Effects of aflatoxin B 1 on myelopoiesis in vitro

Abstract

The short-term cultures of mouse myeloid progenitor cells for granulocytes and monocytes, granulocyte-monocyte colony-forming units (CFU-GM) (CFU-GM assay) and mouse long-term bone marrow culture (LTBMC) were used to investigate the hemopoietic suppression caused by aflatoxin B 1 (AFB 1). A dose-related suppression of granulopoiesis in short-term bone marrow cultures was seen when the cultures were treated with 10, 5, 1, 0.5 and 0.1 μg of AFB 1/ml. Two selected doses of AFB 1 (5 and 0.5 μg/ml) considered to be highly and slightly suppressive in CFU-GM assay exerted a strong suppression of myelopoiesis in LTBMC when applied long-term. Short-term (2 h) exposure of LTBMC to 5 μg of AFB 1/ml caused a small damage to the myelopoiesis detected in the non-adherent layer. Short-term exposure to 0.5 μg AFB 1/ml was without any effect on myelopoiesis in LTBMC. The production of colony-stimulating activity (CSA) by an adherent layer of LTBMC was decreased on the second and fifth day after the short-term exposure to both doses of AFB 1 and comparable with non-treated culture on the seventh day after the exposure. Presented results indicate that both short-term culture of CFU-GM and LTBMC can be used in the definition and the prediction of host toxicity of AFB 1 to hemopoiesis. However, comparing these two in vitro systems, the LTBMC appears to be more sensitive and discriminatory in an evaluation of hemopoietic toxicity.