Organic acid transport into the cochlear perilymph.

The passage of exogenous organic and inorganic substances from blood into perilymph is likely to be controlled by the blood-perilymph barrier. This report reviews published data on the transfer of ten exogenous organic acids from the blood into the perilymph of experimental animal models. Although the range of the molecular weights of these acids is within half an order of magnitude, major differences exist in the perilymph concentration as a percentage of simultaneous serum concentration. Furthermore, these studies show that, contrary to previous suggestions, non-ototoxic compounds can achieve marked concentration gradients within the perilymph.