Abstract
To clarify the characteristics and the control of the blood-cochlea barrier, we measured EP (the endocochlear potential) and the furosemide concentration in the perilymph of guinea pigs. It was recognised that: 1) glycerol increased the toxicity of furosemide against the EP in adults, 2) the toxicity of furosemide against EP was stronger in neonates than in adults, 3) glycerol did not increase furosemide toxicity against EP in neonates, 4) acute hypertension also increased the ototoxicity of furosemide, 5) glycerol increased furosemide concentration in the perilymph.
These findings suggest that glycerol facilitates the permeability of blood-cochlea barrier to furosemide. Therefore, it is assumed that glycerol and acute hypertension can facilitate the access of some drugs used to treat inner ear diseases.
