76 ENZYMES 



are then neutralized. Indole and skatole are oxidized into less harm- 

 ful substances. 



The Indophenol Reaction. i" — Alplui-naplitliol and dimethyl-para-plicnylendia- 

 min. wlieii lirouglit louctln'r in alkaline solntioii, become oxidized in the pres^ence 

 of air and form an insoluble blue dye, indophenol. Tliis reaction is jireatiy 

 accelerated by oxidizing' agents, and it has liien found that certain tissues pos- 

 sess this property, hence the indophenol synthesis has been used for microchemical 

 study of the presence and distribution of oxidizing enzymes in cells. As the in- 

 tracellular agent which causes this reaction is, ho\.ever, so resistant to heat and 

 chemicals that it can be demonstrated in sections fixed in formalin and prejiared 

 by the ordinary paralbn imbedding method (Dunn), there is room for much doubt 

 as to whetlier' it represents a true enzyme of the polyphenol oxidase class. It 

 may be that it is identical with phenolase.n In tiie presence of small amounts 

 of peroxide tiie granules of leucocytes and myelocytes are stained with alpha- 

 naphthol alone, which Graham na interprets as oxidation by an enzyme of the 

 peroxidase type. The indophenol reaction is observed best in the granules of 

 neutroi>hile leucocytes of blood and in myeloid cells of bone marrow, leukemic 

 blood and fetal organs; eosinophiles and basophile leucocytes also give reactions, 

 but not lymphocytes, mature erythrocytes, or most fixt tissue cells. ( See Dunn, 

 Quart. Jour. Med., 1913 (6), 293.) By using alkali-free, unfixt tissues Gierke 

 found granules present in tissue ceils generally, and Griiff states that they occur 

 in proportion to the metabolic activity of the cells; they are abundant in 

 carcinomas, scanty in sarcoma and connective tissue growths generally, arc not 

 destroyed in cloudy swelling or fatty changes, but disappear in infarcts and 

 autolyzing tissues, and in tissues asphyxiated with illuminating gas.i- Lung 

 tissue is especially poor in this form of oxidative activity,i2a but giant cells of 

 tubercles contain oxidase granules. 12b During experimental pneumococcus sep- 

 ticemia the indophenol oxidase reaction is decreased in the tissues. 12c 



Glycolytic Enzymes.^^ — The oxidation of sugar by the tissues, 

 which is one of the chief sources of energy in the animal body, presum- 

 ably takes place through several steps. Of these, it is believed by some 

 that the first is the formation of glycuronic acid — 



CH,OH— (CHOH),C— H + 0, = COOH— ( CHOH ) ,C— H + H,0, 

 (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 nnich 

 dissension, but it is probable, because of these failures, that no such 

 enzyme exists in quantities sufficient to account for the amount of 



10 Literature given bv Schultze, Ziegler's Beitr., 1909 (45), 127: Dunn. Jour. 

 Path, and Bact., 1910 ('l5), 20; Griiff, Frankfurter Zeit. f. Path., 1912.(12), 358. 



11 Bach and Marvanovitsch, Biochem. Zeit.. 1912 (42), 417. 

 1 la Jour. Med. Ues., .1916 (35), 231. 



12 See Klojifcr, Zeit. exp. Pharm., 1912 (11), 407. 

 12a Weiss, Wien. klin. Woch., 1912 (25), t)97. 

 i2bMakino, Verh. Jai)an. Patli. Gesell., 1915 (5), 71. 

 i2.Medigrcceanu. Jour. Exp. .Med., 1914 (19), ,303. 



13 Also discussed under "Diabetes," chap. xxil. As glycolysis by blood and 

 tissues can <)(<nr without oxygen, Battelli and Stern exclude the glycolytic from 

 the oxidizing enzymes. 



