Thrombocytosis-Promoting Activity of Normal Plasma. ∗

Abstract

Summary

Filtrates of normal human plasma that had been boiled for 30 minutes were administered by gastric tube to groups of normal rats. Ten daily doses each equivalent to 2 ml of the original plasma per 100 g body weight induced a 30% increase in the recipients'thrombocyte counts. Smaller doses, i.e., 0.5 or 1 ml per 100 g body weight, did not promote thrombocytosis. All other hematologic measurements in these animals remained stable. These findings provide additional support for the hypothesis that thrombopoiesis is subject to humoral regulatory control.