Intrathecal injection of ketamine and clonidine for chronic neuropathic pain model in rats / 中南大学学报(医学版)

OBJECTIVE@#To observe the effect of intrathecal injection of ketamine and clonidine for chronic constriction injury (CCI) in rats.@*METHODS@#Thirty-two SD male rats weighing 220-280 g were anesthetized with intraperitoneal chloral hydrate 300 mg/kg. A catheter was implanted in the subarachnoid space at the lumbal region and CCI rat models were made successfully. On the 4th day after the surgery, the rats were randomly divided into 4 group: a control group,injecting 0.9%NS 20 microL intrathecally; a ketamine group, injecting ketamine 1 mg/kg(20 microL) intrathecally; a clonidine group (CL), injecting clonidine 20 microg/kg (20 microL) intrathecally; a combined ketamine and clonidine group, injecting ketamine 0.5mg/kg and clonidine 10 g/kg (20 microL) intrathecally, once a day for 1 week. BME-410A Plantar Analgesia Tester was used to measured pain threshold before the administration and 30 min after the administration. The rats were killed after the test was finished. And then we detected the nitric oxide synthase (NOS) activity and the NO production in the spinal cord.@*RESULTS@#The combined injection of ketamine (0.5mg/kg)and clonidine(10 g/kg) produced significantly more potent analgesia than the injection of ketamine (1 mg/ kg) or clonidine (20 microg/ kg)alone. The NOS activity and the production of NO in the combined injection group were significantly lower than those of the single injection group (P<0.05). The weight of rats post-administration increased obviously in the 4 groups (P<0.05).@*CONCLUSION@#The combined injection of ketamine and clonidine can produce synergistic ab-irritation without obvious side effects.

The Construction of Lentiviral-delivery Human Interleukin-10 Expression Vector and the Abirritative Effect of Pain on CCI Rats / 中国生物工程杂志

Objective:To construct the lentiviral-vector encoding human interleukin-10 protein(LV-hIL-10) and to observe the effect of LV-hIL-10 on controlling neuropathic pain via intrathecal administration in CCI rats. Methods:hIL-10 gene fragment was isolated and amplified from pCYIL-10 plasmid by PCR, and was cloned into pWPXL. The recombinant plasmid pWPXL-IL-10,envelope plasmid pMD2.G and packaging plasmid psPAX2 were cotransfected into 293T cells, LV-hIL-10 is prepared by concentrating the collected supernatant .At the same time, the empty plasmid pWPXL-GFP,pMD2.G and psPAX2 were cotransfected into 293T cells, LV-GFP is prepared for contrast.135 sheer breed pathogen-free adult male Sprague-Dawley rats divided into 9 arrays at random: CCI models 4 arrays (C0,C1,C2,C3), sham operatived rats 4 arrays (S0,S1,S2,S3) and a normal contrast array (N), each respectively intrathecal injection LV-hIL-10 (C1,S1)、LV-GFP (C2, S2),isotonic Nachloride (C3,S3) and control (no implanted catheters and no administration, C0,S0), the pain threshold of each array and the expression of mRNA and protein of IL-10 in spinal cord,pallium and hippocampus on different time were observed after intrathecal administration LV-hIL-10 in successful CCI model rats . Results:The hIL-10 gene fragment was obtained from pCYIL-10 plasmid, pWPXL-hIL-10 was recombinated successfully. the cloned gene segment was validated by DNA sequencing .High titer(2?1010)and highly purified LV-hIL-10 particles were obtained by three plasmids were cotransfected into 293T cells. The mechanical allodynia and thermal hyperalgesia were alleviated via intrathecal injection LV-hIL-10 in CCI rats. The overexpression of IL-10 were detected in spinal cord,pallium and hippocampus , especially in the spinal cord .Conclusions:The mechanical allodynia and thermal hyperalgesia can be relieved by intrathecal injection LV-hIL-10 in CCI rats.