Incorporation of glycerol in the organ of Corti: predominance in hair cells and effects of kanamycin.

A biochemical study revealed that [3H]glycerol was incorporated into various kinds of phospholipids in the guinea pig cochlea. The sites of incorporation of [3H]glycerol injected into the scala tympani were localized autoradiographically. The most active incorporation occurred in the hair cells, especially in the outer ones, followed by the inner ones and the nerve endings attached to hair cells. Glycerol incorporation into hair cells appeared to increase as the apex was approached. Chronic intoxication with kanamycin selectively suppressed glycerol incorporation in the hair cells. The site of glycerol incorporation shown by the present autoradiographic study is likely to reflect the site of phospholipid synthesis. Autoradiographic studies could constitute a new approach to understanding the possible involvement of phospholipid metabolism in the function and pathology of the cochlea.