[[Intercellular information flow in the process of immunogenesis. VII. The effect of low- and high-polymer immune nuclear RNA on antibody synthesis by the cells of rat transplantable]U].

Rats were immunized with sheep red cells. From their spleen tissue 4S and 26S electrophoretically homogenous RNA fractions were extracted. Effects of these RNA fractions on the hemolysin synthesis were studied in cells of rat transplantable lymphosarcoma in the presense of actinomycin D (AD). The time intervals between the introduction if RNA into the lymphosarcoma cells suspension and the addition of AD were different. The duration of the period within which no synthesis of antibodies occurred was determined, this period being termed the AD-dependent period in induction of antibody synthesis. AD being introduced later (after the end of this period) failed to exert its inhibiting action. With highmolecular (26S) RNA, the AD-dependent period was somewhat shorter as compared with the lowmolecular (4S) RNA. This difference is suggested to be due, presumably, to different mechanism of action of both the RNA fractions on recipient cells.