Biolaser Endothelial Trauma as a Means of Quantifying Platelet Activity in vivo

Abstract

ALTHOUGH several methods of studying platelet behaviour in vitro have been described, there has not been a simple and precise technique for making quantitative studies. Useful measurements have been obtained by counting the platelet microemboli formed in response to injury caused by pinching exposed rabbit pial vessels with ophthalmic forceps¹. This method has been used in preliminary studies of drugs claimed to affect platelet adhesiveness^2,3. The degree of trauma, however, cannot be reproducibly controlled and, in addition, the animals must be anaesthetized. Trauma is inflicted during exposure of the pial vessels before the experiment, and afterwards the animal has to be killed. A more precise method involves the use of a microelectrode applied to the wall of a blood vessel in the cheek pouch of the hamster and the measurement in mA of the minimal stimulus required to induce a platelet thrombus^4,5. But reproducible application of the microelectrode is difficult and as with the pial vessel method the animals are anaesthetized, subjected to preliminary trauma and later killed.