Veterinary Immunology and Immunopathology
Volume 62, Issue 3 , 16 April 1998, Pages 245-260

Zinc, thymic endocrine activity and mitogen responsiveness (PHA) in piglets exposed to maternal aflatoxicosis B1 and G1

Eugenio Mocchegiania, *, Attilio Corradib, Lory Santarellia, Alberto Tibaldia, Elena DeAngelisb, Paolo Borghettib, Alberto Bonomic, Nicola Fabrisa and Enrico Cabassib

a Immunology Center, Res. Dept., Italian National Research Centres on Aging (INRCA), Via Birarelli 8, 60100 Ancona, Italy
b Institute of Veterinary Anatomy Pathology, Veterinary Medical Faculty, University of Parma, Parma, Italy
c Zootechnic Institute Food and Nutrition, Veterinary Medical Faculty, University of Parma, Parma, Italy

Accepted 1 December 1997. Available online 14 August 1998.

Growth retardation, thymic involution and impaired peripheral immune efficiency are constant events in piglets exposed to maternal aflatoxicosis. Zinc may play a key role because of its requirement for good immune responses, including thymic endocrine activity. Zinc is required to activate a thymic hormone, i.e. thymulin (ZnFTS), which is responsible for cell-mediated immunity. Zinc deficiency and decreased thymic endocrine activity are present in piglets fed from sows exposed to aflatoxins (AF) B1 and G1 as compared with healthy control piglets. In particular, active ZnFTS is decreased while concentrations of inactive thymulin (FTS) are high. The in vitro addition of zinc up to the plasma samples induces a reduction of inactive thymulin. The lymphocytes mitogen responsiveness (PHA) is decreased and a thymic cortical lymphocyte depletion is also present. These data suggest that the thymic defect, followed by impaired peripheral immune efficiency, may largely depend by the low peripheral zinc bioavailability to saturate all thymulin molecules produced.

Author Keywords: Zinc; Thymulin; Mitogen responsiveness; Aflatoxins; Piglets

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