| Objective:To observe the effect of Jingzhaotoxin-V(JZTX-V) injected intrathecally on mechanical allodynia which is induced by sciatic chronic constriction injury(CCI) in rats, in order to provide experimental evidence for therapeutic of JZTX-V in neuropathic pain.Method:60SD rats which are male and healthy were randomly divided into6groups (n=10), normal group:rats underwent surgery of CCI only; Group control:CCI+saline group, normal saline(NS) was intrathecally injected in rats after sciatic CCI surgery, Group M: CCI+morphine group, morphine was intrathecally injected in rats after sciatic CCI surgery. JZTX-V experimental group were divided into3groups.Group J1:CCI+JZTX-V (20μg/kg) group,20μg/kg of JZTX-V was intrathecally injected in rats after sciatic CCI surgery.Group J2:CCI+JZTX-V (40μg/kg) group,40μg/kg of JZTX-V was intrathecally injected in rats after sciatic CCI surgery.Group J3:CCI+JZTX-V (60μg/kg) group,60μg/kg of JZTX-V was intrathecally injected in rats after sciatic CCI surgery.Measure the basic pain threshold before inserting intrathecal catheter and CCI surgery, the rats which was not up to the stand will be rejected, then to repeat the operations on all the rats on the3rd,5th,7thdays after inserting intrathecal catheter and CCI surgery. Rats were administrated NS, morphine or JZTX-V of three kinds of doses (20μg/kg,40μg/kg, 60μg/kg) respectively, then the mechanical withdrawal thresholds of rats in each group which underwent the inserting intrathecal catheter and CCI surgery were measured with the von Frey method in1/2h,1h,1.5h,2h after intrathecal injection. Compare with the mechanical withdrawal thresholds of each groups with statistical analysis, compare with adverse effects of each groups.Result:1. In Group control, one rat was anaesthetized excessively to death, one rat was paralyzed after CCI surgery. In other groups,2rats died in surgery of inserting intrathecal catheter,4rats died in the1-2days after surgery of inserting intrathecal catheter,4rats were paralyzed in the day after surgery of inserting intrathecal catheter. Compared with basic pain threshold, a significant decrease in PWT was observed in the same time after surgery in both CCI group and CCI+inserting intrathecal catheter group(P<0.05), but there is no difference in decreases of these two groups(P>0.05).2. In the same time after giving the NS, morphine or JZTX-V of different doses, compared with N1group, a significant increase in PWT was observed in group M, group J1, group J2, group J3(P<0.05). In Group M, PWT was at its peak an hour after administration and returned to original level two hours after administration. In Group J1and Group32, PWT was at its peak an hour after administration but still preceded original level two hours after administration. In Group J3, PWT at its peak1.5hours after administration, preceded original level and Group J1level but in the same level with group J2two hours after administration.3. In the same time after giving the JZTX-V of different doses, the levels of increase in PWT of J1group, J2group, J3group is:J3>J2>J1 (P<0.05).4. In the time of the best analgesic activity of the drugs, the PWT level of Group J3<the PWT level of Group M (P<0.05), but the PWT level of Group J3went down more slowly than that of Group M.5. There was no significant effect for motor function and death in the rats after giving JZTX-V through the inserting intrathecal catheter, verifying that giving JZTX-V through the inserting intrathecal catheter is safe for this experiment.Conclusion:1. Intrathecal administration with JZTX-V attenuated neuropathic pain in rats induced by CCI in a dose-dependent manner, Intrathecal administration with JZTX-V is safe for rats in the experiment.2. The maximum efficacy of intrathecal administration with JZTX-V is less than morphine in the same time after giving drugs, but the efficacy of intrathecal administration with JZTX-V last longer than morphine’s.3. Intrathecal administration with JZTX-V has no significant effect for rats’motor function, so it is safe for rats in the experiment.4. JZTX-V can be as a therapeutic method for neuropathic pain, and provide an idea and method for drug’s development of neuropathic pain. |
PDF Full Text Request