etilmicinの妊娠モルモットおよび胎仔の聴器に及ぼす影響

抄録

The ototoxicity of netilmicin (NTL) in pregnant guinea pigs (Hartley strain) and the newborn was examined and compared to that of gentamicin (GM).
NTL was administered intramuscularly at dose of90mg/kg to pregnant guinea pigs from day0today35of pregnancy (the early period of pregnancy) or from day42of pregnancy to1day prior to delively (the late period of pregnancy). GM at dose of45mg/kg or physiological saline were administered intramuscularly to pregnant guinea pigs during the late period of pregnancy. Four of5dams given NTL during the early period of pregnancy, 4of7dams given NTL during the late period of pregnancy, and2of4dams given GM during the late period of pregnancy died.
No pinna reflex loss in frequency range from2to20KHz were detected in mother guinea pigs treated with NTL either during the early period of pregnancy or during the late period of pregnancy.
GM caused a loss of pinna reflex at20KHz in mother guinea pigs treated during the late period of pregnancy. Histopathologically, no damages were detected in the cochlea of mother guinea pigs treated with NTL during the early or late period of pregnancy, whereas slight scattered loss of hair cells was seen in the vestibulum.However, GM at dose of45mg/kg, caused an incomplete scattered loss of outer hair cells in the spiral organ, moderate atrophy of the spiral ganglion cells and a partial loss of hair cells in the vestibular organs in mother guinea pigs treated during the late period of pregnancy. In newborn guinea pig from the pregnant one treated with NTL during the early period of pregnancy, there was no loss of pinna reflex. The same results were obtained in newborn guinea pigs from the pregnant ones treated with either NTL or GM during the late period of pregnancy.No histopathological damages were detected.
The present study suggests that NTL has a minimal effect on the auditory and vestibular organs in pregnant guinea pigs and the newborn and is considered to be1of the aminoglycosides with low ototoxic potential.