DOCSLIB.ORG

A History of Gastric Secretion and Digestion a History of Gastric Secretion and Digestion Experimental Studies to 1975

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
A History of Gastric Secretion and Digestion a History of Gastric Secretion and Digestion Experimental Studies to 1975 A History of Gastric Secretion and Digestion A History of Gastric Secretion and Digestion Experimental Studies to 1975 HORACE W. DAVENPORT William Beaumont Professor of Physiology Emeritus The University of Michigan Springer New Y ork 1992 Copyright © 1992 by the American Physiological Society Originally published by American Physiological Society in 1992 Softcoverreprint of the bardeover 1st edition 1992 All rights reserved. No partoftbis publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior permission ofOxford University Press. Library ofCongress Cataloging-in-Publication Data Davenport, Horace Willard, 1912- A history of gastric secretion and digestion : experimental studiesto 1975 I Horace W. Davenport. p. cm. lncludes bibliographical references and index. ISBN 978-1-4614-7602-3 (eBook) DOI 10.1007/978-1-4614-7602-3 I. Gastroenterology-History. 2. Gastric-Secretion-Research-History. 3. Digestion-Research-History. I. Title. [DNLM: I. Digestion. 2. Gastric Acid-secretion. 3. Gastroenterology-history. 4. Research-history. 5. Stomach-chemistry. 6. Stomach-physiology. Wlll.l D247h] QP145.D325 1992 612.3'2'072-dc20 DNLM/DLC for Library ofCongress 91-31832 987654321 For Charles F. Code, known to every gastroenterologist as "Charlie Code" and as their preeminent physiologist for the last fifty years Preface For centuries men speculated about the process of gastric digestion, but Iate in the eighteenth and early in the nineteenth centuries physiologists, both physicians and laymen, began to accumulate experimental evidence about its nature. At the same time, others discovered that the stomach is capable of secreting a strong mineral acid, and the questions of how that secretion is produced and how it is controlled became enduring problems. A Iittle later, the discovery that an acid extract of dead gastric mucosa is capable of digesting meat put the study of gastric secretion and digestion on a firm mechanistic foundation. From that time to the present, physi­ ologists have assiduously investigated gastric secretion and digestion, with the result that knowledge ofthose topics is as comprehensive and penetrating as isthat about other physiological processes. In addition, that knowledge is the basis of discrimi­ nating and effective clinical practice. I have described the experimental study of gastric secretion and digestion for two reasons. The firstisthat the successes and some ofthe failures ofphysiologists over two centuries are important parts of intellectual history that deserve to be recorded. The second is that some of those who use the accumulated knowledge every day are curious about its genesis. I assume that my readers have the technical knowledge to understand what I have written. If my account does not fully satisfy their curiosity, I have provided references that will open the path to further study. This account is necessarily conditioned by my own knowledge, ability, and enterprise, and those have their Iimits. Furthermore, I Iimit my account by begin­ ning with the period 1777 to 1833 when the pioneers of experimental gastroenter­ ology, Edward Stevens, William Beaumont, Johann Eberle, and their contempo­ raries, began to gather experimental evidence. I end in 1975, the date of Charlie Code's retirement from the Mayo Clinic and Mayo Foundation, for ifl attempted to bring the account more nearly up-to-date, it would have degenerated into an indigestible review of current work. I have myself studied gastric physiology in the laboratory for more