Distribution and Stimulus Secretion Coupling of Enteroendocrine Cells along the Intestinal Tract

Abstract

The enteroendocrine system of the gut acts both locally and peripherally, regulating gastrointestinal function as well as metabolism, energy expenditure, and central appetite control through the release of a variety of hormones. The chemosensing ability of enteroendocrine cells is integral to their role in eliciting physiological changes in response to fluctuations in the composition of the intestinal lumen. Regulation of enteroendocrine cell activity is complex, and requires that these cells can integrate signals deriving from dietary sources as well as the nervous and endocrine systems. Here, we provide an overview of enteroendocrine cell form and function, with a focus on new insights into their distribution throughout the intestine and the stimulus secretion coupling mechanisms underlying the activity of these important members of the gut-brain axis. © 2018 American Physiological Society. Compr Physiol 8:1603-1638, 2018.

Gastrointestinally Digested Protein from the Insect Alphitobius diaperinus Stimulates a Different Intestinal Secretome than Beef or Almond, Producing a Differential Response in Food Intake in Rats

“…This suggests that the total amount of protein is not the only factor responsible for the secretion of these satiety hormones. CCK secretion has been reported to be stimulated by lipids and protein [23,42], and PYY is secreted in proportion to caloric intake [42,43]. The reduction of ghrelin levels is proportional to the energy load and macronutrient content, and its suppression is greatly promoted by protein and less effectively by lipids [44,45].…”

“…The enteroendocrine cells (EECs) present in the gastrointestinal tract interact with nutrients and secrete hormones in response to food ingestion, acting as chemosensors of the lumen content [21]. EECs are scattered throughout the gastrointestinal tract, and the hormones they produce are concentrated in specific regions of the gut, according to their roles in regulating these physiological functions [22,23]. Each gut hormone appears in the bloodstream based on its individual temporal profile, which is determined by patterns of food intake, nutrient absorption, and the distribution of EECs along the intestinal tract [24,25].…”

Incretin Hormones and Type 2 Diabetes – Mechanistic Insights and Therapeutic Approaches

“…Transporter proteins resulting in co-transport of amino acids and ions are also linked to GLP-1 release. Uptake of Lglutamine is for example Na + coupled and results in an elevation of intracellular Ca 2+ channels [33]. L-glutamine, and other amino acids to a lesser extent, may act to elevate intracellular cAMP levels, another important stimulus to GLP-1 release [34].…”

Antagonizing somatostatin receptor subtype 2 and 5 reduces blood glucose in a gut- and GLP-1R-dependent manner

“…Hormones secreted from the gut are known to be of importance for the regulation of glucose metabolism (1)(2)(3), with the incretin hormone glucagon-like peptide-1 (GLP-1) in particular, contributing to enhance postprandial insulin secretion (4)(5)(6)(7)(8). Patients with type 2 diabetes have significantly impaired incretin function (9)(10)(11)(12), and treatment with stabile GLP-1 receptor agonists (GLP-1RAs) or enhancing endogenous levels of active GLP-1 using dipeptidyl peptidase 4 inhibitors (DPP-4is) effectively lowers blood glucose levels (13,14).…”