Accession Number : AD0642778

Title :   STUDIES ON THE TRANSFER OF MYELOMA PROTEIN SYNTHESIS WITH RNA ISOLATED FROM THE C3H PLASMA CELL TUMOR (X5563). II. UPTAKE OF ISOTOPICALLY LABELED TUMOR RNA BY LYMPHOID CELLS,

Corporate Author : NAVAL RADIOLOGICAL DEFENSE LAB SAN FRANCISCO CALIF

Personal Author(s) : Chin,Paul H. ; Silverman,Myron S.

Report Date : 02 DEC 1966

Pagination or Media Count : 37

Abstract : Studies were carried out to establish the conditions necessary for increasing quantitatively the uptake of exogenous RNA by incubating dissociated lymphoid cells of C3H mice with H3-or P32-labeled RNA in vitro. The problem of adsorption of labeled RNA onto the surfaces of the cells was minimized by treatment of the cells with RNAse. The effects of RNA concentration, cell concentration and pretreatment of the lymphoid cells with protamine was investigated. In addition, attempts were made to identify the cell types involved. Uptake of exogenous RNA by normal lymphoid cells amounted to only 0.2% of the input RNA. Pretreatment of the cells with protamine sulfate, however, resulted in a twenty to thirty-fold enhancement in uptake. A further additional increase was observed when cells from mice injected with phytohemagglutinin were treated with the basic protein. Uptake by protamine-treated cells was very rapid and a nearly maximal amount was taken up after only 15 minutes of incubation. With a given RNA concentration, increasing the number of cells in the incubation mixture diminished the amount of RNA incorporated. Similarly, an inverse relationship was found between RNA concentration and uptake. Comparable amounts of RNA were taken up by lymph node and spleen cells and no difference was observed in the uptake of the different molecular species of RNA. Uptake by peritoneal cells, however, was marginal even after treatment with protamine. The cells primarily involved in the uptake of exogenous RNA appeared to be lymphoblasts. (Author)

Descriptors :   (*RIBONUCLEIC ACIDS, LYMPHOCYTES), LABELED SUBSTANCES, PROTAMINES, CELLS(BIOLOGY), AGGLUTININS, LYMPHATIC SYSTEM, SPLEEN, NEOPLASMS, PROTEINS, BIOSYNTHESIS

Subject Categories : Biochemistry
      Radiobiology

Distribution Statement : APPROVED FOR PUBLIC RELEASE