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Turbidimetry on Human Washed Platelets: The Effect of the Pannexin1-inhibitor Brilliant Blue FCF on Collagen-induced Aggregation
Published on: April 6, 2017
Collagen/endogenous thrombin-induced platelet aggregation in cord versus adult whole blood
Gerhard Cvirn1, Joerg Kutschera, Thomas Wagner
1Institute of Physiological Chemistry, Medical University of Graz, Graz, Austria. gerhard.cvirn@meduni-graz.at
Background:
In previous studies, neonatal platelets have been shown to be hypoaggregable to various agonists when compared with adult platelets.
Objectives:
It was the aim of this study to investigate the aggregability of neonatal versus adult platelets when the physiological relevant agonist collagen/endogenous thrombin is used.
Methods And Results:
Whole blood (WB) aggregation experiments employing the impedance method revealed the same responsiveness of neonatal and adult platelets to collagen/endogenous thrombin. Maximum aggregation (13.5 +/- 3.2 vs. 13.6 +/- 3.2 Omega; p = 0.94), slope (5.8 +/- 1.8 vs. 6.2 +/- 2.6 Omega/min; p = 0.79) and lag time until the onset of platelet aggregation (38.7 +/- 8.9 vs. 42.6 +/- 16.5 s; p = 0.59) were similar in cord and adult WB. However, the rise in serotonin plasma levels due to platelet activation was significantly lower in neonates versus adults (227.57 +/- 57.65 vs. 473.34 +/- 155.75 ng/ml; p = 0.0001). Furthermore, we found a fast capability of cord plasma to generate (the efficient platelet agonist) endogenous thrombin: thrombin generation started significantly earlier in cord compared with adult plasma (215 +/- 19 vs. 247 +/- 21 s; p = 0.01). Moreover, thrombelastometry revealed significantly shorter coagulation times in cord versus adult WB activated with collagen/endogenous thrombin (229.8 +/- 12.5 vs. 256.3 +/- 25.3 s; p = 0.003).
Conclusions:
The efficient platelet aggregation in cord WB provoked by collagen/endogenous thrombin might help to explain the clinically observed well-functioning primary hemostasis of neonates.
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