Zhou Q, Hellermann G R, Solomonson L P
Department of Biochemistry and Molecular Biology, College of Medicine, University of South Florida, Tampa 33612.
Thromb Res. 1995 Jan 1;77(1):87-96. doi: 10.1016/0049-3848(95)90868-g.
In this study, we have investigated the release of nitric oxide from resting human platelets. Nitric oxide was detected and quantitated by either measuring the conversion of oxy-hemoglobin to met-hemoglobin or generation of nitrite and nitrate by the cells. Nitric oxide was released from both intact resting platelets and platelets activated by collagen. Nitric oxide release was proportional to platelet concentration, and was equivalent to approximately 4.5 +/- 0.6 pmol (or 2.8 +/- 0.3 pmol in the presence of prostaglandin I2) and 11.2 +/- 1.3 pmol nitric oxide released per minute per 10(8) cells at 37 degrees C for resting platelets and platelets activated by collagen, respectively. The generation of nitric oxide by resting platelets was linear with respect to time over a two hour period, while the release of nitric oxide from platelets following activation was transient and was linear for only the first 10 min, after which it slowed to completion at approximately 30 min. The release of nitric oxide was it slowed to completion at approximately 30 min. The release of nitric oxide was stimulated by L-arginine, but was inhibited by L-nitro-arginine methyl ester (L-NAME). The inhibitory effect of L-NAME could be reversed by addition of L-arginine. The release of nitric oxide from platelets was also partially inhibited by prostaglandin I2, prostaglandin E1, aspirin and EDTA. The amount of nitric oxide released from resting platelets compared with that released from endothelial cells suggests that platelet-derived nitric oxide may play a significant role in the maintenance of vascular tone and blood flow.
在本研究中，我们调查了静息人血小板中一氧化氮的释放情况。通过测量氧合血红蛋白向高铁血红蛋白的转化或细胞产生的亚硝酸盐和硝酸盐来检测和定量一氧化氮。一氧化氮从完整的静息血小板和经胶原激活的血小板中均有释放。一氧化氮的释放与血小板浓度成正比，在37℃时，静息血小板和经胶原激活的血小板每分钟每10⁸个细胞释放的一氧化氮分别约为4.5±0.6皮摩尔（在前列腺素I₂存在时为2.8±0.3皮摩尔）和11.2±1.3皮摩尔。静息血小板产生一氧化氮在两小时内随时间呈线性关系，而激活后血小板释放一氧化氮是短暂的，仅在最初10分钟呈线性，之后在约30分钟时减缓至释放完毕。一氧化氮的释放约在30分钟时减缓至释放完毕。L - 精氨酸刺激一氧化氮的释放，但L - 硝基精氨酸甲酯（L - NAME）抑制其释放。添加L - 精氨酸可逆转L - NAME的抑制作用。血小板释放一氧化氮也受到前列腺素I₂、前列腺素E₁、阿司匹林和乙二胺四乙酸（EDTA）的部分抑制。与内皮细胞释放的一氧化氮相比，静息血小板释放的一氧化氮量表明，血小板衍生的一氧化氮可能在维持血管张力和血流方面发挥重要作用。
