Sensing of L‐Arginine by Gut‐Expressed Calcium Sensing Receptor Stimulates Gut Satiety Hormones Cholecystokinin and Glucose‐Dependent Insulinotropic Peptide Secretion in Pig Model. Issue 9 (8th August 2018) - Wang, Chao
Abstract : Abstract: Nutrients regulate the secretion of gut satiety hormones, which is related to the modulation of food intake and blood glucose levels. Calcium‐sensing receptor (CaSR) is involved in regulating gut hormone secretion in response tol ‐amino acids and multivalent cations. Rodents are often used to investigate the effect of nutrients on these hormonal release. However, results obtained using rodent models are difficult to be applied in humans, we used pigs as a model in this study because their physiology is similar to that of humans. In this study, we investigated whetherl ‐Arginine (l ‐Arg) could induce gut hormones cholecystokinin (CCK) and glucose‐dependent insulinotropic peptide (GIP) secretion in the porcine duodenum and if so, whether CaSR mediatedl ‐Arg‐regulated gut satiety hormone secretion. Our data showed that treatment with 20 and 50 mMl ‐Arg induced CCK and GIP secretion compared with 0 mMl ‐Arg. However, treatment withd ‐Arg (an inactive isomer) failed to elicit this response. The potency ofl ‐Arg to induce CCK and GIP secretion was enhanced in the presence of extracellular Ca 2+ and CaSR agonist cinacalcet. However, the effect of Arg on CCK and GIP secretion was attenuated by blocking CaSR and its downstream signaling molecules adenylate cyclase (AC) and phospholipase C (PLC). Taken all together, pig duodenum provides an appropriate model to explore the effects ofl ‐Arg on the secretion of the satiety‐related gut hormones CCK and GIP and the role of CaSR in this effect. Further investigations are needed to verify the effect ofl ‐Arg on food intake and blood glucose in human study. Practical Application: l ‐Arginine is able to modulate cholecystokinin and glucose‐dependent insulinotropic peptide secretion through the CaSR in pig model, which has a potential role in regulating food intake and blood glucose levels.