Department of Cell and Neurobiology, University of Southern California, Los Angeles, California 90089-9112, USA.
Invest Ophthalmol Vis Sci. 2010 Jun;51(6):2960-7. doi: 10.1167/iovs.09-4687. Epub 2010 Jan 27.
To develop a nomenclature for the lacrimal duct system in the rabbit, based on the anatomic and structural characteristics of each duct segment, and to provide RT-PCR and immunofluorescence data to support the notion that the duct system plays important roles in lacrimal function.
Paraffin-embedded lacrimal glands (LGs) were stained with hematoxylin and eosin (H&E) and evaluated with a stereomicroscope. Cryosections of LG were stained with cresyl violet, and acinar cells and ductal epithelial cells were isolated from each duct segment by laser capture microdissection (LCM). mRNA levels from these cells were analyzed by real-time RT-PCR. Standard protocol was followed for immunofluorescence detection of ionic transporters.
The lacrimal duct system was divided into six segments on the basis of morphologic characteristics: the intercalated, intralobular, interlobular, intralobar, interlobar, and main excretory ducts. Although the morphologic features change incrementally along the entire duct system, the gene expression of ionic transporters and aquaporins, including AE3, AQP4, AQP5, CFTR, ClC2gamma, KCC1, NHE1, NKAalpha1, NKAbeta1, NKAbeta2, NKAbeta3, and NKCC1 varied greatly among duct segments. Immunofluorescence results were generally in accordance with the abundance of mRNAs along the acinus-duct axis.
Most LG research has focused on the acinar cells, with relatively little attention being paid to the lacrimal ducts. The lack of knowledge regarding the lacrimal ducts was so profound that a precise nomenclature had not been established for the duct system. The present data establish a nomenclature for each segment of the lacrimal duct system and provide evidence that ducts play critical roles in lacrimal secretion.
根据每个导管段的解剖和结构特征，为兔泪道系统开发一个命名法，并提供 RT-PCR 和免疫荧光数据，以支持导管系统在泪液功能中发挥重要作用的观点。
用苏木精和伊红（H&E）对石蜡包埋的泪腺（LG）进行染色，并通过立体显微镜进行评估。用 cresyl 紫对 LG 的冷冻切片进行染色，并通过激光捕获显微切割（LCM）从每个导管段分离腺泡细胞和导管上皮细胞。通过实时 RT-PCR 分析这些细胞的 mRNA 水平。遵循离子转运体免疫荧光检测的标准方案。
根据形态特征，泪道系统分为六个节段：插入、小叶内、小叶间、小叶内、小叶间和主排泄管。尽管形态特征沿着整个导管系统逐渐变化，但离子转运体和水通道蛋白的基因表达，包括 AE3、AQP4、AQP5、CFTR、ClC2gamma、KCC1、NHE1、NKAalpha1、NKAbeta1、NKAbeta2、NKAbeta3 和 NKCC1，在导管段之间差异很大。免疫荧光结果通常与沿腺泡-导管轴的 mRNA 丰度一致。
大多数 LG 研究都集中在腺泡细胞上，而对泪道的关注相对较少。对泪道的了解如此之少，以至于尚未为其导管系统建立精确的命名法。本研究为泪道系统的每个节段建立了一个命名法，并提供了证据表明导管在泪液分泌中起着关键作用。
