Toluene Disrupts Outer Hair Cell Morphometry and Intracellular Calcium Homeostasis in Cochlear Cells of Guinea Pigs

摘要: Abstract The aromatic hydrocarbon, toluene, has been demonstrated to disrupt auditory system function both in occupational epidemiological and laboratory animal investigations. This agent, along with several other organic solvents, impairs hearing preferentially at middle frequencies—a finding that distinguishes these agents from the traditional high-frequency impairment observed ototoxic drugs such as aminoglycoside antibiotics cisplatin. Prior investigations have identified outer hair cell a probable target for toluene exposure, although studies designed evaluate spiral ganglion not reported. purpose of this investigation was determine directly whether cells isolated guinea pig cochlea show morphological alterations consistent toxic response exposure. Since slow adjustments length can result alteration free intracellular calcium concentration, effect on homeostasis monitored cells. A dose–response relationship extent shortening produced by significant concentrations 100 μ m higher. By contrast, nonototoxic solvent, benzene, little 1 concentrations. Studies conducted using fluorescent probe, Fura-2, showed enhanced levels within 5 min exposure 30 Intracellular were elevated only slightly following benzene administration , but lower Cells cultured artificial perilymph nominally containing no those which EGTA added still maximal increase level when treated toluene. These data indicate elevation results release stores.