THE ENTERIC NERVOUS SYSTEM IN THE RUMINANT STOMACH OF THE SHEEP (OVIS ARIES) HET ENTERISCHE ZENUWSTELSEL IN DE HERKAUWERSMAAG VAN HET SCHAAP (OVIS ARIES) THE ENTERIC NERVOUS SYSTEM IN THE RUMINANT STOMACH OF THE SHEEP (OVIS ARIES) HET ENTERISCHE ZENUWSTELSEL IN DE HERKAUWERSMAAG VAN HET SCHAAP (OVIS ARIES) PROEFSCHRIFT TER VERKRIJGING VAN DE GRAAD VAN DOCTOR AAN DE ERASMUS UNIVERSITEIT ROTTERDAM OP GEZAG VAN DE RECTOR MAGNIFICUS PROF. DR. A.H.G. RINNOOY KAN EN VOLGENS BESLUIT VAN HET COLLEGE VAN DEKANEN. DE OPENBARE VERDEDIGING ZAL PLAATSVINDEN OP VRIJDAG 17 JUNI 1988 OM 13.30 UUR DOOR ANDRE AUGUST LOUIS MATHILDE WEYNS GEBOREN TE BONN PROMOTIECOMMISSIE : PROMOTOR: Prof. Dr. P. Krediet OVERIGE LEDEN : Prof. Dr. H. Galjaard Prof. Dr. G. Vantrappen Prof. Dr. J. Voogd CO-PROMOTOR : Dr. A.A.J. Verhofstad IN GRATEFUL DEDICATION TO MY PARENTS MY WIFE AND OUR CHILDREN LIST OF ABBREVATIONS A. Arteria IP3 Inositol triphosphate ABO Abomasum IR Immunoreactive, -reactivity AC Adenylate Cyclase IV Intravenous ACh Acetylcholine iso-OMPA iso-Octamethyl Pyrophosphoramide AChE Acetylcholinesterase LDH Lactic Acid Dehydrogenase ADP Adenosine Diphosphate LES Lower Esophageal Sphincter AH After Hyperpolarization MAO Monoamine Oxydase AMP Adenosine Monophosphate mm millimeter ANS Autonomic Nervous System MMC Migrating Myoelectrical Complex AP Antrum Pyloricum mV millivolt (s) APP Avian Pancreatic Polypeptide NA Noradrenaline APUD Amine Precursor Uptake Decarboxylation NANC Non-Adrenergic, Non-Cholinergic ATP Adenosine-5'-Triphosphate NGF Nerve Growth Factor c-AMP cyclic-Adenosine Monophosphate NGS Normal Goat Serum CMC Carboxy-Methyl-Cellulose nm nanometer C-R Crown-Rump NNE Non-Neuronal Enolase CA Catecholamine(s) NPY Neuropeptide Y Ca Canis familiaris NSE Neuron Specific Enolase CCK Cholecystokinin OMA Omasum CGRP Calcitonin Gene Related Peptide ORO Ostium Reticulo-Omasicum ChAT Choline Acetyltransferase pA protein A CNS Central Nervous System PAK Pyruvic Acid Kinase CoA Coenzyme A PAP Peroxidase Anti-Peroxydase CSF Cerebro-Spinal Fluid PBS Phosphate Buffer Saline DAB 3,3'-Diaminobenzidine tetrahydrochloride PHI Peptide HI DAG Diacylglycerol PNS Peripheral Nervous System DBH Dopamine-Beta-Hydroxilase PYL Pylorus DNES Diffuse Neuro-Endocrine System pyy Peptide Y Y DYN Dynorphin RDS Rumina! Dorsal Sac EC Enterochromaffin RET Reticulum EDTA Ethylenediamine Tetraacetic Acid RG Reticular Groove EEC Entero-Endocrine Cell(s) RIA Radioimmunoassay ENK Enkephalin(s) RITC Rhodamin B Isothiocyanate ENS Enteric Nervous System RVS Rumina! Ventral Sac EPSP Excitatory Post Synaptic Potential SAM Slowly-Adapting Mechanoreceptor(s) Eq Equus caballus (horse) SN Sodium Nitroprusside FAM Fast-Adapting Mechanoreceptor(s) SOM Somatostatin FIF Formaldehyde Induced Fluorescence Su Sus scrofa domestica (pig) FITC Fluorescein Isothiocyanate Sub.P Substance P FUN Fundus TBS Tris Buffer Saline G.I. Gastro-Intestinal TTBS Triton Tris Buffer Saline GABA Gamma Amino Butyric Acid TTEN Tonic-Type Enteric Neuron ggl. ganglion J.Lg microgram GIP Gastric Inhibitory Peptide Jlm micrometer GRP Gastrin Releasing Peptide v. Vena HPLC High Pressure Liquid Chromatography VFA Volatile Fatty Acid(s) 5-HT 5-Hydroxytriptamine or serotonin VIP Vasoactive Intestinal Polypeptide HRP Horseradish Peroxydase WDHA Watery Diarrhoea Hypokalemia Achloremia IA Intra-arterial IgG Immunoglobuline G PART I THE ENTERIC NERVOUS SYSTEM (ENS) TABLE OF CONTENTS Chapter 1. SETTING OF THE STUDY 1.1.1. Formulation of the problem .......................................................................................... 11 1.1.2. Objectives of the study .................................................................................................. 12 1.1.3. Morphology of the ruminant stomach Embryology ................................................................................................................... 12 Macroscopic Anatomy .................................................................................................. 14 Microscopic Anatomy ................................................................................................... 17 1.1.4. Functional Morphology of the ruminant stomach ........................................................ 19 Chapter 2. THE AUTONOMIC NERVOUS SYSTEM (ANS) 1.2.1. Definition ...................................................................................................................... 25 1.2.2. Embryology of the ANS .................................. ... ........................................................... 25 1.2.3. Structure of the ANS The afferent link ............................................................................................................ 26 The central part ............................................................................................................. 