Neural emergency system in the stomach

Peptidergic sensory neurons in the control of vascular functions: mechanisms and significance in the cutaneous and splanchnic vascular beds.

Tachykinins in the gut. Part II. Roles in neural excitation, secretion and inflammation.

J.H. Gaddum began his long and most productive career in pharmacology in 1925, when he joined the Wellcome Research Laboratories in Beckenham, under the guidance of J.W. Trevan. It was here that he was exposed to problems in bioassay, the generation of quantitative data and its subsequent mathematical and statistical evaluation. Three years later, when he joined Sir Henry Dale at the National Institute of Medial Research in Hampstead, he retained his enthusiasm for such analytical pharmacology, while developing interests in many other areas including peripheral neuronal regulatory mechanisms and the production and actions of novel local mediators. Of particular relevance to the theme of this review was his detection in 1931, along with U.S. von Euler, of an unknown depressor substance in extracts of various tissues, particularly the brain and intestine (Euler & Gaddum, 1931). This factor, which they called substance P, for no better reason than this was the letter on the label used on the original standard preparations of the extracts, was more fully characterized in collaboration with H.O. Schild (Gaddum & Schild, 1934). These studies by Gaddum thus initiated the field of pharmacological study on sensory neuropeptides. Only more recently, however, has there been appropriately detailed research on the actions and role of this diverse group of peptides with potent biological properties. As will be discussed later, the sensory neuropeptide, calcitonin gene-related peptide (CGRP), plays an important role in the regulation of gastric mucosal integrity, interacting with other local mediators. During his time at the College of the Pharmaceutical Society in Bloomsbury, Gaddum also developed and refined techniques to determine the release of neurotransmitters into the perfused vasculature of isolated tissues (Gaddum et al., 1939). It is therefore fitting, in view of his interest in neuronal modulatory processes and the release of local mediators, to describe in this Thirteenth Gaddum Memorial Lecture, our current understanding of the mechanisms that regulate microvascular blood flow in the gastric mucosa. It will become apparent that local neuronal and endotheliumderived factors that affect the microcirculation have a crucial influence on the processes that allow the gastric mucosa to

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Neuronal and endothelium-derived mediators in the modulation of the gastric microcirculation : integrity in the balance

The stomach is in a state of continuous exposure to potentially hazardous agents. Hydrochloric acid together with pepsin constitutes a major and serious threat to the gastric mucosa. Reflux of alkaline duodenal contents containing bile and pancreatic enzymes are additional important injurious factors of endogenous origin. Alcohol, cigarette smoking, drugs and particularly aspirin and aspirin-like drugs, and steroids are among exogenous mucosal irritants that can inflict mucosal injury. The ability of the stomach to defend itself against these noxious agents has been ascribed to a number of factors constituting the gastric mucosal defense. These include mucus and bicarbonate secreted by surface epithelial cells, prostaglandins, sulfhydryl compounds and gastric mucosal blood flow. The latter is considered by several researchers to be of paramount importance in maintaining gastric mucosal integrity. The aim of this paper is to review the experimental and clinical data dealing with the role of mucosal blood flow and in particular the microcirculation in both damage and protection of the gastric mucosa.

Gastric mucosal integrity: gastric mucosal blood flow and microcirculation. An overview.

Stimulation of sensory neurons in the rat stomach by intragastric capsaicin leads to a marked rise in gastric mucosal blood flow (GMBF). The gastric mucosa, in particular submucosal blood vessels, is densely innervated by afferent neurons containing peptides, of which calcitonin gene-related peptide (CGRP) is the most potent vasodilator. Using selective ablation of either the vagal or spinal sensory innervation to the stomach by perineural application of capsaicin, and by intra-arterial infusion of the CGRP receptor antagonist hCGRP-(8-37) close to the stomach, we investigated 1) the origin (vagal or spinal) of the sensory neurons and 2) whether CGRP mediates this hyperemic response. Perivagal application of capsaicin to the rat 10-20 days before experiments had no effect on the hyperemic response to intragastric capsaicin. In contrast, periceliac application of capsaicin significantly reduced this response by 60%. Intra-arterial infusion of CGRP (20 pmol/min) close to the stomach produced a marked rise i...

