TRAPANI 



O CONTROLS 



• GOLD-EXPOSED 



4 8 12 16 20 24 28 32 36 40 44 48 52 



TIME (WEEKS) 



Figure 1. Circulating antibody levels in rabbits immunized with BSA plus Freund's 

 adjuvent (10 mg BSA per kg body wt) at time zero. The cold exposed group, kept at an 

 environmental temperature of -15° C, was progressively clipped during the first 8 weeks 

 and immunized after a 10-week exposure, 



of circulating antibody in the cold exposed group was approximately 

 50 per cent of that in the control group. 



If these data alone are considered, it would appear that the cold 

 exposed animal does not synthesize antibody as well as the non- 

 exposed animal. However, it must be remembered that curves of 

 this type represent not only antibody production, but also antibody 

 decay. Thus, part of the difference maybe attributed to an increase 

 in protein degradation, as inferred from passive antibody decay 

 studies. 



Since cold exposed animals have been shown to have increased 

 thyroid activity, it seemed important to investigate the activity of 

 the thyroid gland on the immune response. Studies were based on 

 the a priori assumption that hj^Der activity of the thyroid contributed 

 to the immune response of cold exposed animals. The interesting 

 and complicating fact is that eventhough the assumption may be va- 

 lid, the experimental observations did not answer completely our 

 questions. 



92 



