一氧化氮介导内毒素所致体外培养肝细胞凋亡

Nitric oxide mediates hepatocyte apoptosis induced by lipopolysaccharide

目的 研究一氧化氮 (NO)介导内毒素 (LPS)所致的肝细胞损伤的细胞死亡类型。方法 采用体外肝细胞 /库普弗细胞混合培养 ,以光镜、电镜及抽提细胞DNA电泳观察受LPS刺激后NO产生增多所致肝细胞损伤的形态学及生物化学改变情况。结果 受LPS刺激后 ,培养基中NO产物水平显著升高 ,肝细胞变小、变圆 ,细胞表面出泡 ,核染色质致密、结块 ,核膜皱折变形等 ,DNA电泳呈明显“云梯形式”。而同时加用诱导型一氧化氮合酶抑制剂氨基胍后 ,培养基中NO产物水平显著降低 ,光镜、电镜及DNA电泳分析肝细胞均无上述改变。结论 NO介导LPS所致的混合培养肝细胞损伤主要为肝细胞凋亡 。

Objective To explore the death type of hepatocyte mediated by nitric oxide.Methods The nitric oxide levels in culture supernatants as well as the cytomorphologic and biochemical changes of cultured hepatocyte and kupffer cells. Were investigated after the challenge of lipopolysaccharide (LPS). Results After incubation with LPS, the level of nitric oxide (NO) in culture supernatant was higher than that of the control group; the shape and size of the hepatocytes changed obviously, electron microscopic observation revealed that nuclear chromatin was compact, lumped and margined, while nuclear membrane was folded; and DNA gel electrophoresis displayed ladder pattern. These alterations were attenuated by aminoguanidine, an inhibitor of inducible nitric oxide synthase. Conclusion These results indicate that NO is involved in hepatocyte injury, primarily through the induction of hepatocytes apoptosis.