T 



INTERNAL SECRETION 499 



his secretion diminishes temporarily the normal toleration or assimilation 

 i sugar and in some unknown way leads to a hyperglycemia and glycosuria. 1 

 "f the customary amount of sugar is ingested a portion of it will be eliminated 



n the urine. 



If the posterior lobe with its epithelial investment is totally removec 

 )r if the infundibular stalk is compressed by a clip so as to prevent the dis- 

 -harge of the secretion into the ventricle the animal becomes very tolerant of 

 jugar and is enabled to assimilate larger quantities than formerly without 

 :he development of alimentary glycosuria. As a probable result of the in- 

 Teased carbohydrate assimilation, a condition of nutrition is established, 

 Characterized by a general deposition of fat suggesting a conversion of the 

 sugar into fat. There is probably at the same time an imperfect oxidation 

 of the carbohydrates as indicated by the lowered temperature. 



That the condition of generalized adiposity is probably due to deficient 

 posterior lobe secretion is shown by the fact that the increased tolerance for 

 sugar can be lowered very promptly by the coincident intravenous or sub- 

 cutaneous injection of extracts of the posterior lobe. 



From the foregoing facts it may be assumed that the secretion ot 

 posterior lobe in some unknown way influences the metabolism of sugar. 

 From the facts at hand it may be assumed that a hypersecretion from any 

 cause whatever, leads to a diminished tolerance for or assimilation of sugar, 

 as shown by the hyperglycemia and glycosuria, though the manner in which 

 the hyperglycemia is developed, whether by a more rapid conversion < 

 elycogen to sugar or by an inefficient storage of sugar as glycogen is unknown. 

 A hyposecretion from any cause leads to an increased tolerance for or 

 assimilation of sugar which eventually contributes to the formation and 

 deposition of fat. In the complexus of symptoms that accompany patho- 

 logic changes in the hypophysis either in the anterior or posterior lobe i 

 difficult to indicate those which are to be attributed to increased or '****"* 

 secretion of either the anterior or posterior lobe by reason of their close 

 juxtaposition and their possible simultaneous involvement; again it is ate 

 uncertain as to whether the secretions produce their effects alone or through 

 the cooperation of the secretions of other organs having more or less influ- 

 ence in the metabolism of the carbohydrates. 



The Effects of Injections of Extracts.-The extracts of the anterior 

 lobe when intravenously injected appear to be without "W^J^ 

 on any of the physiologic mechanisms. Injections of the extracts of 

 posterior lobe, however, give rise very promptly as shown by Howel o an 

 increase in the blood-pressure which appears to be due to an men 

 *5 of the arterLle muscle rather than to a 

 motor centers, as the contraction takes place even after 

 spinal cord and medulla oblongata. The action of 

 of the extract eral as 



normal tolerance for cane-sugar in te 



urine 



. 



indkafng iaf te assimilation limit has been exceeded 



