Objective:To study the effect of spironolactone,an aldosterone receptor antagonist(ARA),on neuroendocrine of SD rats with dilated cardiomyopathy,so as to investigate its mechanism in treatment of dilated cardiomyopathy.Methods: Male SD rats,weighting (300±50) g,were intraperitoneally injected with adriamycin (2 mg/kg) once a week for 8 weeks to induce dilated cardiomyopathy models.The rat models were randomly divided into 4 groups: control group,low dose spironolactone group (10 mg/\[kg·d\],i.g.\],middle dose spironolactone group (20 mg/\[kg·d\],i.g.) and high dose spironolactone group (40 mg/\[kg·d\],i.g.).Rats in the normal control group received normal saline (10 mg/\[kg·d\],i.g.).Spironolactone was given for 8 weeks.Angiotensin Ⅱ(AngⅡ) and aldosterone (ALD) levels in the plasma and cardiac muscle homogenate were determined 9 weeks later.The plasma nitrogen monoside (NO),N-terminal popeptide of collagen type Ⅲ (PⅢNP) in serum and atrial natriuretic peptide (ANP) in the plasma were also measured.Results: Eight weeks after treatment,the Ang Ⅱ levels in the plasma of animals in the middle dose group and high dose group were significantly decreased(P<0.05),the levels of ALD were elevated(P<0.05),those of PⅢNP and ANP were decreased(all P<0.05).Conclusion: Spironolactone at 20 mg/(kg·d) or 40 mg/(kg·d) for 8 weeks can correct the disorder in neuroendocrine system to some extents.