艾灸对膝关节骨关节炎大鼠血浆氨基酸代谢的影响

Effect of moxibustion on plasma amino acid metabolism in rats with knee osteoarthritis

目的:观察艾灸“足三里”对膝关节骨关节炎(KOA)大鼠血浆氨基酸代谢的影响,探讨艾灸修复KOA软骨损伤的氨基酸代谢机制。方法:SD大鼠随机分为正常组、模型组与艾灸组。模型组与艾灸组予以双侧膝关节腔内注射L-半胱氨酸与木瓜蛋白酶混合液制备KOA模型。艾灸组艾灸双侧“足三里”,30 min/次,每天1次,连续30 d。测量大鼠膝关节直径并计算各组大鼠膝关节肿胀度,Von Frey丝测定大鼠机械性痛阈值,HE染色法观察膝关节软骨组织损伤情况,ELISA法检测膝关节滑膜组织基质金属蛋白酶-13(MMP-13)含量,液相色谱-质谱法检测并筛选血浆差异氨基酸代谢物。结果:与正常组比较,模型组膝关节软骨表面不平整,软骨细胞数量减少,分布不均匀,局部可见簇集软骨细胞,潮线模糊,关节肿胀度升高(P<0.01),机械性痛阈值降低(P<0.01),滑膜组织MMP-13含量升高(P<0.01),血浆脯氨酸、色氨酸含量下调(P<0.01,P<0.05)。与模型组比较,艾灸组膝关节软骨组织损伤减轻,膝关节肿胀度降低(P<0.05),机械性痛阈值升高(P<0.05),滑膜组织MMP-13含量降低(P<0.01),血浆谷氨酸与组氨酸的含量下调(P<0.05)。结论:艾灸“足三里”能显著减轻KOA模型大鼠膝关节疼痛、关节炎性肿胀状态,缓解软骨损伤,通过调节部分血浆氨基酸代谢物水平调控KOA大鼠软骨的合成与分解,发挥抗炎镇痛和软骨损伤保护作用。

Objective To observe the effect of moxibustion at“Zusanli”(ST36)on the plasma amino acid metabolism in rats with knee osteoarthritis(KOA),and to explore the amino acid metabolism mechanism of moxibustion in repairing cartilage injury in KOA.Methods A total of 30 SD rats were randomly divided into normal,model and moxibustion groups,with 10 rats in each group.Rats in the model and moxibustion groups were injected with the mixture of L-cysteine and papain into bilateral knee joint cavity to make the KOA model.The moxibustion group received moxibustion at bilateral ST36 for 30 min,once daily for 30 days.At the end of the experiment,the swelling degree of knee joint was calculated,the mechanical pain threshold was measured by the Von Frey filament,the cartilage tissue injury was observed by HE staining,the matrix metalloproteinase-13(MMP-13)content in the synovial tissue was detected by enzyme-linked immunosorbent assay(ELISA),and the differential amino acid metabolites in plasma were detected and screened by liquid chromatography-mass spectrometry(LC-MS).Results Compared with the normal group,the model group showed irregular cartilage surface,decreased number of chondrocytes,uneven distribution,and local clusters of chondrocytes;the contour of the tide line was blurred.The degree of joint swelling in the model group was higher than that in the normal group(P<0.01),the mechanical pain threshold was lower(P<0.01),and the content of MMP-13 in synovial tissue was higher(P<0.01).The contents of proline and tryptophan in the model group were down-regulated(P<0.01,P<0.05).Compared with the model group,the cartilage tissue damage and knee joint swelling were decreased(P<0.05),mechanical pain threshold was increased(P<0.05),MMP-13 content in synovial tissue and levels of glutamate and histidine expression were decreased(P<0.01,P<0.05).Conclusion Moxibustion at ST36 significantly alleviated arthritis-related swelling and pain in KOA model rats,attenuated cartilage damage,and regulated levels of certain plasma amino acid metabolites.Moxibustion may regulate KOA cartilage synthesis and degradation through amino acid metabolic pathways such as proline,tryptophan,glutamate and histidine,exerting anti-inflammatory,analgesic,and protection of cartilage injury effects.