92 ENZYMES 



significance in view of the observation that pneumonic lungs are more 

 acid than normal organs, acidity as high as pH 6.0 to 5.4 having been 

 found. 2^ 



Rzentkowski^" found an increase of non-coagulable nitrogen in the 

 blood of pneumonics, probably resulting from autolysis in the exu- 

 date. According to Dick^^ the blood serum after the crisis contains 

 an enzyme which acts specifically on the pneumococcus proteins. 

 Petersen and Short^^ found an increase of serum ereptase in the blood 

 preceding or accompanying crisis or lysis, and suggest that it may have 

 a function in attacking the toxic protein fragments. In the liver during 

 experimental pneumococcus septicemia, autolysis is said to be increased 

 in rate..^^ Almagia** suggests that the bactericidal action of the prod- 

 ucts of fibrinolysis in pneumonia may be of importance in checking 

 the disease. 



Necrotic Areas. — Jacoby^^ found that if a portion of a dog's liver 

 was ligated oF and the animal kept alive for some time, the necrotic 

 tissue contained the same products that he had obtained in experi- 

 mental autolysis. The absorption of necrotic tissues generallj^ is 

 ascribable to either autolysis or heterolysis. Presumably there is no 

 great difference in the self-digestion of an organ which is necrotic 

 because its blood supply is cut ofT, and of a similar organ removed 

 from the body aseptically and allowed to undergo aseptic autolysis 

 in an incubator. At the periphery there might be some effects pro- 

 duced in vivo by the inhibitive action of the serum or the digestive 

 action of the leucocytes, but beyond that no marked differences are 

 to be expected. In both cases asphyxia is present, leading to increased 

 acidity, without which little if any autolysis can occur. It has been 

 found that in experimental infarction of the kidney there develops 

 sufficient acidity to permit of autolysis, and the hydrolysis of the 

 proteins increases with the development of acidity (Straus and Morse.^®) 



A study of the relation of autolysis to the histological changes that 

 occur in necrotic areas by Wells^'^ gave evidence that there occurs 

 early a decomposition .of the nucleoproteins of the nuclei, which is 

 probably brought about by the intracellular autolytic enzymes. The 

 liberation of the nucleic acid and the reduction in the bulk of nuclear 

 material through the digestion away of the protein is probably the 

 cause of the pycnosis observed in necrotic areas. Later the nucleic 

 acids are further decomposed through the special enzymes described 

 by Jones, Sachs, and others, the "nucleases." This is prosuniably 



-3 Jour. Amer. Med. Assoc, 1919 (72), 1364. 



30 Virchovv's Arch., 190.5 (179), 405. 



31 Jour. Infect Dis., 1912 (10), 383. 

 '2 Jour. Infect. Dis., 1918 (22), 147. 



" Medigrcceanu. Jour. Exp. Med., 1914 (19), 31. 

 3^ Festschr. for Celli, Torino, 1913, p. 459. 

 ^oZcit. physiol. Chein., 1900 (30), 149. 

 '« Proc. Soc. Exp. Biol. Med., 1917 (14). 171. 

 " Jour. Med. Research, 1900 (15), 149. 



