Role of polyamines in L - arginine inhibiting isoproterenol induced cardiac hypertrophy rat / 中国病理生理杂志

ABSTRACT

AIM: To explore the role and possible mechanism of polyamine in L - arginine inhibiting cardiac hypertrophy induced by isoproterenol (ISO). METHODS: Hypertrophic model of rats was established using ISO. Pretrea-ted with L - arginine, hypertrophy status of rats was determined by hypertrophy coefficient, collagen content and the expression of ANP mRNA. High performance liquid chromatography ( HPLC) was used to measure the concentrations of polyamines. Western blotting was performed to detect the expressions of ornithine decarboxylase ( ODC) and spermidine/ spermine Nl - acetyltransferase (SSAT). The activity and levels of NOS and NO in serum were also observed. RESULTS : Hypertrophy coefficient and expression of ANP mRNA increased significantly after injection of ISO for 7 d. Moreover, cardiac muscle fibres became thick and disorganized. Pretreated with L - arginine, the above index decreased. Meanwhile , the concentration of polyamine was decreased and plasma NO content and NOS activity were increased, the expression of ODC was downregulated and the expression of SSAT was upregulated. CONCLUSION: Exogenous L - arginine inhibits cardiac hypertrophy through downregulating L - arginine/polyamine pathway and upregulating L - arginine/NO pathway.