A plasticizer released from IV drip chambers elevates calcium levels in neurosecretory terminals
Biochemistry & Molecular Pharmacology
Graduate School of Biomedical Sciences; Program in Neuroscience; Department of Biochemistry and Molecular Pharmacology; Treistman Lab; Graduate School of Biomedical Sciences, Neuroscience Program
We report that intracellular calcium levels rise in mammalian neurosecretory terminals and in cultured pheochromocytoma cells during acute exposure to physiological medium incubated in IV drip chambers. The agent responsible for this effect is shown to be di(2-ethylhexyl)phthalate (DEHP). DEHP (800 nM) added to saline solution caused a rise in [Ca(2+)](i) similar to that elicited by the contaminant-containing solution. The extraction of this contaminant from the IV drip chamber, as measured by spectrophotometry, was time-dependent and was markedly accelerated by the presence of 50 mM ethanol in the solution. Larger [Ca(2+)](i) increases were observed in terminals exposed to solutions incubated in IV drip chambers for greater durations. The rise in calcium requires transmembrane calcium flux through membrane channels, as the response is blocked by either 100 microM cadmium or by lowering the extracellular free Ca(2+) concentration to 10 microM. Our results suggest that acute alterations in intracellular calcium should be considered in addition to long-term effects when determining the safety of phthalate-containing plastics and that laboratory researchers using plastic perfusion materials consider this potential source of artifactual results.
DOI of Published Version
Toxicol Appl Pharmacol. 2000 Nov 1;168(3):183-8. Link to article on publisher's site
Toxicology and applied pharmacology
Tully, Keith; Kupfer, David; Dopico, Alejandro M.; and Treistman, Steven N., "A plasticizer released from IV drip chambers elevates calcium levels in neurosecretory terminals" (2000). GSBS Student Publications. 1263.