title: Effect of Pomphorhynchus laevis (Acanthocephala) on putative neuromodulators in the intestine of naturally infected Salmo trutta.
abstract: Immunohistochemical and pathological studies were carried out on the digestive tract of parasitized and uninfected specimens of Salmo trutta (L.). A total of 124 brown trout were collected on several occasions from 3 tributaries of the Brenta River, northern Italy. Twenty-eight individuals of S. trutta (22.6%) were parasitized with Pomphorhynchus laevis (Miller, 1776). The occurrence of P. laevis in the trout gut significantly increased the number of endocrine cells immunoreactive to calcitonin gene-related peptide (CGRP), beta-endorphin, met-enkephalin, neuropeptide Y (NPY) and Substance P (SP) antisera. Moreover, bombesin-, cholecistokinin-8- (CCK-8), leu-enkephalin- and serotonin- (5-HT)-like immunoreactive cells were less numerous in the intestine of the parasitized brown trout. A strong positive immunoreactivity was observed in nerve fibres and neurones of the myenteric plexus of the parasitized fish; the antisera involved in this positive reactivity were bombesin, met-enkephalin, SP and vasoactive intestinal peptide (VIP). More neurones immunoreactive to anti-CGRP and anti-5-HT sera were noted in the myenteric plexus and in the inner layer of the tunica muscularis of the infected fish. Most of the above-mentioned neuromodulators are known to control gut motility, digestive/absorptive processes, as well as the immune response. The changes induced by parasites in the neuroendocrine system of the brown trout are discussed.
authors.affiliation: Department of Biology, University of Ferrara, Italy. dzb@dns.unife.it
authors.forename: Bahram Sayyaf
authors.initials: BS
authors.lastname: Dezfuli
authors.forename: Flavio
authors.initials: F
authors.lastname: Pironi
authors.forename: Luisa
authors.initials: L
authors.lastname: Giari
authors.forename: Cinzia
authors.initials: C
authors.lastname: Domeneghini
authors.forename: Giampaolo
authors.initials: G
authors.lastname: Bosi
mesh_terms: D000049:Acanthocephala / Q000472:pathogenicity*; D000818:Animals; D004064:Digestive System / Q000378:metabolism* / Q000469:parasitology / Q000473:pathology; D005393:Fish Diseases / Q000469:parasitology* / Q000473:pathology / Q000503:physiopathology; D006374:Helminthiasis, Animal / Q000469:parasitology* / Q000473:pathology / Q000503:physiopathology; D006790:Host-Parasite Interactions; D007150:Immunohistochemistry / Q000662:veterinary; D009490:Neurosecretory Systems / Q000378:metabolism* / Q000469:parasitology / Q000473:pathology; D018377:Neurotransmitter Agents / Q000378:metabolism; D014337:Trout / Q000469:parasitology*
chemical_list: D018377:Neurotransmitter Agents