^
m-Fluorotyrosine convulsions and mortality: relationship to catecholamine and citrate metabolism.
1967 Journal of Pharmacology and Experimental Therapeutics
ABSTRACT
WEISSMAN, ALBERT AND B. KENNETH KOE. m-Fluorotyrosine convulsions and mortality:
Relationship to catecholamine and citrate metabolism. J. Pharmac. exp. Ther. 155: 135-144,
1967. The characteristic convulsions and mortality induced by DL-m-fluorotyrosine (m-FT),
in mice were antagonized by anticonvulsant drugs, but not by high doses of chlorproma-
zinc, atropine, lysergic acid diethylamide or several drugs variously affecting catecholamine
metabolism or storage. Sublethal doses of m-FT were slightly potentiated by ce-methyltyro-
sine and by catecholamine depletors, but these effects were marginal and a variety of other
centrally acting drugs was ineffective in potentiating m-FT. Despite the structural simi-
larity of rn-FT to several potent tyrosine hydroxylase inhibitors, rn-FT was essentially in-
active as a tyrosine hydroxylase inhibitor in vitro ; similarly, rn-FT only slightly reduced
norepinephrine concentrations in mouse brain. rn-FT did, however, cause pronounced ac-
cumulation of citric acid in mouse kidney and brain. It is postulated that the convuLsions
and mortality caused by rn-FT are primarily unrelated to catecholamine metabolism, but
are instead the result of metabolism of rn-FT through tyrosine pathways to fluoroacetate.
Supporting evidence was provided by a study of o-, rn- and p-fiuorophenylalanine ; only
the m isomer was lethal at low doses, and only this compound caused citric acid accumula-
tion. The speculative explanation that rn-FT is toxic by being metabolized to fluoroacetate
does not, however, explain why in mice rn-FT has more convulsant properties and is more
toxic than fluoroacetate, its proposed active metabolite; drug penetration factors may ac-
count for these discrepancies.
now just imagine a meta-fluoro group
ps-look at the compounds they just got to play with !!! the good ole days
