Abstract
In 1909 and the following years Lépine and Boulud1 asserted that besides the usual form of sugar, blood contains a latent form of glucose which does not reduce alkaline copper solutions, but after being set free by acid hydrolysis behaves as ordinary glucose, reduces copper, and is fermented by yeast. This “sucre virtuel” plays an important part in carbohydrate metabolism. They believed that glucose and “sucre virtuel” were readily converted into one another, and that free sugar before utilization had to be incorporated into the larger complex molecule. In the diabetic this elastic shift from one form to the other was impaired. Sugar disappearing during glycolysis they claim to have recovered as “sucre virtuel.” Lépine characterizes this sugar as glucose in combination with blood proteins in a glucoside linkage.
Lêpine's analytical method consisted of precipitation of the blood proteins by coagulation with Na2SO4 and heat. The coagulum was separated by filtration, washed and hydrolyzed by means of hydrofluoric acid in lead crucibles for from 22 to 30 hours. Each determination required 10 cc. portions of blood and the life of a rabbit. Few have tried to repeat Lépine's work, and those who have failed to confirm his observations and his theories have been entirely discredited.
During the early part of last year we observed that the blood of animals in extreme insulin hypoglycemia yielded, on heating in a water bath for 2 hours with N/2 HCl, a substance giving typical reduction of alkaline copper solutions, and which disappeared completely if incubated 24 hours with yeast.
Get full access to this article
View all access options for this article.