OXIDASES OR OXIDISING ENZYMES. 271 



organ. He ground up the pancreas, with aseptic pre- 

 cautions, immediately on removal from the body, and 

 macerated it for two to three hours at 38 C. in water con- 

 taining '2 per cent, of a mineral acid, and then neutralised 

 the extract with sodic hydrate. To 100 cc. of the liquid 

 resulting, he added half a gramme of glucose and digested 

 it for an hour at 38 C. In a series of such experiments he 

 found that there was a disappearance of sugar ranging from 

 10 to 50 per cent. A fresh pancreas similarly extracted 

 with water instead of dilute acid, yielded an extract with 

 very little power of causing destruction of sugar. Lepine 

 inferred that from the tissue he used a glycolytic enzyme 

 could be prepared just as similar treatment yields trypsin 

 from the same gland. 



He supported his hypothesis by an experiment, in which 

 he compared the glycolytic power of the blood leaving the 

 pancreas during active secretion with that possessed by it 

 when the gland was at rest. He found that during the 

 secretion caused by stimulation of the vagus, blood drawn 

 from the pancreatic vein possesses little glycolytic power, 

 but that the latter becomes considerable in the blood from 

 the same vein during the hours immediately following the 

 cessation of the secretion. 



The power of oxidation possessed by blood was examined 

 in 1894 by Abelous and Biarnes, who experimented on its 

 action on salicyl-aldehyde. This body is not oxidised to 

 salicylic acid by the air, nor by distilled water, nor by nor- 

 mal saline solution (a solution of sodium chloride, containing 

 •6 per cent, of the salt). But when defibrinated blood or 

 blood-serum is added to the_aldehyde and the mixture kept at 

 a temperature of T,y° C. the acid is formed. The oxidation 

 was found to vary in amount with the blood of different animals. 



These investigators attribute the action, as did Lepine, 

 to the presence of a specific enzyme, which they say is de- 

 stroyed by boiling. 



They found that besides blood, various tissues of the 

 body possess the same power, notably the testes, the thyroid 

 glands, the liver, kidneys, lungs and spleen. Only when 

 living however can they effect the destruction. 



