热化疗对人体结肠癌LoVo细胞中一氧化氮含量的影响

Effect of nitric oxide on LoVo cells after hyperthermia combined with MMC

目的 :探讨热化疗对人结肠癌LoVo细胞株中一氧化氮 (NO)含量的影响及其作用机制。方法 :实验分为对照组 ,单纯加热组、单纯化疗组及热化疗组 ,处理后用铜 镉还原法测定各级培养基中的NO含量。结果 :对照组NO含量 (45 91± 16 12 ) μmol/L ,明显低于热化疗组 (91 31± 2 4 30 ) μmol/L和单纯加热组 (6 7 6 7± 15 48) μmol/L ,P值分别 <0 0 1及 <0 0 5 ;热化疗组和单纯加热组明显高于单纯化疗组 (47 0 3± 16 0 3) μmol/L ,P值分别 <0 0 1及 <0 0 5 ;热化疗组高于单纯加热组 (P <0 0 5 ) ;单纯化疗组高于对照组 ,但无统计学意义。结论 :在肿瘤的热化疗中 ,热疗联合化疗和单纯加热能明显地增加LoVo细胞所致高浓度的NO ,单纯化疗也可以增加NO浓度 ,其机制可能是这些因素激活肿瘤细胞内NO合成酶 (NOS)产生过高浓度的NO ,产生细胞毒作用。这可能将成为热化疗肿瘤的机制之一。

Aim: To study the effect of nitric oxide (NO) on LoVo cells after hyperthermia combined with MMC and their mechanisms. Methods: The levels of NO were determined in cell culture medium of LoVo cells by Cu Cd reduction method.Results: The levels of NO in control (45.9±16.12) μmol/L group were lower than those in chemohyperthermy(92.3±24.30) μmol/L and hyperthermia (67.67±15.48)μmol/L group ( P <0 01, P <0 05 respectively). Levels of NO in chemohyperthermy and hyperthermia groups were higher than those in chemotherapy(47.03±16.32)μmol/L( P <0 01, P <0 05 respcevtively). The levels of NO in chemo hyperthermy group were higher than those in hyperthermia group( P <0 05), and those in chemotherapy group higher than in control group but without statistical significance.Conclusion: Chemohyperthermy and hyperthermia could remarkably enhance the levels of NO produced by LoVo cells. NO levels could also be enhanced by chemotherapy. It could be concluded that Nitric Oxide Synthase (NOS) in tumor cells might be activated by hyperthermia, chemohyperthermy and chemotherapy, and increased NO level which induced cytotoxic reaction. This may be one of the mechanisms of treatment with chemohyperthermy.