248 Hypophysial Diabetes 



uted to the absence of the posterior lobe because it was observed that they 

 appeared in dogs in which that lobe had been removed and because the in- 

 jection of posterior-lobe extracts decreases the sugar tolerance of normal and 

 hypophysectomized dogs. 



Weed, Gushing and Jacobson" assumed that the hypophysis secreted a glyco- 

 genolytic and glycosuric hormone which was liberated by the action of nervous 

 stimuli sent by the superior cervical ganglion. But in 1930 Gushing" was in- 

 clined to attribute these effects to the action of the hypothalamus: "Our find- 

 ings may be capable of other interpretations now that attention has been 

 drawn to the importance of the hypothalamic region whence possibly our 

 glycogenolytic responses originated rather than in the hypophysis itself." 



2. After 1924, the Hypersensitivity of Hypophysectomized Animals to In- 

 sulin. After the discovery of insulin in 1922 it was prepared in Buenos Aires 

 early in 1923 by Dr. Sordelli and we formed a team for studying its metabolic 

 action and also its effects on the chemistry of blood and milk in different 

 species, its antagonistic or coadjuvant action with different substances, and 

 especially the influence of removing endocrine glands as well as the role of 

 the nervous system, etc. A review on the latter subjects was published in 

 Endocrinology in 1925 by Houssay.^" 



In 1923 the action of insulin in thyroidectomized (Ducheneau^^) and adre- 

 nalectomized (Lewis and Magenta") animals was studied in our Institute. 



Houssay and Magenta^^ published in 1924 experiments showing the striking 

 hypersensitivity of hypophysectomized dogs to insulin. These studies were 

 extended in 1927^* and in 1929." In 1924 the great sensitivity to insulin was 

 found in the toad after removal of the entire hypophysis or of the anterior 

 lobe (Houssay, Mazzocco and Rietti'*). Three years afterwards (1927) Ceiling, 

 Campbell and Ishikawa,^" confirmed our findings that hypophysectomized dogs 

 are more sensitive to insulin but wrongly attributed the hypersensitivity to 

 the absence of the posterior lobe. 



In 1927 Davidoff and Gushing"* wrote: "An experimentally induced hyper- 

 glycemia, brought on by removal of a large portion of the pancreas, tended 

 to subside when a partial hypophysectomy was subsequently performed." 

 "If loss or diminution of the internal secretion of the pancreas robs the tissues 

 of their power of metabolizing carbohydrates, certainly loss or diminution of 

 the secretion of the hypophysial posterior lobe [sic] greatly enhances their 

 power in this respect." Two important points are mentioned in this para- 

 graph: 1st, the attenuation of pancreatic diabetes by hypophysectomy; 2d, the 

 possibility that the part played by the hypophysis might not belong to its 

 posterior lobe. Unfortunately the authors published no experimental details, 

 such as the amount of pancreas removed, etc. It is well known that the changes 

 produced by partial hypophysectomy or partial pancreatectomy are not per- 

 manent and often subside spontaneously and completely. Moreover these 

 studies were not properly completed by their authors and this is why they did 

 not carry a general conviction. 



