Effect of piperphentonamine hydrochloride on expressions of interleukin-1β and TNF-α mRNA and Fas protein in guinea pigs with cochlear ischemiareperfusion injury.
To investigate the relationship between IL-1β and TNF-α mRNA and Fas protein expressions and cochlear ischemia reperfusion injury and investigate the protective mechanism of PPTA against cochlear reperfusion injury. Sixty-four guinea pigs were randomly divided into normal control group, blank control group, ischemiareperfusion (by clamping the bilateral vertebral artery and right common carotid artery for 1 h) control group, and ischemiareperfusion with PPTA treatment group. In PPTA group, PPTA was injected via the femoral vein immediately after reperfusion, and ischemiareperfusion control group received saline injection. In 6 guinea pigs from each group, the cochlear tissues were removed after 24 h of reperfusion for examination of expressions of IL-1β and TNF-α mRNA by real-time PCR, and the rest animals were used for immunohistochemical detection of Fas protein. Compared with those of normal group and blank control group, the expressions of IL-1β and TNF-β mRNA increased significantly after cochlear ischemiareperfusion (P<0.001), but were lowered significantly by PPTA (P<0.001). Positive expression of Fas protein expression was detected in the Corti organ, spiral ganglion and stria vascularis in ischemiareperfusion control group with significantly higher IOD values than those of the other 3 groups (P<0.05). The IOD value showed no significant difference between PPTA-treated group, normal control group, and blank control group (P>0.05). PPTA can suppress the expression of Fas protein and IL-1β and TNF-β mRNAs in the cochlea of guinea pigs with cochlear ischemiareperfusion. The protective effect of PPTA against cochlear ischemiareperfusion is mediated probably by inhibition of inflammatory responses and cell apoptosis.