PARENTERAL INTRODUCTION OF PROTEIN 509 



Modern methods of immunity investigation (particularly by 

 precipitins and anaphylaxins ) make it possible to follow up 

 the fate of proteins which are introduced into the system; 

 such substance may be recognized for days in the circulating 

 blood, in the peritoneal fluid and in various tissues. It has 

 been found possible to substitute two-thirds of the required 

 food protein in a dog by horse-serum injected subcutaneously 

 without disturbing the nitrogen equilibrium. 70 Homologous 

 protein is evidently better tolerated than foreign protein. 71 

 After free transfusion of homologous blood directly from an 

 artery of one dog into a vein of a second dog there is usually 

 observable in the latter an increase of the nitrogen elimina- 

 tion as evidence of an increased protein break-down; 72 

 but at times this may not occur. Maintenance .of nitrogen 

 equilibrium seems impossible, however, even with infusion of 

 specifically identical serum. 73 Kornel v. Korosy, 74 as well 

 as Levene, has been able to prove (contrary to opposed state- 

 ments) 75 that it is of no consequence, as far as the fate of 

 proteins injected intravenously is concerned, whether they 

 have passed with the circulating blood through the intestinal 

 wall or not. 



E. Heilner (Physiol. Instit., Munich), Zeitschr. f. Biol., 50, 26, 1908; 

 P. Rona and L. Michaelis, Pfliiger's Arch., 124, 578, 1908. 



67 Cramer, 1. c. ; V. C. Vaughn, J. G. Gumming and C. B. M. Glumphy 

 (Univ. of Michigan), Zeitschr. f. Immunitatsfor., 9, 16, 1910. 



98 L. Michaelis and P. Rona, Pfluger's Arch., 121, 163, 1908. 



68 L. B. Mendel and E. W. Rockwood (Yale Univ.), Amer. Jour, of Physiol., 

 12, 336, 1905. 



70 P. Rona and L. Michaelis, Pfliiger's Arch., 124, 579, 1908. 



71 U. Friedemann and S. Isaak, Zeitschr. f. exper. Pathol., 4, 830, 1907, and 

 earlier works ; F. Lommel ( D. Gerhard's Clinic, Jena ) , Arch, f . exper. Pathol., 

 58, 50, 1907. 



72 P. Hari (F. Tangl's Lab., Budapesth), Biochem. Zeitschr., 34, HI, 1911; 

 cf. also H. D. Haskins (Western Reserve Univ.), Jour, of Biol. Chem., 3, 321, 

 1907. 



73 G. Quagaliariello (Bottazzi's Lab., Naples), Arch, di Physiol., 10, 150, 

 1912. 



7 *K. v. Korosy (Physiol. Instit., Budapesth), Zeitschr. f. physiol. Chem., 

 69, 313, 1910. 



75 E. Freund and H. Popper (Vienna), Biochem. Zeitschr., 15, 272, 1909. 



