SEQUENTIAL HISTOCHEMICAL STUDIES OF THE ESOPHAGEAL CARCINOMA IN RATS INDUCED BY N-METHYL-N-AMYLNITROSAMINE

Abstract

Sequential changes of four enzymes, glucose-6-phosphate dehydrogenase (G-6-P-DH), reduced nicotinamido adenine dinucleotide dehydrogenase (NADH-DH), aldolase and alkaline phosphatase (Al-Pase), were examined histochemically during the course of esophageal carcinogenesis in rats induced by N-methyl-N-amylnitrosamine. G-6-P-DH activity was found in the outer layer of the normal epithelium, whereas NADH-DH and aldolase activities were found in the basal layer. Localization of activities of these three enzymes in hyperplasia and papilloma was nearly the same as in the normal epithelium. In the early squamous cell carcinoma, G-6-P-DH and aldolase displayed increased and diffused activities, whereas NADH-DH disappeared. In the advanced carcinoma, only G-6-P-DH activity was elevated, while no NADH-DH or aldolase activity could be detected. No Al-Pase showed activity in the esophageal epithelium and carcinoma. These results suggest that the enzymes activity undergose alteration during the course of esophageal carcinogenesis in rats.