Role of calcitonin gene-related peptide in gastric hyperemic response to intragastric capsaicin.

Alloying is a well‐accepted strategy for modulating the electronic structures of catalyst materials. Compared to disordered solid‐solution alloys, intermetallic compounds feature ordered atomic arrangements and provide a unique platform with a rich and diverse resource to study the relationships among chemical composition, atomic structure, electronic structure, and properties. Unfortunately, it is still challenging to synthesize the nanostructures of intermetallic compounds for catalysis research. In this study, a series of intermetallic silicides (PtSi, RhSi, Ru2Si3, IrSi), germanide (Ru2Ge3), and stannides (Ru3Sn7, IrSn2, PdSn3, PdSn2) are rationally designed and constructed through a facile molten‐salt‐assisted route. As an example, the PtSi not only shows highly desirable electrocatalytic properties for the hydrogen evolution reaction (HER) with low overpotentials of 22, 38, and 66 mV at a current density of 10 mA cm‐2 in acidic, alkaline, and neutral media, respectively, but exhibits superior durability, as well as >97% faradic efficiency. The theoretical calculations suggest that the introduction of Si to Pt could weaken the binding energy between Pt and H atoms, which further facilitates the hydrogen generation during the HER process. Further, the findings inspired the authors to develop other kinds of metal‐based carbon‐group intermetallic phases with excellent activity in the HER and beyond.

General Synthesis of Transition‐Metal‐Based Carbon‐Group Intermetallic Catalysts for Efficient Electrocatalytic Hydrogen Evolution in Wide pH Range

Recent advances of functional heterometallic-organic framework (HMOF) materials: Design strategies and applications

Dye-Anchoring Strategy with a Metal–Organic Framework for a Highly Efficient Visible-Light-Driven Photocatalytic CO2 Reduction through the Solid–Gas Mode

The design of white-light phosphor is highly desirable for practical applications in SSL (solid-state lighting) and its related fields. Dye-loaded metal-organic frameworks (MOFs) have been widely demonstrated as one type of promising down conversion materials for WLEDs (white-light-emitting diodes), but two issues (dye leakage and inadequate quantum efficiency) require to be addressed before possible applications. Here, a series of single-phase dyes@In-MOF phosphors have been prepared in two different ways: the in-situ process and soaking method. The study of these dyes@In-MOF phosphors confirms the importance of this in-situ process that could effectively increase dye loading and quantum efficiency and greatly decrease dye leakage. As a result, a perfect WLED, fabricated using the in-situ-synthesized (AF/RhB@In-MOF)-3 (AF: Acriflavine; RhB: Rhodamine B) and 450 nm blue LED chip, exhibited a very high quantum yield (QY, up to 42.27%), a high luminous efficacy (LE) of 50.75 lm/W, a high color rendering index (CRI) of 91.2, and nearly identical Commission International ed'Eclairage (CIE) coordinates (0.33,0.31), indicating the potential application of the dye-loaded MOFs with good color quality in smart white LEDs.

Dong-Sheng Li

Papers

Role of calcitonin gene-related peptide in gastric hyperemic response to intragastric capsaicin.

General Synthesis of Transition‐Metal‐Based Carbon‐Group Intermetallic Catalysts for Efficient Electrocatalytic Hydrogen Evolution in Wide pH Range

Recent advances of functional heterometallic-organic framework (HMOF) materials: Design strategies and applications

Dye-Anchoring Strategy with a Metal–Organic Framework for a Highly Efficient Visible-Light-Driven Photocatalytic CO2 Reduction through the Solid–Gas Mode

Encapsulating Organic Dyes in Metal-Organic Frameworks for Color-Tunable and High-Efficiency White-Light-Emitting Properties.