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目的研究不同周龄对大鼠心肌细胞收缩/舒张功能的影响。方法SD大鼠分为三个周龄组:A组(12~15周)、B组(36~41周)和C组(51~55周),并以常规酶解法分离成年大鼠心肌细胞,观察分离即刻(D时间点)、复钙1h后(E时间点)和电刺激10min后(F时间点)心肌细胞成活率,采用IonOptix单细胞动缘探测系统同步检测心肌细胞的收缩幅度、收缩/舒张速度和钙瞬变等,这些指标均由计算机自动实时采集并记录。结果复钙1h后和电刺激10min后心肌细胞成活率降低均有统计学意义(P<0.05或P<0.01),周龄越大越明显,随着周龄的增大,心肌细胞收缩幅度(峰值高度,ph)、心肌细胞收缩幅度/单个心肌细胞的长度百分比(ph/bl%)、最大收缩速率(maxi mal velocity of contraction,+dL/dt)、最大舒张速率(maxi mal velocity of relaxation,-dL/dt)和钙瞬变幅度(FFI)降低,ph在A组、B组和C组分别为(0.14±0.06),(0.12±0.05),(0.11±0.05)μm;ph/bl%分别为(9.17±3.54)%、(7.14±2.58)%和(6.56±2.36)%;+dL/dt分别为(2.01±0.74),(1.82±0.51),(1.51±0.56)μm/s;-dL/dt分别为(2.10±0.75),(1.70±0.62),(1.41±0.52)μm/s;FFI分别为(0.38±0.05),(0.35±0.04),(0.25±0.05)。其中C组ph/bl%、+dL/dt、-dL/dt和FFI均较A组显著降低(P<0.05),降低幅度分别为27%,26%,33%和31%。结论随着周龄的增大,分离大鼠心肌细胞的成活率下降,大鼠心肌细胞的收缩/舒张功能降低,钙瞬变幅度减小。
Objective To study the effects of different weeks of age on the contractile / diastolic function of rat cardiomyocytes. Methods SD rats were divided into three groups: group A (12-15 weeks), group B (36-41 weeks) and group C (51-55 weeks). The normal rat myocardial cells . The survival rate of cardiomyocytes was observed immediately after separation (D time point), 1 h after rehydration (E time point) and 10 min after electrical stimulation (F time point). The contractile amplitude of cardiomyocytes was detected by IonOptix single- Systolic / diastolic velocity and calcium transient, these indicators are collected by the computer automatically in real time and recorded. Results After 1 h of rehydration and 10 min of stimulation, the survival rate of cardiomyocytes was significantly decreased (P <0.05 or P <0.01). The larger the age, the more obvious. With the increase of age, the amplitude of myocardial cell contraction Height, ph), myocardial cell contraction amplitude per individual cardiomyocyte length percentage (ph / bl%), maxi mal velocity of contraction (+ dL / dt), maxi mal velocity of relaxation (0.14 ± 0.06), (0.12 ± 0.05) and (0.11 ± 0.05) μm, respectively; Ph / bl% Were (9.17 ± 3.54)%, (7.14 ± 2.58)% and (6.56 ± 2.36)%, respectively. The values of + dL / dt were 2.01 ± 0.74, 1.82 ± 0.51 and 1.51 ± 0.56 μm / dL / dt were (2.10 ± 0.75) and (1.70 ± 0.62) and (1.41 ± 0.52) μm / s, respectively; FFI was (0.38 ± 0.05) and (0.35 ± 0.04) and (0.25 ± 0.05) respectively. Among them, ph / bl%, + dL / dt, -dL / dt and FFI in group C were significantly lower than those in group A (P <0.05), decreasing by 27%, 26%, 33% and 31% respectively. Conclusion With the increase of age, the survival rate of isolated rat cardiomyocytes decreased, while the contractile / diastolic function of rat myocardial cells decreased and the amplitude of calcium transient decreased.