Salo A, Virta E, Uusitalo H
Department of Anatomy, University of Helsinki, Finland.
Regul Pept. 1995 Jan 26;55(2):155-65. doi: 10.1016/0167-0115(94)00102-4.
Indirect immunohistochemical methods were used to study presence and number of CGRP-immunoreactive (CGRP-IR) nerve fibers in the submandibular gland and ganglion cells of the superior cervical, submandibular and trigeminal ganglia of the developing rat. The effect of CGRP on peroxidase and total protein release was also studied in the developing postnatal submandibular glands of 1, 5, 12 and 30-day-old, as well as adult rats by in vitro methods. The possible costimulation of CGRP with SP, NKA or carbachol on 5-day-old and adult rats was also tested. The stimulatory effects of these compounds were compared to the basic release of peroxidase and total amount of proteins from submandibular gland fragments in incubation solution. CGRP-IR nerve fibers were found in relatively high number during post-natal development, mainly around blood vessels and ducts. Some CGRP-IR nerve fibers were also detected around acini. The number of these fibers was quite low and remained constant during the post-natal development. The number of CGRP-IR trigeminal ganglion cells was higher on the 5th and 12th post-natal day than later in development and in adult animals. At the same time, superior cervical- and submandibular ganglion cells were non-reactive for CGRP, suggesting trigeminal origin of CGRP-IR nerve fibers during the development in the submandibular gland. In the secretory studies, CGRP per se stimulated both peroxidase and total protein release in the submandibular gland most effectively on 5th and 12th post-natal days, while there was no clear secretory response in the adult glands. In the 5-day-old submandibular gland CGRP in combination with SP, NKA or carbachol clearly enhanced the total protein secretory response when compared with the release caused by these substances alone. However, in the adult submandibular gland, the combinations did not enhance total protein release more than any of the substances alone. Furthermore, it can be concluded that the presence of a more dense CGRP-IR innervation during the early postnatal period in the developing submandibular gland is accompanied with an increased responsiveness of the secretory elements to CGRP.
采用间接免疫组织化学方法研究了发育中大鼠下颌下腺以及颈上神经节、下颌下神经节和三叉神经节中降钙素基因相关肽免疫反应性（CGRP-IR）神经纤维的存在情况和数量。还通过体外方法研究了CGRP对出生后1日龄、5日龄、12日龄、30日龄以及成年大鼠下颌下腺过氧化物酶释放和总蛋白释放的影响。同时测试了CGRP与P物质（SP）、神经激肽A（NKA）或卡巴胆碱对5日龄和成年大鼠的协同刺激作用。将这些化合物的刺激作用与孵育溶液中下颌下腺碎片过氧化物酶的基础释放量和蛋白质总量进行了比较。在出生后发育过程中发现CGRP-IR神经纤维数量相对较多，主要分布在血管和导管周围。在腺泡周围也检测到一些CGRP-IR神经纤维。这些纤维数量相当少，在出生后发育过程中保持恒定。出生后第5天和第12天，CGRP-IR三叉神经节细胞的数量高于发育后期和成年动物。同时，颈上神经节和下颌下神经节细胞对CGRP无反应，提示下颌下腺发育过程中CGRP-IR神经纤维起源于三叉神经。在分泌研究中，CGRP本身在出生后第5天和第12天对下颌下腺过氧化物酶和总蛋白释放的刺激作用最为有效，而成年腺体中未观察到明显的分泌反应。在5日龄下颌下腺中，与单独使用这些物质相比，CGRP与SP、NKA或卡巴胆碱联合使用明显增强了总蛋白分泌反应。然而，在成年下颌下腺中，联合使用这些物质对总蛋白释放的增强作用并不比单独使用任何一种物质更强。此外，可以得出结论，在发育中的下颌下腺出生后早期存在更密集的CGRP-IR神经支配，同时分泌元件对CGRP的反应性增强。
