Bosin T R
Pharmacology Section, Indiana University School of Medicine, Bloomington 47405.
Biochem Pharmacol. 1990 Aug 15;40(4):723-9. doi: 10.1016/0006-2952(90)90307-7.
The effect of H2O2 on the active transport of serotonin (5-HT) by human platelets was investigated. Platelets were exposed to either a single dose of H2O2 or to H2O2 generated by the glucose/glucose oxidase or xanthine/xanthine oxidase enzyme systems. H2O2 (12.5 to 100 microM) produced a rapid, concentration-dependent and time-dependent increase in 5-HT transport which was maximal after a 2-min incubation and decreased with continued incubation. Catalase (1000 units) completely prevented H2O2-induced stimulation, and fluoxetine (1 microM) totally blocked 5-HT uptake into stimulated platelets. The glucose/glucose oxidase (3.12 to 100 milliunits) and the xanthine/xanthine oxidase system, superoxide dismutase (250 units) failed to alter the stimulation, whereas catalase (1000 units) effectively prevented the response. The kinetics of 5-HT transport indicated that H2O2 treatment did not alter the Km of 5-HT transport (Km control = 1.0 +/- 0.2 x 10(-6) M vs Km H2O2 = 1.1 +/- 0.1 x 10(-6) M) but markedly increased the maximal rate of 5-HT transport (Vmax control = 131.4 +/- 4.6 pmol/10(8) platelets/4 min vs Vmax H2O2 = 206.7 +/- 9.1 pmol/10(8) platelets/4 min). These data demonstrated that exposure of human platelets to H2O2 resulted in a stimulation of the active transport of 5-HT and suggested that H2O2 may function to regulate this process.
研究了过氧化氢（H₂O₂）对人血小板中5-羟色胺（5-HT）主动转运的影响。血小板分别暴露于单剂量的H₂O₂或由葡萄糖/葡萄糖氧化酶或黄嘌呤/黄嘌呤氧化酶系统产生的H₂O₂中。H₂O₂（12.5至100微摩尔）使5-HT转运迅速增加，呈浓度和时间依赖性，孵育2分钟后达到最大值，继续孵育则下降。过氧化氢酶（1000单位）完全阻止了H₂O₂诱导的刺激，氟西汀（1微摩尔）完全阻断了5-HT摄取到受刺激的血小板中。葡萄糖/葡萄糖氧化酶（3.12至100毫单位）和黄嘌呤/黄嘌呤氧化酶系统、超氧化物歧化酶（250单位）未能改变这种刺激，而过氧化氢酶（1000单位）有效地阻止了这种反应。5-HT转运的动力学表明，H₂O₂处理并未改变5-HT转运的米氏常数（米氏常数对照组=1.0±0.2×10⁻⁶ M，H₂O₂组=1.1±0.1×10⁻⁶ M），但显著增加了5-HT转运的最大速率（最大速率对照组=131.4±4.6皮摩尔/10⁸个血小板/4分钟，H₂O₂组=206.7±9.1皮摩尔/10⁸个血小板/4分钟）。这些数据表明，人血小板暴露于H₂O₂会导致5-HT主动转运受到刺激，并提示H₂O₂可能在调节这一过程中发挥作用。
