Expression of β2 adrenoceptors within enteric neurons of the horse ileum.
The activity of the gastrointestinal tract is regulated through the activation of adrenergic receptors (ARs). Since data concerning the distribution of ARs in the horse intestine is virtually absent, we investigated the distribution of β2-AR in the horse ileum using double-immunofluorescence. The β2-AR-immunoreactivity (IR) was observed in most (95%) neurons located in submucosal plexus (SMP) and in few (8%) neurons of the myenteric plexus (MP). Tyrosine hydroxylase (TH)-IR fibers were observed close to neurons expressing β2-AR-IR. Since β2-AR is virtually expressed in most neurons located in the horse SMP and in a lower percentage of neurons in the MP, it is reasonable to retain that this adrenergic receptor could regulate the activity of both secretomotor neurons and motor neurons innervating muscle layers and blood vessels. The high density of TH-IR fibers near β2-AR-IR enteric neurons indicates that the excitability of these cells could be directly modulated by the sympathetic system.
Department of Veterinary Medical Science, University of Bologna, 40064 Ozzano dell'Emilia, Bologna, Italy. Electronic address: cristiano.bombardi@unibo.it.
Cristiano
C
Bombardi
Annamaria
A
Grandis
Anna
A
Gardini
Caterina
C
Sorteni
Paolo
P
Clavenzani
Roberto
R
Chiocchetti
D000818:Animals; D000906:Antibodies / Q000276:immunology; D015153:Blotting, Western / Q000662:veterinary; D017615:Enteric Nervous System / Q000378:metabolism*; D005260:Female; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D006736:Horses; D007082:Ileum / Q000294:innervation* / Q000378:metabolism; D008297:Male; D009197:Myenteric Plexus / Q000378:metabolism; D018343:Receptors, Adrenergic, beta-2 / Q000096:biosynthesis* / Q000276:immunology
D000906:Antibodies; D018343:Receptors, Adrenergic, beta-2
AR; CCK; CG; CGRP; CML; CaudMG; CranMG; DBH; ENS; Enteric nervous system; FITC; GIT; Horse; ICJ; IFANs; IML; IPANs; IR; Ileum; Immunofluorescence; LML; MP; PVG; SMP; TH; Tyrosine hydroxylase; WB; Western blot; adrenoceptor; calcitonin gene-related peptide; caudal mesenteric ganglia; celiac ganglia; cholecystokinin; circular muscular layer; cranial mesenteric ganglia; dopamine β-hydroxylase; enteric nervous system; fluorescein isothiocyanate; gastrointestinal tract; ileocaecal junction; immunoreactivity, immunoreactive; intermediolateral cell column; intestinofugal neurons; intrinsic primary afferent neurons; longitudinal muscle layer; mm; muscularis mucosae; myenteric plexus; prevertebral ganglia; submucosal plexus; tyrosine hydroxylase; β(2) Adrenoceptors