476 EMIL GOETSCH 



hypersensitive to the action of epinephrin. It is upon this fact that the 

 epinephrin l^ypersensitiveness test devised by Goetsch is based, and has 

 been recommended by him in the diagnosis of clinical states of hypo- 

 and hyper-thyroidism. Secondly, during the past twenty-five years 

 abundant evidence has accumulated to show that thyroid secretion has 

 an additional stimulating action upon metabolic processes causing, when 

 present in excessive amounts, increased metabolism and when pres- 

 ent in diminished amounts, decreased metabolism. It is due to these 

 facts that the determination of the metabolic rate may be used as an 

 index of the presence of an excessive or diminished amount of thyroid 

 secretion. Thirdly, thyroid secretion has a definite action upon the 

 mobilization of carbohydrates, particularly in the liver, and a retarding 

 action upon the combustion of sugar in the blood as a result of which 

 liyperglycemia follows when this secretion is present in increased amounts. 

 As a consequence the determination of blood sugar or, in other words, 

 the test for hypergiycemia has been used as corroborative evidence of an 

 increased or diminished thyroid activity. These three tests are at the 

 present time the most practical and the most helpful. 



It may bo advisable, however, to outline briefly the older tests of 

 historical interest which are occasionally still used, but which have not 

 proved to bo of very great practical help. They have, however, a con- 

 firmatory value. Of the three tests mentioned, the first two, namely, the 

 epinephrin hypersensitiveness test and the basal metabolism test are those 

 that have proved to be of definite clinical value, and have come into very 

 general use. The blood sugar determinations or hypergiycemia tests are 

 valuable but of no specific diagnostic importance in thyroid disorders since 

 carbohydrate metabolism is so closely related to the function of practically 

 all of the ductless glands and is disturbed in a relatively large number of 

 unrelated diseases. The action of thyroid secretion upon carbohydrates 

 is not specific to this secretion, hence the disturbance in carbohydrate 

 metabolism is not at all restricted to disorders of the thyroid. Fortunately 

 for the first test, we know of no other endocrin gland than the thyroid, 

 which has a significant stimulating action upon the sympathetic system. 

 In other words, this is a specific action characteristic of this gland. Thy- 

 roid intoxication, according to available evidence, is the commonest cause 

 of hyperirritability of the sympathetic system to the action of epinephrin, 

 although perhaps not the only cause. The hyperirritability of the sympa- 

 thetic to epinephrin in a few conditions other than thyroid intoxications 

 is characterized by a response different from that seen in hyperthyroidism, 

 thus aiding materially in the differentiation. Furthermore, in support of 

 the second test we have the fact that there is no gland which has such a 

 powerful stimulating action as the thyroid upon metabolism. The pituitary 

 gland possesses it in a much less degree and is not so apt to be confused in 

 its clinical disorders with the thyroid. 



