Effect of urotensin ¢ò on the proliferation of cardiac myofibroblasts and its intracellular signaling mechanism in newª²born SD rats

    YANG Jingª²Xiao, ZHAO Lianª²You, ZHENG Qiangª²Sun, SHANG Fuª²Jun, YU Xinª²Ya, LI Aiª²Guo

    Department of Cardiology, Tangdu Hospital, Fourth Military Medical University, Xi¬ðan 710038, China

    ¡¾Abstract¡¿ AIM: To explore the effects of urotensin¢ò (U¢ò) on the proliferation of the cardiac fibroblasts (CFs) and its intracellular signaling mechanism in newª²born SD rats. METHODS: CFs from newª²born SD rats were isolated and cultured. Cell number was observed by MTT assay. Cell cycle was evaluated by flow cytometry (FCM). RESULTS: With the treatment of 10-10, 10-9, 10-8 mol/L U¢ò, the cell number, S phase cell percentage and the proliferation index (PI), were significantly higher than those of control group. G0/G1 phase cell percentage was significantly lower than that in control group (P<0.01), but the indices in the 10-7 mol/L U¢ò group were not significantly different from those of control(P>0.05). The OD values in 10-6 mol/L Che+10-8 mol/L U¢ò, 10-5 mol/L PD98059+10-8 mol/L U¢ò and 5 mg/L CsA+10-8 mol/L U¢ò groups increased significantly compared with those in control group (P<0.05), but decreased compared with those in 10-8 mol/L U¢ò group (P<0.05). Compared with those in control group, S phase cell percentage and PI increased, but G0/G1 phase cell percentage decreased in 10-6 mol/L Che+10-8 mol/L U¢ò and 5 mg/L CsA+10-8 mol/L U¢ò groups (P<0.05). No difference was found between 10-5 mol/L PD98059+10-8 mol/L U¢ò and control groups (P>0.05). Compared with those in 10-8 mol/L U¢ò group, S phase cell percentage and the PI declined significantly (P<0.01), while G0/G1 phase cell percentage rose remarkably in 10-6 mol/L Che+10-8 mol/L U¢ò, 10-5 mol/L PD98059+10-8 mol/L U¢ò and 5 mg/L CsA+10-8 mol/L U¢ò groups (P<0.01). CONCLUSION: U¢ò can stimulate the proliferation of CFs in newª²born SD rats and the U¢òª²induced proliferation of CFs is probably mediated by PKC/MAPK/CaN. ......