This study aims to evaluate the role of insulin and the glucocorticoid effect of dexamethasone on the inflammatory cellular response in inflammatory in the exudate present in swim bladder of Nile tilapia, Oreochromis niloticus, challenged with Aeromonas hydrophila. 216 tilapia, weighing about 150g each, packed in 27 tanks, 250 L capacity, supplied with water devoid of chlorine, will be distributed in nine treatments: T0 = not challenged and untreated (control), T1 = No treated and challenged, T2 = Treated with insulin (INS), and challenged, T3 = Treated with Alloxan + INS (ALOX) and challenged, T4 = Treated with insulin (INS) + dexamethasone (DEXA), and challenged; T5 = Treated and ALOX challenged T6 = + ALOX Treaty with DEXA and challenged, T7 = DEXA Treaty and challenged; T8 = Treated with INS + + ALOX DEXA and challenged. After a period of acclimatization, the fish will be anesthetized in an aqueous solution of benzocaine (1:10,000) to the challenge by inoculation of 1.0 x 108 CFU of A. hydrophila in the swim bladder, as well as treatment with INS (100 IU / kg bw, im), ALOX (200 mg / kg bw, via EV) and DEXA (4mg/kg of bw, im). Therefore, six, 24 and 48 HPD, the tilapia will be subjected to deep anesthesia blood samples for determination of complete blood count and serum biochemistry, as well as dissect the bladder in order to obtain inflammatory exudate to total count of inflammatory cells in a chamber Neubauer and differential counts in the exudate extensions. At the same time, the organs will be collected to evaluate the liver, spleen and kidney somatic index, and collecting fragments of liver, spleen and kidney for histological analysis. However, the correlation between the studies: hematologic, biochemical, histopathological, somatic and cell present in the inflammatory exudate, will provide important support in understanding and characterization of these events in the pathophysiology of acute inflammatory process of Nile tilapia, as well as the involvement of insulin and the glucocorticoids effect on this response, including the effect of alloxan-induced diabetic fish.
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