28 The efferent link ............................................................................................................ 28 1.2.4. Functional significance of the ANS .............................................................................. 33 Chapter 3. THE ENTERIC NERVOUS SYSTEM (ENS) 1.3.1. Introduction ................................................................................................................... 35 1.3.2. Embryology of the ENS ................................................................................................ 35 1.3.3. Morphology of the ENS Microscopic Anatomy ................................................................................................... 41 Ultrastructure ................................................................................................................. 55 1.3.4. Neurochemistry of the ENS Acetylcholine ..... ... .. .. .. .. ... .. .. .. .. .. ... .. .. .. ..... ........ ....... .. .. .. ... .. .. ...... ... .. .. .. .. ... .. .. ...... ... .. .. .. .. 60 Noradrenaline ................................................................................................................ 61 The NANC system ........................................................................................................ 64 1.3.5. Functional significance of the ENS .............................................................................. 73 First link: the intestinal receptors .................................................................................. 75 Second link: the afferents .............................................................................................. 80 Third link: the intramural ganglia ..................... .. .. ... .. .. .. ....... .. ........... .. .. .. ......... .. .. ..... ... 81 Final link: the target organs .......................................................................................... 86 1.3.6. Clinical significance of the ENS ................................................................................... 93 PART I I SETTING OF THE STUDY FoRMULATION oF THE PRoBLEM AND OBJECTIVES Chapter 1. SETTING OF THE STUDY I. 1. 1. products to volatile fatty acids (VFA) and convert nitrogenous substances to ammonia and protein. Addi­ FORMULATION tionally, essential amino acids and water-soluble B vitamins are synthesized by them. Hence, microbial OF THE PROBLEM digestion is quite different from mammalian enzymatic digestion and supplies energy, protein, essential amino acids and vitamins to the body from sources that Quantitatively and economically the ruminants repre­ mammalian systems cannot utilize (36; see 36). So, it is sent, undoubtedly, the most important group of large clear that in herbivores digestion not only depends on domestic animals. Their enormous economical impact the motor and secretory functions of the digestive tube (over the 13 x 1012 Bfr/year) is already clearly demon­ but, to a large extent, on the activity of the micro flora strated by a schedule simply based upon two aspects: as well. In consequence, different circumstances e.g. milk and meat (see Addendum/Part I/ table 1). How­ failure to provide the correct diet, prolonged starvation ever, the real economical importance of the domestic or loss of appetite, hyperacidity (engorgement ofgrain) ruminants encompasses much more since many other etc, that modify the activity of the flora lead to an aspects, not mentioned in this discussion, play also a abnormal or even a cessation of the digestion (81; 528; role e.g. animal food, textile, leather and the pharma­ see 528). ceutical industry; veterinary research; and the produc­ As a result of such a digestion-strategy any animal, tion of manure, power etc. Furthermore, one has to subsisting on a fibrous diet, must provide its digestive realize that hundreds of thousands of people depend tract with a fermentation chambers in which bacteria entirely or to a very high degree for their subsistence on can break down the fibrous parts of plants (16; 391). this group of animals. Consequently, diseases in rumi­ Since herbivores largely depend on the products of nants not only implicate considerable economical microbial activity a part of their alimentary tract is losses but, even worse, they would threaten the exis­ expanded to form an organ that harbors a microbial tence of entire communities. So, it needs no arguing population valuable in the digestion of foods for which why in veterinary medicine ruminants are still a very the animals themselves do not have the necessary important, probably the most important, group of complement of enzymes (16; 527). Therefore, the domestic animals and why the ruminant has been -and bowel