than 40 viii / PREFACE years, and some readers may think I have unduly emphasized my own work. That may be the case, and the limits of my own outlook may have prevented me from giving appropriate weight to the work ofothers. A far more restrictive limit has been imposed by an attitude typical of one who has been a professor of physiology in an American medical school all bis professionallife. I and my colleagues on medical faculties assume, often unconsciously, that the proper aim of physiological research is to reach an understanding of normal and abnormal function in the human being. We may work at the molecular or subcellular level, or we may use the ubiquitous medical student or patient as our experimental animal, but our goal is the same. Consequently, when I write about the history ofthe physiology of gastric secretion and digestion, I am writing about a very limited number of species, the human sub­ ject and the dog, cat, and frog. I completely ignore ruminant physiology and the large and diverse knowledge of the physiology of the stomach in other species, invertebrate as well as vertebrate. I make no apology for the narrowness of my out­ look, for I believe my potential readers share it. Ann Arbor, Mich. H.W.D. September 1991 Acknowledgments My greatest debt is to the University of Michigan and to Jack Kostyo and John Williams, my successors as chairmen ofthe department ofphysiology, for allowing me the use of an office long past my retirement from the faculty. The university's Taubman Medical Library and Hateher Graduate Library have been rieb resources, and their reference librarians have been uniformly helpful. I am grateful to the many gastroenterologists who made my task easier by sending me their bib­ liographies and in particular to Paul Guth, who took the trouble to find a Iist of Morton Grossman's numerous publications. Charlie Code gave me a copy ofhis even moreimpressive bibliography and a guide to the work ofhis colleagues at the Mayo Clinic. Code read my original typescript, and bis comments and corrections improved it. I am, however, entirely responsible for errors, oversights, and misin­ terpretations. Contents 1 . Secretion of Hydrochloric Acid, 3 Site of Secretion, 3 Structure ofthe Oxyntic Cell, 4 Site of Appearance of Acid, 5 Concentration of Acid, 8 Free and Combined Acid in the Human Stomach, 8 In the Dog: Two Components, l3 The Problem ofTonicity, 18 An Alternative to Two Components: Back-Diffusion, 19 Secretion of Anions, 24 Bromide and Chloride, 24 Active Secretion ofChloride: Adrian Hogben, 27 Iodide, 29 Mechanism of Acid Secretion, 32 Carbonic Anhydrase in Parietal Cells, 33 Thiocyanate and Carbonic Anhydrase, 36 Carbonic Anhydrase and Sulfanilamide, 39 Digression on Sulfonamide Secretion into Gastric Juice, 41 Postwar Theories of the Mechanism, 46 The Redox Theory: E. J. Conway, 46 Acid Secretion by the Frog Stomach: Robert E. Davies, 47 ls the Ratio ofQuotients Greater Than 4?, 51 xii / CONTENTS Electrophysiology ofSecretion: Warren S. Rehm, 56 Electrolyte Composition ofthe Gastric Mucosa, 59 Chloride Transport by Isolated Oxyntic Cells, 62 Asymmetry ofthe Gastric Mucosa, 64 Identification ofPotassium Fluxes, 67 Thiocyanate Again, 67 Potential Differences Caused by Ion Transport, 68 Energy for Acid Secretion, 69 The Canalicular Membrane, 71 SUMMARY Secretion of Hydrochiarie Acid as of 1975, 74 2. Pepsinsand Pepsinogens, 76 Chemistry of Pepsins to 1900, 76 Proteins: Their Names, 76 Characterization of Proteins, 77 Organic Components of Proteins, 78 Gastric Digestion ofProteins, 78 The Discovery of Pepsin, 80 Does Gastric Juice Merely Dissolve Proteins?, 81 ChiefCells and Their Contents, 82 Chemistry of Pepsin and lts Substrate, 84 The Peptide Bond, 84 Characteristics of Proteins: Their Individuality, 85 Characteristics of