Jane A. Russell 



525 



trast to the small amounts of pituitary substance necessary; since in fasted 

 hypophysectomized rats treated with cortical extract there is still seen a rapid 

 rate of carbohydrate disappearance despite intense glyconeogenesis; and since 

 cortical extracts always cause liver-glycogen deposition rather than peripheral 

 storage of carbohydrate; it seems likely that different processes are affected by 

 the two hormones. It is possible that the cortical hormone affects glycogen 

 storage in the liver directly, and hence, when it is causing such deposition, 



TABLE 8 



Comparison of the Effects of Cortical and Anterior Piti 'itary Hormones 



ON THE Disposition of Fed Glucose in Hypophysectomized Rats 



(Four hours after feeding) 



prevents other forms of utilization. In agreement with this suggestion is the 

 fact that liver slices of adrenalectomized rabbits fail to form glycogen from 

 glucose at a normal rate.^° The anterior pituitary may then more directly 

 affect peripheral oxidation of carbohydrate. 



It has already been seen that in fasted hypophysectomized animals, the 

 effects of cortical hormone and of APE are different, that they are additive, 

 and that by combining the two types of therapy we are able to reproduce 

 normal conditions in the carbohydrate metabolism of these animals. If our 

 analysis of the factors affecting the metabolism of fed carbohydrate is correct, 

 we ought to be able to do the same thing in fed hypophysectomized rats. Here 

 the difference between the actions of APE and of cortical hormone is also clear, 

 the APE affecting muscle-glycogen deposition and the adrenal hormone the 

 liver glycogen (table 8). The experiment has not been carried out, but if the 

 two substances were given together, there ought to be obtained a fair approach 

 to the normal in the distribution of the fed carbohydrate. Since thyroxin does 

 not affect this distribution but does restore to normal the oxygen-consumption 

 and glucose-absorption rates, and since APE act as usual in the presence of 

 thyroxin in these animals, if all three types of therapy were given at the same 

 time, it should be possible to reconstitute the hypophysectomized rat in regard 

 to its metabolism of fed carbohydrate. 



