ANTIBODY FORMATION 

 DISCUSSION 



BERRY: I am very much interested in this report. Dr. Tra- 

 pani, and would like to point out some of the effects of exposure 

 to a simulated altitude higher than yours; that is, 20,000 feet. 

 One of the things that we have noticed is that mice show an in- 

 crease in urinary nitrogen excretion. By inference, this would 

 suggest that protein catabolism is increased. If one attains 

 an elevation in nitrogen excretion, this says that the animal 

 is breaking protein down fast. We find it in mice that have been 

 exposed to simulated 20,000 feet for as long as a month, and 

 these animals are about as fully acclimated, as judged by their 

 general metabolism responses as any animals that we have 

 studied. We have kept them for as long as three months, and 

 we can find no difference in animals kept for three months at 

 simulated 20,000 feet than those kept for three or four weeks. 

 We can also get this elevated urinary nitrogen excretion in 

 animals that have been exposed for one day at 1000 feet; and I 

 don't know what this means. This is a very bewildering thing 

 to us, 



I wonder if in any of these rabbits urinary nitrogen excretion 

 was determined? 



TRAPANI: No. I would suspect that almost any stress im- 

 posed on the animal would charge its urinary nitrogen excretion. 

 If an animal is put in a cage which is wired with electrical cur- 

 rent which goes on and off at intervals, I imagine this sort of 

 a stress might influence nitrogen excretion. Experiments that 

 you just mentioned are somewhat similar to those done by Mefford 

 and Hale^ in which the metabolic interrelationships of cold, 

 heat, and altitude were studied. One of their points, of course, 

 is that there is an increase in nitrogen excretion. 



BERRY: What produces the increase in nitrogen excretion. 



1 Am. J. Physiol. 193: 443. 1958. 



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