Responsiveness of rat nonparenchymal liver cells and spleen cells to the decomposition of erythrocytes exposed to di-n-butyl phthalate and its metabolite

Abstract

We have reported that di-n-butyl phthalate (DBP) caused the depletion of circulating iron, characterized by the release of iron from both haemoglobin (Hb) and transferrin (Tf). The present study investigated whether the erythrocytes from DBP-treated rats were destroyed by nonparenchymal liver cells (NPC, including Kupffer cells) or spleen cells (SC). In the in vivo study, there were observed depletions of Hb in the blood and of iron in the hepatic Tf fraction, as well as an accumulation of iron in the hepatic hemosiderin (Hs) and splenic Tf fractions. In the in vitro study, mono-butyl phthalate (MBP), a metabolite of DBP, caused a depletion of iron in the plasma Tf, although a direct release of iron from Tf was not delectable. When erythrocytes from DBP-treated rats and erythrocytes preincubated with MBP both were incubated with NPC, respectively, the Hb was decomposed and the iron also accumulated in the cell debris. However, when the two kinds of erythrocytes were incubated with SC, respectively, no decomposition of Hb was observed at low and medium doses, but the highest dose induced an accumulation of iron to Tf. Therefore, the NPC may contribute in part to the decomposition of DBP- or MBP-affected erythrocytes.