间尼索地平对5-羟色胺诱导的大鼠肺动脉平滑肌细胞增殖中Ca2+/CaM/CaN通路的影响

探讨Ca²⁺/CaM/CaN信号通路在5-羟色胺 (5-HT) 诱导的大鼠肺动脉平滑肌细胞 (PASMCs) 增殖中的作用以及间尼索地平 (m-Nis) 对此的影响。采用细胞培养、噻唑蓝 (MTT) 比色检测、激光共聚焦显微镜及反转录聚合酶链反应 (RT-PCR) 等方法, 研究5-HT (1 μmol·L^?1) 对大鼠PASMCs细胞增殖的影响以及m-Nis对此的抑制作用, 并通过检测m-Nis对5-HT诱导的大鼠PASMCs增殖中Ca²⁺/CaM/CaN通路的影响深入探讨其作用机制。结果显示, 5-HT (1 μmol·L^?1) 可明显诱导大鼠PASMCs增殖 (P < 0.01), m-Nis对此有明显的抑制作用, 并呈现一定的浓度依赖性 (P < 0.05或P < 0.01); 另外, m-Nis还明显抑制了5-HT引起的Ca²⁺]_i的升高 (P < 0.01)、CaM和CaN mRNA的表达以及CaN活性的升高 (P < 0.05或P < 0.01)。结果表明, Ca²⁺/CaM/CaN信号通路在5-HT诱导的大鼠PASMCs增殖中起重要作用, m-Nis抗5-HT诱导的增殖作用可能与抑制Ca²⁺]_i增高从而阻断了Ca²⁺/CaM/CaN信号通路有关。

Effect of m-nisoldipine on the Ca~(2+)/CaM/CaN signal pathway in 5-HT-induced proliferation of rat PASMCs

This study is to explore the activation of the Ca²⁺/CaM/CaN signal pathway in 5-HT-induced  proliferation of rat pulmonary artery smooth muscle cells (PASMCs) and the inhibitory effect of m-nisoldipine (m-Nis) on this pathway.  PASMCs were cultured with the explant technique.  The proliferation of PASMCs was evaluated by MTT assay.  Confocal microscopy was used to measure the change of Ca²⁺]_i.  The mRNA expression of CaM and CaN was evaluated by RT-PCR and the activity of CaN was measured according to   the instruction of kits.  The results of MTT assay suggested that 5-HT (1 μmol·L⁻¹) significantly induced the proliferation of rat PASMCs (P < 0.01), which was inhibited obviously by m-Nis (P < 0.05 or P < 0.01).  Similarly, m-Nis inhibited 5-HT-induced elevation of Ca²⁺]_i (P < 0.01).  The mRNA expression of CaM, CaN and the  activation of CaN were also inhibited by m-Nis at different degrees (P < 0.05 or P < 0.01).  Thus, the results of this study suggested that Ca²⁺/CaM/CaN signal pathway played an important role in 5-HT-induced proliferation of rat PASMCs, the inhibition of m-Nis on proliferation of rat PASMCs may be related to the blockage of Ca²⁺/CaM/CaN signal pathway by inhibiting the elevation of Ca²⁺]_i.