Proteins: Molecular Weight, 85 Characteristics of Proteins: Amino Acid Sequence, 85 Characteristics of Proteins: Configuration, 86 Pepsin as a Protein and a Proteolytic Enzyme, 87 Is Pepsin a Protein?, 87 Activity ofPepsin: Bonds Split, 89 Pepsinogen: Crystallization and Properties, 89 Pepsinogen in Urine and Blood, 89 Source ofUropepsin, 91 Clinical Studies ofSerum Pepsinogen and Uropepsin, 92 Uropepsin and Stress, 92 Multiple Pepsinsand Pepsinogens, 94 Questions About Pepsin, 94 S.Oren S.Orensen's Contribution, 94 Pepsin's pH Activity Curve, 95 CONTENTS / xiii New Methods, New Pepsins, 96 SUMMARY Pepsinsand Pepsinagens as of 1975, 99 3. Mucus and Cell Renewal, 101 The Second Component of Gastric Secretion, 101 ldentification ofthe Second Component, 101 lnorganic Constituents by Extrapolation, 102 lnorganic Constituents by Analysis, 103 Mucus: The Organic Constituent, 104 Sources ofGastric Mucus, 105 Structure ofGastric Mucus, 107 Heterogeneity ofGastric Mucus, 111 Discovery ofthe lntrinsic Factor, 111 Nature ofthe lntrinsic Factor, 115 Source ofthe lntrinsic Factor, 116 Gastrone, 11 7 Functions ofMucus, 117 M ucus and Pepsin: Diffusion and Inhibition, 118 Mucus and Diffusion of Acid, 123 Nervous Control ofMucus Secretion, 123 Cell Turnover, 125 Early Studies ofCell Replacement, 125 Arrest of Mitosis, 125 Radioautography, 126 Synthesis ofCell Components, 126 Use ofTritiated Thymidine, 127 Origin ofParietal and ChiefCells, 128 SUMMARY Mucus and Cell Renewal as of 1975, 131 4. Reflex Control of Gastric Secretion, 134 Inhibition of Gastric Secretion, 134 Local Reflex Stimulation, 136 Gastric Fistulas and Vagal Reflexes, 138 Pouches and Their Reflex Control, 140 Reflexes from the lntestine, 144 Efferent Pathways, 144 The Peripheral Nerve Center, 145 xiv / CONTENTS Insulin and the Vagus, 146 2-Deoxy-o-Glucose and the Vagus, 148 The Vasovagal Reflex, 148 Psychic Secretion in Man, 148 SUMMARY Reflex Control of Gastric Secretion as of 1975, 151 5. Histamine, 153 Histamine and Peptic Ulcer, 153 Frank Mann and Experimental Peptic Ulceration, 153 Preventing Mann-Williamson Ulcers: Urogastrone, 155
Load more

Recommended publications
  • Coffee and Its Effect on Digestion
    Expert report Coffee and its effect on digestion By Dr. Carlo La Vecchia, Professor of Medical Statistics and Epidemiology, Dept. of Clinical Sciences and Community Health, Università degli Studi di Milano, Italy. Contents 1 Overview 2 2 Coffee, a diet staple for millions 3 3 What effect can coffee have on the stomach? 4 4 Can coffee trigger heartburn or GORD? 5 5 Is coffee associated with the development of gastric or duodenal ulcers? 6 6 Can coffee help gallbladder or pancreatic function? 7 7 Does coffee consumption have an impact on the lower digestive tract? 8 8 Coffee and gut microbiota — an emerging area of research 9 9 About ISIC 10 10 References 11 www.coffeeandhealth.org May 2020 1 Expert report Coffee and its effect on digestion Overview There have been a number of studies published on coffee and its effect on different areas of digestion; some reporting favourable effects, while other studies report fewer positive effects. This report provides an overview of this body of research, highlighting a number of interesting findings that have emerged to date. Digestion is the breakdown of food and drink, which occurs through the synchronised function of several organs. It is coordinated by the nervous system and a number of different hormones, and can be impacted by a number of external factors. Coffee has been suggested as a trigger for some common digestive complaints from stomach ache and heartburn, through to bowel problems. Research suggests that coffee consumption can stimulate gastric, bile and pancreatic secretions, all of which play important roles in the overall process of digestion1–6.
