INTERNAL SECRETION OF TUMORS 507 



that the hvcr tissue between sccoiuhiry cancer nodules, and also the 

 liver in cases of cancer in the portal area, shows diminished catalase, 

 lipase and lecithinase function, with increased autolysis, but these 

 changes are not observed in the livers when the cancer is in other parts 

 of the body. However, chol'ne has been found in necrotic sarcomas 

 of rats,^^ whicli would seem to indicate the presence of enzj'ines dis- 

 integrating lecithin. As mentioned elsewhere (See Melanin), me- 

 lanotic tumors may contain enzymes oxidizing tyrosine, epinephrine, 

 pyrocatechin, or other related aromatic substances, with the forma- 

 tion of pigmentary substances. (See also, Autolysis in Tumors, 

 chap, iii.) 



Other enzymes are also present in tumor cells. Buxton^*^ exam- 

 ined a large number of tumors for their enzymes by the plate {auxan- 

 ographic) method, and found considerable variations in different 

 growths. All contained amylase (splitting starch) and lipase (split- 

 ting butyrin). Most, but not all, tumors coagulated milk and liquefied 

 casein, and also liquefied gelatin (rennin, proteases). Peroxidase was 

 nearly always, and catalase always, present. Digestion of fibrin, co- 

 agulated serum, and coagulated egg albumen could not be observed. 

 Practically all tumors split glycogen. Tyrosinase could not be demon- 

 strated. The fact that early embryonic tissues were found poor in 

 enzymes*^ speaks against the common assumption that tumors repre- 

 sent strictly an embryonic formation, but Long^^ found that xanthine- 

 oxidase, which in normal development does not appear until late in 

 fetal life, was absent from primary carcinomas of sheep livers, al- 

 though normal adult sheep liver tissue is rich in this enzyme. 



MacFadyen and Harden^^ studied the juices obtained by grinding 

 up tumor cells made brittle by liquid air, and found by direct methods 

 (chiefly in breast cancers) invertase, maltase, amylase, proteases 

 acting in both acid and alkaline solutions, catalase, oxidase, with per- 

 haps traces of lipase and peroxidase, but no lactase. 



Tumors arising from the gastric mucosa, according to Waring,^" 

 contain both pepsin and rennin; those from the pancreas, both pri- 

 mary and secondary growths, contain trypsin, steapsin, amylase, and 

 rennin. 



(5) Internal Secretion. — If tumors are derived from an organ 

 with an important internal secretion, the tumor cells in many cases 

 produce the same internal secretion, which seems to have the same 

 functional properties as the normally produced secretion. Thus a 

 metastatic growth from a thyroid tumor has been said to functionate 

 in place of the resected gland; Gierke^^ found in about 20 grams of 



85 Ellinger, Munch, med. Woch., 1914 (61), 2336. 



8« Jour. Med. Research, 1903 (9), 356. 



" Ibid., 1905 (13), 543. 



88 Jour. Exper. Med., 1913 (18), 512. 



8' Lancet, 1903 (ii), 224. 



^o Jour. Anat. and Physiol., 1894 (28), 142. 



" Hofmeister's Beitr., 1902 (3), 286. 



