THE EFFECTS OF BCG, CYCLOPHOSPHAMIDE AND X-RADIATION ON RETICULOENDOTHELIAL SYSTEM AND IMMUNE RESPONSIVENESS IN MICE (PART 1)

Abstract

The effects of BCG and X-radiation of sublethal dose on reticuloendothelial system (RES) were studied in mice. An attempt was also made to evaluate the action of BCG on the recovery of immune responsiveness in irradiated mice.
1) Carbon clearance test and measurement of spread macrophage in peritoneal cells were used to assay the function of RES. The result of carbon clearance was in good accordance with the one of macrophage spreading test.
2) Either intracutaneous or intravenous route of BCG administration increased the activity of RES. The functional levels of RES reached a maximum 3 to 5 weeks after BCG inoculation. When BCG was given intravenously, the highly increased level of phagocytic activity was obtained even one week after BCG injection.
3) Whereas X-radiation of sublethal dose caused a marked reduction of the number of peritoneal cells, the decrease of RES activity was not found. Although X-radiation suppressed markedly the immune response to sheep red blood cells (SRBC), delayed type reactivity recovered quickly to a normal level. The production of plaque forming cells (PFC) in spleen also recovered within 2 weeks after X-radiation and thereafter increased rather, while PFC in the draining lymph node reduced markedly and its recovery was protracted. BCG inoculation in X-radiated mice could not increase the number of peritoneal cells while it increased the activity of RES and the immune responsiveness to SRBC.
4) BCG inoculation made mice extremely susceptible to pseudomonas infection either 2 to 3 weeks after i. v. inoculation or 5 weeks after i. c. inoculation. But a marked resistance than normal controls was found 10 weeks after the i. c. inoculation of BCG. On the other hand, X-radiation caused a serious damage to protective activity against pseudomonas infection and no increase of resistance throughout experimental period.