Kampf G, Ritter J M
Department of Clinical Pharmacology, United Medical School, Guy's Hospital, London, United Kingdom.
Br J Clin Pharmacol. 1994 Jul;38(1):80-2. doi: 10.1111/j.1365-2125.1994.tb04326.x.
Glyceryl trinitrate is a weak inhibitor of platelet aggregation in vitro. Its effect on platelet aggregation in response to U46619 (a thromboxane/endoperoxide receptor agonist) was studied turbidometrically in platelet-rich plasma from healthy volunteers. The object was to determine whether inhibition was influenced by a period of preincubation between preparation of platelet-rich plasma and addition of glyceryl trinitrate. Incubation was performed at 37 degrees C and 22 degrees C. Samples were removed at intervals and transferred to an aggregometer cuvette at 37 degrees C. Glyceryl trinitrate (100 microM) or an equal volume of distilled water was added 5 min before U46619 (2 microM), and aggregation recorded as change in light transmission. Inhibition by glyceryl trinitrate was markedly time and temperature dependent, with a progressive increase in inhibitory potency between 120 and 300 min preincubation at 37 degrees C but not at 22 degrees C. The explanation of this is unknown but the effect was not influenced by lipopolysaccharide or by cycloheximide, so it does not appear to be due to exposure to endotoxin or to enzyme induction in vitro.
硝酸甘油在体外是血小板聚集的弱抑制剂。在来自健康志愿者的富血小板血浆中，采用比浊法研究了其对U46619（一种血栓素/内过氧化物受体激动剂）诱导的血小板聚集的影响。目的是确定在富血小板血浆制备与添加硝酸甘油之间的预孵育时间是否会影响抑制作用。孵育在37℃和22℃下进行。每隔一段时间取出样品，并转移至37℃的血小板聚集仪比色杯中。在加入U46619（2μM）前5分钟加入硝酸甘油（100μM）或等体积的蒸馏水，并将聚集记录为透光率的变化。硝酸甘油的抑制作用明显依赖时间和温度，在37℃预孵育120至300分钟之间抑制效力逐渐增加，但在22℃时则不然。其原因尚不清楚，但该效应不受脂多糖或环己酰亚胺的影响，因此似乎不是由于体外接触内毒素或酶诱导所致。
