Aalto Y, Forsgren S, Kjörell U, Franzén L, Gustafsson H, Henriksson R
Department of Oncology, Umeå University, Sweden.
Int J Radiat Oncol Biol Phys. 1995 Sep 30;33(2):297-305. doi: 10.1016/0360-3016(95)00173-V.
The expression of different neuropeptides in the innervation of submandibular and parotid glands of the rats was examined 2 and 5 days after initiation of radiation treatment as well as 10 and 180 days following the termination of irradiation.
The irradiation was given on 2 or 5 consecutive days with daily doses of 4-8 Gy up to a total dose of 20-40 Gy. Immunohistochemical methods were used for the demonstration of substance P (SP), calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY) and, the rate-limiting enzyme in the catecholamine synthetic pathway, tyrosine hydroxylase (TH). The content of SP was also analyzed by the use of radioimmunoassay (RIA).
In the parenchyma of both the submandibular and the parotid glands of control animals as well as after 2 days of irradiation treatment, a few nerve fibers showing SP-like immunoreactivity (LI) were observed. A marked increase in the expression of SP in the innervation of the parenchyma in both glands was observed 10 days after cessation of radiation treatment. The number of stained nerve fibers and the intensity of fluorescence in the fibers seemed to be dose dependent because the group subjected to a total dose of 40 Gy displayed a more pronounced staining intensity than that treated with 30 Gy. These results were supported by the RIA analysis. One hundred eighty days after treatment no obvious differences in SP-expression were seen between control and irradiated animals. No acute and long-term alterations were seen with regard to the other peptides and TH.
These results suggest that specific dose- and time-dependent changes in the expression of SP in the parenchyma of both submandibular and parotid glands occur in response to fractionated irradiation. The observations add further aspects to the tissue differences in physiological response and sensitivity to irradiation.
在放射治疗开始后2天和5天以及照射结束后10天和180天，检测大鼠下颌下腺和腮腺神经支配中不同神经肽的表达情况。
连续2天或5天给予照射，每日剂量为4 - 8 Gy，总剂量达20 - 40 Gy。采用免疫组织化学方法检测P物质（SP）、降钙素基因相关肽（CGRP）、神经肽Y（NPY）以及儿茶酚胺合成途径中的限速酶酪氨酸羟化酶（TH）。还通过放射免疫分析（RIA）检测SP的含量。
在对照动物以及照射治疗2天后的下颌下腺和腮腺实质中，观察到少数显示SP样免疫反应性（LI）的神经纤维。放射治疗停止10天后，观察到两个腺体实质神经支配中SP表达显著增加。染色神经纤维的数量和纤维中的荧光强度似乎呈剂量依赖性，因为接受40 Gy总剂量的组比接受30 Gy治疗的组显示出更明显的染色强度。这些结果得到了RIA分析的支持。治疗180天后，对照动物和照射动物之间在SP表达上未见明显差异。关于其他肽和TH，未观察到急性和长期变化。
这些结果表明，分次照射会导致下颌下腺和腮腺实质中SP表达出现特定的剂量和时间依赖性变化。这些观察结果为生理反应和对辐射敏感性的组织差异增添了更多方面的内容。
