CAMPBELL 



California Institute of Technology, Dr. Irving and I continued this 

 work using rabbits. Dr. Trapani and Dr. Sutherland joined our team 

 there. 



At the Galifcrnia Institute, we found that when we kept the rab- 

 bits at about -20° C, their body temperature didn't go down, ant 

 therefore, one couldn't call them hypothermic animals. In order 

 to keep rabbits alive in a "naked" state, their hair must be re- 

 moved slowly. In our experiment, a strip the width of a safety 

 razor blade was removed about every three or four days over a 

 period of weeks until the rabbit was shaved. If the rabbit was 

 previously conditioned to -20° C for about two weeks, he would 

 survive and live happily at -20° C, while an unconditioned shaved 

 rabbit would die within 24 to 28 hours. We studied these conditioned 

 rabbits for antibody formation, half-life of antigen, and particularly 

 the half- life of antibodies. 



While in the Arctic, we also carried out a study of blood types, 

 including Rh, in several Eskimo villages. Following thiSj some 

 preliminary stuaies were made on lemmings. They turned out to be 

 very poor antibody formers, which indicates for the first time that 

 the metabolic state of the animal plays a very important role in 

 immune mechanisms. In the cold animal stored in a cold box, anti- 

 body disappeared very rapialy, which is probablj^ due to the rapid 

 protein turnover. In a normal rabbit, this process was about 1/3 as 

 fast. 



If we put antigen in the arctic ground squirrels about the be- 

 ginning of hibernation, it would be there at the end of hibernation 

 just before they became active, and the same thing was true with 

 passively transferred antibody. If either antigen or antibiXiy was 

 injected during the summertime when they were active, it wruL^ 

 disappear very rapidly. Rabbits were active in the coi<j ana their 

 metabolism was high; under these conditions the protein turned 

 over at a very fast rate. When antibody was injected, it rapidly 

 disappeared. Antigen behaves in somewhat the same way, although 

 little study has been made on this aspect as yet. 



These experiments brought to mind some survival studies in 

 Sonoma Pass that I heard about in which there occurrev^ a very 



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