ENNG诱发犬胃癌过程细胞动力学的研究

Studies on cell kinetics in canine stomach carcinogenesis induced by N-Ethyl-N'-Nitro-N-Nitrosoguanidine

本研究利用实验犬胃癌模型,采用纤维胃镜活检,体外胃粘膜培养掺入~3H-TdR 放射自显影方法,研究 ENNG 诱发犬胃癌过程的细胞增殖动力学。结果表明,随着犬正常胃粘膜向癌前、癌发展,细胞标记指数(LI)出现三期变化,最初期下降,接着细胞 LI 不断增高,最终处于相对高值的平坦期(P【0.01),说明细胞增殖速率加快。T_S 有延长趋势,但十分缓慢,表现相对恒定。T_C 逐渐缩短,与实验前的 T_C 差异呈高度显著性(P【0.01)。正常胃粘膜向癌演变过程中,胃粘膜的增殖区逐渐扩大,显示细胞的去分化现象。

The cell kinetics was studied in the experimental ENNG-induced canine gastric cancer by autoradiographic method with tritiated thymidine in vitro incubated biopsy specimens obtained from lesions through a serial gastroscopic examinations.The results showed that,with canine background mucosa developing to cancer,there was an alteration of LI in the form of an initial reduction,an increase phase and a plateau phase with a high value.The S-phase duration showed a tendency to be prolonged,but it appeared slow and seemed to be relatively constant.The Tc became shorter with the mucosal changes progressing from normal background to cancer.In the process of transformation,the proliferative zone of gastric epithelial cell was shown to be enlarged gradually. There is dedifferentiation phnenomenon which may be an important step in melignant transformation.