THE GROWTH-PROMOTING HORMONE 



ments in the diet, the rats of Anderson and Smith (1932) 

 were made to grow as rapidly as those of Bryan and Gaiser, 

 which received growth-promoting hormone in addition to the 

 better diet of Bryan and Gaiser. Even the injected rats of 

 Evans and Long (1921) weighed, on the average, 228 g. at an 

 age of 75 days, whereas the rats of Anderson and Smith 

 weighed 300 g. at an average age of 63 days.^ The male in- 

 jected rat of Evans and Simpson (Fig. 25) weighed 500 g. at 

 an age of 175 days; twelve normal rats of x'\nderson and 

 Smith weighed the same at an average age of 123 days. The 

 experiments with growth-promoting extract, therefore, do not 

 indicate the maximum possible growth-acceleration which 

 can be obtained. 



Gough and Silva (1933) found that the pars glandularis of 

 the ox contained 40-50 international units of antiscorbutic 

 vitamin (C) per gram of fresh tissue. They also studied the 

 reducing properties of the pituitary as well as other glands in 

 different animals by applying a solution of silver nitrate to 

 the fresh tissue. Their results suggested that the pars glandu- 

 laris might contain considerable amounts of ascorbic acid. 

 Later (1934), Gough concluded that the pars glandularis of 

 the ox is the richest known source of ascorbic acid — contain- 

 ing even more than the adrenal cortex or the corpus luteum 

 (pig). From a study of the reduction of silver nitrate by the' 

 anterior lobe tissue of human hypophyses, he concluded that 

 the concentration of ascorbic acid in the pars glandularis is 

 greater in young than in aged individuals, and is low (or al- 

 most nil) in individuals dying in an emaciated condition after 

 a long illness. From their study, using Tillmanns' technique, 

 Giroud and others (1934-35) found that the pars glandularis 

 (ox) contained the largest amount of ascorbic acid (1.65 mg. 



' In this comparison, account must be taken of three facts: Anderson and 

 Smith used only male rats which naturally grow larger and for a longer period than 

 females; Evans and Long used female rats which, however, respond to the growth- 

 promoting hormone better than males; the rats were not of the same race. 



[95] 



