Effects Of Inhabitor Of Phosphodiesterases In Experimental Secondary SCI In Rats

Spinal cord injury(SCI) is a severe disease result from lesionmostly. According to the reviews in peiking region, the incidence of SCI was 6.8/mollion/year in 1988, lower than developed countries. In recent years,however ,this figure is getting higher and traffic accident is the foremost cause.The complications of SCI has brought heavy spirital and financial burden to patients,their families and even the whole society.Researches has shown that spinal cord has certain ability to recover.So aiming at the recovery it is one of the key factors to protect the injuried spinal cord to reduce the death of neural cells during the SCI.How to bring down the secondary lesion,which may be manifested as the death or apoptosis of neural cells,acts a most important role during the peroid of SCI.Besides Ischemia,the main reason of the apoptosis of neural cells,There are some other important causes like high Ca^level and FR.Surgery can ellivate compression,stabilize spinal column and considerate nursing can help to reduce complication ,a lot of researchs on recovery of SCI have been made.Many new medicines and new methods such as Methylprednisolone(MP),GM-l,the implantation of Schwann cells and the implantation of fetal spinal cord cell were found,yet the curative effects were not certain.MP has been accepted as a better medicine to SCI.But its expensive price and the complication impede to its long-term use.Pentoxifyline(PTX)is a non-selective inhabitor to PDE,which can raise ATP content in red blood cell,reduce the diameter of red blood cell,improve the hemodynamics,lower plasminogen,strengthenfibrinolysis,control aggregation of platelets, restrain FR response and so on.PTX has been used for cardiopathy and apoplexy.But there are neither domestic nor abroad reports about its use in SCI treatment therapy. Objective:To observe the effects of the inhibitor of PDE(PTX) to secondary SCI ,study the mechanism of PTX to neural cells apoptosis and to provide experimental data for to the clinical application of PTX in treating SCI. Methods:In the study, 124 male SD rats of three or four months weighting approximately 250gram were offered.They were divided randomly into three group.Single SCI group,SCI with MP treatment group.SCI with PTX treatment group.Each group in which has forty rats were divided into five part(4h,8h,24h,3d,7d).SCI+MP group were given 3Omg-kg-1d-1 of MP jvith intraperitoneally injection.SCI+PTX group were given 30mg-kg-1-d-of PTX with intraperitoneally injection. (l)to assess hind limb neurological function. (2)to test the water content and ion level in the spinal cord tissue. (3)to test the level of MDA in the spinal cord tissue with Thibabituric Acid(TBA)method and SOD with xanthine oxidase system method. (4)the histomorphonetry of spinal cord tissue.The spinal cord tissue in each group were stabilized and stained with hematoxylin and eosin(HE) and TUNEL so as to observe the microarchitecture by microscopy.Statistical data were described as mean盨EM.According to the statistical principles,data were compared with analysis of variance. Results:(1) hind limb neurological function :Both SCI with MP group and SCI with PTX group were significantly beeter than single SCI group.(P<0.05),no statistically significantly difference was identified between SCI with MP group and SCI with PTX group(P>0.05)(2) the water content and ion level testing in the spinal cord tissue rwater content,Ca2+Na+ level in spinsl cord tissue of both SCI with MP group and SCI with PTX were significantly lower than single SCI group.(P<0.05). K+ level in spinsl cord tissue of both SCI with MP group and SCI with PTX were significantly higher than single SCI group.(P<0.05).no statistically significantly difference was identified betweenSCIwith MP group and SCI with PTX group(P>0.05). (3)the level of MDA SOD in the spinal cord tissue:MDA: both SCI with MP group and SCI with PTX were significantly lower than single SCIgroup.(P<0.05).no statistically si...