The Diurnal Rhythms in Lymphocyte Counts and Antibody Formation in Chicks

Abstract

The diurnal variations of total lymphocyte counts, rates of B⁺ cells and sIg⁺ cells, number of IgM-PFC in the spleen and anti-GRBC and anti-BA antibody titers were studied in 6 to 12 week-old chicks. It was evident that total lymphocyte counts, rates of B⁺ cells and sIg⁺ cells in the peripheral blood, number of IgM-PFC and antibody titers had clear diurnal rhythms. The inverse fluctuation patterns were observed between diurnal variations of B⁺ sIg⁺ cells and B⁺ sIg^- cells in the blood, but the exact reason for this is not clear at present. There was a correspondence between the fluctuation pattern of lymphocyte count and those of IgM-PFC and antibody titers. This suggests that the circadian rhythm of antibody production of chicks is caused by the diurnal variation in the number of lymphocytes and antibody producing activity of lymphocytes.