The Clearance Mechanism of Chilled Blood Platelets

The Clearance Mechanism of Chilled Blood Platelets

Platelet transfusion is a very common lifesaving medical procedure. Not widely known is the fact that platelets, unlike other blood cells, rapidly leave the circulation if refrigerated prior to transfusion. This peculiarity requires blood services to store platelets at room temperature, limiting platelet supplies for clinical needs. Here, we describe the mechanism of this clearance system, a lo...

Mechanism of shape change in chilled human platelets.

The so-called cold activation of platelets that precludes refrigeration of platelets for storage has long been recognized, but its mechanism has remained a mystery. Cooling of discoid resting platelets to temperatures below 15 degrees C causes shape distortions, and the chilled cells rewarmed to above 25 degrees C are spheres rather than discs. As platelet shape change responsive to receptor ac...

The Blood Platelets

The Histogenesis of Blood Platelets

1. Under normal circumstances blood platelets are largely derived from the megakaryocyte of the blood-forming organs. 2. The transitional leucocyte, representing a persistent form of the embryonic premegakaryocyte, is a circulating homologue of the megakaryocyte and probably plays some part in normal platelet formation. 3. Under conditions of excessive demand for platelet production, there may ...

The Enumeration of Blood Platelets.