【摘要】 目的观察缺血预处理(IPC)对下颌下腺缺血再灌注(I/R)损伤大鼠的保护作用,并探讨其机制。方法将48只大鼠随机分为模型组和观察组各24只,均制作右侧下颌下腺I/R损伤模型。观察组在制模前行IPC,夹闭颌外动脉下颌下腺供血支3 min,再灌注3 min,重复3次。以左侧下颌下腺作为对照组。再灌注1、12、24、72 h,取6只大鼠检测各组腺体分泌量、组织学变化、紧密连接结构及M受体表达情况。结果对照组腺体分泌量、组织形态、紧密连接结构及M受体表达情况均正常。I/R后1、12 h,模型组腺体分泌量明显降低,观察组稍有降低,24h时两组分泌量开始增加,至72 h逐渐恢复正常。模型组腺实质细胞萎缩,间质水肿及炎症浸润,电镜下超微结构观察显示紧密连接结构破坏,宽度降低,均在再灌注12 h后最为严重,观察组部分腺体组织出现上述情况,且反应较轻。模型组I/R后,M受体水平1、12 h下降明显,观察组稍有下降,72 h时逐渐恢复。结论 IPC对下颌下腺I/R损伤大鼠具有保护作用,其机制与上调下颌下腺M受体的表达、保护下颌下腺紧密连接结构有关。更多还原

【Abstract】 Objective To observe the protective effect of ischemic preconditioning( IPC) on the rat submandibular gland after ischemia-reperfusion( I / R) injury and to investigate the mechanism. Methods Forty-eight healthy male Wistar rats were randomly divided into the observation group and model group,24 in each group. The right glands of rats in both groups received the I / R injury to make the I / R injury models. The glands of the observation group were obtained by 3min of ischemia,followed by 3 min of reperfusion,and we performed three times before modeling. The left glands were taken as the control group. Salivary secretion,histological changes,alternations of tight junctions( TJs) and m ACh-receptor levels in 6 rats were detected at different time points( 1 h,12 h,24 h and 72 h after I / R). Results In the control group,the salivary secretion,histological changes,alternations of tight junctions( TJs) and m ACh-receptor expression levels were all normal. In the model group,the secretion of the glands significantly decreased after I / R 1 h and 12 h,and it showed a slightly lower in the observation group. The secretion of both groups gradually increased at 24 h and got back to normal at 72 h after reperfusion. Cellular atrophy,inflammatory cells infiltration,tissue edema,the collapse and reduced widths of TJs were observed especially after reperfusion for 12 h in the model group,a little part showed the status and the reaction was lighter in the observation group. The level of m ACh-receptor exhibited the same tendency,and lower m AChreceptor levels at 12 h after reperfusion were observed in the model group; while in the observation group,it gradually returned to normal. Conclusion IPC has the protective effect on the rat submandibular gland after I / R injury,whose mechanism may be related with the down-regulation of m ACh-receptor and protection of TJs.更多还原