 In addition, the platelets of mice lacking TP receptors have similarly defective adhesion, aggregation, and degranulation responses and these TP deficient mice cannot form stable blood clots and in consequence exhibit bleeding tendencies.TP, as studies show, is part of a positive feedback loop that functions to promote platelet adhesion, aggregation, degranulation, and platelet-induced blood clotting-responses in vitro and in vivo.The platelet-directed functions of TP are in many respects opposite to those of the IP receptor.