Muscle fiber and satellite cell apoptosis in the aging human thyroarytenoid muscle: a stereological study with confocal laser scanning microscopy.

Abstract

This study determines the role of changes in numerical densities of apoptotic myonuclei and satellite cells in age-related remodeling of the thyroarytenoid muscle (TA). Changes in numerical densities of apoptotic myonuclei and satellite cells were estimated for the entire TA by using stereological techniques. There was an increase in N(V apoptotic myonucleus, fiber type) (P < 0.05) and in the percentage of apoptotic myonuclei (P < 0.05) in type 1 but not in type 2 muscle fibers. There was also an increase in N(V apoptotic satellite cell, fiber type) (P < 0.05) and in the percentage of apoptotic satellite cells (P < 0.05) in type 1 fibers but not in type 2 fibers. Apoptosis may contribute to age-related fiber loss and atrophy in the TA. Therapeutic techniques based on decreasing the frequency of apoptosis may block age-related fiber loss and atrophy in the TA.