GLP-1R expression in the major salivary glands of rats

Abstract

ObjectivesGlucagon-like peptide 1 receptors (GLP-1R) are expressed in various tissues involved in glucose metabolism. The salivary glands, located at the start of the digestive organs, are involved in early glucose metabolism through the secretion of amylase. Expression of GLP-1R in salivary glands has not been reported; therefore, we investigated the expression and distribution of GLP-1R in the major salivary glands of rats. MethodsMale Wistar rats (8-weeks-old) were used in this study. Nested reverse transcription polymerase chain reaction (RT-PCR) assays and immunohistochemistry were performed to examine the expression and distribution of GLP-1R in the rat parotid gland (PG), submandibular gland (SMG), and sublingual gland (SLG). ResultsThe expression of GLP-1R mRNAs was detected in PGs, SMGs, and SLGs by RT-PCR. Immunohistochemical analyses revealed the presence of GLP-1R, predominantly in the ductal areas of PGs, SMGs, and SLGs. ConclusionsThis is the first time that GLP-1R expression has been detected in rat PG, SMG, and SLG. Our findings provide new insights into the effects of GLP-1 and GLP-1R in the major salivary glands of rats. Furthermore, our results indicate a new role for GLP-1 in salivary secretion, and potentially a new pathway for glucose metabolism.