Prolonged exposure to low levels of methylisothiazolinone (MIT) restricted growth of axons and dendrites of immature rat nerve cells in culture, apparently by disengaging the machinery of a key enzyme that is activated in response to cell-to-cell contact, and may have potentially damaging consequences to a developing nervous system, the researchers report.
"While more research is needed to determine what effect MIT would have in rodent models, both at the cellular level and to a developing nervous system, our results thus far suggest there is potential that everyday exposure to the chemical could also be harmful to humans. I would be particularly concerned about occupational exposure in pregnant women and the possibility of risk to the fetus," said senior author Elias Aizenman, Ph.D., professor of neurobiology at the University of Pittsburgh School of Medicine.
Dr. Aizenman became interested in MIT as an offshoot to his primary area of research on the mechanisms of neuronal cell death. The first he heard of the chemical was when its name came up in a literature search for compounds with specific chemical properties that he thought would incite a particular cell death pathway he recently had identified. As it turned out, MIT activated a different, novel pathway, but Dr. Aizenman remained intrigued, in large part because of the considerable lack of scientific data about a compound that he came to realize was listed on numerous consumer product labels and was very widely used in industry.