The lacrimal sac (LS) empties in the nasolacrimal duct to drain the tears in the inferior nasal meatus. Different studies indicated the role of the lacrimal pump in the lacrimal drainage. Although controversial, the lacrimal pump mechanism is an extrinsic one, either active, or passive. An intrinsic contractile potential of the LS was not documented previously. We thus aimed a retrospective immunohistochemical study to test the alpha-smooth muscle actin (α-SMA) and h-caldesmon expression in the LS wall. We used archived paraffin-embedded samples of LS from ten adult patients. The α-SMA + phenotype was detected in basal epithelial cells, in subepithelial ribbons of stromal cells, in vascular smooth muscle cells, as well as in pericytes. H-caldesmon was exclusively expressed in pericytes, vascular smooth muscle cells and myoepithelial cells of the subepithelial glands. The most striking feature we found in all samples was a consistent stromal network of α-SMA+/h-caldesmon- myofibroblasts. This finding supports an intrinsic scaffold useful for the lacrimal pump.

中文翻译：

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在泪液泵中添加成肌纤维细胞。

泪囊（LS）在鼻泪管中排空，以排走鼻下鼻道的眼泪。不同的研究表明泪泵在泪液引流中的作用。尽管引起争议，但泪泵机制是外在的，主动的或被动的。LS的固有收缩潜力以前没有记录。因此，我们旨在进行回顾性免疫组织化学研究，以测试LS壁中的α平滑肌肌动蛋白（α-SMA）和h-caldesmon表达。我们使用了来自十名成人患者的LS的石蜡包埋样本。在基底上皮细胞，基质细胞的上皮下带，血管平滑肌细胞以及周细胞中检测到α-SMA+表型。H-caldesmon仅在周细胞中表达，上皮下腺的血管平滑肌细胞和肌上皮细胞。我们在所有样品中发现的最显着特征是一致的α-SMA+ / h-caldesmon-成纤维细胞基质网络。该发现支持了对于泪泵有用的固有支架。