THE PITUITARY BODY 



were due to an increase in glycogenolysis (liver). The latest 

 period began with the observations of Houssay and Potick 

 (1929) and Houssay and Biasotti (1930) who showed, by 

 means of experiments in toads and dogs, that the pars 

 glandularis contains a substance (or substances) antagoniz- 

 ing the effect of insulin in hypophysectomized animals and 

 causing a recurrence of diabetic symptoms in animals which 

 were both pancreatectomized and hypophysectomized. 



A number of investigators have confirmed the earlier re- 

 port of Johns and his colleagues (1927) that the injection of 

 anterior pituitary extract may cause, in normal animals, 

 symptoms resembling those of diabetes mellitus.'^ The im- 

 portant changes, which may occur 2-6 days after injections 

 have been started, are a hyperglycemia (as high as 475 mg. 

 per cent), a glycosuria (the rabbit may excrete as much as 

 10-35 g- of glucose per day), and a reduced glucose tolerance. 

 Lipemia, ketonuria, polyuria, polydipsia, polyphagia, and 

 emaciation may also be present. Although injections are con- 

 tinued, the symptoms may persist for only a week, the blood- 

 sugar concentration then falling to a normal or slightly 

 subnormal level (Evans). Houssay, Biasotti, and Rietti ob- 

 served that the ease with which hyperglycemia and glycosuria 

 could be produced in different animals was as follows: cat > 

 dog > guinea pig > rabbit. They also produced similar changes 

 in the pigeon, rat, and mouse but not in the toad and snake. 

 A diet rich in carbohydrate facilitated the effect, particularly 

 in the dog. Similar changes were not produced by extracts 

 of other tissues (pars neuralis, thyroid, liver, spleen, kidney, 

 and skeletal muscle). 



Differing from other investigators whose work is discussed 

 later, Houssay, Biasotti, and Rietti concluded that extracts 

 were still diabetogenic in the absence of the adrenal medulla 



''•Houssay and Biasotti (1931); Baumann and Marine (1932); Evans and others 

 (1932-33); Houssay, Biasotti, and Rietti (1932, 1934); Gaebler, 1933 (observed no 

 change in carbohydrate metabolism; he mentions some of the negative results of 

 others); Houssay (1933); and Biasotti (1934). 



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