Abstract
The content of acidic glycosaminoglycans (AGAG) was determined quantitatively by electrophoretic microanalysis in the cochlea, kidney and brain of the guinea pig. Kanamycin treatment (400 mg/kg body weight/ day, i.m., 10 successive days) reduced the content of AGAG markedly in the lateral wall of the membranous cochlea. Furthermore, from the results of the ultrahisto-chemical and freeze-fracturing study, we propose here an “excretion system for basic aminoglycoside antibiotics” by means of the co-operation of spiral ligament cells and AGAG produced by them. Thus we have tentatively concluded both that kanamycin is excreted via the above-mentioned “excretion system” in the lateral wall of the membranous cochlea and that it damages this system to form the circulus vitiosus of its ototoxicity.