Thermal Regulation of the Immune Response in South American Toads <em>Bufo marinus</em>.

Thermal regulation of the immune response was studied in toads following single injections of bacteriophage f2. The immune response was markedly inhibited in animals kept at 15&#176; as compared to the controls (25&#176;). The appearance of serum antibodies was delayed in animals kept at 15&#176; for the first post-immunization week but their peak antibody levels were similar to those in toads maintained at 25&#176; throughout. Transfer of animals from 25&#176; to 15&#176; 2 weeks after immunization only temporarily depressed the serum antibody levels but caused a marked delay in conversion from heavy to light antibodies. Our results are in keeping with the hypothesis that lowered environmental temperatures inhibit a variety of metabolic processes which may be concerned with the utilization of antigen and/or the synthesis of antibodies. [ABSTRACT FROM AUTHOR]