Glucagon like peptide 1 and glucose-dependent insulinotropic polypeptide stimulate the release of substance P from TRPV1 and TRPA1 expressing sensory nerves.

Glucagon like peptide 1 and glucose-dependent insulinotropic polypeptide stimulate the release of substance P from TRPV1 and TRPA1 expressing sensory nerves. Am J Physiol Gastrointest Liver Physiol. 2020 May 18;: Authors: Mayer F, Gunawan AL, Tso P, Aponte GW Abstract Glucagon-like peptide 1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from enteroendocrine cells (EEC) in response to nutrient ingestion and lowers blood glucose levels by stimulation of insulin secretion, and thus are defined as incretins. GLP-1 receptor (GLP-1R) expression has been identified on enteric neurons that include intrinsic afferent neurons, extrinsic spinal and vagal sensory afferents, but has not been shown to have an incretin effect through these nerves. GLP-1 and GIP enter the mesenteric lymphatic fluid (MLF) after a meal via the interstitial fluid (IF) from local tissue secretion and/or blood capillaries. We tested if MLF could induce diet dependent intransient increases in intracellular calcium ( [Ca2+]i) in cultured sensory neurons. Postprandial rat MLF, collected from the superior mesenteric lymphatic duct, induced a significant 2 - fold higher intransient increase in [Ca2+]iin primary-cultured sensory neurons than MLF from fasted rats. Inhibition of transient receptor potential vanilloid 1 (TRPV1) and TRPV1 and ankyrin 1 cation channels (TRPA1) with ruthenium red eliminated the difference. Substance P (SP) (a peptide th...
Source: American Journal of Physiology. Gastrointestinal and Liver Physiology - Category: Physiology Authors: Tags: Am J Physiol Gastrointest Liver Physiol Source Type: research