    [Show full text]
  • Study Guide Medical Terminology by Thea Liza Batan About the Author
    Study Guide Medical Terminology By Thea Liza Batan About the Author Thea Liza Batan earned a Master of Science in Nursing Administration in 2007 from Xavier University in Cincinnati, Ohio. She has worked as a staff nurse, nurse instructor, and level department head. She currently works as a simulation coordinator and a free- lance writer specializing in nursing and healthcare. All terms mentioned in this text that are known to be trademarks or service marks have been appropriately capitalized. Use of a term in this text shouldn’t be regarded as affecting the validity of any trademark or service mark. Copyright © 2017 by Penn Foster, Inc. All rights reserved. No part of the material protected by this copyright may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying, recording, or by any information storage and retrieval system, without permission in writing from the copyright owner. Requests for permission to make copies of any part of the work should be mailed to Copyright Permissions, Penn Foster, 925 Oak Street, Scranton, Pennsylvania 18515. Printed in the United States of America CONTENTS INSTRUCTIONS 1 READING ASSIGNMENTS 3 LESSON 1: THE FUNDAMENTALS OF MEDICAL TERMINOLOGY 5 LESSON 2: DIAGNOSIS, INTERVENTION, AND HUMAN BODY TERMS 28 LESSON 3: MUSCULOSKELETAL, CIRCULATORY, AND RESPIRATORY SYSTEM TERMS 44 LESSON 4: DIGESTIVE, URINARY, AND REPRODUCTIVE SYSTEM TERMS 69 LESSON 5: INTEGUMENTARY, NERVOUS, AND ENDOCRINE S YSTEM TERMS 96 SELF-CHECK ANSWERS 134 © PENN FOSTER, INC. 2017 MEDICAL TERMINOLOGY PAGE III Contents INSTRUCTIONS INTRODUCTION Welcome to your course on medical terminology. You’re taking this course because you’re most likely interested in pursuing a health and science career, which entails ­proficiency­in­communicating­with­healthcare­professionals­such­as­physicians,­nurses,­ or dentists.
    [Show full text]
  • The Role of Lactic Acid in Gastric Digestion
    [Reprinted from The Medical News, December 30, 1893.] THE ROLE OF LACTIC ACID IN GASTRIC DIGESTIOA ALLEN A. JONES, M.D., CLINICAL INSTRUCTOR IN MEDICINE AND INSTRUCTOR IN PRACTICE, MEDICAL DEPARTMENT, UNIVERSITY OF BUFFALO. Lactic acid is present in the stomach under nor- mal conditions from thirty to forty minutes after a test-meal composed of a roll and water or of chopped lean beef, dry bread, and water. At the expiration of that time lactic acid should entirely disappear from the stomach-contentsand free hydro- chloric acid alone should prevail. During the first thirty or forty minutes after meals the digestion of starches and albuminoids progresses quite rapidly, as may be proved by finding the middle-products and end-products of gastric digestion present, so that the presence of free lactic acid does not pro- hibit digestion. As soon as food enters the healthy stomach the secretion of hydrochloric acid is excited and it increases in amount until the production of lactic acid is checked. The exact origin of lactic acid in the healthy stomach is still a matter of debate. It may arise wholly from fermentation, or from the combination of some food-product with a secretion 1 Read before the Buffalo Academy of Medicine, November x 4) 1893. 2 from the gastric glandules, or from the gastric mucosa as a distinct secretion, although electric stimulation of the gastric glandules excites the se- cretion of hydrochloric acid and not of lactic acid. I think it arises largely from fermentation of the food, as its amount is usually proportionate to the amount of starchy, saccharine, and milk foods taken.
