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Physiology. — "A method to extract enzymes and pro-enzymes from 

 the mucous membrane of the digestive tube and to establish 

 the topic, distribution of them." By Prof. H. J, Hamburger. 



I. Introduction ; principle op the method. 



The method applied as yet to extract enzymes and pro-enzymes 

 from the mucous membranes of the stomach and the intestines consists 

 in preparing the mucous membrane and extracting it in a fine state 

 of division, with or without the addition of antiseptics; by repeated 

 precipitation and dissolution the body to be examined is finally 

 obtained in a more or less pure slate. If we wish to be informed 

 as to the distribution of the enzyme over the various parts of the 

 mucous membrane, in other words to establish the topic distribution 

 of it, extracts are made of equal weights or of equal surfaces, and 

 of these the specific action is determined quantitatively. 



It need hardly be said that these methods are rather complicated 

 and lengthy as well. A great drawback more especially is, that in 

 extracting, the enzyme is polluted with so many other substances of 

 the mucous membrane. 



Now, we have occupied ourselves for some time with the question 

 by what force enzymes (pro-enzymes) are brought to the surface of 

 the mucous membrane, and more especially tried to determine whether 

 we have to do with kataphoresis, in other words whether in normal 

 life enzymes (pro-enzymes) are carried along by the electric current 

 arising when the secretory nerve fibres are stimulated in the natural 

 way. ') We will not dwell on the results of these investigations 

 now. Let us only observe here that the method consisted in laying 

 on the mucous membrane a small column of solidified agar-agar, 

 into which a platinum electrode had been melted ; then it was in- 

 vestigated whether under the influence of a weak electric current, 

 moving from the muscular side of the mucous membrane, to the 

 free surface of it, enzyme or pro-enzyme passed from the epithelium 

 cells into the agar agar. 



That, if the enzyme or pro-enzyme was indeed moved by kata- 

 phoresis it would also pass into the agar-agar, we had a reason to 

 expect after the investigations of Graham'), Voigtlander 3 ) and others 



') Hamburger. Onmotischer Druck u. lonenlebre. Bd. II. S. 433 ff. 

 2 ) Graham, Liebig's Annalen 121, 1862 S. 1. 

 8) Voigtlander, Zeitschr. f. physik. Chemie. 3, 1889 S. 316. 

 For the literature on this subject compare, Cohen, Vortrage für Aerzte über 

 Physikalische Chemie 2e Aufl. 1907 S. 128. 



