胫骨癌痛大鼠脊髓背角5-羟色胺水平的变化

目的 评价胫骨癌痛大鼠脊髓背角5-羟色胺(5-HT)水平的变化.方法 雌性SD大鼠60只,体重160～180 g,采用随机数字表法,将其随机分为3组(n=20):对照组(C组)、假手术组(S组)和胫骨癌痛组(P组).C组不做任何处理;S组于右侧胫骨上段骨髓腔注射D-hank液10 μl;P组于右侧胫骨上段骨髓腔接种Walker 256大鼠乳腺癌细胞悬液10μl制备胫骨癌痛模型.于接种前1d、接种后3、5、7、9、11、14、16、18和21 d时测定机械痛阈.于接种前1 d、接种后7、14和21 d时,每组痛阈测定结束后随机处死大鼠4只,取脊髓组织,采用高效液相色谱法测定脊髓背角5-HT含量;接种后14 d取接种侧胫骨组织,光镜下观察胫骨破坏情况.脊髓背角5-HT含量与机械痛阈进行直线相关分析.结果 与C组和S组比较,P组接种后7～21 d时机械痛阈降低,接种后7、14和21 d时脊髓背角5-HT含量升高(P＜0.05),且5-HT含量与机械痛阈呈负相关(r=-0.973,P＜0.05).C组和S组各时点机械痛阈和脊髓背角5-HT含量比较差异无统计学意义(P＞0.05).光镜下P组大鼠术侧胫骨骨质严重破坏.结论 大鼠胫骨癌痛的形成与维持可能与脊髓背角5-HT水平升高有关.

Abstract：

Objective To investigate the change in 5-hydroxytryptomine (5-HT) content in spinal dorsal horn in a rat model of tibial bone cancer pain (BCP). Methods Sixty female SD rats weighing 160-180 g were randomly divided into 3 groups ( n = 20 each): control group (group C), sham operation group (group S) and BCP group. BCP was induced by intra-tibial inoculation of 10 μl Walker 256 breast cancer cell suspension in group BCP, while group S received intra-tibial inoculation of 10 μl D-hank solution. Paw withdrawal threshold to mechanical stimulation with yon Frey filaments (MWT) was measured 1 d before (baseline) and at 3, 5, 7, 9, 11,14, 16, 18 and 21 d after breast cancer cell inoculation. At 1 d before and 7, 14 and 21 d after breast cancer cell inoculation, four animals in each group were sacrificed after measurement of MWT. Their lumber segments of the spinal cord were removed for assay of 5-HT content in spinal dorsal horn using HPLC with fluorescence detector.HE staining was used to detect the damage to the tibia. Correlation between the 5-HT content and MWT was analyzed. Results MWT was significantly decreased after breast cancer cell inoculation in group BCP ( P ＜ 0.05).Microscopic examination showed serious bone destruction of tibia at the injection site in group BCP, while no bone destruction was found in groups C and S. 5-HT content in spinal dorsal horn was significantly higher in group BCP than in groups C and S (P ＜ 0.05). There was strong negative linear correlation between 5-HT content in spinal dorsal horn and MWT ( r = - 0.973, P ＜ 0.05 ). Conclusion The 5- HT content in spinal dorsal horn is significantly increased in rats with tibial BCP and is involved in the development of BCP.

Change in 5-hydroxytryptamine level in spinal dorsal horn in a rat model of tibial bone cancer pain

Objective To investigate the change in 5-hydroxytryptomine (5-HT) content in spinal dorsal horn in a rat model of tibial bone cancer pain (BCP). Methods Sixty female SD rats weighing 160-180 g were randomly divided into 3 groups ( n = 20 each): control group (group C), sham operation group (group S) and BCP group. BCP was induced by intra-tibial inoculation of 10 μl Walker 256 breast cancer cell suspension in group BCP, while group S received intra-tibial inoculation of 10 μl D-hank solution. Paw withdrawal threshold to mechanical stimulation with yon Frey filaments (MWT) was measured 1 d before (baseline) and at 3, 5, 7, 9, 11,14, 16, 18 and 21 d after breast cancer cell inoculation. At 1 d before and 7, 14 and 21 d after breast cancer cell inoculation, four animals in each group were sacrificed after measurement of MWT. Their lumber segments of the spinal cord were removed for assay of 5-HT content in spinal dorsal horn using HPLC with fluorescence detector.HE staining was used to detect the damage to the tibia. Correlation between the 5-HT content and MWT was analyzed. Results MWT was significantly decreased after breast cancer cell inoculation in group BCP ( P ＜ 0.05).Microscopic examination showed serious bone destruction of tibia at the injection site in group BCP, while no bone destruction was found in groups C and S. 5-HT content in spinal dorsal horn was significantly higher in group BCP than in groups C and S (P ＜ 0.05). There was strong negative linear correlation between 5-HT content in spinal dorsal horn and MWT ( r = - 0.973, P ＜ 0.05 ). Conclusion The 5- HT content in spinal dorsal horn is significantly increased in rats with tibial BCP and is involved in the development of BCP.