    [Show full text]
  • Intestinal and Liver Morphometry of the Yellow Tail Tetra (Astyanax Altiparanae) Fed with Oregano Oil
    Anais da Academia Brasileira de Ciências (2016) 88(2): 911-922 (Annals of the Brazilian Academy of Sciences) Printed version ISSN 0001-3765 / Online version ISSN 1678-2690 http://dx.doi.org/10.1590/0001-3765201620150202 www.scielo.br/aabc Intestinal and liver morphometry of the Yellow Tail Tetra (Astyanax altiparanae) fed with oregano oil POLLYANNA M.F. FERREIRA, DÉBORA W. CALDAS, ANA LÚCIA SALARO, SIRLENE S.R. SARTORI, JERUSA M. OLIVEIRA, ALEX J.S. CARDOSO and JENER A.S. ZUANON Departamento de Biologia Animal, Universidade Federal de Viçosa/UFV, Av. PH Rolfs, s/n, 36570-900 Viçosa, MG, Brasil Manuscript received on April 6, 2015; accepted for publication on August 20, 2015 ABSTRACT This study aimed to evaluate the effect of oregano oil on the intestinal and liver morphometry of yellow tail tetra, Astyanax altiparanae. Fish (1.46 ± 0.09 g) were kept in a 60-L aquaria, at a stocking density of 0.5 fi sh L-1. Six diets containing varying amounts of oregano oil were evaluated (0.0; 0.5; 1.0; 1.5; 2.0 and 2.5 g of oregano oil kg-1). At the end of 90 days, the fi sh were euthanised. Four intestines and four livers were collected per treatment, which were fi xed in Bouin and embedded in resin. For height and width folds, the absorption surface area and thickness of the muscular layer a positive linear effect of oregano oil was observed. A decrescent linear effect on the total number of goblet cells was also observed. For the cytoplasmic percentage of hepatocytes and liver glycogen, a positive linear effect of oregano oil was observed.
    [Show full text]
  • New Developments in Goblet Cell Mucus Secretion and Function
    REVIEW nature publishing group New developments in goblet cell mucus secretion and function GMH Birchenough1, MEV Johansson1, JK Gustafsson1, JH Bergstro¨m1 and GC Hansson1 Goblet cells and their main secretory product, mucus, have long been poorly appreciated; however, recent discoveries have changed this and placed these cells at the center stage of our understanding of mucosal biology and the immunology of the intestinal tract. The mucus system differs substantially between the small and large intestine, although it is built around MUC2 mucin polymers in both cases. Furthermore, that goblet cells and the regulation of their secretion also differ between these two parts of the intestine is of fundamental importance for a better understanding of mucosal immunology. There are several types of goblet cell that can be delineated based on their location and function. The surface colonic goblet cells secrete continuously to maintain the inner mucus layer, whereas goblet cells of the colonic and small intestinal crypts secrete upon stimulation, for example, after endocytosis or in response to acetyl choline. However, despite much progress in recent years, our understanding of goblet cell function and regulation is still in its infancy. THE INTESTINE system of mucus covering the epithelium. There is a The gastrointestinal tract is a remarkable organ. Not only can it two-layered mucus system in the stomach and colon and a digest most of our food into small components, but it is also single-layered mucus in the small intestine.5 The mucus layers filled with kilograms of microbes that live in stable equilibrium in these three regions perform their protective function using with us and our immune system.
    [Show full text]
  • Control and Efficiency of Digestive Function of Marine Fish Larvae
    Control and Efficiency of Digestive Function of Marine Fish Larvae Ivar Rønnestad Department of Zoology, University of Bergen, Allegt 41, N 5007 Bergen, Norway Tel. + 47 55 58 35 86, Fax, +47 55 58 9276. [email protected] ABSTRACT Recent downscaling and improvements of tube feeding techniques have allowed more detailed studies on the digestive and absorptive efficiency of larval fish, including the transfer kinetics of selected nutrients from the lumen of the digestive tract into the tissues of the body. Freely dissolved amino acids seem to be absorbed rapidly and with a high efficiency. There has also been some progress towards understanding how the digestive process is controlled in marine fish larvae. The peptide hormone cholecystokinin (CCK) has been targeted since it is believed to play an important role in controlling digestive function in vertebrates. Key words: digestive function, cholecystokinin, absorption, amino acids, marine fish larvae INTRODUCTION When fish larvae commence exogenous feeding, the flow of nutrients formerly supplied only from yolk reserves becomes supplemented through the digestive tract. The majority of marine fish larvae currently targeted for cultivation hatch from pelagic eggs and their digestive system is still developing at the onset of exogenous feeding. A fully developed digestive tract, including gastric digestion, develops during metamorphosis. Although the larval gut is not completely developed at the onset of exogenous feeding, it is sufficiently efficient to support larval growth by digesting such prey as is available under natural conditions in the sea. The physiological constraints of the gut with respect to digestion of cultivated live prey and particularly formulated starter feeds still remain to be elucidated.
