Induction of Changes in Morphology, Reactive Nitrogen/Oxygen Intermediates and Apoptosis of Duck Macrophages by Aflatoxin B1

Abstract

The purpose of this study was to investigate the effects of aflatoxin B1 (AFB1) on the ultracellular morphology alteration, apoptosis induction and reactive nitrogen and oxygen intermediates production of peritoneal macrophages (DPM) from mule ducks. The ducklings were purchased from a commercial hatchery, and were fed a corn-soybean based diet. As the ducklings were grown up to 3 wk of age, the Sephadex-elicited peritoneal exudative cells (PEC) were used as the source for duck peritoneal macrophages. The ultracellular morphology study showed that significant number of cells shifted from category I (normal cell with ruffled membrane) and II (cell membrane blebbing) to category III (cell membrane blebbing and even rupture) after DPM were incubated with AFB1 (20 µg/ml) for 12 to 48 h. When DPM were exposed to AFB1 in vitro, the production of NO, H2O2 and O2 - in macrophages was reduced after 12-48 h incubation with previous LPS stimulation. There was a DNA laddering pattern observed in DPM incubated with AFB1 5, 10, 20, 50 or 100 µg/ml for 12 h. Evidence also revealed that the percentage of apoptotic cells was increased along with the elevation of AFB1 concentration. The results suggest that AFB1 exposure causes duck macrophages going on apoptotic pathway through evidence of ultracellular morphology alteration and DNA laddering in agarose electrophoresis. The production of reactive nitrogen and oxygen intermediates of duck macrophages also depressed after AFB1 exposure, and this implied that AFB1 could cause deteriorated functions of bacteriocidal and tumoricidal activity in duck macrophages. (Asian-Aust. J. Anim. Sci. 2002. Vol 15, No. 11 : 1639-1645)