Abstract: AIM: To observe the effects of transforming growth factor beta-1(TGFβ₁)on the expression of α-smooth muscle actin(α-SMA) and connexin43 (Cx43) in cultured cardiac fibroblasts (CFs). METHODS: CFs were isolated from neonatal rat by trypsin dissociation and differential adhension. Primary cultures of CFs for one day were subjected to TGFβ₁ (10 ng/mL) incubation for 24 hours. The expressions of α-SMA and Cx43 were determined by immunofluorescence staining. Semiquantitative analysis of mRNA and protein for α-SMA and Cx43 was finished by RT-PCR (reverse transcription polymerase Chain reaction) and Western blots. RESULTS:Little expression of protein and mRNA levels for α-SMA and Cx43 were observed in cultured 2 days primary CFs. TGFβ₁ stimulation for 24 hours led to significantly increased protein and mRNA expression of α-SMA and Cx43.CONCLUSION: Transient TGFβ₁ stimulation causes differentiation of CFs into MFs and up-regulations protein and mRNA expression of α-SMA and Cx43.

Key words: cardiac fibroblasts (CFs), myofibroblasts (MFs), α-smooth muscle actin(α-SMA);, connexin43 (Cx43), transforming growth factor beta-1(TGFβ₁);