    [Show full text]
  • Cf Facts — the Digestive System
    Beginning CF Care — CF FACTS — THE DIGESTIVE SYSTEM CF FACTS — THE DIGESTIVE SYSTEM THE GI TRACT THE PANCREAS AND LIVER the small intestine through a series Digestion * takes place in the Two other organs found in the of tubes. When there is food in gastrointestinal (GI) tract .* The abdomen * (belly) help with the small intestine, the enzymes GI tract is also called the digestive digestion: the pancreas * and the help break the food down so it tract. The GI tract is basically a liver .* The pancreas is an organ can be absorbed and used by the long tube that begins with the that sits in the upper abdomen body. The pancreas also produces mouth and continues through the behind the stomach. The pancreas insulin * that helps the body use esophagus ,* stomach, small, and produces enzymes * or special glucose ,* a sugar that comes from large intestines .* (The small and proteins that break down fat * and the digestion of carbohydrates .* large intestines together are about protein * in food. These enzymes Insulin is released into blood that 25 feet long!) The GI tract ends at include lipase ,* protease ,* and passes through the pancreas. the rectum * and anus .* amylase .* The enzymes pass into The liver is an organ that sits in the upper right side of the abdomen. The gallbladder * is attached to the liver and helps store extra bile * fluid that is made by the liver. The liver and gallbladder are connected to the small intestine by a tube. The liver does many things for the body. Bile fluid is sent from the liver to the small intestine to help with digestion.
    [Show full text]
  • GLOSSARYGLOSSARY Medical Terms Common to Hepatology
    GLOSSARYGLOSSARY Medical Terms Common to Hepatology Abdomen (AB-doh-men): The area between the chest and the hips. Contains the stomach, small intestine, large intestine, liver, gallbladder, pancreas and spleen. Absorption (ub-SORP-shun): The way nutrients from food move from the small intestine into the cells in the body. Acetaminophen (uh-seat-uh-MIN-oh-fin): An active ingredient in some over-the-counter fever reducers and pain relievers, including Tylenol. Acute (uh-CUTE): A disorder that has a sudden onset. Alagille Syndrome (al-uh-GEEL sin-drohm): A condition when the liver has less than the normal number of bile ducts. It is associated with other characteristics such as particular facies, abnormal pulmonary artery and abnormal vertebral bodies. Alanine Aminotransferase or ALT (AL-ah-neen uh-meen-oh-TRANZ-fur-ayz): An enzyme produced by hepatocytes, the major cell types in the liver. As cells are damaged, ALT leaks out into the bloodstream. ALT levels above normal may indicate liver damage. Albumin (al-BYEW-min): A protein that is synthesized by the liver and secreted into the blood. Low levels of albumin in the blood may indicate poor liver function. Alimentary Canal (al-uh-MEN-tree kuh-NAL): See Gastrointestinal (GI) Tract. Alkaline Phosphatase (AL-kuh-leen FOSS-fuh-tayz): Proteins or enzymes produced by the liver when bile ducts are blocked. Allergy (AL-ur-jee): A condition in which the body is not able to tolerate or has a reaction to certain foods, animals, plants, or other substances. Amino Acids (uh-MEE-noh ASS-udz): The basic building blocks of proteins.
