Ryberg Anders T, Warfvinge Gunnar, Axelsson Louise, Soukup Ondrej, Götrick Bengt, Tobin Gunnar
Department of Pharmacology, The Sahlgrenska Academy at Göteborg University, Sweden.
Arch Oral Biol. 2008 Jan;53(1):66-74. doi: 10.1016/j.archoralbio.2007.07.012. Epub 2007 Sep 6.
In rat parotid, submandibular and sublingual glands and in ovine parotid and in human labial glands, the expression of muscarinic receptor subtypes was examined by immunoblotting and immunohistochemistry. Functional correlates were searched for in rat salivary glands. In the rat submandibular and sublingual glandular tissues clear signals of muscarinic M1 and M5 receptors could be detected in the immunoblotting and vague bands for muscarinic M3 and, in particular for, M4 receptors. The rat parotid gland differed. In this gland, the signal was less obvious for the muscarinic M1 receptor, and further, muscarinic M4 receptors appeared more strongly marked than in the submandibular glands. The results from the immunohistochemistry could be interpreted as the muscarinic M4 receptors are located on nerve fibres, since the outer layer of lobuli were densely stained. Intraglandular vessels in the rat submandibular and parotid glands showed expression of M3 receptors. In contrast to the parotid gland, the submandibular vessels also expressed M1 and M2 receptors. Occasionally M5 receptors appeared in the arteries and veins also. The functional studies in the rat confirmed muscarinic M1 receptor mediated secretion in the submandibular gland. Since the M1 receptor blockade did not affect submandibular blood flow, indirect vascular effects could not in total explain the secretory inhibition. Also in the human labial glands, muscarinic M1, M3 and M5 receptors occurred. No or low amounts of muscarinic M2 and M4 receptors could be detected. In patients with Sjögren-like symptoms an up-regulation of M3, M4 and M5 receptors was apparent in the labial glands. In ovine parotid glands all receptors could be detected, but constantly with vague bands for muscarinic M2 receptors. In conclusion, muscarinic M1 receptors seem to be expressed in seromucous/mucous glands. A secretory effect by muscarinic M5 receptors is not to be excluded, since they were expressed in all the glands examined. However, other functions, such as promotion of inflammation, cell growth and proliferation are possible as well.
在大鼠腮腺、颌下腺和舌下腺以及绵羊腮腺和人类唇腺中，通过免疫印迹法和免疫组织化学法检测了毒蕈碱受体亚型的表达。在大鼠唾液腺中寻找功能相关性。在大鼠颌下腺和舌下腺组织中，免疫印迹法可检测到毒蕈碱M1和M5受体的清晰信号，以及毒蕈碱M3受体的模糊条带，尤其是M4受体的条带。大鼠腮腺有所不同。在该腺体中，毒蕈碱M1受体的信号不太明显，此外，毒蕈碱M4受体的标记比颌下腺更强。免疫组织化学结果可解释为毒蕈碱M4受体位于神经纤维上，因为小叶外层染色密集。大鼠颌下腺和腮腺中的腺内血管显示出M3受体的表达。与腮腺不同，颌下血管也表达M1和M2受体。偶尔在动脉和静脉中也出现M5受体。大鼠的功能研究证实毒蕈碱M1受体介导颌下腺的分泌。由于M1受体阻断不影响颌下腺血流，间接血管效应不能完全解释分泌抑制。在人类唇腺中也存在毒蕈碱M1、M3和M5受体。未检测到或仅检测到少量毒蕈碱M2和M4受体。在具有干燥综合征样症状的患者中，唇腺中M3、M4和M5受体明显上调。在绵羊腮腺中可检测到所有受体，但毒蕈碱M2受体的条带始终模糊。总之，毒蕈碱M1受体似乎在浆液性/粘液性腺中表达。不排除毒蕈碱M5受体的分泌作用，因为它们在所有检测的腺体中均有表达。然而，其他功能，如促进炎症、细胞生长和增殖也有可能。
