Investigation and studies of pulmonary diseases and injuries require pre-clinical animal models. The rabbit lung model is widely used and allows for a diverse set of readouts. Among them, histology and immunohistochemistry are of invaluable merit because qualitative and quantitative information about tissue morphology and composition can be easily obtained. In this technical note, we performed several histological and immunohistochemical stainings in the rabbit healthy naïve lung tissue. Overnight formalin fixation with subsequent paraffin embedding was compared to cryopreservation with a subsequent 10-minute formalin fixation prior to staining. Antigen retrieval (AR) for paraffin embedded sections proved to enhance the corresponding signals compared to analogous staining without AR. Advantages and disadvantages of chromogenic versus immunofluorescence stainings were discussed. In addition, several morphological structures, such as the intrapulmonary bronchus with its mucosal folds, the pulmonary artery, the alveoli and the lymph nodes, were stained with various stainings at the same site in order to give a comprehensive picture of their composition. Besides Haematoxylin&Eosin and Elastica van Gieson staining, collagen I, collagen III, fibronectin, α-SMA, ki-67 and protease-activated receptor-2 (PAR-2) immunohistochemistry was performed. Collagen I, collagen III and fibronectin expression was positive at the outer rim of the pulmonary arteries, while the inner rim was collagen III positive. Moreover, the fibronectin staining in the intrapulmonary bronchus showed an opposite trend when compared to the collagen III staining. The alveoli exhibited PAR-2 expression, while PAR-2 was not expressed in lymph nodes of the healthy rabbit lung.

肺部疾病和损伤的调查和研究需要临床前动物模型。兔肺模型被广泛使用，并允许多种读数。其中，组织学和免疫组织化学具有无价的价值，因为可以轻松获得有关组织形态和组成的定性和定量信息。在本技术说明中，我们对兔健康幼稚肺组织进行了多次组织学和免疫组织化学染色。将福尔马林过夜固定和随后的石蜡包埋与冷冻保存和染色前 10 分钟福尔马林固定进行比较。与没有 AR 的类似染色相比，石蜡包埋切片的抗原修复 (AR) 被证明可以增强相应的信号。讨论了显色染色与免疫荧光染色的优缺点。此外，几种形态结构，如具有粘膜皱襞的肺内支气管、肺动脉、肺泡和淋巴结，在同一部位用各种染色剂染色，以便全面了解它们的组成。除了苏木精和曙红和 Elastica van Gieson 染色外，还进行了胶原蛋白 I、胶原蛋白 III、纤连蛋白、α-SMA、ki-67 和蛋白酶激活受体-2 (PAR-2) 免疫组织化学。肺动脉外缘胶原I、胶原III和纤连蛋白表达阳性，而内缘胶原III阳性。此外，与胶原 III 染色相比，肺内支气管中的纤连蛋白染色显示出相反的趋势。