Transplacental Kanamycin (KM) distribution to inner ear of 30 to 60 day-embryo was investigated by immunohistological technique.
1) KM easily penetrated placenta and localized in the cochlea in every embryonal stage. This means that placenta does not have so tight barrier function to KM.
2) Drug pathway to organ of Corti consists of 2 routes; spiral limbus-tectorial membrane pathway and spiral vessel, its derivative-hair cell pathway.
3) Immaturation of strial capillary contributes to littel accumulation of KM in stria vascularis.
