An analysis of the platelet and polyploid megakaryocyte response to acute thrombocytopenia and its biological implications.

Thrombocytopenia was induced in rabbit by a single injection of anti-platelet serum. The circulating platelet number and concomitant mean platelet volume were measured 6 h after the injection and daily thereafter. The megakaryocyte nuclear DNA content was measured in control rabbits and after 2 h and 24 h of thrombocytopenia respectively. The observed recovery of circulating platelet number is used to construct the variation of platelet destruction rate and platelet production rate with time during thrombocytopenia. The observed rebound thrombocytosis is explained by using a balance equation of these two rates. Platelet production is linked to the megakaryocyte by physical fragmentation theory and an explanation of the observed variation of mean platelet volume is used to obtain an estimated bleeding time and circulating platelet biomass during recovery from thrombocytopenia. An interpretation is given of the homeostatic control of megakaryocytopoiesis and thrombopoiesis.