Objective:To observe the effects and mechanisms of beraprost on cross linked collagen in angiotensinⅡ (AngⅡ)-stimulated cardiac fibroblasts. Methods:The cultured neonatal rat cardiac fibroblasts were pre-treated with beraprost followed with Ang Ⅱ (100 nmol/L) stimulation for 24 h. Total collagen and cross linked collagen were examined in culture medium. Lysyl oxidase (LOX) expression was determined with real time PCR and western blot. Results:Beraprost dose-dependently inhibited collagen secretion with Ang Ⅱ stimulation,among which 10 μmol/L presented with the most robust suppression. Beraprost (10 μmol/L) pre-treatment for 4 h followed with AngⅡ stimulation significantly reduced collagen secretion,as well as the cross linked degree and ratio of cross linked collagen to non-cross linked collagen,accompaying with decreasing mRNA and protein expression of LOX. Conclusion:Beraprost inhibited cross linked collagen in AngⅡ-stimulated cardiac fibroblasts,which may be associated with suppression of LOX expression.