OBJECTIVE: To investigate the effects of angiotensin II (AngII) and AT1a blocker losartan on growth and proliferation of rat hepatic stellate cells (HSCs). METHODS: Rat HSCs were isolated, cultured and identified, followed by incubation with AngII or losartan at different concentrations. The cell growth and proliferation were assessed via cell counting and MTT assay, and the effects of the agents on HSC DNA synthesis evaluated by way of (3)H-thymidine incorporation ((3)H-TDR). RESULTS: AngII (1 x 10(-9) to 1 x 10(-7) mol/L) stimulated HSC proliferation as demonstrated by cell counting, MTT assay and thymidine incorporation test (P < 0.05), but such effect was not observed at lower doses (<1 x 10(-9) mol/L). Losartan had significant inhibitory effect on HSC growth at the concentration of 1 x 10(-8) to 1 x 10(-6) mol/L (P < 0.05), but not at lower doses (<1 x 10(-8) mol/L). Co-stimulation of the cells with losartan and AngII did not result in a significant increase in cell number as compared with the control group (P > 0.05). CONCLUSION: Rapid proliferation of rat HSCs occurs in response to AngII treatment, but is inhibited after AT1a receptor is blocked with the antagonist losartan.
OBJECTIVE: To investigate the effects of angiotensin II (AngII) and AT1a blocker losartan on growth and proliferation of rat hepatic stellate cells (HSCs). METHODS:Rat HSCs were isolated, cultured and identified, followed by incubation with AngII or losartan at different concentrations. The cell growth and proliferation were assessed via cell counting and MTT assay, and the effects of the agents on HSC DNA synthesis evaluated by way of (3)H-thymidine incorporation ((3)H-TDR). RESULTS:AngII (1 x 10(-9) to 1 x 10(-7) mol/L) stimulated HSC proliferation as demonstrated by cell counting, MTT assay and thymidine incorporation test (P < 0.05), but such effect was not observed at lower doses (<1 x 10(-9) mol/L). Losartan had significant inhibitory effect on HSC growth at the concentration of 1 x 10(-8) to 1 x 10(-6) mol/L (P < 0.05), but not at lower doses (<1 x 10(-8) mol/L). Co-stimulation of the cells with losartan and AngII did not result in a significant increase in cell number as compared with the control group (P > 0.05). CONCLUSION: Rapid proliferation of rat HSCs occurs in response to AngII treatment, but is inhibited after AT1a receptor is blocked with the antagonist losartan.