[macleod-pendergast] glycogen 39 



portion of the auricle consisted of blood vessels and other non-muscular 

 tissue. Considering the ventricle alone, much more glycogen was 

 found in every case in the starved animals than in those that were 

 well fed. The least difference occurs in the case of two animals that 

 were both in very poor general condition. 



Taking the result as a whole, it is plain that glycogen is deposited 

 in the heart of rabbits and dogs during the. first three days of starvation 

 to an extent that is greater than when carbohydrate-rich food is being 

 ingested. This accumulation is particularly evident in the ventricle. 



2. The Skeletal muscles usually contain a higher percentage of 

 glycogen after feeding with carbohydrate-rich food than during starvation 

 and the difference is more evident in dogs than in rabbits. The observa- 

 tions were made on the same animals as were employed for those on 

 the heart and the results are given in the same order. In the case 

 of the rabbits red and pale muscles were separately investigated, the 

 soleus and semitendinosus being taken to represent red, and the 

 adductor magnus to represent pale muscle. In the case of the dogs, 

 the muscles used were the soleus and adductor magnus. 



Rabbits Fed—paXe muscle . 39, . 225, . 13G ; average, . 325 

 red muscle 0.27, 0.46, 0.396; average, 0.375 



Starved — pale muscle 0.23, 0.44, ; average, 0.335 



red muscle 0.34, 0.34, ; average, 0.340 



Only in the case of the red muscle is there uncertain evidence of a 

 higher percentage of glycogen due to feeding. It is of interest to note 

 that the average of all estimations for red muscle is 0.361 per cent, 

 (min. 0.27, max. 0.396) and for pale muscle, 0.329 per cent. (min. 

 0.225, max. 0.440). 



Dogs Fe^— 1.16, 0.98,* 0.735; average, 0.958 



5tort;gc/— 0.38, 0.436, 0.821; average, 0.546 



There is very decided evidence that starvation reduces the percentage 

 of glycogen, although the degree to which the reduction occurs is not 

 equal in different animals. It is possible that the variability depends 

 on the amount of glycogen remaining in the liver but unfortunately 

 this was not controlled in these observations. The average percentage 

 of glycogen in the muscles of the starved dogs is 0.549 (min. 0.38, 

 max. 0.821) which is above that for all the observed muscles of both 

 fed and starved rabbits. This difference between the two species 

 becomes very distinct in the case of fed animals. 



*See note on p. 38 

 —41 



