【摘要】 用电子显微镜观察争光霉素A₅和A₂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A₅和A₂引起肺病变的轻重程度。结果表明,A₅引起的肺病变明显的较A₂为轻。目前,国外临床使用的博莱霉素是以A₂为主要组分的复合物,肺毒性是它的主要毒副作用。A₅的肺病变较A₂轻,这一结果提示了争光霉素A₅临床肺毒性较低的可能性,值得深入研究。更多还原

【Abstract】 The lung toxicities of bleomycins A₅ and A₂ in the mouse were studied with electron microscopy. The initial site of drug induced damage appeared to lie chiefly in the endothelium of the capillaries in the alveolar walls. The endothelial cell changes consisted of marked increase in the number of pinocytotic vesicules, appearance of vacuoles, formation of pseudopodia-like protrusions and fragmentation of the cell body. Blood platelets were frequently seen to adhere to the endothelial surface of the endothelium and at times clump together forming microthrombi. For quantitative comparison of the damages elicited by A₅ and A₂, fifty capillaries from each animal treated with either component were examined and the percentage of injured capillaries was calculated for each group. It was found that higher percentages of injured capillaries occurred in the lungs of the mice treated with A₂ than those treated with A₅. As it is known that lung toxicity is the most severe side effect of bleomycin and that bleomycin A₂ is the main component in the bleomycin complex which is now available for clinical use, the observation that bleomycin A₅ is less toxic for the mouse lung while displaying approximately the same therapeutic effect in experimental animals as compared with A₂ suggests that further investigations on bleomycin A₅ as an antitumor agent might be desirable.更多还原