Abstract: Objective To observe differences in the expression of β3-adrenergic receptor (β3-AR) under different pathological factors associated with heart failure in neonatal rat cardiac myocytes and cardiac fibroblasts. Methods The neonatal rat cardiomyocytes and cardiac fibroblasts were isolated and cultured, and both were identified by immunofluorescence. Then angiotensin Ⅱ (AngⅡ) and norepinephrine (NE) were given to stimulate the cells. And qPCR was used to detect cardiomyocyte hypertrophy-related genes (ANP, BNP and β - MHC), cardiac fibroblast-related genes(Col-Ⅰ, COL-Ⅲ) and β3-AR mRNA expression in two kinds of cells. Results Immunofluorescence identification showed that the isolated and cultured cardiomyocytes and cardiac fibroblasts were in good condition. After 48 hours of AngⅡ and NE stimulation, the expressions of ANP, BNP, β-MHC and β3-AR were increased significantly in cardiomyocytes compared with those in control group, while the expressions of Col-Ⅰ and COL-Ⅲ were increased significantly in cardiac fibroblasts compared with those of the normal control group. However, the expression of β3-AR did not change significantly.Conclusion AngⅡ and NE, pathological factors involved in the development of heart failure, mainly cause an increase in the expression of β3-AR in cardiomyocytes rather than cardiac fibroblasts.

Key words: myocytes, cardiac, fibroblasts, norepinephrine, β3-adrenergic receptor, angiotensin Ⅱ