Jancinová Viera, Drábiková Katarína, Nosál' Radomír, Petríková Margita, Cíz Milan, Lojek Antonín, Danihelová Edita
Institute of Experimental Pharmacology, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04, Bratislava, Slovak Republic.
Thromb Res. 2003 Mar 15;109(5-6):293-8. doi: 10.1016/s0049-3848(03)00239-1.
Previously, we reported that human blood platelets significantly decreased the concentration of reactive oxygen species (chemiluminescence) produced by Ca(2+)-ionophore-stimulated neutrophils and that the reduction was partially mediated by serotonin liberated from platelets during their activation. The aim of the present study was to investigate whether platelet inhibition can occur independently of serotonin liberation and whether it can be pharmacologically enhanced.
Chemiluminescence was measured after stimulation of human neutrophils with N-formyl-L-methionyl-L-leucyl-L-phenylalanine (FMLP) in the presence of luminophore luminol. Concentration of platelet serotonin was estimated fluorometrically.
Platelets, added to neutrophils in the physiological cell ratio 50:1, decreased neutrophil chemiluminescence by 47%. The inhibition was not accompanied with liberation of platelet serotonin and rose after addition of chloroquine to platelet-neutrophil samples. In the absence of platelets, this drug did not affect neutrophil chemiluminescence. Chloroquine actively liberated serotonin; amine concentrations found in platelet supernatants were sufficient to inhibit neutrophil chemiluminescence.
The presented results indicate that unstimulated platelets decreased neutrophil chemiluminescence by a serotonin-independent mechanism, yet their inhibitory effect could be enhanced pharmacologically through chloroquine-induced serotonin liberation.
此前，我们报道过人类血小板可显著降低钙离子载体刺激的中性粒细胞产生的活性氧物质浓度（化学发光），且这种降低部分是由血小板激活过程中释放的血清素介导的。本研究的目的是调查血小板抑制是否能独立于血清素释放而发生，以及其是否能通过药理学方法增强。
在用发光体鲁米诺存在的情况下，用N-甲酰-L-蛋氨酰-L-亮氨酰-L-苯丙氨酸（FMLP）刺激人类中性粒细胞后测量化学发光。用荧光法估算血小板血清素的浓度。
以50:1的生理细胞比例将血小板添加到中性粒细胞中，可使中性粒细胞化学发光降低47%。这种抑制并未伴随着血小板血清素的释放，且在向血小板-中性粒细胞样本中添加氯喹后增强。在没有血小板的情况下，这种药物不影响中性粒细胞化学发光。氯喹可有效释放血清素；在血小板上清液中发现的胺浓度足以抑制中性粒细胞化学发光。
呈现的结果表明，未受刺激的血小板通过一种不依赖血清素的机制降低中性粒细胞化学发光，但其抑制作用可通过氯喹诱导的血清素释放而在药理学上增强。
