THE INFLUENCE OF THE ENDOCRINE ORGANS 

 ON INTESTINAL ABSORPTION 



SEVERAL OF THE glaiids ol internal secretion inlluence intestinal absoi ption. 

 In table i are recorded the rates of absorption for dextrose in female rats 

 subjected to removal of the thyroid, the adrenals, the hypophysis, or the ova- 

 ries. These data were obtained by experiments on young rats weighing be- 

 tween 1 50 and 250 gm. which, after they had been fasted for twenty-four hours 

 to clear their intestines, were given by stomach tube known amounts of various 



TABLE 1 



Intestinal Absorption of Dextrose in Female Rats Following Removal of 

 Thyroid, Adrenals, Ovaries, or Hypophysis 



Experimental conditions 



iNormal 



Thyroidectomized. . 

 Adrenalectomized. . 



Spayed 



Hypophysectomized . 



* Standard deviation. 



substances. After a certain period of time, the residue in the digestive tract was 

 determined and the amount absorbed per 100 gm. of weight Avas calculated. 



After it had been ascertained that a particvdar endocrine organ plays a part 

 in intestinal absorption, experiments were devised in an attempt to determine 

 the mechanism of its action. Our findings are set forth under the headings of 

 the various endocrine organs. 



The Thyroid Gland. It has been shown by us that intestinal absorption of 

 dextrose not only is decreased by thyroidectomy in rats but also is increased 

 l)y administration of thyroxin to normal animals.' Therefore the effect of the 

 thyroid gland on absorption of various substances was studied in rats rendered 

 hyperthyroid by daily injections of doses of thyroxin that increased the basal 

 metabolic rate to approximately 50 per cent plus. 



The data in table 2 show that administration of thyroid hormone increases 

 the intestinal absorption of dextrose, galactose, starch, and oleic acid. These 

 substances enjoy preferential absorption through a chenii( ;il mechanism in the 

 intestinal mucosa and are susceptible to phosphorylation. Administration of 

 thyroid hormone does not increase the absorj)ti()n of xylose, alanin, calcium 

 lactate or thiamine chloride-substances which are absorbed by simple diffu- 

 sion and which are incapable of phosphorylation. These experiments indicate 

 that the thvroid gland influences absorption not by increasing the permeability 



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