脂联素与醛固酮介导的SD大鼠心脏损害的关系

目的 探讨脂联素与醛固酮介导的SD大鼠心肌损害的关系.方法 雄性SD大鼠0.75μg/h皮下持续输注醛固酮4周,观察血压、心肌结构改变,测定血浆脂联素水平和附睾脂肪垫脂肪组织脂联素基因表达.体外培养3T3-L1脂肪细胞,10-8和10-6 mol/L醛固酮作用24和48 h,观察脂联素基因表达和培养液中脂联素浓度的变化.结果 醛固酮作用SD大鼠4周,血压轻微上升(123±7)mm Hg,P<0.05],但心肌超微结构已有明显损伤如线粒体肿胀、内部结构不清等;同时,大鼠血浆脂联素水平较对照组降低22.8%(P<0.05).10-8和10-6mol/L醛固酮干预3T3-L1脂肪细胞24 h,培养液中脂联素浓度分别降低21.8%和27.2%(P<0.05);干预48 h,脂联素mRNA表达分别降低22.1%和37.4%(P<0.05).螺内酯可逆转醛固酮对心肌的影响.结论 脂联素水平的降低可能与醛固酮介导的心脏损伤有关.

Relationship between adiponectin and cardiac damage induced by aldosterone in SD rats

Objective To investigate relationship between adiponectin and cardiac damage induced by aldosterone in SD rats. Methods Male SD rats were treated with aldosterone infusion for 4 weeks, systolic blood pressure (SBP) was measured every week. At the end of experiment, the myocardial structure was observed, the levels of adiponectin in plasma and adiponectin mRNA expression of adipose tissue in epididymal fat pad were measured. 3T3-L1 adipocytes treated with 10-8 and 10-6 moL/L aldosterone for 24 and 48 h, adiponectin mRNA expressions and adiponectin concentrations in culture medium were measured. Results Aldosterone induced only a slight increase in the SBP of SD rats(123±7)mm Hg, P<0.05]. However, aldosterone significantly induced cardiac ultrastructure changes, such as mitochondrial swelling and disordered internal structures. Furthermore, the level of plasma adiponectin decreased 22.8% after aldosterone treatment for 4 weeks ( P<0. 05 ). When 3T3-L1 adipocytes were treated with 10-8 and 10-6 mol/L aldosterone for 24 h, adiponectin concentrations in culture medium decreased 21.8% and 27. 2%, respectively (P < 0. 05); for 48 h, adiponctin mRNA expressions decreased 22.1% and 37.4%, respectively ( P<0. 05 ). The effect of aldosterone was reversed by spironolactone,which was partly independent of SBP. Conclusions Low level of adiponectin may be involved in cardiac damage induced by aldosterone in SD rats.