Enhanced mitogen-induced proliferation of rat splenocytes by low-dose whole-body X-irradiation.
To elucidate the stimulative effect on the immune system, we studied the effect of acute low-dose whole-body X-irradiation on the mitogen-induced proliferative responses of rat splenocytes and thymocytes. Concanavalin A (Con A)-induced mitogen response of rat splenocytes 4 hours after 5 cGy irradiation was significantly higher (by 80%, p < 0.02) than that in sham-irradiated controls; whereas that of rat thymocytes did not show change after irradiation of 1-10 cGy. In the rats X-irradiated with doses greater than 25 cGy, Con A-induced mitogen responses of splenocytes and thymocytes were reduced. In a way similar to the Con A-induced mitogen response of splenocytes, the mitogen response of splenocytes induced by phytohemagglutinin (PHA) or lipopolysaccharide (LPS) was significantly increased by X-irradiation with 5 cGy (by 50%, p < 0.02). The enhancement of mitogen response of splenocytes was observed within a few hours after irradiation, being a temporary effect. After 5 cGy irradiation the level of leukotriene B4 (LTB4) in the supernatant fraction of the splenocyte suspension showed a significant increase (by 40%, p < 0.05).
Ishii
K
K
Radiation Safety Group, Central Research Institute of Electric Power Industry, Tokyo, Japan.
Yamaoka
K
K
Hosoi
Y
Y
Ono
T
T
Sakamoto
K
K
D000818:Animals; D002478:Cells, Cultured; D003208:Concanavalin A; D004307:Dose-Response Relationship, Radiation; D007700:Kinetics; D007975:Leukotriene B4 / Q000032:analysis / Q000378:metabolism; D008070:Lipopolysaccharides / Q000494:pharmacology; D008213:Lymphocyte Activation / Q000528:radiation effects*; D008214:Lymphocytes / Q000187:drug effects / Q000276:immunology / Q000528:radiation effects*; D008297:Male; D010835:Phytohemagglutinins; D051381:Rats; D011916:Rats, Inbred F344; D013154:Spleen / Q000276:immunology; D013950:Thymus Gland / Q000276:immunology; D013997:Time Factors; D014916:Whole-Body Irradiation; D014965:X-Rays
D008070:Lipopolysaccharides; D010835:Phytohemagglutinins; D003208:Concanavalin A; D007975:Leukotriene B4