Origins and projections of nerve fibres in rat pyloric sphincter.
Nerve fibres play an important role in the regulation of gastric emptying. The aims of this study were to clarify the distribution, projections and origin of neuronal type nitric oxide synthase (NOS)-, tyrosine hydroxylase (TH)-, vesicular acetylcholine transporter (VAchT)- and peptide-containing nerve fibres of the rat pyloric sphincter. Extrinsic and local denervations of the sphincter were performed in order to reveal the origin and projections of the various nerve fibre populations. Pylorus from control and denervated animals were processed for the immunocytochemical demonstration of cholecystokinin (CCK), enkephalin, gastrin-releasing peptide (GRP), somatostatin, calcitonin gene-related peptide (CGRP), neuropeptide Y (NPY), pituitary adenylate cyclase-activating peptide (PACAP), substance P (SP), vasoactive intestinal peptide (VIP), galanin, NOS, VAchT and TH. VAchT, TH, nNOS, and all of the peptides investigated were found in nerve fibres innervating the pyloric sphincter, and coexistence of several putative neurotransmitters were revealed. Extrinsic denervation caused a total loss of NPY/TH-, SP/CGRP- and SP/CGRP/VIP/NOS/PACAP-containing nerve fibres. Local denervation immediately proximal to the sphincter markedly reduced the numbers of VIP/NOS/galanin- and VIP/NOS/galanin/PACAP +/- NPY-containing fibres within the sphincter suggesting an origin of these fibres in myenteric ganglia in the antral region; denervation at the level of the oxyntic-pyloric border had no effect. Local denervation immediately distal to the sphincter caused a marked decrease in VAchT-, SP/enkephalin-, enkephalin-, somatostatin-, CCK- and GRP-containing fibres within the sphincter suggesting that these emanate from the duodenum. The latter procedure also reduced the number of SP/CGRP-containing fibres of extrinsic origin within the pyloric sphincter.
Department of Physiology and Neuroscience, University of Lund, Sweden.
Lille-Mor
LM
Lindeström
Eva
E
Ekblad
D000818:Animals; D015740:Calcitonin Gene-Related Peptide / Q000378:metabolism; D002352:Carrier Proteins / Q000378:metabolism; D002766:Cholecystokinin / Q000378:metabolism; D003714:Denervation; D004745:Enkephalins / Q000378:metabolism; D005260:Female; D019004:Galanin / Q000378:metabolism; D019886:Gastrin-Releasing Peptide / Q000378:metabolism; D007150:Immunohistochemistry; D026901:Membrane Transport Proteins; D009130:Muscle, Smooth / Q000294:innervation; D009412:Nerve Fibers / Q000737:chemistry / Q000145:classification / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D009474:Neurons / Q000378:metabolism; D009478:Neuropeptide Y / Q000378:metabolism; D009479:Neuropeptides / Q000378:metabolism; D019001:Nitric Oxide Synthase / Q000378:metabolism; D052248:Nitric Oxide Synthase Type I; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; D011708:Pylorus / Q000294:innervation*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013004:Somatostatin / Q000378:metabolism; D013373:Substance P / Q000378:metabolism; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D014660:Vasoactive Intestinal Peptide / Q000378:metabolism; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins
C495403:Adcyap1 protein, rat; D002352:Carrier Proteins; D004745:Enkephalins; D026901:Membrane Transport Proteins; D009478:Neuropeptide Y; D009479:Neuropeptides; D051219:Pituitary Adenylate Cyclase-Activating Polypeptide; C493461:Slc18a3 protein, rat; D050494:Vesicular Acetylcholine Transport Proteins; D033921:Vesicular Transport Proteins; D013373:Substance P; D014660:Vasoactive Intestinal Peptide; D013004:Somatostatin; D019886:Gastrin-Releasing Peptide; D019004:Galanin; D002766:Cholecystokinin; D019001:Nitric Oxide Synthase; D052248:Nitric Oxide Synthase Type I; C496322:Nos1 protein, rat; D014446:Tyrosine 3-Monooxygenase; D015740:Calcitonin Gene-Related Peptide