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目的观察不同浓度大鼠甲状旁腺素1-34(rat parathyroid hormone 1-34,rPTH1-34)对体外培养心室肌细胞的致肥大作用,观察细胞外信号调节激酶1/2(extracellular signal regulated kinases 1/2,ERK1/2)的变化。方法体外培养新生大鼠心室肌细胞,以1×10-8~1×10-6mol/L rPTH1-34分别孵育24 h,测定细胞直径、3H-亮氨酸(3H-Leu)掺入率、心房钠尿肽(atrial natriuretic peptide,ANP)mRNA、ERK1/2、磷酸化ERK1/2(p-ERK1/2)蛋白的表达。结果与正常组相比,1×10-8mol/L rPTH1-34可使体外培养的心肌细胞直径、细胞蛋白合成速率轻度增加,ANPmRNA表达轻度升高,但无统计学意义;1×10-7,1×10-6mol/L rPTH1-34均可显著增加心肌细胞直径(P<0.01),细胞蛋白合成速率(P<0.01)和ANP mRNA表达(P<0.01)。与正常组比较,PTH呈浓度依赖性地增加了ERK1/2和p-ERK1/2的表达(P<0.01)。结论1×10-7,1×10-6mol/L rPTH1-34能在体外诱导新生大鼠心室肌细胞发生肥大反应,且呈一定的浓度依赖性;PTH能呈浓度依赖性地刺激心肌ERK1/2过度表达。
Objective To observe the hypertrophic effects of different concentrations of rat parathyroid hormone 1-34 (rPTH1-34) on ventricular myocytes in vitro and observe the effects of extracellular signal regulated kinases 1/2, ERK1 / 2) changes. Methods Newborn rat ventricular myocytes were cultured in vitro and incubated with 1 × 10-8 ~ 1 × 10-6 mol / L rPTH1-34 for 24 h. The cell diameter, 3H-Leu incorporation, Atrial natriuretic peptide (ANP) mRNA, ERK1 / 2, phosphorylated ERK1 / 2 (p-ERK1 / 2) protein expression. Results Compared with the normal group, 1 × 10-8 mol / L rPTH1-34 increased the diameter of cardiomyocytes, the rate of cellular protein synthesis and the expression of ANP mRNA slightly in vitro, but no significant difference was found -7,1 × 10-6mol / L rPTH1-34 significantly increased the diameter of cardiomyocytes (P <0.01), the rate of cellular protein synthesis (P <0.01) and the expression of ANP mRNA (P <0.01). Compared with the normal group, PTH increased the expression of ERK1 / 2 and p-ERK1 / 2 in a concentration-dependent manner (P <0.01). Conclusions 1 × 10-7, 1 × 10-6mol / L rPTH1-34 can induce hypertrophy of neonatal rat ventricular myocytes in vitro and in a concentration-dependent manner. PTH can stimulate ERK1 / 2 overexpression.