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. Key words: Aldosterone; Mineralocorticoid receptor; Heart; Adiponectin