Biochemical Studies of Otosclerosis: Enzymes and Protein in Malleus and Incus

Abstract

Differences were found in the biochemical composition of mallei from individuals with and without clinical otosclerosis. The same differences were noted with incudes. No differences were noted, however, between mallei and incudes in otosclerotic individuals or between mallei and incudes in normals. The protein extracted from heads of mallei from individuals with clinical otosclerosis was 50% higher than the protein extracted from normal heads of mallei. The same difference in extracted protein was found for incudes. Lactic, malic, and gIucose-6-phosphate dehydrogenase, aldolase, aspartic aminotransferase, and acid and alkaline phosphatase activities were determined on extracts of both types of ossicles in individuals with and without clinical otosclerosis. Differences in individual enzyme activities were observed between the two types of ossicles (mallei and incudes) in the two groups of subjects. The results of these investigations could, under certain circumstances, support the assumption that otosclerosis is a manifestation of a generalized metabolic disorder which is characterized by certain biochemical changes in the supporting tissues.