Rabkin Simon W, Tsang Michael Y
University of British Columbia, Vancouver, BC, Canada.
Pharmacology. 2008;82(1):74-82. doi: 10.1159/000134380. Epub 2008 May 27.
The objective of this study was to examine the interaction ofa 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase inhibitor (statin) with a nitric oxide (NO) donor from the perspective of the impact on cardiomyocyte cell viability.
Embryonic chick cardiomyocytes in culture were treated with a wide range of concentrations of sodium nitroprusside (SNP), which releases NO and also generates toxic reactive nitrogen species. SNP was combined with the HMG-CoA reductase inhibitor lovastatin and cell viability was assessed by the MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay.
SNP and lovastatin each produced a significant (p < 0.01) concentration-dependent increase in cell death. Using SNP concentrations at or below the ED50, SNP (0.01, 0.1 or 0.5 mmol/l) increased the amount of cell death when combined with lovastatin (1, 10, 50 and 100 micromol/l). At lovastatin concentrations of 50 micromol/l and less, the amount of cell death was consistently similar to the arithmetic sum of SNP and lovastatin, suggesting that there was an additive and not synergistic relationship between SNP and lovastatin. In combination with lovastatin (100 micromol/l), however, the amount of cell death was consistently lower than the calculated expected value and suggested saturation of a common mechanism. The combination of SNP and lovastatin produced the characteristic microscopic changes of apoptosis. Considering that both SNP and lovastatin can activate caspase-3, cells were treated with the caspase-3 inhibitor Ac-DEVD-CHO. This inhibitor produced a significant (p < 0.05) and consistent 30% reduction in the amount of cell death induced by SNP and lovastatin.
These data suggest that the cardiomyocyte toxicity from NO continues to be evident uninterrupted by and not accentuated by the presence of an HMG-CoA inhibitor. The cardiac adverse effect of each of these agents utilizes a common pathway involving caspase-3 so that their cardiotoxicity can be blunted by a caspase-3 inhibitor.
本研究的目的是从对心肌细胞活力的影响角度，研究3-羟基-3-甲基戊二酰辅酶A（HMG-CoA）还原酶抑制剂（他汀类药物）与一氧化氮（NO）供体之间的相互作用。
用一系列不同浓度的硝普钠（SNP）处理培养的胚胎鸡心肌细胞，SNP可释放NO并产生有毒的活性氮物质。将SNP与HMG-CoA还原酶抑制剂洛伐他汀联合使用，通过MTT [3-(4,5-二甲基噻唑-2-基)-2,5-二苯基溴化四氮唑] 法评估细胞活力。
SNP和洛伐他汀各自均使细胞死亡显著（p < 0.01）呈浓度依赖性增加。使用等于或低于半数有效剂量（ED50）的SNP浓度时，SNP（0.01、0.1或0.5 mmol/l）与洛伐他汀（1、10、50和100 μmol/l）联合使用时会增加细胞死亡量。在洛伐他汀浓度为50 μmol/l及更低时，细胞死亡量始终与SNP和洛伐他汀的算术和相似，这表明SNP和洛伐他汀之间存在相加而非协同关系。然而，与洛伐他汀（100 μmol/l）联合使用时，细胞死亡量始终低于计算的预期值，提示存在共同机制的饱和。SNP和洛伐他汀的联合使用产生了凋亡的特征性微观变化。鉴于SNP和洛伐他汀均可激活半胱天冬酶-3，用半胱天冬酶-3抑制剂Ac-DEVD-CHO处理细胞。该抑制剂使SNP和洛伐他汀诱导的细胞死亡量显著（p < 0.05）且持续降低30%。
这些数据表明，NO对心肌细胞的毒性在存在HMG-CoA抑制剂的情况下仍持续明显，且未被加重。这些药物各自的心脏不良反应利用了涉及半胱天冬酶-3的共同途径，因此它们的心脏毒性可被半胱天冬酶-3抑制剂减弱。
