ヒト気管腺の加齢による変化

Abstract

The histochemical and ultrastructural differences between young and aged human tracheal glands were studied. The materials were obtained at necropsy or during surgical procedures of the larynx and trachea. In human tracheal gland, remarkable differences between young (10 to 21-year-old) and aged (61 to 81-year-old) ones were especially seen in serous cells. Mucosubstances of young tracheal serous cells were classified as serum glycoprotein types, but those of the aged cells were mainly mucin types. Ultrastructurally, young tracheal serous cells contained homogeneously electron dense or biphasic secretory granules. On the other hand, the aged cells contained not only homogeneous electron dense granules but also multiform ones, hiphasic or electron lucent, resembling mucous cell granules. In aged human tracheal serous cells, alterations of histochemical and ultrastructural properties of secretory materials reflected depression of host defence mechanism of the trachea. By these results, the reason why various airway deseases increase with aging could be explained. In aged human, in addition, oncocytes were found within the mucous tubule and they occasion ally contained secretory granules. Although appearance of oncocytes in the tracheal gland was closely related with aging, this phenomenon seemed not to directly participate in depres sion of the defence mechanism.