    [Show full text]
  • Somatostatin Inhibits Gastric Acid Secretion After Gastric Mucosal Prostaglandin Synthesis Inhibition by Indomethacin in Man
    Gut: first published as 10.1136/gut.26.11.1189 on 1 November 1985. Downloaded from Gut, 1985, 26, 1189-1191 Somatostatin inhibits gastric acid secretion after gastric mucosal prostaglandin synthesis inhibition by indomethacin in man M H MOGARD, V MAXWELL, T KOVACS, G VAN DEVENTER, J D ELASHOFF, T YAMADA, G L KAUFFMAN JR, AND J H WALSH From the Centerfor Ulcer Research and Education, VA Wadsworth MedicallSurgical Services and UCLA, LosAngeles, California, USA. SUMMARY The inhibitory effect of indomethacin, 200+200 mg administered per os over 24 hours, on the prostaglandin E2 generative capacity of gastric mucosal tissue was determined in healthy male volunteers. The effect of prostaglandin synthesis inhibition on somatostatin induced suppression of food-stimulated acid secretion was tested. Peptone meal stimulated acid secretion was quantified in five healthy volunteers by intragastric titration with and without indomethacin pretreatment. Somatostatin doses of 200, 400, and 800 pmol/kg/h each significantly inhibited the peptone stimulated acid output. Indomethacin treatment, resulting in 90% inhibition of prostaglandin E2 synthesis, did not affect glucose- or peptone-stimulated acid output or modify the inhibitory action of somatostatin. Clinically, acid inhibition by somatostatin has been used to treat bleeding peptic ulcers. Ulcer haemorrhage may be preceded by an excessive use of drugs that inhibit prostaglandin synthesis such as aspirin or other non-steroidal anti-inflammatory agents. Recent observations in the rat indicate that prostaglandins mediate the inhibitory action of somatostatin on gastric acid secretion. The present results suggest that prostaglandins are not http://gut.bmj.com/ required for inhibition of gastric acid secretion by somatostatin in man.
    [Show full text]
  • A Review of Normal Function and Role of Gastrin in Zollinger-Ellison
    When Gastrin Goes Awry: A Review of Normal Function and Role of Gastrin in Zollinger-Ellison Syndrome Leigha LaTourette1, Janel Cross2, Barbara Brabetz2 Department of Plant and Animal Science1, Department of Natural Sciences and Mathematics2 Introduction Gastrin: Normal Mode of Action Gastrin’s Role in Zollinger-Ellison Syndrome MEN 1 & ZES Gastrin is a digestive hormone that acts on the MEN1 is an inheritable disease that causes over neuroendocrine and parietal cells of the secretion of hormones via tumors on the gastrointestinal tract to ultimately secrete gastric endocrine glands throughout the body.4 Around a acid. Gastrin secretion begins even before food 30% of these tumors are found to be malignant. is consumed, as the mere anticipation of a meal ZES is commonly associated with the MEN1 due can lead to a series of events ending in the to the presence of tumors found in the stomach creation of the gastric acid needed to breakdown and small intestine.4 These gastrointestinal foods. Not only does Gastrin support the tumors caused by MEN 1 give the person a digestion of foods, but it also stimulates growth, higher likelihood of contracting ZES, as the secretion, blood flow, and acts as a defense probability of having pancreatic or duodenal mechanism against bacteria in the tumors is increased.4 gastrointestinal system. When the production of Gastrin becomes overt, major consequences like that of Zollinger Ellison Syndrome (ZES). ZES is an extremely rare disease occurring in people between the ages of 30-60.4 ZES is related to the uncontrolled secretion of gastrin due to the presence of certain pancreatic or duodenal tumors.
