Neurotoxicity produced by intracranial administration of methylmercury in rats.
Toxicol Appl Pharmacol 1974 Aug; 29(2):289-300
Methylmercuric-chloride (115093) administered as a single intracranial injection in microgram quantities produced a neurological syndrome in rats within 24 hours that resembled the effects produced by repeated subcutaneous injection of 10 milligrams per kilogram over a period of 7-14 days. Neuromuscular function evaluated semiquantitatively by graded performance in simple strength and coordination tests showed severe impairment at 24 hours in intracranially methylmercury-treated animals, with recovery taking place by 72 hours. Body weight decreased and recovered during a similar time course. Incorporation of tritiated leucine into brain protein was increased significantly at 24 hours as measured in vitro in and in vivo. Incorporation returned to control values by 72 hours after the methylmercury injection. Residual brain mercury (7439976) concentrations at 24 hours were about 5-fold lower than those accompanying overt neurological signs in rats produced by subcutaneous administration. Histological examination of brains from intracranially and subcutaneously dosed rats revealed that the lesions produced by the 2 methods were substantially different. Intracranial injection of methylmercury was found to produce an isolated neurotoxic syndrome similar in some respects to the neurotoxicity seen in systemic intoxications but dissimilar histopathologically.
NIOSH-Publication; NIOSH-Grant; Toxicology; Mercury-poisoning; Metal-poisoning; Organo-mercury-compounds; Nervous-system-disorders; Time-dose-relationship; Neuromuscular-system-disorders; Histopathology; Radioactive-tracer-analysis; Brain-disorders; Test-methods
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Toxicology and Applied Pharmacology
Harvard University, Boston, Massachusetts