抄録
As well known, lower fatty acids were one of the important factors on the destruction of bone by chronic otitis media with cholesteatoma. Propionic acid, one of the lower fatty acids, was used to destroy the bone (tympanic bulla of guinea pigs) as a model system. In the saline solution of propionic acid, the bone was destroyed in the pH 2.8 to about 5.0 regions and the pH value of these solutions became constant (about 5.3) in any case for 1 week at 37°C. From the results of bony destruction by propionic acid, it was suggested that hydroxylapatite presented in the bone matrix was decomposed (demineralized) to phosphate anions and the resulting phosphate anions caused the buffer effect. The Raman spectra of samples, obtained from the diseased parts of patients by the surgery, were agreed well with those of model systems. From the results of model systems and of Raman spectroscopic analysis of bone surfaces, it may be concluded that the degree of destruction (demineralization) was depended upon the concentration of propionic acid and that org. compd. /ν1 ratio was strongly related to the degree of destruction of the bone.
