器官形態学的に見た唾液腺排泄管拡張症及びその腺腔の変化についての実験的研究

含気腔理論の導入

抄録

The anatomical resemblance of the submaxillary gland to other pneumatized cavities such as the mastoid cells and the lung in fetal stage has led us to be interested in. their pathological resemblance study. Thus a series of experiments were conducted to study pathogenesis of ectasia in the excretory duct of the salivary gland, using as background our proved experimental knowl-edge on pathogenesis of bronchiectasis interpreted by pneumatization theory.
At first, relationship between the salivary glands and other pneumatized cavities was studied by morphological comparison of the structure of the excretory duct and alveoli of the submaxill-ary gland with that of the mastoid cells, bronchial tree and pulmonary alveoli. Then 36 dogs underwent two types of surgery, ligation of glandular lobule en masse on one group and ligation of excretory duct at its base on the other before they were observed from 2nd to 120th postopera-tive day mainly on atrophy, regeneration and dilatation of the glandular alveoli and proliferation of the excretory duct. The result was carefully checked on the surgical specimen of the subma-xillary glands of chronic inflammation before following information was obtained.
1. Result of the lobular ligation
In the early experiments dilatation of the excretory duct and proliferation of the duct wall associated with diminuction of its lumen are seen proximally to the line of ligation. In the distal area the excretory duct underwent irregular cystic dilatation and degeneration, even partial necrosis. In the four month old experiments, dilatation and proliferation of proximal part of the duct beco-mes distinct associated with merging of alveoli into a large cavity and now formation of excretory ducts in its vicinity. In the distal side of the ligation the duct wall becomes thin with increased cystic dilatation and marked alveoli are organized into connective tissues holding irregular regene-rated or enlarged alveoli.
2. Resilt of the ductal ligation
The excretory ducts reveal marked dilatation with thin wall and atrophied and detached epit-helium. These changes resemble to those in the distal duct of the lobular ligation group.
Attention should be directed to the fact that dilataton of the duct takes place in the first group not only in the distal part but also in the proximal part if the ligation, coinciding with our finding in the experimental study on pathogenesis of bronchiectasis. Therefore, the obstruction of gland-ular lumen must be the main cause of salivary gland ectasia among which distal dilatation of the lobular ligation group and cystic dilatation of the ductal ligation group are easily explained as the obstructive ectasia. The proxymal dilatation, however, must be interpreted by pneumatization theory as a manifestation of dynamic energy potentiality which is inborn to the excretory ducts and glandular alveoli as to anyy other pneumatized cavity. Regeneration and dilatation of the sali-vary gland alveoli have been confirmed experimentally in this study although less significantly than in the pulmonary alveoli.