Abstract
Cell kinetic analysis on gastrointestinal mucosa in Wistar male rats with ENNG-induced carcinoma was studied using anti-bromodeoxyuridine (BrdU) monoclonal antibody. The normal mucosa in rats without ENNG administration, the mucosa without tumor and carcinogenetic lesion in rats with ENNG administration were studied. The results were as follows: 1) It was found that the BrdU labeling index (L.I.) in the gastrointestinal mucosa was elevated and the number of S-phase cell was increased by the carcinogen ENNG according to the carcinogenetic process. 2) In the normal mucosa, the L.I. at small intestine was 8.7%, at antral portion of grandular stomach 6.6% and at fundic portion of grandular stomach 1.9%. Thus the L.I. in most carcinogenetic parts was relatively higher. 3) The L.I. in the carcinogenetic lesion (16.8-23.7%) was significantly higher than that in the normal mucosa or mucosa without carcinogenesis (p<0.001). 4) The histological types and differentiative grades of the carcinogenetic lesions were not correlated with the L.I. of those tissues. But the L.I. of the tumors with invasion to the proper muscle or deeper was slightly higher than those confined to the mucosal or submucosal layer. The present studies suggest that carcinogenesis was highly correlated with the changes in the rate of S-phase cells in the gastrointestinal mucosa.
