Characterization of immune and enteric systems of broilers after imunosupression with dexamethasone
Carvalho, Daiane; Herpich, Juliana Inês; Chitolina, Gabriela Zottis; Gava, Marta Sílvia; Moraes, Lucas Brunelli de; Furian, Thales Quedi; Borges, Karen Apellanis; Fortes, Flávia Bornancini Borges; Moraes, Hamilton Luiz de Souza; Salle, Carlos Tadeu Pippi.
Acta sci. vet. (Online);
46: Pub. 1606, 2018. graf, ilus, tab
Artigo
em Português
| VETINDEX
| ID: vti-19981
Resumo
Background: Bursa of Fabricius (BF) and the thymus are primary lymphoid organs of poultry and play a major role in avian immunity. Enteric system is also involved in immunity. Several pathologic conditions directly impact BF and thymus size, and also affect intestinal parameters. Besides, there are several immune system depressor agents which affect birds. The selection of glucocorticoid as inducer of immunosuppression is applied in many experiments; however there are few studies that are applied to the reality in the field. In this context, the aim of this study was to evaluate the effects of dexamethasone as an inducer of immunosuppression on lymphoid organs and microscopic structures of the jejunum.Materials, Methods & Results: One-day-old chicks were used as a control group (n = 8) and the treated group (n = 25) received intramuscular dexamethasone on 21, 23, 24 and 26 day-old. Control birds and treated birds were euthanized 8, 16, 24, 32 and 40 h after inoculation; four control birds and six treated birds were euthanized on the eighth day after the last inoculation. Thymus, BF and jejunum were collected during the necropsy. The selected organs were processed, stained with hematoxylin and eosin and photographed. The BF and thymus cuts were evaluated by three histopathologists to determine the depletion score. Ten villi of each jejunum were evaluated for width and length of villi, depth crypt, microvillus length, enterocyte length of each villus, and wall thickness. Treated birds presented a mean weight lower than control group during all the experiment. The mean weight and the relative weight of the BF and thymus of control birds were significantly higher than treated ones. The lymphocyte depletion in BF and thymus scores differed significantly between groups, being higher in the group challenged with dexamethasone. There were no significant differences between groups for depth of crypt, height of core and height of microvilli.[...](AU)
Biblioteca responsável:
BR68.1
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