64 ENZYMES 



contain a strong- antitrypsin, to which lie attributes their ability to 

 live bathed in pancreatic juice without being digested.*"'^ Similar 

 properties have been ascribed by other observers to the cells of the 

 mucosa of the stomach*^ and intestine, and to the mucus itself (de 

 Klug)/- but the work of Bensley and Harvey ^^ indicates that the ab- 

 sence of free acid in the gland cells and lumen is perhaps the chief 

 protection of the stomach from pepsin. Kirchheim ** holds that the 

 intestines are protected less by anti-enzymes than by rapid absorption 

 and removal of the enzymes, which are really not present in any con- 

 siderable excess in the intestinal contents. The anti-enzymes seem 

 only to inhibit enzyme action, and not to destroy the enzyme itself.*"' 

 Normal anti-enzj-mes do not seem to be at all specific, according to 

 V. Eisler,*" that is, human serum is no more resistant to human tryp- 

 sin than is pig serum — indeed, it is less so.*' 



Cathcart ** found that antitrypsin is connected ^\^th the ' ' albumin 

 fraction" of the serum, i. e., the fraction precipitated between half 

 and full saturation with ammonium sulphate. Globulins do not pos- 

 sess this action, but they are not easily digested. Antitrypsin is 

 found in all varieties of serum, and is little or not at all specific. It is 

 destroyed by 65-70° C.*" for one-half hour, but retains its anti-enzy- 

 matic activity after drying, and is equally effective against all sorts 

 of proteins. The normal anti-tryptic activity decreases during fast- 

 ing and increases during digestion (Rosenthal ^") ; it is increased 

 during pregnancy ^"^ and the blood of the fetus shows less than that 

 of the mother. Normal antitrj^psin unites with trypsin according to 

 the law of multiple proportions (^leyer) and the reaction is not re- 

 versible (Rondoni). It is found in the urine, and in inflammator}' 

 exudates, but not in normal serous fluids, and it resists putrefaction. 

 Normal serum does not seem to inhibit the enzymes which act upon 

 purines. Fuld and Spiro '^^ found that the natural antirennin of 



4oa Burge (Jour. Parasitol., 1915 (1), 179) suggests that the protection of 

 parasites, and perhaps of the alimentary epithelium, depends on tlie active 

 oxidative pro])erties of tliese tissues destroyinsr tlie en/.vmes. 



41 See Blum and Fuld, Zeit. Iclin. Med., 'lOOG (fiS), 505; LangensldoUl. Skand. 

 Arch. Physiol., 1914 (31), 1. 



•»2 Arch, internat. d. phvsiol., 1007 (5), 297. 



■»3 Biological Bulletin, 1912 (2.3), 225. 



44Arch. exp. Bath. u. Pharm., 1912 (71), 1 



45 l^ayliss and Starling (Jour, of Physiol.. 1905 (.32). 129; and Meyer. Biochem. 

 Zeit., 1909 (23), OS. o])pose the view of Dele/enne that the antitryptic action of 

 the hlood is due to an antikinase. and believe the antibody acts upon trypsin. 



■»« Ber. d. Wien. Akad., 1905 (104), 119. 



4" This is contradicted by Claessncr; llofmeister's Beitriige, 1903 (4), 79. 



48 .Tour, of Phvsiol., 1904 (31), 497; also see Kiimmercr and Aubrv . l?i(iclicni. 

 Zeit., 1913 (48),' 247. 



40 Unless otherwise specified, all tem])craturcs are given according to the Centi- 

 grade scale. 



->o Folia Serologica. 1910 (0), 2S5 ; also Fran/, and Jarisdi, Wien. klin. Woch.. 

 1912 f25). 1441. 



noaSee Franz, Arch. f. CJvn., 1914 (102). 579. 



51 Zeit. f. phvsiol. Chem." 1900 (31). 132. 



