The Expression Changes Of AI-CDA In Spinal Cord Of Bone Cancer Painmorphine Tolerance In Rats

Objective: To explore activation induced cytidine deaminase(AI-CDA)participating in the possible mechanisms of bone cancer pain-morphine tolerance by evaluating spinal cord AI-CDA in rats with bone cancer pain-morphine tolerance.Methods: 30 healthy female wistar rats were randomly divided into 3 groups(n=10 each): the control group(group I),bone cancer pain group(group II)and bone cancer pain-morphine tolerance group(group III).Nasopharyngeal carcinoma HONE1 cell was injected in the left hind tibia bone marrow cavity inoculation,preparation of rat model of bone cancer pain.After operation,we measure withdraw mechanical threshold(MWT)every day and check the damage of bone with X-Ray on the 14 th day of postoperative.Bone cancer pain-morphine tolerance group(group III)subcutaneous injection of morphine 10mg/kg on the 15~21th day after operation and bone cancer pain group(group II)was injected with equal dose of normal saline.Observe tibial pathological specimen and extract L4~L6 lumbar spinal on 21 th day after operation.Detecting the activation induced cytidine deaminase mRNA expressions by RT-PCR.Results:(1)Compared with group II,the first three days of injection of morphine,the MWT of the group III significantly increased(P<0.05).Compared with the first three days,the MWT of the group III significantly reduced in the last 3 days of injection of morphine.(2)Compared with group I,the X-ray of group II and group III appears different degree of bone destruction.(3)Operate side tibia pathological show,cancer cells in the marrow cavity can be seen on the group II and group III,the trabecular bone has been destructioned.(4)Compared with group II,the expression of AI-CDA mRNA was increased(P<0.05).Conclusion: The expression of AI-CDA was increased in spinal cord.AI-CDA may participate in the formation of rat bone cancer pain-morphine tolerance mechanism.