支气管给予黄曲霉毒素G_1对大鼠肺组织CC-10表达的影响

Effects of intratracheal administration of aflatoxin G_1 on the expression of CC-10 in rat lung tissues

目的:探讨1次性支气管给予黄曲霉毒素G1(AFG1)对大鼠肺组织CC-10表达的影响。方法:按30μg/kg剂量经支气管1次性给予雄性SD大鼠AFG1处理。处理1、3、7和14d后分别处死动物。收集肺泡灌洗液(BALF),采用生化法检测乳酸脱氢酶(LDH)活力。采用流式细胞术(FCM)和蛋白免疫印迹(Western blotting)方法检测肺组织中CC-10蛋白的表达;采用反转录-聚合酶链反应(RT-PCR)方法检测CC-10mRNA水平的表达。结果:给予AFG1作用后肺泡灌洗液中LDH活力升高(P<0.01),至14d时恢复到正常水平。FCM和蛋白免疫印迹方法检测CC-10蛋白结果发现AFG1作用3、7和14d,CC-10蛋白表达明显低于对照组(P<0.01,P<0.01),蛋白免疫印迹结果同FCM一致。AFG1作用3、7和14d大鼠肺组织CC-10 mRNA表达明显低于对照组(P<0.01)。结论:支气管1次性给予AFG1作用对大鼠肺组织具有明显的致损伤作用,降低CC-10蛋白和mRNA的表达水平。

AIM： To explore the putative effects of single intratracheal administration of aflatoxin G1 （AFG1） on the expression of CC - 10 of lung tissues in SD rats. METHODS： Male SD rats were intratracheally administrated with AFG1（30 μg/kg body weight） and the animals were respectively sacrificed at 1, 3, 7 and 14 d after AFG1 treatment. Bronchial alveolar lavage fluid （BALF） was centrifuged and the supernatants were collected for LDH release assay using Detection Kit with biochemical method. The expression of clara cell 10 kD protein （CC - 10 protein） in lung tissues was determined by FCM analysis and Western blotting respectively. The expression of CC - 10 at mRNA level was analyzed by RT - PCR. RESULTS ： LDH activity in BALF after AFG1 treatment for 1, 3 and 7 d was significantly increased as compared to that in their corresponding control group （ P 〈 0. 01 ） and restored to control level at 14 d after AFG1 treatment. FCM, Western blotting and RT - PCR results showed that no significant changes in CC - 10 expression at both protein and mRNA levels were found between AFG1 group and control group 1 day after AFG1 treatment. While the CC - 10 expressions of lung tissues at both protein level and mRNA levels in AFG1 treated group were significantly decreased as compared to those in their corresponding control group at 3, 7 and 14 d after AFG1 treatment （all P 〈0. 01 ）. CONCLUSION： Intratracheal administration of AFG1 may cause injuries and decrease the expression of CC - 10 in lung tissues of SD rats in vivo.