争光霉素对亚硝胺诱发大鼠食管上皮癌变的抑制作用

长期输入为人体治疗用量20倍的争光霉素,没有引起大鼠正常的食管上皮细胞的形态改变,但对甲基苄基亚硝胺引起的增生及癌前病变(乳头状瘤)具有较为明显的抑制作用。争光霉素对癌的发生也有阻断作用。争光霉素引起的食管异常上皮的病理改变,主要表现为核固缩、核周空晕、核旁空泡、核碎裂等细胞的渐进性坏死和死亡。同时还看到上皮的液化灶与灶性的增生抑制区。重要的内脏器官除发现肾变性之外,其他未见异常。争光霉素对食管上皮的增生和癌前病变选择性的抑制与破坏作用,也为食管癌的予防性治疗提供一项有用的药物。争光霉素是我国自己生产的,与博莱霉素(Bleomycin)相类似的抗菌素,在临床上已证明对鳞状上皮癌,如皮肤癌与食管癌等有疗效。为了探索争光霉素能否阻断亚硝胺诱发食管鳞状上皮的癌变,特别是对增生与癌前病变有无抑制作用,我们进行了以下的试验。

The Inhibitory Effect of Bleomycinon the Malignisation of Esophageal Epithelia Induced by Methylbentylnitrosamine in Rats

The administration of Bleomycin did not produce any morphological change on the normal esophageal epithelium of rats,but marked innhibitory effects were observed in the hyperplastic and precancerous lesions.Besides this,Bleomycin decreased the cancer incidence.The pathological changes caused by Bleomycin in the hyperplastic andprecancerous epithelia were as follows:nuclear pyknosis,karyorrhexis,chro-matolysis and vacuolar formation around or at one side of the nucleus,an indication of necrobiosis and necrosis of cells.Furthermore,there were loca-lized areas of liquefaction and inhibition on the hyperplastic epithelia.Beside the occurrence of nephrosis in some cases,there were no other visceral changes.The selective inhibitory effects of Bleomycin against the hyperplastic and precancerous epithelia of the esophagus would provide a useful drug in the prophylatic therapy of the esophageal carcinoma.