大鼠小肠降钙素基因相关肽在肠型放射病时的变化

本文应用免疫细胞化学(整装分层铺片和恒冷箱冰冻切片)和放射免疫测定技术,对大鼠小肠降钙素基因相关肽(CGRP)的分布特征及其在肠型放射病时的变化进行了观察。 结果表明:小肠各层均有丰富的CGRP-免疫反应性(CGRP-Ⅰ)神经,以肌间神经丛、粘膜下神经丛和粘膜神经丛密度为高,小肠壁内小血管及肠腺周围也较丰富,在肌间和粘膜下神经丛中见有一些CGRP-Ⅰ神经细胞。肠型放射病时,小肠CGPR水平有一双相改变,24h下降,48和72h升高。 以上结果提示,CGRP可能与胃肠道运动,吸收,分泌,感觉和局部血流的调节有关,CGRP在AIRS时可能有一应激性释放,并通过多种途径,尤其是影响局部血流和增加血管的通透性,参与AIRS的损伤机制。

Change of Calcitonin Gene-Related Peptide in Small Intestine of Rats in Acute Intestinal Radiation Sickness (AIRS)

By using immunocytochemistry (the whole mount stretch preparations and cryostat sections) and radioimmunoassay, the characteristics of distribution of calcitonin gene-related peptide (CGRP) in small intestine of rats and its change in acute intestinal radiation sickness are studied.The results show that all layers of the small intestine are rich in CGRP-immunoreactive(CGRP-I)nerves with a high density in the myenteric, submucosal and mucosal plexuses. Also it has a rather high density around the small blood vessels of the small intestine and intestinal crypts.Same CGRP-I neurons are seen in the myenteric and submucosal plexuses.In AIRS the level of CGRP in small intestine has a double-phase change which is lower at the 24th h followed by a higher level at 48th h, 72th h after the exposure. The results indicate that CGRP may be related to the regulation of motility, secretion,absorption sensation and regional blood flow of the gastrointestinal tract. CGRP is probably released under the stress of AIRS and participates in the mechanism of injury of AIRS through multiple ways, in particular, the influence on the regional blood flow and the increase of permeability of blood vessels.