title: The influence of phase shift in the light-dark cycle on humoral immune responses of mice to sheep red blood cells and polyvinylpyrrolidone.
abstract: The influence of a phase shift in the light-dark cycle on humoral immune responses against sheep red blood cells (SRBC), a thymus-dependent antigen, and against polyvinylpyrrolidone (PVP), a thymus-independent antigen, was studied by using 180 BALB/c mice and 150 C3H/HeN mice. Significant suppression of the immune response to SRBC and the number of splenic plaque-forming cells (PFC) and hemagglutination (HA) titers was observed on days 5 and 6 after inversion of the light-dark cycle. On the other hand, the number of splenic PFC and HA titers in the blood against PVP were minimally suppressed by the phase shift in C3H/HeN mice, except for distortion of the rhythmicity. Corticosterone levels in the blood on days 5 and 6 after inversion were higher than those under a normal lighting regimen. The appearance of the high corticosterone level in the blood after the inversion almost concurred with the suppression of the immune response to SRBC. A decrease of the proportion of splenic T cells was also observed on day 6 after the inversion. These results show that a phase shift in the light-dark cycle provokes suppression of the immune response to SRBC, possibly through an increase of secretion of corticosterone after light-dark inversion, which induces a decrease of the proportion of T lymphocytes in the spleen.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000921:Antibody-Producing Cells; D000955:Antigens, T-Independent / Q000276:immunology; D001789:Blood Group Antigens / Q000276:immunology*; D002940:Circadian Rhythm; D003345:Corticosterone / Q000097:blood; D006462:Hemolytic Plaque Technique; D008027:Light; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008809:Mice, Inbred C3H; D011205:Povidone / Q000276:immunology*; D012756:Sheep; D013601:T-Lymphocytes
chemical_list: D000955:Antigens, T-Independent; D001789:Blood Group Antigens; D011205:Povidone; D003345:Corticosterone