Forsgren S, Franzén L, Funegård U, Gustafsson H, Henriksson R
Department of Oncology, Anatomy and Oto-laryngology, University of Umeå, Sweden.
Neuroscience. 1992;46(1):233-40. doi: 10.1016/0306-4522(92)90023-u.
Substance P and calcitonin gene-related peptide (CGRP) are present in nerve fibers innervating the submandibular gland. Radiotherapy of tumors in the head and neck region usually embraces the salivary glands in the irradiated field and consequently a dramatic decrease in salivary function is seen. In this study, the submandibular glands and ganglia of rats subjected to fractionated irradiation were examined by use of immunohistochemical techniques for demonstration of substance P and CGRP. Irradiation was given on five consecutive days (daily doses of 6-9 Gray) with unilateral or bilateral irradiation techniques. Specimens of control and experimental animals were processed in parallel. A marked increase in the expression of substance P in the ganglionic cells--presumably parasympathetic--and in the number of fibers showing substance P-like immunoreactivity in association with acini and small ducts was seen in response to bilateral irradiation. (Surprisingly, unilateral irradiation of the parotid area had no effect on peptide distribution in the irradiated gland and ganglion). No changes in the pattern of CGRP immunoreactivity occurred. In the trigeminal ganglion, which supplies the submandibular gland with the majority of the sensory substance P- and CGRP-containing nerve fibers, no changes in the expression of substance P or CGRP immunoreactivity were seen. The results suggest that bilateral irradiation leads to an increase in the synthesis of substance P-like substance in the parasympathetic ganglionic cells supplying the submandibular gland with secretory nerves, and can thus be an additional factor in explaining the altered secretory capacity of salivary glands.
P物质和降钙素基因相关肽（CGRP）存在于支配下颌下腺的神经纤维中。头颈部肿瘤的放射治疗通常会将唾液腺包含在照射野内，因此会出现唾液功能急剧下降的情况。在本研究中，使用免疫组织化学技术对接受分次照射的大鼠下颌下腺和神经节进行检查，以显示P物质和CGRP。采用单侧或双侧照射技术，连续五天给予照射（每日剂量为6 - 9格雷）。对照和实验动物的标本并行处理。双侧照射后，可见神经节细胞（可能是副交感神经节细胞）中P物质的表达显著增加，并且与腺泡和小导管相关的显示P物质样免疫反应性的纤维数量也增加。（令人惊讶的是，腮腺区域的单侧照射对受照射腺体和神经节中的肽分布没有影响）。CGRP免疫反应性模式没有变化。在为下颌下腺提供大部分含P物质和CGRP感觉神经纤维的三叉神经节中，未观察到P物质或CGRP免疫反应性表达的变化。结果表明，双侧照射导致为下颌下腺提供分泌神经的副交感神经节细胞中P物质样物质的合成增加，因此可能是解释唾液腺分泌能力改变的一个额外因素。
