Protective Effects of Beta-carotene on Myocardial Hypertrophy Induced by Norepinephrine in Rats

Objective: To investigate the protective effects of β-carotene(BC) on myocardial hypertrophy induced by norepinephrine(NE) in rats.Methods: Myocardial hypertrophy models of rats were induced by injection of NE(2 mg/kg,i.p.) twice daily for 15 days,and then were intervened by β-carotene at 250 mg/(kg·d)intragastrically.The heart weight(HW),left ventricular weight(LVW),the ratio of HW/BW and LVW/BW(LV index,LVI) were measured;the content of angiotensin(AngⅡ) and the expression of angiotensin type one receptor(AT1R) in left ventricle were determined by radioimmunoassay and immunochemistry respectively.Thiobarbituric acid method and xanthineoxidase method were used to determine the contents and activities of malondialdehyde(MDA) and superoxide dismutase(SOD) in myocardial tissue respectively.Results: In NE model group,HW/BW,LVI,content of AngⅡ and the expression of AT1R in left ventricle increased markedly.The content of MDA in left ventricle and blood increased but that of SOD decreased.Conclusion: BC was shown to prevent remodeling of myocardial hypertrophy induced by NE in rats.