Protective Effects Of Ischemic Preconditioning On Motoneurons And Muscles In Rat Lumbosacral Enlargement Following Limb Ischemia/Reperfusion Injury

Objective:A large number of experiments has been confirmed that Ischemic preconditioning (IPC) on the heart, skeletal muscle ischemia and reperfusion (I/R) injury have protective effects, while fewer reports of peripheral nerve ischemia-reperfusion injury have been reported. Scholars have little researches for common clinical peripheral nerve ischemia and reperfusion injury. But in the medical circle, peripheral nerve ischemia and reperfusion injury happen in a certain instance. The protective effect of ischemic preconditioning is a simple ischemia-induced method in a short time and less effect of damage. This experiment focuses on whether ischemic preconditioning on peripheral nerve ischemia reperfusion injury has the protective effect, and in order to find the best method. Through the establishment of the side of the hind limbs in rats reperfusion injury model, ischemic preconditioning has been done in different conditions. The morphology and ultrastructure changes of rat tibialis anterior muscle and motor neuron in lumbosacral enlargement were observed. To explore the protective effect of ischemic preconditioning in ischemia-reperfusion injury. To provide a reference for clinical ischemia-reperfusion injury of peripheral nerve protection.Methods:Firstly, we choose male64SD rats (3month), randomly divided into8groups and8rats in each group. The rats were divided into A and B group according to2-hour and12-hour reperfusion. Group A and B were subdivided into four sub-groups respectively (A0、A1、A2、A3and B0、B1、B2、B3) which were based on no ischemic preconditioning, once preconditioning, twice preconditioning and three times preconditioning. The limb ischemia preconditioning was10minutes reperfusion after10minutes ischemia. We selected the tissues in the anterior horn of lumbar enlargement and the Tibialis anterior muscles, and observed the changing of ultra structure of the different condition groups of IPC by TEM (transmission electron microscope).Result:1. An ischemia-reperfusion injury model has been successfully prepared.2. Morphology observation indicates that:A0group:After ischemia and reperfusion injury, neurons reduced and nuclear lysed significantly, after pretreatment we can saw neuron cells were increased and the visible part of the nucleus existed; Bo group:After ischemia and reperfusion injury, most of the neuron cells necrolysis, after pretreatment, part of the neuron cells necrolysis.3. Ultrastructural observation:Both A0and Bo groups spinal anterior horn neurons cells have in some instant expansion injuries, within the endoplasmic reticulum expansion, and a large number of mitochondria vacuolization and nuclear membranes were dissolved away, but Bo group has more damage than Ao group. After pretreatment of reperfusion, injury was alleviated, after Superposition pretreatment, the injury to further reduced.4. The muscles were observed the injury in all groups. There were more injury in the longer times for reperfusion and less injury in the more preconditioning.Conclusion:1. There was the protective effect of limb ischemic preconditioning on rat spinal cord following ischemia/reperfusion injury, which can reduce the injury obviously. The protective effect of three times ischemic preconditioning is better than the others in spinal cord ventral horn following ischemia/reperfusion injury.2. There was the protective effect of ischemic preconditioning on the muscles, which was better in the twice preconditioning than once. There were not different in the twice and three times preconditioning. There was more injury in the longer time for reperfusion.