ABSTRACT
Objective To investigate the effect of intrathecal CLP257 on the bone cancer pain in rats.Methods Forty adult female Sprague-Dawley rats,weighing 180-200 g,were divided into 4 groups (n=10 each) using a random number table:sham operation group (group S),bone cancer pain group (group BCP),dimethyl sulfoxide (DMSO) group,and CLP257 group.Bone cancer pain was induced by inoculating Walker 256 mammary gland carcinoma cell suspension (about 1× 105cells) 10 μl into the medullary cavity of the left tibia.On 7th-9th days after establishment of the model,5％ DMSO 10 μl was injected intrathecally once a day in group DMSO,and 10 μg/μl CLP257 10 μl was injected intrathecally once a day in group CLP257.The mechanical paw withdrawal threshold (MWT) was measured on 1 day before establishment of the model (T0),on 1st-6th days after establishment of the model (T1-6),and at 4 h after intrathecal administration on 7th-9th days after establishment of the model (T7-9).After the last intrathecal administration,the L4-6 segments of the spinal cord were removed for determination of the expression of potassium chloride cotransporter 2 (KCC2) protein and mRNA by Western blot and fluorescent quantitative real-time polymerase chain reaction,respectively.Results Compared with group S,the MWT was significantly decreased,and the expression of KCC2 protein and mRNA was down-regulated in BCP and DMSO groups,and the MWT was significantly decreased (P＜0.05),and no significant change was found in the expression of KCC2 protein and mRNA in group CLP257 (P＞0.05).Compared with group BCP,the MWT was significantly increased,and the expression of KCC2 protein and mRNA was up-regulated in group CLP257 (P＜0.05),and no significant change was found in the parameters mentioned above in group DMSO (P＞0.05).Conclusion Intrathecal CLP257 can attenuate the bone cancer pain in rats.
ABSTRACT
Aim To investigate the changes in the ex-pression of WNK1 in spinal cord of a rat model with bone cancer pain. Methods Female SD rats, weig-hing 170 ~200 g, were randomly divided into three groups:normal control group (group C, n=3), sham operation group ( group S, n =3 ) and bone cancer pain group ( group BCP, n =24 ) . Group C was not given any treatment, and group S was injected into the bone marrow of left tibia with 5 μl PBS solution while group BCP with 5 μl WALKER 256 mammary gland cancer cell suspension (approximately 1 × 105 cells). Mechanical paw withdrawal threshold ( MWT ) was measured at d1 before inoculation ( baseline) and d3, 6,9,10,11,12 after inoculation. Group S and C were sacrificed at d 12 while group BCP at d 3 ,6 ,9 ,12 after inoculation and spinal cord ( L4~6 ) were removed at different time points for detection of WNK1 mRNA ex-pression by qRT-PCR and WNK1 protein expression by Western blot. Results Compared with group C and S,group BCP’ s MWT started to decrease since d 3 ( P0. 05 ) while the protein expression upregulated since d6 and also showed an in-creasing trend to d 12 ( P<0. 01 ) . Conclusion The expression of WNK1 in spinal cord of a rat model with bone cancer pain increased abnormally, which may be involved in the occurrence and maintenance of a rat model with bone cancer pain.