Apoptosis in the lymphoid depletion induced by T-2 toxin in broiler chicks. Histomorphometry of the bursa of Fabricius

M.A. Rachid A.C. Vasconcelos V.A. Nunes About the authors

It was studied by the histomorphometry of the bursa of Fabricius the involvement of apoptosis as a mechanism of lymphoid depletion in broiler chicks, after the intake of feed containing T-2 toxin of Fusarium sporotrichioides. Forty-two one-day-old chicks were distributed randomly in three groups. The treated group (n=15) received contaminated feed with 2.64 mg/kg of the T-2 toxin. The residual group (n=12) received contaminated feed up to 7 and 14 days and noncontaminated feed during the last week. One control group (n=15) received noncontaminated feed. Five animals from each control and treated groups were killed at 7, 14 and 21 days, and six from the residual group at 14 and 21 days, and their bursa of Fabricius (BF) were collected for histomorphometric analysis and determination of apoptotic index. The apoptosis was confirmed by in situ labeling of the fragmentation of the genome (TUNEL) and by electrophoresis of DNA in agarose gel. BF of treated and residual groups showed moderate to intense depletion of the lymphoid follicles and higher apoptotic index than the control group (P< 0.05). These results allowed to conclude that apoptosis is involved in the mechanism of lymphoid depletion caused by T-2 toxin in broiler chicks.

Broiler chick; bursa of Fabricius; apoptosis, T-2 toxin

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