Summary
Intravenous injection of Phenylhydrazine into intact rabbits resulted in a thrombocytosis
of 1.85 fold and megathrombocytosis (large platelets) of 2.30 fold. Splenectomy markedly
impaired this response. The intravenous injection of red blood cell hemo-lysates gave
a response similar to that of Phenylhydrazine in both intact and splenec-tomized animals.
Basal data obtained from intact and splenectomized animals; as well as kinetic data
obtained following apparent splenic blockade secondary to Phenylhydrazine hemolysis
revealed the presence of a splenic platelet pool with preferential splenic sequestration
of megathrombocytes.
It is suggested that the thrombocytosis and absolute megathrombocytosis of hemolysis
is due to splenic blockade by red blood cell hemolysate.
