鼓索神経切除後のラット顎下腺の形態的変化に関する神経組織学的研究

抄録

The purpose of this study is to asses the influence of parasympathetic nerve to submandibular gland. 173 Wistar rats were used for this study and examined by biochemistry and neurohistology from 1 to 90 days after denervation of Chorda tympani. The experiments gave the following results : 1. The wet weight of submandibular gland was decreased gradually up to 30 th day, thereafter, the greatest loss was observed. 2. The portion of granular tubule in submandibular gland revealed atrophy and destruction at 1st day, but there was no change at 3 rd day. Then, the regenerating duct epithelium appeared and formed duct-like structure around the peripheral area of some lobes at 5 th day, thereafter, the atrophic or destructive region was gradually replaced by duct-like structure and granulation tissue till 45 th day. However it was shown that fibrotic change was quite obvious from 45 th to 90 th day. 3. The squamous metaplasia of duct epithelium, which was found at 30 th day, decreased at 60 th day. Moreover. the acinus-like structure, which appeared from 60 th day, was smaller than controls in size. 4. There were no obvious changes in ganglia and nerve fibers which were distributed in submandibular gland at 3 rd day and they degenerated at 5 th day. 5. Almost all the primitive nerve fibers disappeared at 45 th day, thereafter, regenerating nerve fibers surrouding the submandibular gland and duct which might be sympathetic nerve appeared after 60 th day. From these results, we conclude (1) that the time of paralytic salivation may be within the 7 th day after the denervation of Chorda tympani, and (2) that the function of salivary secretion and morphologic maintenance are related to the innervation of parasympathetic nerve.