【摘要】 目的观察维生素A对弹性蛋白酶所致肺气肿大鼠肺组织基质金属蛋白酶2,9(MMP-2和MMP-9)的影响,探讨维生素A防治肺气肿的可能机制。方法Wistar大鼠24只,随机分为3组:对照组、模型组、维生素A组,每组8只。模型组,维生素A组采用弹性蛋白酶气管内滴入的方法复制肺气肿模型,正常饲养4周后,维生素A组用维生素A(10万u/kg.d-1)给大鼠灌胃,连续给药4周后观察各组大鼠的病理学变化,免疫组织化学染色测定MMP-2、MMP-9相对阳性面积。结果与对照组比较,模型组平均肺泡数(MAN)减少、平均肺泡面积(MAA)、平均肺泡直径(MAD)增加(P均<0.01),MMP-2和MMP-9相对阳性面积增加(P均<0.01)。与模型组比较,维生素A组MAN增加(P<0.05)、MAA和MAD均减少(P均<0.01),MMP-2和MMP-9相对阳性面积均减小(分别P<0.05、P<0.01)。结论维生素A对弹性蛋白酶所致大鼠肺气肿有一定治疗作用,作用机制可能与抑制MMP-2、MMP-9的表达而减少肺组织中弹性基质的降解有关。更多还原

【Abstract】 Objective To observe the effect of vitamin A on MMP-2 and MMP-9 in the lungs of rats with elastase-induced emphysema and explore the mechanism.Methods Twenty-four Wistar rats were randomly divided into 3 groups(n=8 each group):control group,model group,and vitamin A group.The rat model of emphysema was established by instilling elastase into the lungs of rats in model group and vitamin A group.Gastric lavage with vitamin A(1.0×105 U/kg,once a day)was performed in vitamin A group from week 5 to week 8.At the end of week 8,the pathological changes were observed,and the expressions of MMP-2 and MMP-9 in the lung tissue were determined by im-munohistochemical staining and quantitative image analysis.Results Compared with control group,the mean alveolar number(MAN)significantly decreased and the mean alveolar area(MAA),mean alveolar diameter(MAD),and percentage of the positive area of MMP-2 and MMP-9 significantly increased in model group(all P < 0.01).Compared with model group,MAN significantly increased(P < 0.05)and MAA,MAD,and percentage of the positive area of MMP-2 and MMP-9 significantly decreased in vitamin A group(P < 0.01,P < 0.01,P < 0.05,P < 0.01,respectively).Conclusion Vitamin A could ameliorate the pathological changes of elastase-induced emphysema in rats.The mechanism may be related to the inhibition of the expressions of MMP-2 and MMP-9 in the lung tissue.更多还原