Abstract：
OBJECTIVE: Immunohistochemical methods were employed to investigate the morphological heterogeneity and localization of fibroblasts associated with the function of major salivary glands in rats.
METHODS: Histochemical and electron microscopic observations were made in rat parotid, submandibular, and sublingual glands and pancreas. Fibroblasts were immunostained using their specific marker, 47 kDa heat shock protein (Hsp47).
RESULTS: Hsp47-immunopositive fibroblasts within the intralobular connective tissue exhibited a notably smaller size compared with the interlobular connective tissue. They were loosely distributed throughout the connective tissue. However, fibroblasts with elongated long processes were explicitly identified at the intercalated ducts in parotid, sublingual, and submandibular glands. Fibroblastic bodies and processes were tightly approximated with the basement membrane of the duct. Electron microscopy confirmed these findings, revealing a thin layer consisting of collagen fibers was found between the fibroblasts and the basement membrane. Double staining of Hsp47 and α-smooth muscle actin (αSMA) in parotid glands indicating that Hsp47-positive fibroblasts enveloped both the duct and αSMA-positive myoepithelial cells. Additionally, They projected long and thin processes longitudinally at the straight portion or circularly at the bifurcated portion of the duct. The three-dimensional reconstruction showed a frame-like structure of fibroblasts surrounding the intercalated duct with longitudinal myoepithelial cells. However, such specific localization of fibroblasts was not detected in the exocrine pancreas lacking myoepithelium.
CONCLUSIONS: Small fibroblasts with long processes connecting or overwrapping each other and thin collagen layers surround the intercalated ducts in rat major salivary glands, presumably contributing to protecting the ducts from salivary flow and myoepithelial contraction.
METHODS: Histochemical and electron microscopic observations were made in rat parotid, submandibular, and sublingual glands and pancreas. Fibroblasts were immunostained using their specific marker, 47 kDa heat shock protein (Hsp47).
RESULTS: Hsp47-immunopositive fibroblasts within the intralobular connective tissue exhibited a notably smaller size compared with the interlobular connective tissue. They were loosely distributed throughout the connective tissue. However, fibroblasts with elongated long processes were explicitly identified at the intercalated ducts in parotid, sublingual, and submandibular glands. Fibroblastic bodies and processes were tightly approximated with the basement membrane of the duct. Electron microscopy confirmed these findings, revealing a thin layer consisting of collagen fibers was found between the fibroblasts and the basement membrane. Double staining of Hsp47 and α-smooth muscle actin (αSMA) in parotid glands indicating that Hsp47-positive fibroblasts enveloped both the duct and αSMA-positive myoepithelial cells. Additionally, They projected long and thin processes longitudinally at the straight portion or circularly at the bifurcated portion of the duct. The three-dimensional reconstruction showed a frame-like structure of fibroblasts surrounding the intercalated duct with longitudinal myoepithelial cells. However, such specific localization of fibroblasts was not detected in the exocrine pancreas lacking myoepithelium.
CONCLUSIONS: Small fibroblasts with long processes connecting or overwrapping each other and thin collagen layers surround the intercalated ducts in rat major salivary glands, presumably contributing to protecting the ducts from salivary flow and myoepithelial contraction.
摘要：
目的：采用免疫组织化学方法研究大鼠涎腺功能相关成纤维细胞的形态异质性和定位。
方法：对大鼠腮腺进行组织化学和电镜观察，颌下,舌下腺和胰腺.成纤维细胞使用其特异性标记进行免疫染色，47kDa热休克蛋白(Hsp47)。
结果：与小叶间结缔组织相比，小叶内结缔组织内的Hsp47免疫阳性成纤维细胞表现出明显更小的尺寸。它们在整个结缔组织中松散分布。然而,在腮腺的插入导管中明确鉴定出具有细长长突的成纤维细胞，舌下，和颌下腺。成纤维细胞和过程与导管的基底膜紧密接近。电子显微镜证实了这些发现，在成纤维细胞和基底膜之间发现了一层由胶原纤维组成的薄层。腮腺中Hsp47和α-平滑肌肌动蛋白（αSMA）的双重染色表明Hsp47阳性成纤维细胞包裹了导管和αSMA阳性肌上皮细胞。此外,它们在管道的直线部分纵向突出或在管道的分叉部分圆形突出。三维重建显示成纤维细胞围绕插入导管的框架状结构，并带有纵向肌上皮细胞。然而,在缺乏肌上皮的外分泌胰腺中未检测到成纤维细胞的这种特异性定位。
结论：小成纤维细胞，长突起彼此连接或包裹在一起，而薄的胶原层围绕大鼠主要唾液腺的插层导管，可能有助于保护导管免受唾液流和肌上皮收缩的影响。
方法：对大鼠腮腺进行组织化学和电镜观察，颌下,舌下腺和胰腺.成纤维细胞使用其特异性标记进行免疫染色，47kDa热休克蛋白(Hsp47)。
结果：与小叶间结缔组织相比，小叶内结缔组织内的Hsp47免疫阳性成纤维细胞表现出明显更小的尺寸。它们在整个结缔组织中松散分布。然而,在腮腺的插入导管中明确鉴定出具有细长长突的成纤维细胞，舌下，和颌下腺。成纤维细胞和过程与导管的基底膜紧密接近。电子显微镜证实了这些发现，在成纤维细胞和基底膜之间发现了一层由胶原纤维组成的薄层。腮腺中Hsp47和α-平滑肌肌动蛋白（αSMA）的双重染色表明Hsp47阳性成纤维细胞包裹了导管和αSMA阳性肌上皮细胞。此外,它们在管道的直线部分纵向突出或在管道的分叉部分圆形突出。三维重建显示成纤维细胞围绕插入导管的框架状结构，并带有纵向肌上皮细胞。然而,在缺乏肌上皮的外分泌胰腺中未检测到成纤维细胞的这种特异性定位。
结论：小成纤维细胞，长突起彼此连接或包裹在一起，而薄的胶原层围绕大鼠主要唾液腺的插层导管，可能有助于保护导管免受唾液流和肌上皮收缩的影响。
