Objective:To study whether ADM affect the
expression of mdr1 gene in guinea pig cochlea
lateral wall.Method:Sixty white guinea
pigs with red eyes were divided into three groups:control group,NS group and ADM group.
Guinea pigs were administered an intravenous injection of 30 mg/kg ADM.Four hoars later,ten animals were then immediately sacrificed ,and the bony labyrinths were removed.The remaining ten animals were sacrificed after 24 h.The effect of ADM,an ototoxicity drug,on
expression of mdr1 gene in guinea pigs cochlea lateral walls were observed with RT-PCR.Furthermore, the ADM concentration in endolymph were measured by high performance liquid chromatography.Result:For ADM group,the density ratio of mdr1 to β-action of the 24 h was significantly greater compared to that of the 4 h or controls;In contrast,the ADM concentration of 4 h was significantly higher than that of the 24 h.Conclusion:mdr1 gene in normal guinea pig cochlea lateral wall is a stress gene.It can be induced by ADM;it may be not only related to reduce the accumulation of ototoxicity drug in endolymph,but also associatd with the protective function of inner ear.