Pathogenesis of myocardial fibrosis in hypertension: Effects of angiotensin II on the expression of monocyte chemoattractant protein-1 in fibroblasts

Aim: To investigate the mechanism of heart lesion in essential hypertension by observing the expression of monocyte chemoattractant protein-1 (MCP-1) in cultured adult rat cardiac fibroblasts (CFs) under angiotensin II stimulation. Methods: Adult rat cardiac fibroblasts were cultured in vitro and stimulated by angiotensin II with different concentration and different time. The concentrations of MCP-1 in the cells and supernatant were determined with western blot and ELISA. Results: 1 MCP-1 could be detected in the cells and supernatant. 2 The amount of MCP-1 expression in the cells and supernatant was increased with the increasing concentration and prolonged time of angiotensin II stimulation. The MCP-1 concentration in the supernatant were (1.60 ± 0.21), (3.18 ± 0.15), (4.70 ± 0.22), (9.18 ± 0.52) and (8.75 ± 0.42) μg/L respectively with the stimulation of 1 × 10^-11, 1 × 10^-9, 1 × 10^-8, 1 × 10^-7 and 1 × 10^-6 mol/L of angiotensin II, which were significantly different as compared with the control group[(1.13 ± 0.09) μg/L] except for the group of 1 × 10^-11 mol/L of angiotensin II (t = 26.21 - 39.67, P < 0.05). 3 The significant difference was also found in the concentration of MCP-1 between the groups at 3, 6, 12 and 24 hours of 1 × 10^-7 mol/L of angiotensin II stimulation [respectively (2.13 ± 0.31), (3.25 ± 0.20), (5.28 ± 0.50) and (9.18 ± 0.52) μg/L] and the control group[(1.13 ±0.09) μg/L] (t = 6.93 - 34.11, P < 0.05). Conclusion: The expression of MCP-1 in cultured adult rat cardiac fibroblasts is concentration-dependant and time-dependant to the angiotensin II stimulation. The expression of MCP-1 in the cardiac fibroblasts may play an important role in the inflammation and fibrosis in the myocardium in essential hypertension.