Giulivi C, Turrens J F, Boveris A
Instituto de Química y Fisicoquímica Biológicas, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Argentina.
Mol Biochem Parasitol. 1988 Sep;30(3):243-51. doi: 10.1016/0166-6851(88)90093-x.
The spontaneous emission of chemiluminescence by Trypanosoma cruzi epimastigotes was 133 +/- 5 counts s-1 (mg protein)-1. The measured intracellular steady state concentration of hydrogen peroxide in the same cells was 1.5 +/- 0.5 microM. These two values are about 12- and 15-times higher than the corresponding ones for isolated rat hepatocytes. The intracellular steady state concentrations of superoxide radical and hydrogen peroxide were apparently increased by inhibiting superoxide dismutase (with diethyldithiocarbamate or KCN addition) and by the addition of two different trypanocidal agents (beta-lapachone and nifurtimox) capable of intracellular redox cycling and in each case an increased chemiluminescence was observed. Depletion of intracellular reduced non-protein SH groups by 80% increased 3-fold the chemiluminescence of T. cruzi cells. It is apparent that both an increase in the intracellular steady state concentration of superoxide anion or hydrogen peroxide and a decrease in the level of reduced SH groups lead to an increase in the level of peroxy radicals which are the precursor species for light emission.
克氏锥虫前鞭毛体的化学发光自发发射率为133±5计数·秒⁻¹·（毫克蛋白）⁻¹。在相同细胞中测得的细胞内过氧化氢稳态浓度为1.5±0.5微摩尔。这两个值分别比分离的大鼠肝细胞的相应值高约12倍和15倍。通过抑制超氧化物歧化酶（添加二乙基二硫代氨基甲酸盐或氰化钾）以及添加两种能够进行细胞内氧化还原循环的不同杀锥虫剂（β-拉帕醌和硝呋替莫），超氧阴离子和过氧化氢的细胞内稳态浓度明显增加，并且在每种情况下均观察到化学发光增强。细胞内还原型非蛋白巯基减少80%会使克氏锥虫细胞的化学发光增加3倍。显然，超氧阴离子或过氧化氢的细胞内稳态浓度增加以及还原型巯基水平降低都会导致过氧自由基水平升高，而过氧自由基是发光的前体物质。
