Abstract: Objective To investigate collagen metabolism modulation of Intermedin1－53 (IMD1－53) on angiotensin Ⅱ (Ang Ⅱ)-induced rat cardiac fibroblasts. Metheds Cultured SD neonatal rat cardiac fibroblasts, and divided them into control group, AngⅡ + different concentrations IMD1－53 groups.Ⅰand Ⅲ collagen expression in cardiac fibroblasts were measured by Westem blot, IMD1－53 receptor - like receptor (calcitonin receptor-like receptor, CRLR) and transforming growth factor-β (TGF-β) mRNA expression by SYBR Green Ⅰ real-time PCR. Results IMD1-53 significantly inhibited AngII-induced collagen synthesis in cardiac fibroblasts, and this effect was more obvious with the increasment of IMD1－53( P < 0.01，P < 0.05). Similar phenomenon took place on TGF-β expression in cardiac fibroblasts( P < 0.05). Conclusion IMD1－53 inhibited collagen synthetic in cardiac fibrosis induced by AngⅡ, downed TGF-β expression. These might relate to IMD1－53 anti myocardial fibrosis.

Key words: Intermedin1－53, cardiac fibroblast, angiotensin Ⅱ, transforming growth factor-β