The Relationship Between The Anti-nociception Of Propentofylline On Rats Of Incisional Pain And MKP-1/p-p38

Part ? Calculate the IC50 about Ro 318220 Inhibiting MKP-1 ExpressionObjective: To calculate the IC50 about intrathecal injection of Ro 318220 inhibiting the expression of MKP-1.Methods: 30 healthy male rats,weighing 250-280 g,1.5-2.0 months were randomly divided into 5 groups using a random number table(n=6):Na?ve group(group?),Ro 318220 10ug/20 ul group(group?),Ro 318220 20ug/20 ul group(group?),Ro 318220 40ug/20 ul group(group?),Ro 318220 80ug/20 ul group(group?).Group?,?,?,? were respectively intrathecal injection of Ro 318220 10?20?40?80ug/20 ul,group?didn't do any process.All groups detected the rat spinal cord MKP-1 expression by Western blot after injection 24 h.Results: The IC50 about Ro 318220 inhibiting the expression of MKP-1 is 33 ug.Conclusion: Ro 318220 inhibited the rat spinal cord MKP-1 expression and the IC50 about Ro 318220 inhibiting the expression of MKP-1 is 33 ug.Part ? The Relationship between the Anti-nociception of Propentofylline on Rats of Incisional Pain and MKP-1/p-p38Objective: To investigate the anti-nociception effect of intrathecal injection of PPF on rats model of acute incisional pain and the role of MKP-1/p-p38 expression in this anti-nociception effect.Methods: 90 Male SD healthy rats weighting 250-300 g,1.5-2.0 months old were divided into6 groups using a random number table:Na?ve group(n=6),NS group(n=6),DMSO group(n=6),IP group(n=30),PPF group(n=36),Ro group(n=6).IP,PPF,Ro group made paw incision,NS group was intrathecal injection of 10 ul NS,DMSO group was intrathecal injection of 10ul10%DMSO,PPF group was intrathecal injection of PPF 10ug/10 ul on postoperative 30 min,Ro group was respectively intrathecal injection of Ro 318220 40ug/20 ul and PPF 10ug/10 ul preoperative and postoperative 30 min.Na?ve,NS,DMSO,Ro group test the Mechanical Withdrawal Threshold(MWT)on preoperative and postoperative 1d,IP and PPF group test MWT on preoperative 2h and postoperative 2h,5h,1d,2d,3d.Took 6 rats from PPF group randomly detecting the MKP-1 spinal cord location by Immunoflusorescence and other groups detected the spinal cord MKP-1/p-p38 expression by Western blot.Results: Compared with na?ve group,there is no changed MWT and MKP-1/p-p38 expression in NS and DMSO group(P>0.05);Compared with baseline,2h,5h,1d,2d,3d after paw incision,the MWT is decreased and postoperative 5h is the lowest(P<0.05),the spinal cord MKP-1 expression is declined and p-p38 is elevated(P<0.05);Compared with IP group,2h,5h,1d,2d,3d after intrachecally injection PPF,The MWT is increased(P<0.05),the spinal cord MKP-1expression is increased and p-p38 is decreased(P<0.05);Compared with PPF group,after intrachecally injection Ro 318220,The MWT is decreased(P<0.05),the spinal cord MKP-1expression is decreased and p-p38 is increased(P<0.05).Conclusion: The decrease of MKP-1 and elevation of p-p38 may generate rat paw incisional pain,PPF could relief this acute pain,and the mechanism may be related with the elevation of MKP-1 and the decreased p-p38.