[Effect of sodium salicylate on the auditory brain stem response threshold and expression of glutamic acid decarboxylase in spiral ganglion of juvenile and adult guinea pigs]

To study the differences of regulation of sodium salicylate on the auditory brain stem response (ABR) threshold and expression of glutamic acid decarboxylase (GAD) protein in spiral ganglion of juvenile and adult guinea pigs.Fourty juvenile guinea pigs which were born just four days and fourty adult guinea pigs which were born thirty days were selected. They were divided four groups (group A; group B; group C; group D). ABR threshold was detected before administration, after administration for 15 days and after administration stopped for 30 days. The protein expression of GAD were measured after administration for 15 days and after administration stopped for 30 days by the method of immunohistochemistry.ABR threshold of juvenile sodium salicylate groups (group C) was increased remarkably than that of before administration and the control after administration for 15 days (P0.001). ABR threshold of group C was returned to the level of that of before administration and after administration stopped for 30 days. ABR threshold of adult sodium salicylate groups (group D) was increased remarkably than that of before administration and the control after administration for 15 days (P0.001). ABR threshold of group D was kept the high level after administration stopped for 30 days. The protein expression of GAD of sodium salicylate groups (group C and D) was decreased than that of the control after administration for 15 days. The protein expression of group C was more visible regression than that of group D (t = 4.7, P0.001). The protein expression of group C was returned the level of before administration after administration stopped for 30 days, but the protein expression of group D was kept the high level.The results suggest that sodium salicylate can regulate differently ABR threshold and expression of GAD protein in spiral ganglion of juvenile and adult guinea pigs. The effects of sodium salicylate on ABR threshold and expression of GAD protein in spiral ganglion of juvenile pigs are more noticeable than that of adult guinea pigs, but these changes are easier to return the normal than that of adult guinea pigs.