急性百草枯中毒大鼠肺组织MMP-2和TIMP-1的基因表达

目的 利用实时荧光定量PCR法测定急性百草枯中毒大鼠肺组织中基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶组织因子抑制剂-1(TIMP-1)基因的表达,探讨其在急性百草枯中毒所致的大鼠急性肺损伤及纤维化中的作用.方法 80只SD大鼠,随机分为对照组(n:8)、染毒组(n:72);对照组一次性腹腔注射与染毒组等体积的生理盐水,染毒组一次性腹腔注射百草枯溶液(18mg/kg)染毒;分别于1、3、5、7、14、28 d光镜下观察两组大鼠的肺组织病理变化,同时利用实时荧光定量PCR法动态测定MMP-2、TIMP-1的mRNA表达量.结果 与对照组相比,染毒组大鼠早期主要表现为肺脏的急性炎症反应,肺水肿和出血明显,染毒5 d后观察到肺纤维化变化,第28天纤维化最明显;染毒组肺组织中的MMP-2的mRNA表达较对照组从第1天开始即明显增强,第7天达到高峰,为对照组的2.83倍,以后逐渐下降,但28 d时仍高于对照组,差异无统计学意义(P<0.01);TIMP-1的mRNA表达第1天也明显高于对照组,逐渐增强至14 d达到峰值,为对照组的7.28倍,后开始缓慢下降,28 d时仍明显高于对照组(P<0.01).结论 MMP-2、TIMP-1在急性百草枯中毒所致的急性肺损伤中起了重要的作用,同时大鼠的肺纤维化进程与MMPs/TIMPs的基因表达比例失调有很大的关系.

Analysis of MMP-2 and TIMP-1 gene expression in lung of paraquat intoxicated rats by real-time fluorescence quantitative PCR

Objective Using real-time fluorescence quantitative PCR to detect the gene expression of MMP-2,T1MP-1 in the rats' lung intoxicated by paraquat, and to discuss the effect of the MMP-2,T1MP-1 in the acute lung injury and pulmonary fibrosis afltr paraquat intoxication. Method Eighty Sprague-Dawley rats were randomly divided into control group and the intoxication group. The rats of the control group were given equivalent volume of normal saline, and the rats of the intoxication group were given a intraperitoneal injection of paraquat(18 mg/kg) . At 1,3,5,7,14 and 28 days after intoxication, the pathological changes were observed under the light microscope and the expression of MMP-2, TTMP-1 mRNA in the rats lung were detected by using real-time fluorescence quantitative PCR. Results Compared with the control group, in the early days after intoxication, the lung tissue of the intoxication group showed obvious inflammation, pulmonary edema and bleeding. Five daye after intoxication, pulmonary fibrosis could be ideatified and the fibrosis became obvious. At 28 days later the expression of MMP-2 mRNA was remarkably increased in lung tissue from the day of intoxication, and reached the peak 7 days later, It was control group, that in and then gradually, declined however, higher than that in control group (P < 0.01). The expression of TIMP-1 mRNA in lung tissue was also higher than the control group on the day 1, then increased gradually, reached the peak on day 14,7.28 times more than the control group, decreased from the fourteenth day,higher than the control group on day 28 (P < 0.01) . Conclusions MMP-2,TIMP-1 played a very important role in the acute lung injury induced by paraquat, meanwhile the development of pulmonary fibrosis had great relations on their disproportion.