Comparison of Two Blood-Brain Barrier in Vitro Systems: Cytotoxicity and Transfer Assessments of Malathion/oxon and Lead Acetate.
Balbuena P, Li W, Magnin-Bissel G, Meldrum B, Ehrich M.
Toxicol Sci. 2010 Jan 11. [Epub ahead of print]
Toxicol Sci. 2010 Jan 11. [Epub ahead of print]
Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, VA.
Toxicity and integrity disruption in response to transport through the blood-brain barrier (BBB) of the organophosphates malathion and malaoxon, and heavy metal lead acetate were assessed in two in vitro barrier systems. One system was constructed using bovine brain microvascular endothelial cells (BMEC), while the other system was constructed with rat brain microvascular endothelial cells (RBE4); both were co-cultured with rat astrocytes. We hypothesized that these models would respond differently to neurotoxic compounds. Concentrations of malathion, malaoxon and lead acetate between 0.01 muM and 1 mM were assessed for their capacity to cause cytotoxicity to the astrocytes and endothelial cells utilized to construct the BBB systems, with the least cytotoxic concentrations chosen for transfer assessments of neurotoxicants through the barrier systems. Concentrations of malathion at 10 muM, malaoxon at 1 muM, and lead acetate at 1 and 10 muM were selected. Lead concentrations were measured in media of the abluminal and luminal sides of both systems using graphite furnace atomic absorption at the beginning of the treatment (T0) and 14 hr later (T14). Passage of organophosphate compounds was determined utilizing inhibition of acetylcholinesterase (AChE) enzyme in a neuroblastoma cell line (SH-SY5Y) localized below the barrier system. Transendothelial electrical resistance (TEER) was assessed as a measurement of integrity of the barrier systems, with baseline values higher with the RBE4-astrocyte system than with the BMEC-astrocyte system. Metabolic capability, as measured by esterase activity, was higher in BMECs, which were more likely to retain lead than RBE4 cells. Results suggest that differences in endothelial cell source can affect the outcome of studies on toxicant transfer through in vitro BBB systems.
PMID: 20064834 [PubMed - as supplied by publisher]
