Studies on the Incorporation of ³⁵S Labelled Cystine into the Leucocytes of Tumour Bearing Rats.

Abstract

Abstract. In order to study the influence of the development of a tumour on the leucopoiesis and on the life cycle of leucocytes, the incorporation of intraperitoneally administered 35S labelled cystine into the leucocytes of rats injected with Yoshida ascites sarcoma was investigated. The separation of leucocytes and the preparation of the samples were performed according to the method of Weisberger and Levine. Sulfur is incorporated in leucocyte proteins of rats injected with ascites tumour at a rate three times as high as in that of normal rats. The loss of 35S atoms from the leucocytes of tumour animals is more rapid, which suggests a shortening of the life span of W.B.C. due to the presence of the tumour. The striking similarity of these results with that obtained by Ehrenstein in the case of erythrocytes is emphasized. The possibility that the results obtained are due to the presence of tumour cells in the peripheral blood is discussed and ruled out.