Free-radical damage: a possible mechanism of laryngeal aging

We conducted a study of lipid peroxidation as a marker of age-related free-radical damage in the human larynx--the first study of its kind. A colorimetric assay for malondialdehyde (MDA) and 4-hydroxy-2-nonenal (4-HNE) was performed on extracts taken from thyroarytenoid muscle harvested from fresh cadaveric laryngeal specimens. Levels of MDA and 4-HNE were measured by spectrophotometry. Correlation studies were performed by linear regression analysis. We found that MDA levels in human thyroarytenoid muscle appeared to increase with age while 4-HNE levels showed a slight decrease with age. Our findings are consistent with those of previous studies of other organ systems and indicate that there is a need for further study of free-radical damage and the effects of aging on the human larynx and on voice production.