360 



CELLS, TISSUES, AND ORGANISMS 



protoplasm, or growth, the synthesis of protein occupies a position of 

 primal)- importance. 



As has been mentioned, the treatment of normal and hypophysec- 

 tomized animals with various preparations of growth hormone leads to 

 an accumulation of protein in the carcass which is greater than that in 

 the untreated, pair-fed controls. As might be expected from these 

 carcass analyses, the administration of growth hormone causes an in- 

 crease in nitrogen retention. This is illustrated in Figure 2 by an experi- 

 ment in which an immature, actively growing rhesus monkey was 

 placed on a nitrogen-balance regimen and the daily nitrogen balance 

 was determined during a preoperative control period, then after hy- 

 pophysectomy, and then during a course of growth-hormone adminis- 

 tration. This experiment further demonstrates the physiological ineflFec- 

 tiveness of bovine growth hormone in this species, as discussed above. 



The retention of nitrogen occasioned by growth-hormone treat- 

 ment is accompanied by a decrease in circulating non-protein nitrogen 

 (Li ct al., 1949) and free amino acids (Russell, 1953). That these 



o.eoor 



0.500 - 



>■ 0.400 



o 



a 



UJ 



z 



5 0.3001- 



« 0.200 



0.100 



MONKEY 57 



(<^-2.3Kg.) 



Figure 2. The mean daily nitrogen balance (±: S.E.) of an immature rhesus 

 monkey before and after hypophysectomy and during growth-hormone treat- 

 ment. (From Knobil et al, 1957). 



