Abstract: Objective 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. Methods
Sixty-four guinea pigs were randomly divided into normal control group, blank control group, ischemia/reperfusion (by
clamping the bilateral vertebral artery and right common carotid artery for 1 h) control group, and ischemia/reperfusion with
PPTA treatment group. In PPTA group, PPTA was injected via the femoral vein immediately after reperfusion, and ischemia/
reperfusion 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. Results Compared with those of normal group and blank control
group, the expressions of IL-1β and TNF-α mRNA increased significantly after cochlear ischemia/reperfusion (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 ischemia/reperfusion 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). Conclusions PPTA can suppress the expression of Fas protein and IL-1β and TNF-α
mRNAs in the cochlea of guinea pigs with cochlear ischemia/reperfusion. The protective effect of PPTA against cochlear
ischemia/reperfusion is mediated probably by inhibition of inflammatory responses and cell apoptosis.