    [Show full text]
  • Pancreas and Fat/Lipid Digestion
    Exocrine Pancreas Physiology Pancreatic Anatomy Pancreatic secretion Pancreatic enzymes Daniel S. Kamin MD Boston Children’s Hospital [email protected] Content Reviewers: Sohail Z. Husain, MD Veronique Morinville MD, FRCP(C) NASPGHAN Physiology Education Series Series Editors: Christine Waasdorp Hurtado, MD, MSCS, FAAP [email protected] Daniel Kamin, MD [email protected] Learning Objectives • Understand the normal development and anatomy of the pancreas • Understand the stimuli and cellular factors giving rise to pancreatic secretion • Know the mechanisms by which pancreatic enzymes are activated and remain functional • Be aware of age-related deficiency in exocrine pancreatic function Night blindness • A young man with morbid obesity undergoes roux-en-y gastric bypass. • 1 year later he notices that in the evening he falls down his stairs. • Vitamin A deficiency is diagnosed. Understanding the physiology of pancreatic and bile secretion, Used with permission intraluminal lipolysis, and micellar function explains why this happens! http://www.citelighter.com/science/surgery/knowledgecards/gastric-bypass Pancreas Physiology Overview • Bulk of bicarbonate secretion (more than what secreted in bile and from duodenum) • Enzymes for intra- luminal digestion • Secretin and CCK regulate • Maturational pancreatic insufficiency Used with permission Image from http://www.aboutcancer.com/pancreas1.htm Pancreatic Development • See Embryology and Anatomy of the Gastrointestinal Tract Pancreatic Microanatomy Pancreatic Acinar Secretory Products A • Proteases • Trypsinogen* • Chymotrypsinogen* A • Proelastase* • Procarboxypeptidase* • Procarboxypeptidase B* • Amylolytic enzyme • Amylase A • Lipases • Lipase • B Nonspecific esterase • Prophospholipase A2* • Nucleases • Deoxyribonuclease • Ribonuclease • Others • Pro-colipase* • Trypsin inhibitors A. Exocrine pancreas-- ascinar cells filled • Monitor peptid with secretory granules, cuboidal duct Stored and secreted in inactive form cells secrete bicarbonate-rich fluid B.
    [Show full text]
  • Lecture Series Gastrointestinal Tract
    Lecture series Gastrointestinal tract Professor Shraddha Singh, Department of Physiology, KGMU, Lucknow INNERVATION OF GIT • 1.Intrinsic innervation-1.Myenteric/Auerbach or plexus Local 2.Submucosal/Meissners plexus 2.Extrinsic innervation-1.Parasympathetic or -2.Sympathetic Higher centre Enteric Nervous System - Lies in the wall of the gut, beginning in the esophagus and - extending all the way to the anus - controlling gastrointestinal movements and secretion. - (1) an outer plexus lying between the longitudinal and circular muscle layers, called the myenteric plexus or Auerbach’s plexus, - controls mainly the gastrointestinal movements - (2) an inner plexus, called the submucosal plexus or Meissner’s plexus, that lies in the submucosa. - controls mainly gastrointestinal secretion and local blood flow Enteric Nervous System - The myenteric plexus consists mostly of a linear chain of many interconnecting neurons that extends the entire length of the GIT - When this plexus is stimulated, its principal effects are - (1) increased tonic contraction, or “tone,” of the gut wall, - (2) increased intensity of the rhythmical contractions, - (3) slightly increased rate of the rhythmical contraction, - (4) increased velocity of conduction of excitatory waves along the gut wall, causing more rapid movement of the gut peristaltic waves. - Inhibitory transmitter - vasoactive intestinal polypeptide (VIP) - pyloric sphincter, sphincter of the ileocecal valve Enteric Nervous System - The submucosal plexus is mainly concerned with controlling function within the inner wall - local intestinal secretion, local absorption, and local contraction of the submucosal muscle - Neurotransmitters: - (1) Ach (7) substance P - (2) NE (8) VIP - (3)ATP (9) somatostatin - (4) 5 – HT (10) bombesin - (5) dopamine (11) metenkephalin - (6) cholecystokinin (12) leuenkephalin Higher centre innervation - the extrinsic sympathetic and parasympathetic fibers that connect to both the myenteric and submucosal plexuses.
    [Show full text]