Pattern of Hair Cell Damage of the Organ of Corti due to Ototoxic Antibiotics

Abstract

Engstrom and Kohonen 1965, Kohonen 1965, Engstrom 1967 established the general tendency in the pattern of outer hair cell and inner hair cell loss, in the ototoxicosis due to antibiotics by the application of surface specimen technique of the spiral organ. The general tendency is considered as very important for understanding the fundamental pathologic change of the spiral organ due to various kind of antibiotics on the one hand and for the evaluation of ototoxicity due to newly developed antibiotics on the other hand.The present authors intended to reevaluate the general tendency in the pattern of outer hair cell and inner hair cell loss of the spiral organ in the ototoxicosis due to antibiotics by the observation of the horizontally sectioned serial celloidin sections of the cochleas in 140 Hartley guinea pigs received various kinds of antibiotics. The antibiotics used in the present study were divided into 3 groups, that is, aminoglycoside antibiotics (Aminodeoxykanamycin, Aminosidine, Dihydrostreptomycin, Gentamicin, Lividomycin, Kanamycin A and Vistamicin), polypeptide antibiotics (Capreomycin, Enduracidin, Tuberactinomycin and Viomycin), and Rifampicin (Rifamycin). The results obtained were as follows:1) In the present study, hair cell loss of the spiral organ occurred in 62% (87 guinea pigs).2) Outer hair cell loss was found in 100% of the 87 guinea pigs and the pattern of the outer hair cell loss showed the general tendency similar to the tendency reported by Engstrom et al.; that is, loss of the outer hair cell almost always started at the basal end of the spiral organ and then spread upwards.3) Inner hair cell loss occured in 22% (20 guinea pigs) and was always associated with the loss of the outer hair cell. The damage frequently occurred in the apical and 4th turns.4) There was distinct difference in sensitivity to ototoxic antibiotics between the outer hair cell and the inner hair cell. The outer hair cells were more sensitive in the basal and 2nd turns, while the inner hair, cell was more sensitive in the apical and 4th turns.5) There was some difference in the pattern of the hair cell loss between the animals received the aminoglycoside antibiotics and those treated with the polypeptide antibiotics. In the animals received the aminoglycoside antibiotics the loss of the outer hair cell alone occurred more frequently than in the animals received the polypeptide antibiotics. On the contrary, the inner hair cell loss was found more frequently in the animals treated with the polypeptide antibiotics.6) Detection of the loss of the outer hair cell confined to the basal end of the spiral organ is very important in the evaluation of the ototoxicity of the newly developed antibiotics.