The Rôle of the Reticulo‐endothelial System in the Ripening of Reticulocytes.

Abstract

Summary. We briefly describe a method of estimating the amount of reticulocyte ripening principle, present in liver extracts and in plasma. Unlike liver extracts the reticulocyte ripening principle in plasma cannot be further activated by tyrosine. The treatment of plasma with acetone for example transforms the ripening principle into a state in which it can be activated. By means of splenectomy and the intravenous injection of trypan blue we blocked the reticulo‐endothelial system in rabbits. The effect of the blocking was controlled by a modification of the Congo red method, the colour of the plasma being measured in the Pulfrich photometer. After blocking the reticulo‐endothelial system the amount of the ripening principle in plasma first decreases considerably and then increases slowly, following closely the recovery of the reticuloendothelial system. The diminislied quantity of ripening substance can be activated by tyrosine and this obtaining the same effect as before the blocking of the reticulo‐endothelial system. These findings make it seem probable that tyrosine and an unknown substance are linked together in the reticulo‐endothehal system and thus form the reticulocyte ripening principle found in plasma.