308 ISIDOR GREENWALD 



and through the formation of fat. The height of the sluice gates represents 

 the concentration of blood sugar at which the various reactions, or series of 

 reactions, occur. If, in addition, we assume that the electric power plant 

 can deliver all of its energy only if some power is supplied from the first 

 mill to operate accessory machinery, we have a picture of the possibilities 

 of disturbed glucose metabolism. 



In hyperthyroidism and similar conditions, little glycogen can be 

 formed because the sluice between the two ponds is set too high 

 (Cramer and Krause, Kuriyama) ; that is, too great a concentration 

 of glucose is required to bring about the reaction glucose glycogen. 

 The sugar supplied must be oxidized or go over the spillway. In hypo- 

 thyroidism, muscular dystrophy, most cases of dyspituitarism, etc. (Bene- 

 dict and Homans, Cushing(c), Geyelin, Janney, Goodheart and Isaacson, 

 McCrudden and Sargent (a)), the reservoir sluice is abnormally low, 

 and not sufficient glucose is supplied to mill A to operate it at capacity. 

 Added sugar does not go here to the same extent as normally, but is 

 diverted to the reservoir and to the electric power, or fat mill. Here it 

 may be used to furnish needed energy, which is used or else accumulated 

 in the batteries, perhaps to an excessive degree. 



In diabetes, the first mill sluice is set too high, or is choked, and 

 more sugar goes through the fat mill. If the sluice is raised sufficiently 

 high, some sugar goes over the spillway. This, in turn, may be raised and 

 furnish a greater head, or pressure, for the sugar mill. If the obstruction 

 in A is too great, not enough goes through it to operate the accessory 

 machinery in B and "acetone bodies" appear in the urine. 



Obesity might be of two kinds, one related to diabetes, due to deficient 

 sugar oxidation and probably accompanied by high blood sugar, the other 

 due to an abnormally low sluice to the fat mill, and accompanied by a low 

 blood sugar. This type would occur in hypothyroidism, dyspituitarism 

 and similar conditions. Similarly, unusual leanness might be due either 

 to a very high sluice to the fat mill or to a very low sluice to the sugar mill. 

 In the first case, the content of blood sugar would be high, as in hyper- 

 thyroidism, in the second it would be low, as in Addison's disease. 



The high blood sugar of nephritis might be due to raising of the 

 sluice to the sugar mill, or to the reservoir. 



It should follow from this hypothesis that, in obese persons, the in- 

 crease in metabolism following the ingestion of glucose should be less than 

 in those of normal weight. This has not yet been determined. Negative 

 results have been obtained with experiments made with mixed diets and 

 even, in Staehelin's(&) case, with a carbohydrate meal. But most of this 

 carbohydrate was starch. Glucose should be used in order to make the 

 difference more apparent, and the total metabolism during the period of 

 absorption should be determined. It should be remembered that only a 





