pubmed-article:690475 | pubmed:abstractText | Physiological responses at different ambient temperatures and temperature-dependent changes in immune responsiveness are polymorphic. At 4 degrees C, the antigen elimination from the bodies of SJL and C57Bl/6 mice is accelerated. In SJL, but not in C57Bl/mice, the half-life of antigen elimination decreased between the ages of 3 and 11 weeks. Parental mice and their F1 hybrids showed a fall in rectal temperature, which was greatest in young animals. Hypothermia was greater in C57Bl/6 than in SJL and F1 hybrids; in 3 week old C57Bl/6 it resulted in high mortality. The response to aggregated human immunoglobulin (HGG) was evaluated by (a) the number of animals with detectable antibody, (b) the minimal dose of antigen eliciting detectable antibody, and (c) the mean titre of haemagglutinating antibody. SJL mice were more responsive than C57Bl/6 mice. Low antibody formation in the secondary response was dominant, i.e. the amount of antibody produced by (SJL X C57Bl/6)F1 mice was the same as that produced by the parental C57Bl/6 strain. In a primary response, the quantity of antibody varied with the age of the immunized animal; 18 week old mice responded to lower minimal doses of antigen and produced more haemagglutinating antibody than 3 week old animals. After a second injection with HGG, SJL but not C57Bl/6 mice produced more antibody when kept at 14 degrees C rather than at 22 degrees C or 30 degrees C, and produced the lowest antibody titres when kept at 4 degrees C. The relation between ambient temperature and the response of the SJL mice was dominant over that of the C57Bl/6strain. Primary differed from secondary responsiveness in that neither strain produced significantly lower titres when ambient temperature fell to 4 degrees C; only 18 week old SJL mice responded with a marginal decrease in peak antibody production. The described polymorphism may affect both the individual capacity to cope with low temperatures and the evolutionary adaptation of a species to climatic extremes. | lld:pubmed |