70 ENZYMES 



During experimental pneumococcus septicemia the indophenol oxidase reaction 

 is decreased in the tissues.** 



The nature of the granules that exhibit the stain is unknown, but as indophenol 

 blue is a good fat stain it is probable that the stained granules are lipoidal, and it 

 may well be that they are not the site of the oxidative action, but merely selectively 

 stained lipoids in cells capable of forming the indophenol blue. These so-called 

 "oxidase" granules have been divided into stable and labile, the former staining 

 b}^ the Winkler oxidase reaction, the latter by Gierke's reaction. The granules 

 seem to pass from the leucocytes into their environment. When animals are 

 exposed to x-raj's the stable granules are destroyed sooner than the labile granules. 

 The relation of the granules to other cell granules is undetermined, and their dis- 

 tribution is not identical with the granules that take the vital stains. Katsunuma*" 

 considers that they are probably not permanent specific structures, but transitional 

 alterations produced in functional activity of the protoplasm. 



Glycolytic Enzymes.^' — The oxidation of sugar bj' the tissues, which is one of 

 the chief sources of energy in the animal body, presumably takes place through 

 several steps. Of these, it is believed by some that the first is the formation of 

 glycuronic acid — 



O O 



II II 



CH20H-(CHOH)4C-H + 02 = C00H-(CH0H)4C - H + HA 

 (glucose) (glycuronic acid) 



but the subsequent changes which involve decomposition of the straight chain are 

 not at present understood. Attempts to isolate from various organs an enzyme 

 oxidizing glucose, particularly from the pancreas, muscle, and liver, have led to 

 varying results and much dissension, but it is probable, because of these failures, 

 that no such enzyme exists in quantities sufficient to account for the amount of 

 sugar combustion that is normalh' accomplished. O. Cohnheim^- attempted to 

 explain the failures by his observation that the pancreas produces a substance 

 that activates an inactive glycolytic enzyme in the muscles, liver, and probably 

 in other organs. This work is not generally accepted, so we are still in the dark 

 as to how the carbohydrate oxidations are accomplished. (See Chapter xxiv.) 



Lipase " 



Lipase is probably present in greater or less amount in all cells. 

 In the discussion of the reversible action of enzymes (see page 51) 

 the modern conception of fat metabolism has been explained, which 

 considers it to depend upon the existence of lipase in the cells and fluids 

 throughout the body. On account of the technical difficulties in the 

 way of using higher fats, such as triolein, in experimental work, the 

 esters of lower fatty acids have generally been used, particularly ethyl 

 butyrate, salicylic acid esters, and glycerol triacetate. Enzymes split- 

 ting ethyl butyrate, and other esters {esterases) , have been demonstrated 

 in practically all tissues examined, the names of Kastlc and Loeven- 

 hart in this country, and Hanriot in France, being particularly con- 

 nected with this work. What the relation of these esterases may be 



f-s Medigreceanu, Jour. Exp. Med., 1914 (19), 303. 



«» Verb. Jap. Path. Ges., 191G ((>), 76. 



8' Also discussed under "Diabetes," chap. xxiv. As glycolysis by blood and 

 tissues can occur witliout oxygen, Battclli and .Stern exclude tlie glycolytic from 

 the oxidizing enzvmes. 



•^'^ Zeit. physiol. ('hem., 1903 (39), 336; also see Simpson, Hiochcin. .lour., 1910, 

 (5), 126. 



"' For literature ou lii)ase see Connstein, Ergcbnis.se Physiol., 190 I (3, Abt. 1), 

 194; concerning the l)ehavi()r of lipase sec Tavlor, Jour. BioL ('hem., 1906 (2), 

 103; Palk, Proc. Natl. Acad., 1915 (1), 136; Science, 1918 (47), 423. 



