Protective effect and mechanism of ischemic preconditioning on rat submandibular gland after ischemia-reperfusion injury

SUN bin; GAO Jun-tian; SHI Liang; SONG Dai-hui; WEI Feng-cai

doi:10.3969/j.issn.1002-266X.2015.18.009

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 Wist-ar 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 3 min 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 mACh-recep-tor 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 mACh-receptor expression lev-els 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 mACh-receptor exhibited the same tendency , and lower mACh-receptor levels at 12 h after reperfusion were observed in the model group;while in the observation group , it gradually re-turned to normal.Conclusion IPC has the protective effect on the rat submandibular gland after I /R injury, whose mech-anism may be related with the down-regulation of mACh-receptor and protection of TJs .