Human polymorphonuclear leukocytes lack detectable nitric oxide synthase activity.
Human polymorphonuclear leukocytes lack detectable nitric oxide synthase activity.
复制标题
人多形核白细胞缺乏可检测的一氧化氮合酶活性。
DOI：
--
复制
发表时间：
1994
影响因子：
4.4
通讯作者：
Robert L. Danner
中科院分区：
文献类型：
--
作者：
Liang Yan;R. Vandivier;A. Suffredini;Robert L. Danner
一氧化氮调节中性粒细胞(PMN)功能，但人PMN是否表达一氧化氮合酶(NOS)活性仍存在争议。以人主动脉内皮细胞(HAECs)为对照，研究了人PMN中一氧化氮合酶的活性。从L-精氨酸到L-瓜氨酸的转换是一氧化氮合酶活性的一个相对特异的指标，在分离的血管内皮细胞中很容易测量和诱导，而所有L-精氨酸转换的90%可被一氧化氮合酶抑制剂L-氨基-L-精氨酸阻断。在分离的PMN中，L-精氨酸转化率较低，不受L-NAA的影响。此外，内毒素、IL-1β和干扰素-γ均不能诱导中性粒细胞的一氧化氮合酶活性。在全细胞实验中，人PMN的L-精氨酸总转化率明显低于人脐静脉内皮细胞(分别为3.38+/-0.21vs157.5+/-10.28pmol/h/10(6)细胞，p<；0.01)。在体外，内毒素、干扰素-γ、IL-1β或肿瘤坏死因子-α不能增加整个中性粒细胞的这一转化率，钙调素抑制剂W13也不能降低这一转化率。此外，从4名志愿者静脉注射前后分离出中性粒细胞。脂多糖(4 ng/kg)不增加L-精氨酸到L-瓜氨酸的转化率。人多形核细胞亚硝酸盐和硝酸盐的释放比人脐静脉内皮细胞低35倍，且不受L-NAA的抑制。这些数据表明人类中性粒细胞不表达一氧化氮合酶活性。
Nitric oxide regulates polymorphonuclear leukocyte (PMN) function, but whether or not human PMNs express nitric oxide synthase (NOS) activity is controversial. We studied NOS activity in human PMNs by using human aortic endothelial cells (HAECs) for comparison. The conversion of L-arginine to L-citrulline, a relatively specific measure of NOS activity, was easily measured and inducible in fractionated HAECs, and > 90% of all L-arginine conversion was blocked by the NOS inhibitor, N omega-amino-L-arginine (L-NAA). In fractionated PMNs, L-arginine conversion was low and was unaffected by L-NAA. In addition, NOS activity was not induced in PMNs by LPS, IL-1 beta, or IFN-gamma. In a whole-cell assay, total L-arginine conversion was much lower in human PMNs compared with HAECs (3.38 +/- 0.21 vs 157.5 +/- 10.28 pmol/h/10(6) cells, respectively; p < 0.01). This conversion in whole PMNs was not increased in vitro by LPS, IFN-gamma, IL-1 beta, or TNF-alpha nor decreased by W13, a calmodulin inhibitor. Furthermore, PMNs isolated from four volunteers before and after challenge with i.v. LPS (4 ng/kg) showed no increase in L-arginine to L-citrulline conversion. Nitrite and nitrate release from human PMNs was 35-fold lower than for HAECs and was not inhibited by L-NAA. These data suggest that human PMNs do not express NOS activity.