Differential ototoxic reaction to dihydrostreptomycin in two species of Old World monkey

Abstract

Unlike the macaques and most commonly used species of laboratory animals, the African military monkey (Erythrocebus patas) is sensitive to the ototoxic action of dihydrostreptomycin (DHSM) administered daily in doses ranging from 100 to as low as 20 mg/kg. Progressive hearing loss (from high to low frequencies) develops during treatment and continues for some time thereafter. It is irreversible and is correlated with extensive cochlear histopathology, typical of ototoxic injury, including loss of inner and outer hair cells and supporting cells, and degeneration of auditory nerve fibers. The Asian pigtail monkey (Macaca nemestrina), although sensitive to other aminoglycosidic antibiotics (e.g., neomycin and kanamycin), is unaffected by DHSM 100 mg/kg given daily for as long as eight months. This striking difference in sensitivity to DHSM may be related to differences in physiologic function which reflect adaptation to the dissimilar environments in which the patas and the nemestrina live. [Supported by NIH Program Project Grant 05785 and by Research Grants NS 05065 and NS 05077.]