Effect of heat and cold stress on humoral immunity in mice

To evaluate the influence of low and high environmental temperatures on primary response in humoral immunity in mice, four experiments using 108 Swiss outbred mice were conducted. Test mice were immunised with an intraperitoneal injection bf 5% suspension of SRBC and control group ones were injected with both SRBC and normal saline. Different groups of mice were exposed to heat or cold, as stressor either before or after immunisation. Stress regimens included four periods of 45 minutes exposure to heat (40+/-2C) or cold (4+/-2C) with 15 minutes intervals every day for one week. Antibody titers were determined using a microtiter hemagglutination assay. The results demonstrated a significant enhancement of antibody titer ill mice which were exposed to cold stress before (P<0.01) and after (P<0.05) immunisation as well as the heat stress before immunisation (P<0.05), while heat stress after immunisation decreased antibody titer significantly (P<0.05).