ABSORPTION 357 



act in the same wa}^ as the admmistration of large 

 doses of adrenalin. It is probable that two elements are 

 involved — (a) the stimulation of the suprarenals, and (6) 

 the stimulation of the branches of the splanchnic nerves 

 to the liver and that the latter action is merely facilitated 

 or activated by the former, since the accumulation of 

 adrenalin in the blood found in puncture diabetes is not 

 sufficient in itself to cause the glycosuria, and since M'Leod 

 found that section of the hepatic nerves generally prevents 

 its onset (fig. 160). 



4>. The injection of phloridzin and some other substances 

 such as chrome salts, or even solutions of neutral sodium 

 salts, also causes sugar to appear in the urine. Under the 

 influence of these, the sugar in the blood is not increased. 

 It must be concluded that they act by causing the kidneys 

 to excrete glucose too rapidly, so that it is not available for 

 the tissues. But, even when carbohvdrates are withheld or 

 cleared out of the body, phloridzin causes glycosuria. Hence, 

 a formation of glucose from the proteins of the blood plasma 

 must occur (fig. 160). 



5. Removal of the pancreas also causes glyciemia and 

 glycosuria. This may be prevented by transplanting a 

 piece of the pancreas under the skin if the graft grows 

 (p. 601). The pancreas forms something which (i) checks 

 the conversion of glycogen to glucose in the liver, so that, 

 when it is removed, this process goes on too rapidly. (ii) At 

 the same time the utilisation of sugar by the muscles seems 

 to be interfered with. This failure to use sugars is indicated 

 by the fact that the respiratory quotient (p. 258) is low in 

 diabetes, indicating that proteins and fats are being used 

 and not carbohydrates, and that it is not raised when sugar 

 is administered. The carbohydrates of the food are no 

 longer available as a source of energy, and the animal has 

 to use proteins and fats alone. 



(i) But the part of the j^roteins which is normally used 

 as a source of energy is the non-nitrogenous, and this is not 

 available and is simply excreted as sugar. Hence, although 

 the animal decomposes its proteins, the non-nitrogenous 

 part is lost as sugar, and energy is not got from them. 



