Demonstration of a circulating factor regulating blood platelet production using 35S-sulfate in rats and mice.

Abstract

SummaryPlatelet counts and 35S-sulfate incorporation were studied in rats and mice following injection of saline or homologous plasma from normal or platelet-depleted animals, Donor rats were treated with antiplatelet serum 5–18 hr before sarcifice, and donor mice were injected with neuraminidase 40 hr before exsanguination. To prevent the injection of platelet antibody, the simulated and control plasmas were either boiled at acid pH for 10–15 min, or precipitated with goat antirabbit gamma globulin antiserum (GAGGA). The sulfate incorporation into platelets of animals given plasma from depleted donors was significantly increased over control values to levels as high as 116%. These data demonstrated the existence of thrombopoietin control over platelet production. The radiosulfate incorporation method appeared to be more sensitive than assays making use of platelet counts alone.