用电子显微镜观察争光霉素A_5和A_2对小鼠肺的损害作用。除观察形态变化外,还使用病变毛细管计数的方法比较了A_5和A_2引起肺病变的轻重程度。结果表明,A_5引起的肺病变明显的较A_2为轻。目前,国外临床使用的博莱霉素是以A_2为主要组分的复合物,肺毒性是它的主要毒副作用。A_5的肺病变较A_2轻,这一结果提示了争光霉素A_5临床肺毒性较低的可能性,值得深入研究。 The electron microscope was used to observe the damage of lungs of mice with vasodilomycin A_5 and A_2. In addition to observing morphological changes, the severity of lung lesions caused by A_5 and A_2 was also compared using a method of counting capillary lesions. The results showed that A_5 caused lung lesions were significantly lighter than A_2. At present, the bleomycin used abroad is based on A2 as the main component of the compound, pulmonary toxicity is its main toxic side effects. The lung lesions of A_5 are lighter than those of A_2. This result suggests that the clinical lung toxicity of bleomycin A_5 is low and deserves further study.