碘乙酸致大鼠膝骨关节炎疼痛模型的实验研究

目的探讨不同浓度碘乙酸不同处理时间致大鼠膝骨性关节炎(OA)的模型特点。方法将72只清洁级雄性SD大鼠随机分为对照组及碘乙酸低、中、高浓度组,各18只。对照组大鼠双侧膝关节各注射50μL生理盐水,碘乙酸低、中、高浓度组大鼠每侧膝关节分别注射1、3、6mg/50μL的碘乙酸溶液(超纯水配置)50μL。比较注射后第1、7、14、21、28、35天各组大鼠运动功能、疼痛学改变、关节软骨病理变化及Mankind评分。结果碘乙酸低、中、高浓度组大鼠在造模2天后就出现轻微OA症状,造模21天后出现典型的病理、疼痛学改变。与对照组比较,碘乙酸低、中、高浓度组大鼠机械痛值明显下降(229.5±57.6)g、(203.5±47.8)g、(150.5±45.5)g比(424.3±107.0)g,P<0.01],热刺激痛值明显下降(7.1±3.3)s、(5.9±3.0)s、(5.3±1.9)s比(8.9±1.9)s,P<0.01],Mankin评分升高(4.4±0.9)分、(6.2±1.1)分、(9.1±1.0)分比(1.8±0.6)分,P<0.01];且碘乙酸高浓度组机械痛值、热刺激痛值低于低、中浓度组(150.5±45.5)g比(229.5±57.6)g、(203.5±47.8)g,(5.3±1.9)s比(7.1±3.3)s、(5.9±3.0)s,P<0.05或P<0.01],Markin评分高于低、中浓度组(9.1±1.0)分比(4.4±0.9)分、(6.2±1.1)分,P<0.05]。结论关节腔注射碘乙酸能快速建立大鼠OA模型,并且具有剂量效应,随着剂量的加大,大鼠关节损伤越严重。

Experimental Study on Pain Model of Knee Osteoarthritis Induced by Monoiodoacetic Acid in Rats

Objective To investigate the characteristics of knee osteoarthritis(OA)induced by different concentrations of monoiodoacetic acid and different treatment times in rats.Methods Seventy-two clean grade male SD rats were randomly divided into control group,low,medium and high concentration of monoiodoacetic acid group,each with 18 animals.Rats in the control group were injected with 50μL of normal saline on each side of the knee joint,while rats in the low,medium and high concentration groups were injected with 50μL of 1,3 and 6mg/50μL of monoiodoacetic acid solution prepared with ultrapure water.The motor function,pain changes,articular cartilage pathological changes and Mankin score of rats in each group were compared on the 1st,7th,14th,21st,28th and 35th days after injection.Results Rats in low,medium and high concentration of monoiodoacetic acid group showed mild OA symptoms after 2 days of modeling and typical pathological and painful changes after 21 days of modeling.Compared to the control group,the mechanical pain of rats in the low,medium and high concentration group decreased significantly,i.e.,(229.5±57.6)g,(203.5±47.8)g and(150.5±45.5)g vs(424.3±107.0)g,P<0.01].The pain of thermal stimulation decreased obviously,i.e.,(7.1±3.3)s,(5.9±3.0)s and(5.3±1.9)s vs(8.9±1.9)s,P<0.01].The Mankin scores increased significantly,i.e.,(4.4±0.9),(6.2±1.1)and(9.1±1.0)vs(1.8±0.6),P<0.01].Compared to low and medium concentration of monoiodoacetic acid group,the mechanical pain of rats in the high concentration group decreased,i.e.,(150.5±45.5)g vs(229.5±57.6)g and(203.5±47.8)g,P<0.05,P<0.01].The pain of thermal stimulation decreased,i.e.,(5.3±1.9)s vs(7.1±3.3)s and(5.9±3.0)s,P<0.05].The Mankin scores increased,i.e.,(9.1±1.0)vs(4.4±0.9)and(6.2±1.1),P<0.05].Conclusion Intra-articular injection of monoiodoacetic acid can be used to establish rat OA model rapidly and has dose effect.With the in crease of dose,the more serious the joint injury in rats is.