Exposure of Mouse Peritoneal Resident Macrophages to Pristine MWCNT Promote Nitric Oxide Synthase Production and Acute Cytokine Response

摘要

The potential biomedical applications of carbon nanotubesare? greatly limited due to the growing evidences of their toxic effects on consumers. Recently, the cells of the monocyte-macrophage-system were observed to be the main structures of accumulation and toxicity of these nanomaterials.This study aimed to determine the changes in the inflammatory status and apoptosissuffered by macrophages following exposure to pristine multi-walled carbon nanotubes (MWCNT). Macrophages were isolated from the mouse peritoneum and cultivated in vitro following a protocol previously described by Zhang et al.(2008). The immunocytochemicalexpression of iNOs, IL-6 and apoptosis was measured by fluorometry usingConfocal laser scanning microscopy (CLSM). Exposure of peritoneal macrophages to MWCNT promotesiNOs production and IL-6 expression in a dose-related matter. The exposure to 10 and 25 μg/dl MWCNTdoes not induce apoptosis in macrophage culture, although a significant increase in numbers of cellsundergoing apoptosis is observed for the group exposed at 50μg/dl MWCNT. In the present research we demonstrated that exposure of mouse macrophages to pristine MWCNTpromote nitric oxide synthase production and an acute cytokine responsecharacterized by the elevation of IL-6 levels. Apoptosis is increased only at high levels of MWCNT exposure, being in respect of our results, a late expression of toxicity.