Comparison of the Activity of 'Cl. botulinus' Neurotoxin in Two Strains of Mice and in Axenic versus Conventional Rats by in-vitro Test Methods
Final rept. 10 Jul 1972-10 Jul 1973
WOODARD RESEARCH CORP HERNDON VA
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In-vitro tests of the paralytic effects of Botulinus toxin Type A were conducted in parallel on electrically-stimulated phrenic nerve-diaphragm preparations of axenic and conventionally bred Fischer strain F-344 rats, and Charles River versus Fort Detrick strain mice. The data showed no consistent difference in regard to time of onset or degree of paralysis with respect to species. In-vitro tests of effect of toxin on post-ganglionic parasympathetic nerves were conducted using isolated eye preparations of Charles River and Fort Detrick strain mice. Preliminary data confirm that endings of the short ciliary nerves which innervate the pupillary sphincter are blocked by toxin as measured by blockage of miosis produced by cholinesterase inhibitors. The data are not conclusive regarding the sensitivity of the Charles River strain to botulinum toxin, but suggest on the basis of sensitivity to hemicholinium in addition to other data, that Fort Detrick mice have greater in-vitro cholinergic activity.