title: Fluorescent estimation on cytotoxicity of methylmercury in dissociated rat cerebellar neurons: its comparison with ionomycin.
abstract: To study the cellular basis of the neurotoxicity of methylmercury, the effects of methylmercury on dissociated rat cerebellar neurons were examined using a flow cytometer, a confocal laser microscope and three fluorescent dyes, fluo-3 for monitoring the changes in intracellular Ca(2+) concentration ([Ca(2+)](i)) and for detecting live neurons, ethidium for assessing the neurons that are dead or have compromised membranes, and 5-chloromethylfluorescein (CMF) for estimating the cellular content of nonprotein thiols. Methylmercury at concentrations of 1 μM or greater increased the [Ca(2+)](i) of almost all neurons. Prolonged exposure to methylmercury (3 and 10 μM) produced a further increase in [Ca(2+)](i), in association with compromising membranes in some neurons. Thereafter, methylmercury induced blebs on membranes of some neurons with increased [Ca(2+)](i). Methylmercury at concentrations of 0.3 μM or greater dose-dependently decreased the cellular content of nonprotein thiols. Results suggest that methylmercury may induce the loss of membrane integrity through destabilized Ca(2+) homeostasis and oxidative stress in mammalian brain neurons.
authors.affiliation: Graduate School of Human and Natural Environment Sciences, The University of Tokushima, Tokushima 770, Japan.
authors.forename: E
authors.initials: E
authors.lastname: Okazaki
authors.forename: Y
authors.initials: Y
authors.lastname: Oyama
authors.forename: L
authors.initials: L
authors.lastname: Chikahisa
authors.forename: T
authors.initials: T
authors.lastname: Nagano
authors.forename: N
authors.initials: N
authors.lastname: Katayama
authors.forename: M
authors.initials: M
authors.lastname: Sakamoto