The effects of aldosterone on diet-induced fatty liver formation in male C57BL/6 mice: comparison of adrenalectomy and mineralocorticoid receptor blocker.

OBJECTIVE: Obesity, diabetes, fatty liver, and hypertension are major determinants of the metabolic syndrome. The effects of aldosterone and mineralocorticoid receptor blockers on fatty liver are largely unknown. The aim of the present study was to evaluate the relationships between aldosterone and the development of fatty liver.

MATERIALS AND METHODS: In our experiments, we performed adrenalectomy (ADX) or administered 100 mg/kg/day eplerenone, a specific mineralocorticoid receptor blocker, to male C57BL/6 mice fed with a 60% fat diet for 20 weeks.

RESULTS: High-fat diet led to metabolic syndrome as indicated by increased body weight, elevated systolic blood pressure, impaired glucose tolerance, elevated insulin levels, and development of fatty liver. A marked reduction of aldosterone by ADX or blockade of aldosterone interaction with its receptor by eplerenone, which increased serum aldosterone considerably, resulted in reduced blood pressure, and reduced serum insulin and levels of triglycerides. However, differential effects were found on reduction of blood glucose to normal levels, which was observed only in ADX. Neither ADX nor eplerenone affected fatty liver formation or body weight. In cultured hepatocytes, triglyceride loading induced by high glucose, oleic acid or very low density lipoprotein was not affected by aldosterone, spironolactone or eplerenone.

CONCLUSION: Our results suggest that whereas aldosterone might be involved in some of the diet-induced insulin and glucose metabolic effects, it played no role in the development of fatty liver.