Histochemical patterns in early lesions and infiltrating adenocarcinomas induced in mouse duodenum by...

Intravillous, microcrater, and macroscopic invasive lesions induced in the mouse duodenum by N-ethyl-N'-nitro-N-nitrosoguanidine were examined histochemically. The cells of these neoplastic lesions and the proliferative zones of the normal crypts showed similar staining reactions in leucine aminopeptidase, alkaline and acid phosphatases, adenosine 5'-triphosphatase, and glucose-6-phosphate dehydrogenase. However, a slight decrease in succinic dehydrogenase activity and a slight increase in lactic dehydrogenase activity were observed in the intravillous and microcrater lesions compared to the activity in the proliferative zones of the crypts. The neoplastic cells of these lesions showed no mucus secretion. We discussed the origin of the neoplastic lesions using these and other findings.