摘要
目的 为探讨胞浆Ca2 + 是否为一氧化氮 (NitricOxide,NO)诱导弓形虫速殖子凋亡的重要信号分子。方法 采用脱氧核苷酸末端转移酶 (TdT)介导的缺口末端标记法 (TUNEL)、琼脂糖凝胶电泳和流式细胞仪检测凋亡以及应用Fura - 2荧光负载技术测定胞浆游离钙浓度 [Ca2 + ]i。结果 NO供体亚硝基铁氰化钠 (Na2 Fe(CN) 5NO ,SNP)诱导弓形虫速殖子凋亡过程中胞浆 [Ca2 + ]i明显升高。NO清除剂 ,N -乙酰半胱氨酸能明显抑制SNP诱导的速殖子凋亡及SNP诱导的速殖子胞浆[Ca2 + ]i升高 ,而不含NO的SNP类似物 ,铁氰化钾 [K3 Fe(CN) 6]不能诱导速殖子凋亡及其胞浆 [Ca2 + ]i升高。胞外钙螯合剂EGTA ,和L型电压依赖性钙通道阻滞剂异搏定 ,完全或部分抑制SNP引起的速殖子胞浆 [Ca2 + ]i升高 ,胞内钙螯合剂BAP TA/AM及胞外钙螯合剂EGTA明显抑制SNP诱导的速殖子凋亡。结论 证明NO的供体SNP诱导弓形虫速殖子凋亡主要通过促进胞外钙内流 ,胞浆 [Ca2 + ]i升高所致。
Aim To explore whether cytoplasmic free calcium is a critical signal molecule in NO induced apoptosis in toxoplasmatic tachyzoites Methods Apoptosis induced by NO in toxoplasmatic tachyzoites was investigated by TUNEL(terminal deoxynucleotidyl transferase mediated d UTP nick end labeling )method,agarose gel electrophoresis and flow cytometry Cytoplasmic free calcium concentration([Ca 2+ ]i)in toxoplasmatic tachyzoites was determined by applying Fura 2 fluorescein load technic Results NO donor,sodium nitroprusside(Na 2Fe(CN) 5NO,SNP),induced apoptosis and increased in[Ca 2+ ]i in Toxoplasma gondii tachyzoites N acetylcysteine,a NO scavenger,greatly inhibited SNP induced apoptosis and SNP induced increase in[Ca 2+ ]i in toxoplasmatic tachyzoites Potassium ferricyanide[K 3Fe(CN) 6],an analogue of SNP but devoid of NO,alone did not induce apoptosis and the increasing in[Ca 2+ ]i in toxoplasmatic tachyzoites Chelation of extracellular calcium with EGTA entirely inhibited the increase in[Ca 2+ ]i and voltage dependent calciunm channel blockers,verapamil only partially inhibited the increase in[Ca 2+ ]i induced by SNP SNP induced apoptosis in toxoplasmatic tachyzoites was greatly inhibited by intracellular Ca 2+ chelator(BAPTA/AM)and extracellular Ca 2+ chelator(EGTA) Conclusion SNP induced apoptosis is mediated by elevating cytoplasmic free calcium concentration[Ca 2+ ]i in toxoplasmatic tachyzoites,which is mainly resulted from the entry of extra cellular calcium
出处
《中国人兽共患病杂志》
CAS
CSCD
北大核心
2003年第1期27-33,共7页
Chinese Journal of Zoonoses
基金
福建省科技三项费用 (K2 0 0 10 72 )
关键词
一氧化氮
弓形虫
细胞凋亡
钙
Nitric oxide
Toxoplasma gondii
Apoptosis
Calcium
