The effects of direct and microsomal activated aflatoxin B1 on chicken peritoneal macrophages in vitro.

Sephadex-elicited peritoneal exudate cells were cultured on glass coverslips in order to determine the effects of aflatoxin B1 (AFB1) on chicken macrophages. Adherent macrophage monolayers were exposed for 1 h to 5, 10, and 20 micrograms ml-1 of AFB1, directly or to 0.01, 0.1, 0.5, 1, and 5 micrograms ml-1 of AFB1 in the presence of a chicken microsomal mixed function oxidase system (MFO). After exposure, the macrophage cultures were washed and allowed to recover for 2 h in fresh culture medium. Parameters measured at 2 h post recovery period were the substrate adherence potential, morphological alterations, phagocytic ability, and number of sheep red blood cells (SRBC) internalized per phagocytic macrophage. Direct in vitro exposure to AFB1 resulted in a dose-dependent decrease in macrophage adherence potential, and an increase in cell damage as determined by nuclear disintegration and cytoplasmic blebbing, but no detrimental effects were observed on percent phagocytic cells or the number of internalized SRBC. However, significant reductions in adherence potential, increased morphological alterations, and reduced phagocytosis and internalization of SRBC were observed when MFOs were added to cultures treated with much lower doses of AFB1. Addition of piperonyl butoxide (a P-450 inhibitor) abrogated AFB1-MFO induced alterations. This study suggests that microsomal activated AFB1 causes significant alterations in chicken macrophage functions.