目的 · 观察脂多糖（LPS）刺激下心肌细胞线粒体通透性转换孔道（mPTP）开放状态、心肌细胞凋亡情况及环孢霉素 A（CsA） 和兰尼定（Rya）联合应用的抗凋亡作用。方法 · 将 H9c2 细胞分为对照组、LPS 组、LPS+ CsA 组、LPS+ Rya 组、LPS+CsA+Rya 组； 分别检测 mPTP 的开放状态、细胞内及线粒体 Ca2+ 浓度、线粒体膜电位（ΔΦm），以及反映细胞凋亡的 Hoechst 染色，Bax、Bcl-2 的 mRNA 表达，caspase 3 活性，Bax 及 Bcl-2 蛋白水平的变化。结果 · LPS 作用心肌细胞 24 h 后 mPTP 开放，可使细胞质 Ca2+ 荧光强度 增高298%，线粒体Ca2+ 荧光强度增高231%，约1/3 细胞凋亡，caspase 3 活性增加了约1 倍，上调Bax mRNA 表达（P=0.008）；联合 使用 CsA 与 Rya 可有效阻断由LPS 引起的心肌细胞mPTP 开放，降低LPS 所致的细胞质和线粒体的Ca2+ 浓度增高的幅度，维持正常 的 ΔΦm，减轻 LPS 所致的细胞凋亡，抑制 caspase 3 活性，可显著抑制 LPS 对心肌细胞 Bax mRNA 表达的上调作用。结论 · mPTP 在 LPS 所致心肌细胞凋亡中发挥重要作用，而 CsA 与 Rya 联合应用可有效缓解 LPS 所致的心肌细胞凋亡。

Objective · To observe mitochondria permeability transition pore (mPTP) opening and apoptosis of H9c2 myocardial cell stimulated by lipopolysaccharide (LPS), and to explore the anti-apoptotic effect of combined application of cyclosporine A (CsA) and ryanodine (Rya).  Methods · The H9c2 cells were divided into Control group, LPS group, LPS+CsA group, LPS+Rya group, and LPS+CsA+Rya group. The mPTP opening state, Ca2 + concentration within cell and mitochondrial, mitochondrial membrane potential (ΔΦm), cell apoptosis, expression of Bax and Bcl-2 at mRNA and protein levels, and activity of caspase 3 were determined respectively.  Results · mPTP opened after being stimulated by LPS for 24 h, which increased the fluorescence intensity for Ca2+ in cytosolic and mitochondria by 298% and 231% respectively, induced about 1/3 cell apoptosis, improved the activity of caspase 3 approximately twice, and enhanced expression of Bax mRNA (P=0.008). The combined use of CsA and Rya effectively inhibited mPTP opening, increased the enhancement of fluorescence intensity for Ca2+ in both cytosolic and mitochondria, maintained normal ΔΦm, reduced LPS-induced apoptosis, inhibited the activity of caspase 3, and decreased Bax mRNA expression level induced by LPS in the myocardial cells.  Conclusion · mPTP plays an important role in in LPS-induced myocardial apoptosis, whereas the combination of CsA and Rya can alleviate it effectively.