Abstract Arginases are a family of enzymes that convert l-arginine to l-ornithine and urea. Alterations in expression of the isoform arginase-I are increasingly recognized in lung diseases such as asthma and cystic fibrosis. To define expression of murine arginase-I in formalin-fixed tissues, including lung, an immunohistochemical protocol was validated in murine liver, a tissue that has distinct zonal arginase-I expression, making it a useful control. In the lung, arginase-I immunostaining was observed in airway surface epithelium and this decreased from large to small airways, with a preferential staining of ciliated epithelium versus Clara cells and alveolar epithelia. In submucosal glands, the ducts and serous acini had moderate immunostaining, which was absent in mucous cells. Focal immunostaining was observed in alveolar macrophages, endothelial cells, pulmonary vein cardiomyocytes, pulmonary artery smooth muscle, airway smooth muscle, and neurons of ganglia of the lung. Arginase-I immunostaining was also detected in other tissues including salivary glands, pancreas, liver, skin, and intestine. Differential immunostaining was observed between sexes in submandibular salivary glands; arginase-I was diffusely expressed in the convoluted granular duct cells of females, but was rarely noted in males. Strain specific differences were not detected. In a mouse with an incidental case of lymphoma, neoplastic lymphocytes lacked arginase-I immunostaining, in contrast to immunostaining detected in non-neoplastic lymphocytes of lymphoid tissues. The use of liver tissue to validate arginase-I immunohistochemistry produced consistent expression patterns in mice, and this approach can be useful to enhance consistency of arginase-I immunohistochemical studies.

中文翻译：

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福尔马林固定肺和其他组织中精氨酸酶-I表达的免疫组织化学检测

摘要 精氨酸酶是将 l-精氨酸转化为 l-鸟氨酸和尿素的酶家族。在哮喘和囊性纤维化等肺部疾病中，越来越多地认识到同工型精氨酸酶-I 表达的改变。为了确定鼠精氨酸酶-I 在福尔马林固定组织（包括肺）中的表达，在鼠肝中验证了免疫组织化学方案，该组织具有明显的带状精氨酸酶-I 表达，使其成为有用的对照。在肺中，在气道表面上皮细胞中观察到精氨酸酶-I 免疫染色，这种染色从大气道到小气道减少，纤毛上皮细胞优先染色，而不是 Clara 细胞和肺泡上皮细胞。在粘膜下腺中，导管和浆液性腺泡具有中等免疫染色，而在粘膜细胞中则没有。在肺泡巨噬细胞中观察到局灶性免疫染色，内皮细胞、肺静脉心肌细胞、肺动脉平滑肌、气道平滑肌和肺神经节神经元。在其他组织中也检测到精氨酸酶-I 免疫染色，包括唾液腺、胰腺、肝脏、皮肤和肠道。在下颌下唾液腺中观察到性别之间的差异免疫染色；精氨酸酶-I 在雌性的复杂颗粒管细胞中广泛表达，但在雄性中很少被注意到。未检测到菌株特异性差异。在偶发淋巴瘤病例的小鼠中，与在淋巴组织的非肿瘤淋巴细胞中检测到的免疫染色相反，肿瘤淋巴细胞缺乏精氨酸酶-I 免疫染色。使用肝组织验证精氨酸酶-I 免疫组织化学在小鼠中产生一致的表达模式，