I 



A HISTOCHEMICAL STUDY 



I 



OF OXIDATIVE ENZYMES IN CARCINOMA OF 

 THE LARGE INTESTINE IN MAN 



L. W. WATTENBERG 



Department of Pathology, University of Minnesota Médical School, 

 Minneapolis, Minnesota, U. S. A. 



A. histocheraical study of three oxidative enzymes, DPNH diaphorase, 

 TPNH diaphorase and succinic dehydrogenase in normal mucosa, benign 

 adenomatous polyps, and carcinoma of the large bowel in man will be 

 presented. A reaction pattern distinct from that found in normal mucosa 

 or benign adenomatous polyps bas been observed in carcinoma. This pat- 

 tern is characterized by high DPNH diaphorase and TPNH diaphorase 

 activities and by a low succinie dehydrogenase activity as demonstrated 

 by the tetrazolium sait réduction techniques employed. This distinctive 

 reaction pattern is not présent in ail components of thèse malignant neo- 

 plasras. It is most consistently observed in the cells at the invading 

 margin of the tumor, at the periphery of tumor cell aggregates and in iso- 

 lated cell groups. One aspect of this pattern, the low succinic dehydroge- 

 nase activity, occurs in both benign and malignant proliferative processes 

 of the large bowel mucosa. 



- 201 



