Klinge Jens M, Topf Hans-Georg, Trusen Burkhardt, Rauh Manfred, Rascher Wolfgang, Dötsch Jörg
Klinik mit Poliklinik für Kinder und Jugendliche, University of Erlangen-Nuremberg, Germany.
Crit Care Med. 2003 Jul;31(7):2010-4. doi: 10.1097/01.CCM.0000069339.42383.16.
To investigate the role of endothelial cyclooxygenase in the antiaggregatory effect of nitric oxide, and to investigate the significance of the time span between contact of nitric oxide and platelets and laboratory evaluation by platelet aggregation.
Prospective, controlled, in vitro study.
Research laboratory of a university hospital.
Three healthy volunteers.
Incubation of platelets with different concentrations (30 microM, 100 microM, 500 microM, 1000 microM) of the nitric oxide-donor S-nitroso-N-acetyl-d,l-penicillamine (SNAP) for varying incubation times (0 hrs, 1 hr, 2 hrs, 4 hrs) with and without endothelial cells. Induction of platelet aggregation with adenosine diphosphate. Inhibition of the effect of SNAP by 100 microM of the guanylate cyclase inhibitor 1H-(1,2,4)oxadiazolo(4,3-a)quinoxalin-1-one (ODQ). Inhibition of prostacyclin production by endothelial cells with COX inhibitors acetyl salicylic acid (1 mM) and indomethacin (10 microM).
Incubation with endothelial cells (= controls) had no effect on platelet aggregation. Platelet aggregation was significantly inhibited by all concentrations of SNAP. Time course studies with 30 microM of SNAP showed an inhibitory effect only after 0, 1, and 2 hrs of incubation, whereas after 4 hrs of incubation the inhibition of platelet aggregation could not be detected any more. Endothelial cells significantly increased the inhibitory effect of SNAP after 1 and 2 hrs of incubation. Incubation with ODQ with and without endothelial cells reversed the SNAP-mediated inhibition of maximum platelet aggregation regardless of the incubation time. Pretreatment of the endothelial cells with the COX inhibitors acetyl salicylic acid and indomethacin blocked the increased inhibitory effect of the endothelial cells after 1 and 2 hrs of incubation.
The time span between nitric oxide contact with platelets and induction of platelet aggregation by adenosine 5'-diphosphate is important for correct estimation of the antiaggregatory effect of nitric oxide. Endothelial cyclooxygenase plays an important role in the nitric oxide-mediated inhibition of platelet aggregation.
研究内皮细胞环氧化酶在一氧化氮抗聚集作用中的作用，以及一氧化氮与血小板接触时间和通过血小板聚集进行实验室评估之间时间跨度的意义。
前瞻性、对照、体外研究。
大学医院研究实验室。
三名健康志愿者。
在有无内皮细胞的情况下，将血小板与不同浓度（30微摩尔、100微摩尔、500微摩尔、1000微摩尔）的一氧化氮供体S-亚硝基-N-乙酰-d，l-青霉胺（SNAP）孵育不同时间（0小时、1小时、2小时、4小时）。用二磷酸腺苷诱导血小板聚集。用100微摩尔鸟苷酸环化酶抑制剂1H-（1,2,4）恶二唑并（4,3-a）喹喔啉-1-酮（ODQ）抑制SNAP的作用。用环氧化酶抑制剂乙酰水杨酸（1毫摩尔）和吲哚美辛（10微摩尔）抑制内皮细胞产生前列环素。
与内皮细胞共孵育（=对照）对血小板聚集无影响。所有浓度的SNAP均显著抑制血小板聚集。用30微摩尔SNAP进行的时间进程研究显示，仅在孵育0、1和2小时后有抑制作用，而孵育4小时后未检测到对血小板聚集的抑制作用。孵育1和2小时后，内皮细胞显著增强了SNAP的抑制作用。无论孵育时间如何，用ODQ孵育有无内皮细胞均能逆转SNAP介导的对最大血小板聚集的抑制作用。用环氧化酶抑制剂乙酰水杨酸和吲哚美辛预处理内皮细胞可阻断孵育1和2小时后内皮细胞增强的抑制作用。
一氧化氮与血小板接触时间和二磷酸腺苷诱导血小板聚集之间的时间跨度对于正确评估一氧化氮的抗聚集作用很重要。内皮细胞环氧化酶在一氧化氮介导的血小板聚集抑制中起重要作用。
