Department of Histology and Embryology, Graduate School of Medical Sciences, Kanazawa University , 13-1 Takara-machi, Kanazawa, Ishikawa 920-8640, Japan.
Acta Histochem Cytochem. 2014 Jun 28;47(3):95-102. doi: 10.1267/ahc.14005. Epub 2014 Jun 14.
In the major salivary glands of mice, acinar cells in the parotid gland (PG) are known to be the main site for the production of the digestive enzyme α-amylase, whereas α-amylase production in the submandibular gland (SMG) and sublingual gland (SLG), as well as the cell types responsible for α-amylase production, has been less firmly established. To clarify this issue, we examined the expression and localization of both the mRNA and protein of α-amylase in the major salivary glands of male and female mice by quantitative and histochemical methods. α-amylase mRNA levels were higher in the order of PG, SMG, and SLG. No sexual difference was observed in α-amylase mRNA levels in the PG and SLG, whereas α-amylase mRNA levels in the female SMG were approximately 30% those in the male SMG. Using in situ hybridization and immunohistochemistry, signals for α-amylase mRNA and protein were found to be strongly positive in acinar cells of the PG, serous demilune cells of the SLG, and granular convoluted tubule (GCT) cells of the male SMG, weakly positive in seromucous acinar cells of the male and female SMG, and negative in mucous acinar cells of the SLG. These results clarified that α-amylase is produced mainly by GCT cells and partly by acinar cells in the SMG, whereas it is produced exclusively by serous demilune cells in the SLG of mice.
在小鼠的主要唾液腺中，已知腮腺（PG）中的腺泡细胞是产生消化酶α-淀粉酶的主要部位，而颌下腺（SMG）和舌下腺（SLG）中的α-淀粉酶产生以及负责产生α-淀粉酶的细胞类型尚未得到充分证实。为了解决这个问题，我们通过定量和组织化学方法检查了雄性和雌性小鼠主要唾液腺中α-淀粉酶的 mRNA 和蛋白的表达和定位。α-淀粉酶 mRNA 水平的顺序为 PG、SMG 和 SLG。PG 和 SLG 中的α-淀粉酶 mRNA 水平没有性别差异，而雌性 SMG 中的α-淀粉酶 mRNA 水平约为雄性 SMG 的 30%。通过原位杂交和免疫组织化学，发现 PG 中的腺泡细胞、SLG 中的浆液半月细胞和雄性 SMG 中的颗粒卷曲小管（GCT）细胞中α-淀粉酶 mRNA 和蛋白的信号呈强阳性，雄性和雌性 SMG 中的浆液黏液腺泡细胞中呈弱阳性，而 SLG 中的黏液腺泡细胞呈阴性。这些结果阐明了α-淀粉酶主要由 SMG 中的 GCT 细胞和部分腺泡细胞产生，而在小鼠的 SLG 中则由浆液半月细胞特异性产生。
