biostudies-literatureLi HNational Natural Science Foundation of China770430https://www.ebi.ac.uk/biostudies/studies/S-EPMC8581264biostudies-literatureUnknown12<b>Background:</b> Motilin increases left gastric artery (LGA) blood flow in dogs <i>via</i> the endothelial motilin receptor (MLNR). This article investigates the signaling pathways of endothelial MLNR. <b>Methods:</b> Motilin-induced relaxation of LGA rings was assessed using wire myography. Nitric oxide (NO), and cyclic guanosine monophosphate (cGMP) levels were measured using an NO assay kit and cGMP ELISA kit, respectively. <b>Results:</b> Motilin concentration-dependently (EC₅₀=9.1±1.2×10^-8M) relaxed LGA rings precontracted with U46619 (thromboxane A₂ receptor agonist). GM-109 (MLNR antagonist) significantly inhibited motilin-induced LGA relaxation and the production of NO and cGMP. N-ethylmaleimide (NEM; G-protein antagonist), U73122 [phospholipase CFrontiers in physiologyRoles of Endothelial Motilin Receptor and Its Signal Transduction Pathway in Motilin-Induced Left Gastric Artery Relaxation in Dogs.PMC858126431271235Li HYang LJin CJin YfalseRoles of Endothelial Motilin Receptor and Its Signal Transduction Pathway in Motilin-Induced Left Gastric Artery Relaxation in Dogs.<b>Background:</b> Motilin increases left gastric artery (LGA) blood flow in dogs <i>via</i> the endothelial motilin receptor (MLNR). This article investigates the signaling pathways of endothelial MLNR. <b>Methods:</b> Motilin-induced relaxation of LGA rings was assessed using wire myography. Nitric oxide (NO), and cyclic guanosine monophosphate (cGMP) levels were measured using an NO assay kit and cGMP ELISA kit, respectively. <b>Results:</b> Motilin concentration-dependently (EC₅₀=9.1±1.2×10^-8M) relaxed LGA rings precontracted with U46619 (thromboxane A₂ receptor agonist). GM-109 (MLNR antagonist) significantly inhibited motilin-induced LGA relaxation and the production of NO and cGMP. N-ethylmaleimide (NEM; G-protein antagonist), U73122 [phospholipase C2021-01-01T00:00:00Z20212025-04-26T10:41:11.967Z2022-02-11T12:51:01.437ZS-EPMC85812643477702610.3389/fphys.2021.770430