论文部分内容阅读
目的探讨米非司酮对胰岛素抵抗(IR)大鼠儿茶酚胺(CA)含量的影响及可能机制。方法 32只SD大鼠随机均分为空白对照组(A组)、模型对照组(B组)、米非司酮低剂量组(20mg.kg-1.d-1,C组)、米非司酮高剂量组(40mg.kg-1.d-1,D组)。高糖高脂饮食喂养大鼠8周后建立IR模型,通过胰岛素敏感指数(ISI)、胰岛素抵抗指数(HOMA-IR)等指标评估胰岛素的敏感性,同时检测血清皮质酮、血清、下丘脑和脑干CA含量及脑干、下丘脑中丙二醛(MDA)、超氧化物歧化酶(SOD)的变化。结果与A相比,B组大鼠HOMA-IR、血压、血清皮质酮、CA及MDA含量显著增加,ISI、SOD活性下降(P<0.05或P<0.01);而C、D组能明显改善B组上述指标的变化(P<0.05或P<0.01)。结论 IR状态下,交感活性增强引起的血压升高可能与机体氧化应激有关。米非司酮可能通过减少糖皮质激素引起的氧化应激,从而降低CA的含量和IR下高血压的发生。
Objective To investigate the effect of mifepristone on catecholamine (CA) content in insulin resistance (IR) rats and its possible mechanism. Methods Thirty-two Sprague-Dawley rats were randomly divided into three groups: control group (A), model group (B), low dose of mifepristone group (20mg.kg-1.d- Chlordone high-dose group (40mg.kg-1.d-1, D group). The rats in high glucose and high fat diet were fed with IR for 8 weeks. The insulin sensitivity was evaluated by insulin sensitivity index (ISI) and insulin resistance index (HOMA-IR). Serum corticosterone, serum and hypothalamus Contents of brainstem CA, contents of malondialdehyde (MDA) and superoxide dismutase (SOD) in brain stem and hypothalamus. Results Compared with group A, the levels of HOMA-IR, blood pressure, serum corticosterone, CA and MDA in group B were significantly increased and the activities of ISI and SOD were decreased (P <0.05 or P <0.01), while those in groups C and D were significantly improved The changes of the above indexes in group B (P <0.05 or P <0.01). Conclusion In IR state, elevated blood pressure induced by increased sympathetic activity may be related to the oxidative stress in the body. Mifepristone may reduce the content of CA and the occurrence of hypertension under IR by reducing the oxidative stress caused by glucocorticoids.