OBJECTIVE: To observe the effects of sodium tanshinone II A sulfonate (STS) on angiotensin II (Ang II)-induced hypertrophy of myocardial cells through the expression of phosphorylated extracellular signal-regulated kinase (p-ERK1/2). METHODS: In the primary culture of neonatal rat myocardial cells, the total protein content in myocardial cells was determined by coomassie brilliant blue and the protein synthesis rate was measured by [3H]-Leucine incorporation as indexes for hypertrophy of myocardial cells. The expression of p-ERK1/2 was determined using Western blot and immunofluorescence labeling. RESULTS: (1) The total protein and protein synthesis rate increased significantly in contrast to the control group after the myocardial cells were stimulated by Ang II (1 micromol/L) for 24 h; STS markedly inhibited the increment of the total protein level induced by Ang II and the syntheses of protein. (2) After pretreatment of myocardial cells with Ang II (1 micromol/L) for 5 min, the p-ERK1/2 protein expression was increased, with the most obvious effect shown at about 10 min; pretreatment of myocardial cells with STS at different doses (2, 10, 50 micromol/L) for 30 min resulted in obvious inhibition of the expression of p-ERK1/2 stimulated by Ang II in a dose-dependent manner. (3) After the myocardial cells were stimulated by Ang II (1 micromol/L), the immunofluorescence of ERK1/2 rapidly appeared in the nucleus. The activation and translocation process of ERK1/2 induced by Ang II was blocked distinctly by STS. CONCLUSION: STS inhibited the myocardial cell hypertrophy induced by Ang II, and the mechanism may be associated with the inhibition of p-ERK1/2 expression.
OBJECTIVE: To observe the effects of sodium tanshinone II A sulfonate (STS) on angiotensin II (Ang II)-induced hypertrophy of myocardial cells through the expression of phosphorylated extracellular signal-regulated kinase (p-ERK1/2). METHODS: In the primary culture of neonatal rat myocardial cells, the total protein content in myocardial cells was determined by coomassie brilliant blue and the protein synthesis rate was measured by [3H]-Leucine incorporation as indexes for hypertrophy of myocardial cells. The expression of p-ERK1/2 was determined using Western blot and immunofluorescence labeling. RESULTS: (1) The total protein and protein synthesis rate increased significantly in contrast to the control group after the myocardial cells were stimulated by Ang II (1 micromol/L) for 24 h; STS markedly inhibited the increment of the total protein level induced by Ang II and the syntheses of protein. (2) After pretreatment of myocardial cells with Ang II (1 micromol/L) for 5 min, the p-ERK1/2 protein expression was increased, with the most obvious effect shown at about 10 min; pretreatment of myocardial cells with STS at different doses (2, 10, 50 micromol/L) for 30 min resulted in obvious inhibition of the expression of p-ERK1/2 stimulated by Ang II in a dose-dependent manner. (3) After the myocardial cells were stimulated by Ang II (1 micromol/L), the immunofluorescence of ERK1/2 rapidly appeared in the nucleus. The activation and translocation process of ERK1/2 induced by Ang II was blocked distinctly by STS. CONCLUSION: STS inhibited the myocardial cell hypertrophy induced by Ang II, and the mechanism may be associated with the inhibition of p-ERK1/2 expression.
Authors: C A van Kesteren; H A van Heugten; J M Lamers; P R Saxena; M A Schalekamp; A H Danser Journal: J Mol Cell Cardiol Date: 1997-08 Impact factor: 5.000
Authors: T Yamazaki; I Komuro; S Kudoh; Y Zou; I Shiojima; T Mizuno; H Takano; Y Hiroi; K Ueki; K Tobe Journal: Circ Res Date: 1995-08 Impact factor: 17.367