INFLUENCE OF WHOLE-BODY HYPERTHERMIA ON NATURAL CYTOTOXICITY OF LIVERBLOOD-BORNE SINUSOIDAL CELLS

Rat liver sinusoidal cytotoxic cells were examined after exposure to i n vivo and in vitro hyperthermia at 40-41-degrees-C. Whole-body hypert hermia lasting for 4 h caused a decrease in the cytotoxic activity of liver sinusoidal washout cells against YAC-1 and K562 cells. Surprisin gly, the percentage of washout cells with morphology of LGL (large gra nular lymphocyte) increased both in the liver washout and in portal bl ood compared to control normothermic animals. The proportions of pheno typically characterized cell subpopulations isolated from liver sinuso ids did not change. Elimination of i.v. injected I-125-labelled K562 c ells was decreased during hyperthermia. In vitro incubation of liver s inusoidal cytotoxic cells for 3 h at 41-degrees-C decreased their cyto toxic activity by affecting the process of effector-target cell bindin g. However, once the effector-target cell conjugates were formed, the cytotoxic process proceeded as in normothemiic conditions. These data suggest that inhibition of liver sinusoidal cytotoxic cell activity af ter hyperthermia may be a result of deficient target cell recognition by the effector cell.