[Antifibrotic effects of N-acetyl-seryl-aspartyl-lysyl-proline mediated by regulation of transforming growth factor beta and connective tissue growth factor expression on rats with silicosis].

Objective: To investigate whether the effect of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) on transforming growth factor beta (TGF-beta1) and connective tissues growth factor (CTGF) was involved in AcSDKP's antifibrotic effect on the rats with silicosis.

Methods: Rats were divided into 6 groups randomly, 10 rats in each group: Control of silicotic model: 1.0 ml normal sodium and was killed after 4 or 8 weeks; Silicotic model 1: 50 mg/ml silica suspension and was killed after 4 weeks; Silicotic model 2: 50 mg/ml silica suspension and was killed after 8 weeks; Anti-fibrosis treatment of AcSDKP: after each rat was intratracheally instilled with 50 mg/ml silica suspension for 4 weeks, AcSDKP 800 microg/(kg x d) was administered into every rat and rats were killed at the 8 weeks; Preventing fibrosis treatment of AcSDKP: after AcSDKP [800 microg/(kg x d)] was administered into every rat for 48 hours, each rat was intratracheally instilled with 50 mg/ml silica suspension and rats were killed at the 8 weeks.

[Role of extracellular signal-regulated kinase 1/2 on inhibition of N-acetyl-seryl-aspartyl-lysyl-proline on proliferation and collagen synthesis of cultured rat pulmonary fibroblasts induced by platelet-derived growth factor].

Objective: To investigate the role of extracellular signal-regulated kinase 1/2 on the inhibition of N-acetyl-seryl-aspartyl-lysyl-proline (AcSDKP) on the proliferation and collagen synthesis of cultured rat pulmonary fibroblasts induced by platelet-derived growth factor (PDGF).

Methods: Pulmonary fibroblasts were prepared from lungs of neonatal Wistar rats as described previously. Cells were divided into 4 groups: (1) control group (0.