Yamamoto Yoshio, Tanaka Shin, Tsubone Hirokazu, Atoji Yasuro, Suzuki Yoshitaka
Laboratory of Veterinary Anatomy, Faculty of Agriculture, Gifu University, Gifu 501-1193, Japan.
Arch Gerontol Geriatr. 2003 Mar-Apr;36(2):173-83. doi: 10.1016/s0167-4943(02)00165-6.
The aim of the present study was to define the age-related changes in sensory and secretomotor nerve endings in the larynx of F344/N rats. For this purpose, laryngeal tissue sections obtained from 12-, 24- and 35-month-old F344/N rats were compared with respect to the density, distribution and morphology of various types of sensory and secretomotor nerve endings immunoreactive for protein gene product 9.5 (PGP 9.5), calcitonin gene-related peptide (CGRP) and substance P (SP). Two distinct forms of PGP 9.5-immunoreactive motor end-plates were noted; the large sized motor end-plates localized in thyroarytenoid and cricoarytenoid muscles were degenerated in aged rats, while the small sized motor end-plates, localized predominantly in vocal muscles, did not show any age-related changes. CGRP- and SP-immunoreactive nerve fibres of the laryngeal glands did not show any age-related changes. Subepithelial laminar nerve endings immunoreactive to PGP 9.5 showed degeneration with ageing. Aggregates of terminal arborisations in the subepithelial region were smaller in aged animals. PGP 9.5-immunostained taste cells and well-developed subgemmal network were abundant in 12- and 24-month-old rats, but only a few were noted in aged rats. The total number of taste buds decreased significantly with ageing. CGRP- and SP-immunostained taste bud-nerve endings were noted in 12- and 24-month-old rats, but only rarely in 35-month-old rats. The laryngeal epithelium contained PGP 9.5-, CGRP- and SP-immunoreactive thin free nerve endings with many varicosities; their number and distribution were similar between 12- and 24-month-old rats, while only a few endings were observed in 35-month-old rats. Our results indicated that ageing is associated with the reduction of laryngeal sensory and secretomotor nerve endings.
本研究的目的是确定F344/N大鼠喉部感觉和分泌运动神经末梢的年龄相关变化。为此，对取自12、24和35月龄F344/N大鼠的喉部组织切片，就对蛋白基因产物9.5（PGP 9.5）、降钙素基因相关肽（CGRP）和P物质（SP）免疫反应的各种类型感觉和分泌运动神经末梢的密度、分布及形态进行了比较。注意到两种不同形式的PGP 9.5免疫反应性运动终板；位于甲杓肌和环杓肌的大型运动终板在老年大鼠中发生退变，而主要位于声带肌的小型运动终板未显示任何年龄相关变化。喉腺的CGRP和SP免疫反应性神经纤维未显示任何年龄相关变化。对PGP 9.5免疫反应的上皮下层状神经末梢随年龄增长而退变。老年动物上皮下区域的终末分支聚集体较小。PGP 9.5免疫染色的味觉细胞和发育良好的味蕾下网络在12和24月龄大鼠中丰富，但在老年大鼠中仅发现少数。味蕾总数随年龄增长显著减少。在12和24月龄大鼠中可观察到CGRP和SP免疫染色阳性的味蕾神经末梢，但在35月龄大鼠中很少见。喉上皮含有PGP 9.5、CGRP和SP免疫反应性的有许多曲张的细游离神经末梢；其数量和分布在12和24月龄大鼠中相似，而在35月龄大鼠中仅观察到少数末梢。我们的结果表明，衰老与喉部感觉和分泌运动神经末梢的减少有关。
