Mannaioni P F, Masini E, Pistelli A, Salvemini D, Vane J R
Department of Preclinical and Clinical Pharmacology, University of Florence, Italy.
Int J Tissue React. 1991;13(6):271-8.
Rat serosal mast cells (MCs, 85-90% pure), obtained from peritoneal washing of Wistar albino rats, produced a significant amount of superoxide anions (O2.-) as measured by the increase in absorbance due to the reduction of ferricytochrome c; they were also able to generate a nitric oxide (NO)-like factor, as measured by two bioassay systems: i) inhibition of platelet aggregation and ii) stimulation of MCs guanylate cyclase. Incubation of MCs with human washed platelets resulted in an inhibition of thrombin-induced platelet aggregation which was proportional to cell number. The inhibitory activity of MCs was potentiated by substances which preserve NO (superoxide dismutase, SOD), and reversed by compounds which inactivate NO (oxyhaemoglobin, oxyHb) or which inhibit its synthesis (NG-monomethyl-L-arginine, MeArg). Mechanical stimulation of MCs produced a time-dependent increase in the levels of their cGMP but not cAMP; this increase was enhanced by E. coli lipopolysaccharide (LPS). NO generators such as sodium nitroprusside (NaNp) also augmented the levels of cGMP in MCs. NaNp inhibited in a dose-dependent manner the release of histamine evoked by compound 48/80 (0.5 microgram/ml), but not by the O2.--generating system (xanthine-xanthine oxidase), suggesting a bidirectional regulation of histamine release afforded by O2.- and NO.
从Wistar白化大鼠腹腔灌洗获得的大鼠浆膜肥大细胞（MCs，纯度85 - 90%），通过因细胞色素c还原导致的吸光度增加来测量，能产生大量超氧阴离子（O2.-）；通过两种生物测定系统测量，它们还能够产生一种一氧化氮（NO）样因子：i）抑制血小板聚集和ii）刺激MCs鸟苷酸环化酶。将MCs与人洗涤后的血小板共同孵育会导致凝血酶诱导的血小板聚集受到抑制，这种抑制与细胞数量成正比。能保留NO的物质（超氧化物歧化酶，SOD）可增强MCs的抑制活性，而使NO失活的化合物（氧合血红蛋白，oxyHb）或抑制其合成的化合物（NG - 单甲基 - L - 精氨酸，MeArg）可逆转这种抑制活性。对MCs进行机械刺激会使其cGMP水平随时间增加，但cAMP水平无变化；大肠杆菌脂多糖（LPS）可增强这种增加。诸如硝普钠（NaNp）等NO生成剂也会增加MCs中cGMP的水平。NaNp以剂量依赖方式抑制由化合物48/80（0.5微克/毫升）诱发的组胺释放，但不抑制由O2.-生成系统（黄嘌呤 - 黄嘌呤氧化酶）诱发的组胺释放，这表明O2.-和NO对组胺释放具有双向调节作用。
