scores were significantly higher than that in the control group (P ＜ 0.05).Compared with the control group,higher express changes of BDNF and GDNF and lower express of IL-1 can be found in the experimental group.Conclusion Simvastatin can significantly improve the neurological function recovery of spinal cord ischemia reperfusion injury.And it is related to higher express of BDNF GDNF and lower express of IL-1. Key words: Spinal cord ischemia ;  Reperfusion injury;  Simvastatin