Our previous study demonstrated that, different from the parotid and sublingual glands, the submandibular glands of adult mice did not show an immunoblot band for PLCβ3 which is critical in the secretion mechanism by muscarinic cholinergic signaling. Therefore, the submandibular glands of mice at various stages of postnatal development were examined for this enzyme molecule in immunoblot and immunohistochemistry. In immunoblot, a weak band for PLCβ3-expression was detected only at early postnatal stages. In immunohistochemistry, PLCβ3-immunoreactivity was distinctly found in most basally located cells of immature ducts, while the immunoreactivity was weakly seen in terminal tubule cells without significant immunoreactivity in adjacent acinar cells. In contrast, the immunoreactivity was distinctly found in some basal cells of adult excretory ducts, and it was ultrastructurally localized densely in close association with bundles of tonofilaments in the cells. The present finding suggests the possibility that Ca2+ signaling governed by phospholipase Cβ3 is involved in the differentiation of ductal basal cells into apical cells through control of keratin molecule(s) in the cells.

中文翻译：

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小鼠下颌下腺未成熟管和成年排泄管原位局限于基底细胞的内源性磷脂酶Cβ3的表达和定位。

我们先前的研究表明，与腮腺和舌下腺不同，成年小鼠的下颌下腺没有显示PLCβ3的免疫印迹带，而PLCβ3在毒蕈碱胆碱能信号传导的分泌机制中至关重要。因此，在免疫印迹和免疫组化中检查了小鼠在出生后各个阶段的颌下腺中的这种酶分子。在免疫印迹中，仅在产后早期检测到PLCβ3表达的弱带。在免疫组织化学中，在大多数未成熟导管的基底细胞中明显发现了PLCβ3免疫反应性，而在末梢肾小管细胞中免疫反应性较弱，而在相邻的腺泡细胞中没有明显的免疫反应性。相反，在成年排泄管的某些基底细胞中明显发现了免疫反应性，并且它与细胞中的tonnofilament束紧密相关地被紧密地定位在超微结构中。本发现表明由磷脂酶Cβ3控制的Ca 2+信号传导可能通过控制细胞中的角蛋白分子而参与了导管基底细胞向顶细胞的分化。