Abstract:

To observe the influence of pregnant and lactational D-galactose exposure in lipid peroxidation,hearing function and morphology and  structures  of cochlear hair cells  in newborn rats,and to clarify the relation with  cochlear hair cell injury,hearing loss and increased lipid peroxidation.Methods 12 pregnant rats were randomly devided into control group (n=6) and D-galactose group (n= 6) from gestational day 6,the rats in control group were fed on standard rodent diet,and the  rats in  D-galactose group were fed on standard rodent diet supplemented with 30% D-galactose.On postnatal day 21,the blood levels of galactose,superoxide dismutase(SOD),glutathion(GSH),glutathione peroxidase(GSH-Px) and malondialdethyde(MDA) in newborn rats were measured. Then  the distortion product otoacoustic emission (DPOAE)  was examined.The temporal bones were then removed and the morphological changes were detected by silver nitrate staining.Results The levels of blood SOD,GSH-Px and GSH were lower in newborn rats after using D-galactose during pregnancy and lactation compared with control group (P<0.05),and the plasma MDA level was higher than that in  control group (P<0.05).In addition,the DPOAE threshold shifts at different frequencies were lower after using D-galactose during pregnancy and lactation compared with  control group (P<0.05).The structures of cochlea hair cells were impaired and the number of hair cells was decreased in D-galactose group.Conclusion D-galactose exposure may cause oxidative and cochlear function damage in newborn rats.

Key words: lipid peroxidation;ototoxicity;D-galactose