脂多糖对衰老大鼠肺泡巨噬细胞凋亡的影响

Effects of lipopolysaccharide on alveolar macrophages' apoptosis in aged rats

目的探讨脂多糖(lipopolysaccharide,LPS)对衰老大鼠模型肺泡巨噬细胞(alveolar macrophage,AM)凋亡的影响方法用D-半乳糖(D-galactose,D-gal)复制衰老大鼠模型,实验动物分为老年组和青年组,青老年大鼠分别通过支气管肺泡灌洗和细胞贴壁的方法获取AM,将其分为LPS刺激组和对照组,每组6只,LPS刺激组用10mg/l LPS直接攻击细胞,24h后用AnnexinⅤ-FITC细胞凋亡检测试剂盒进行检测。结果衰老大鼠LPS刺激组细胞凋亡百分率(50.57%±2.29%)高于对照组(17.25%±1.68%,P<0.05);青年大鼠LPS刺激组(28.22%±1.75%)较对照组(14.25%±3.09%,P<0.05)高,青老年对照组之间差异无统计学意义。结论LPS刺激组的AM凋亡衰老大鼠明显高于青年组,老年大鼠对LPS刺激的反应程度大于青年组。

Objective ： To investigate the effects of lipopolysaccharide（LPS） on alveolar macrophages＇ apoptosis in aged rats. Methods Four - month - old Wistar rats were used as experimental animals. D - galactose 50mg/kg was used to establish aged animal model. The rats were divided into 4 groups ： aged model group, aged control group, adult group and adult control group. Each group contained 6 rats. The trachea bronthi and lungs were isolated and lavaged with normal saline.One minute later the bronchoalveolar lavage fluid （BALF） was reextracted. Cells were collected from the fluid and put into 6- wells cell culture plate. The alveolar macrophages （AMs） adhered to the wall were collected ,suspended again cultured,re -collected, centrifuged and isolated. The AMs of aged model group and adult group were attacked by LPS 10 mg/ 1,24 hours later the AMs were re - collected . Apoptosis of AMs were measured by flow cytometry. Results： The apoptic rate （APO） of AM in the aged rats stimulated by LPS was 50. 57% ± 2. 29% ,significantly higher than that of the control rats （ 17. 25 %± 1.68 % , P 〈 0.05）. Compared ： with the aged, the adult rats stimulated by LPS （28.22% ± 1. 75% ） was higher than that of the control group（ 14.25% ±3.09% ,P 〈 0. 05 ）. Conclusions The AM APO% of aged rats stimulated by LPS is higher than that of the adult rats. The aged rats are more sensitive to LPS than the adult rats.