降钙素基因相关肽对大鼠小肠缺血预适应的保护作用

Preconditioning induced by calcitonin gene-related peptide in rat intestine

目的探讨降钙素基因相关肽(CGRP)在大鼠小肠缺血预适应中的作用及意义。方法①健康Wistar雄性大鼠,体质量(280±30)g,分为3组(各8只),对照组(CON):仅分离肠系膜上动脉(SMA),不夹闭,观察90 min;缺血再灌组(I/R):分离SMA,夹闭30 min,再灌注60 min,结束实验;缺血预适应组(IP):分离SMA,夹闭SMA 5 min反复3次,然后再夹闭30 min,再灌注60 min,结束实验。②利用放射免疫法测定CGRP含量,以乳酸脱氢酶(LDH)、丙二醛(MDA)含量变化和形态学变化为指标,评价缺血再灌注损伤。结果缺血预适应可明显抑制大鼠小肠缺血再灌注损伤后LDH的水平增高,降低MDA的含量(P<0.01),保护小肠黏膜不受损伤。结论CGRP为大鼠小肠缺血再灌注损伤中关键性介质之一,缺血预适应可提高大鼠小肠缺血再灌注后CGRP的水平,对抗缺血再灌注损伤。

Objective To study the role of ealcitonin gene-related peptide （GRP） in ischemic preconditioning in rat intestine. Methods The ischemic/reperfusion （I/R） injury was made by 30 min of ischemia and 1 hour reperfusion. The preconditioning was first gave 5 min of ischemia and 5 min reperfusion then with 30 min of ischemia and 1 hour reperfusion. It was assayed dehydrogenase （LDH）, molondialdehyde （MDA） and the CGRP content in the plasma after ischemia/reperfusion. Results The result showed dehydrogenase （LDH）, molondialdehyde （MDA） increased in the group of I/R, and IP can respectively decreased this change. The latter compared with the former have significantly difference. It was found that IP could promote the release of CGRP （P 〈 0.05）. Conclusion The result showed IP could induced the protective effect in rat small intestine. Moreover, the protective effect is positively relative with the content of CGRP in plasma. This result revealed CGRP may play a role in the preconditioning induced by IP in rat small intestine.