Department of Pediatrics, Medical University of Graz, Auenbruggerplatz 30, 8036 Graz, Austria.
Hamostaseologie. 2010 Nov;30 Suppl 1:S164-7.
Newborn platelets show hyposensitivity in vitro to many important agonists. However, sensitivity of platelets to these agonists is crucial for a functional clot formation. Nevertheless newborns have an excellent hemostasis. Hence, we examined levels of PAR1 thrombin receptor, GPIb-IX-V (CD42b), and Integrin αIIbβ3 in newborn and adult platelets using Western blot analysis. Materials, methods: Platelets of adult and cord blood were isolated, washed, and lysed. Protein samples were separated by SDS-PAGE and blotted on nitrocellulose membranes. Receptors were visualized using immunodetection and evaluated densitometrically. Statistical analysis was performed using SPSS 16.0.
We found significantly lower levels of PAR1-receptors and higher levels of CD42b in newborn platelets as compared to adult platelets. Levels of Integrin αIIbβ3 in newborn platelets were comparable to adult platelets.
A lower content of PAR1-receptors explains very well the hyposensitivity of cord platelets to thrombin. Higher levels of CD42b may additionally support the effect of larger more adhesive multimeric vWF in newborn plasma.
新生儿的血小板在体外对许多重要的激动剂表现出低敏感性。然而，血小板对这些激动剂的敏感性对于功能性血栓形成至关重要。尽管如此，新生儿的止血功能却非常出色。因此，我们使用 Western blot 分析检查了新生儿和成人血小板中 PAR1 凝血酶受体、GPIb-IX-V（CD42b）和整合素 αIIbβ3 的水平。
分离、洗涤并裂解成人和脐血血小板。用 SDS-PAGE 分离蛋白质样品，并将其印迹到硝酸纤维素膜上。使用免疫检测法检测受体，并进行密度测定。使用 SPSS 16.0 进行统计分析。
与成人血小板相比，我们发现新生儿血小板中的 PAR1 受体水平明显较低，而 CD42b 水平较高。新生儿血小板中整合素 αIIbβ3 的水平与成人血小板相当。
PAR1 受体含量较低很好地解释了脐带血小板对凝血酶的低敏感性。CD42b 水平较高可能还额外支持了新生儿血浆中更大、更具粘附性的多聚 vWF 的作用。
