Objective: To observe the expression of local macrophages and related cytokines tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) after catgut implantation in "Zusanli"(ST 36) in rats, so as to explore its underlying mechanisms in inducing therapeutic effect.
Methods: A total of 110 male SD rats were randomly divided into blank control group (n=10), catgut embedding (CE) group (n=50), and sham CE group (n=50). The CE and sham CE groups were randomly divided into 8 h, 3 d, 7 d, 14 d and 21 d subgroups after the intervention (n=10 in each time point group). Rats of the CE group were uniformly subjected into catgut embedding at ST36 once, and those of the sham CE group received embedding needle puncture at ST36 without catgut retention, and the blank control group was only grasped and fixed without other treatments. Tissues from the ST36 area in each group were collected at the corresponding time points, and the expression of CD68 in macrophages in the acupoint area was detected by immunofluorescence, the contents of TNF-α and IL-1β in the acupoint area were detected by ELISA.
Results: Following catgut embedment at ST36, the contents of TNF-α and IL-1β, and macrophage CD68 expression level began to increase at 8 h, peaked at 3 d, and then gradually decreased at 7, 14, and 21 d, being still higher in the CE group than in the blank control group at 21 d (P<0.05). Compared with the blank control group, the contents of TNF-α and IL-1β, and macrophage CD68 expression were significantly increased at 8 h, and 3, 7, 14 and 21 d in the CE group (P<0.05). Following sham CE at ST36, the content of TNF-α at 8 h and 3 d, IL-1β at 8 h and 3, 7 and 14 d, and expression of CD68 at 8 h were significantly increased in comparison with the blank control group (P<0.05). Comparison between the CE and sham CE groups showed that the contents of IL-1β at 3, 7, 14 and 21 d, and contents of TNF-α，CD68 expression at 8 h, and 3, 7, 14 and 21 d were significantly higher in the CE group than in the sham CE group (P<0.05).
Conclusion: Catgut embedding at ST36 can induce an increase levels of inflammatory cytokines TNF-α, IL-1β and macrophage CD68 in the local microenvironment in rats, which may contribute to its functions in initiating therapeutic effect.
目的：观察大鼠“足三里”穴区羊肠线埋入后局部巨噬细胞和肿瘤坏死因子-α(TNF-α)、白细胞介素-1β(IL-1β)表达的变化规律，初步探讨埋线后穴位局部初始应答机制。方法：SD大鼠随机分为空白组10只、羊肠线埋线组50只、埋线针空刺组50只，羊肠线埋线组、埋线针空刺组又随机分为干预后8 h，3、7、14、21 d组，每组10只。羊肠线埋线组进行“足三里”羊肠线埋线1次，埋线针空刺组进行“足三里”空刺1次。对应时间点采集各组“足三里”穴区组织，采用免疫荧光法检测穴区巨噬细胞CD68的表达，ELISA法检测“足三里”穴区组织TNF-α、IL-1β的含量。结果：与同时点空白组比较，羊肠线埋线组埋线后8 h，3、7、14、21 d穴区组织 TNF-α、IL-1β含量及巨噬细胞CD68表达均升高(P<0.05)；埋线针空刺组TNF-α含量空刺后8 h、3 d升高(P<0.05)，IL-1β含量在空刺后8 h，3、7、14 d升高(P<0.05)，巨噬细胞CD68表达在空刺后8 h升高(P<0.05)。与同时点埋线针空刺组比较，羊肠线埋线组3、7、14、21 d穴区组织IL-1β含量及8 h，3、7、14、21 d TNF-α含量、巨噬细胞CD68表达均升高(P<0.05)。结论：大鼠“足三里”实施羊肠线埋入后，局部巨噬细胞及相关细胞因子TNF-α、IL-1β含量发生变化，羊肠线为引起“足三里”穴区微环境变化的主要因素，其埋入后引起的局部免疫炎性动态变化可能参与了埋线后穴位局部初始应答。.
Keywords: Catgut embedding; Initiating mechanism; Interleukin-1β; Macrophages; Tumor necrosis factor-α.