作者用24只雄性豚鼠,分为数量相等的对照和实验两组。实验组豚鼠置于2ppm二氧化氮的中毒室内,连续染毒。每隔七天分别将三分之一对照组及实验组配对动物处死。取肺组织,用明胶包埋,在-50℃下制成冷冻切片。对每一染毒与对照动物,按上、下肺叶正中位置各作成5张切片。研究时,对每一动物的10张切片,按照一定要求,各随机选择一张切片进行 The authors used 24 male guinea pigs divided into equal numbers of controls and experimental groups. Guinea pigs in experimental group were exposed to 2ppm of nitrogen dioxide poisoning room, continuous exposure. One third of control and experimental animals were sacrificed every seven days. Lung tissue was removed, embedded in gelatin and frozen sections were made at -50 ° C. For each infected and control animals, according to the upper and lower lobe of the middle position made of 5 slices. During the study, 10 slices of each animal were randomly selected according to certain requirements