Changes in the neuromodulators of the diffuse endocrine system of the alimentary canal of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), naturally infected with Eubothrium crassum (Cestoda).
A histopathological and immunohistochemical study on the intestines of 45 specimens of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), from Loch Awe, Scotland, revealed a number of cellular deviations in individuals naturally infected with the pseudophyllidean cestode Eubothrium crassum (Bloch, 1779). Twenty-five individuals (55.5%) were infected with an average worm burden of 18.84 +/- 4.06 (mean +/- SE) cestodes per host (range, 2-80 worms; total 471 worms). The cestodes, measuring an average 8.23 +/- 1.10 cm (mean +/- SE; range, 5.3-13.0 cm) in length, were found attached by their scolices to the mucosal lining of the distal portion of the pyloric caeca. Within the caeca, the strobila evoked a mild catarrhal enteritis, namely an enhanced mucus production with epithelial cellular desquamation, a leucocytic infiltration of the lamina propria-submucosa and vacuolization of the intestinal epithelial cells. Eosinophilic granular cells of the stratum granulosum exhibited granular depletion, while within the catarrh, the presence of a high number of rodlet cells was noticed. Immunohistochemically, the occurrence of E. crassum caused a significant reduction in the number of bombesin-, gastrin-releasing peptide and glucagon-like immunoreactive endocrine cells, but an increase in the relative densities of endocrine cells containing cholecystokinin-8- and gastrin-like substances. There were, however, no significant differences in the number of endocrine cells that were immunoreactive to secretin, neuropeptide Y and peptide histidine-isoleucine antisera in the digestive tracts of either the infected or non-infected O. mykiss.
Bosi
G
G
Department of Veterinary Sciences and Technologies for Food Safety, University of Milan, Milan, Italy.
Shinn
A P
AP
Giari
L
L
Simoni
E
E
Pironi
F
F
Dezfuli
B S
BS
D000818:Animals; D001839:Bombesin / Q000378:metabolism; D002589:Cestoda; D002590:Cestode Infections / Q000378:metabolism / Q000473:pathology / Q000662:veterinary*; D002766:Cholecystokinin / Q000378:metabolism; D019858:Enteroendocrine Cells / Q000378:metabolism* / Q000473:pathology; D005393:Fish Diseases / Q000378:metabolism* / Q000469:parasitology* / Q000473:pathology; D005755:Gastrins / Q000378:metabolism; D005934:Glucagon / Q000378:metabolism; D006728:Hormones / Q000378:metabolism*; D007150:Immunohistochemistry / Q000662:veterinary; D009478:Neuropeptide Y / Q000378:metabolism; D017686:Oncorhynchus mykiss; D010446:Peptide Fragments / Q000378:metabolism; D012606:Scotland; D012633:Secretin / Q000378:metabolism
D005755:Gastrins; D006728:Hormones; D009478:Neuropeptide Y; D010446:Peptide Fragments; C410885:cholecystokinin 8; D012633:Secretin; D005934:Glucagon; D002766:Cholecystokinin; D001839:Bombesin