Vaccine preservative has action similar to methylmercury in neurons.

2004 APR 7 - (NewsRx.com & NewsRx.net) -- Thimerosal, a preservative in vaccines, has an effect similar to methylmercury on the intracellular Ca[superscript]2+ concentration of rat cerebellar neurons.

"The effect of thimerosal, an organomercurial preservative in vaccines, on cerebellar neurons dissociated from 2-week-old rats was compared with those of methylmercury using a flow cytometer with appropriate fluorescent dyes. Thimerosal and methylmercury at concentrations ranging from 0.3 to 10 micromolar increased the intracellular concentration of Ca[superscript]2+ ([Ca[superscript]2+][subscript]i) in a concentration-dependent manner," investigators in Japan report.

"The potency of 10 micromolar thimerosal to increase the [Ca[superscript]2+][subscript]i was less than that of 10 micromolar methylmercury," said Toshiko Ueha-Ishibashi and colleagues at the University of Tokushima. "Their effects on the [Ca[superscript]2+][subscript]i were greatly attenuated, but not completely suppressed, under external Ca[superscript]2+-free condition, suggesting a possibility that both agents increase membrane Ca[superscript]2+ permeability and release Ca[superscript]2+ from intracellular calcium stores. The effect of 10 micromolar thimerosal was not affected by simultaneous application of 30 micromolar L-cysteine whereas that of 10 micromolar methylmercury was significantly suppressed."

"The ...