血管紧张素Ⅱ对乳鼠培养心肌细胞自发性收缩及细胞内游离钙的瞬间变化的影响

Effects of Angiotensin Ⅱ on Spontaneous Contractile Behavior and Cytosolic Free Calcium Transient in Cultured Myocardial Cells

应用倒置显微镜闭路电视系统及Ca^(2+)敏感的荧光指示剂Fura-2/AM的方法,记录培养心肌细胞的自发性收缩及[Ca^(2+)]i瞬间变化、结果发现,应用Ang Ⅱ（10～1000 nmol·L^(-1)）5min后,心肌细胞收缩频率增加,但细胞边缘运动的速度减少。Ang Ⅱ10,100nmol·L^(-1)引起[Ca^(2+)]i瞬间变化最大值的明显增加,但对[Ca^(2+)]i瞬间变化的基线水平没有明显的影响。Ang Ⅱ对心肌细胞收缩及[Ca^(2+)]i瞬间变化的作用机制可能与其影响[Ca^(2+)]i有关。

Using a TV system and Ca2+-sensitive fluorescent indicator, Fura-2/AM, spontaneous contractile behavior and cytosolic free Ca2+ transients were observed in cultured myocardial cells of neonatal rats. There was an increase in the contractile frequency, but the velocity of cell edge motion was decreased after exposed to Ang Ⅱ (1-1000 nmol·L-1) for 5 minutes. Ang Ⅱ(10,100 nmol·L-1) caused an increase in the peak of Ca2+ transient with no apparent change in the basal [Ca2+]i level between beats. The results suggested that mechanisms of Ang Ⅱ on contractile behavior and [Ca2+]i transient were related to its effects on [Ca2+]i.