title: Neurobehavioral assessment of 2,4-dichlorophenoxyacetic acid (2,4-D) in rats.
abstract: 2,4-Dichlorophenoxyacetic acid (2,4-D), an organic acid commonly used as a herbicide, was assessed for behavioral and neurological toxicity in male Fischer-344 rats. When given by gavage twice weekly for 5 weeks, 2,4-D produced a significant increase in fore- and hindlimb grip strength. Other neurological measurements such as negative geotaxis, hindlimb splay, motor activity, and startle responsiveness, were not affected. A second experiment, in which rats were dosed 5 days per week for 4 weeks, replicated the finding that 2,4-D increases grip strength of rats. In addition, the neurological effect was found to dissipate with time following cessation of dosing. That 2,4-D increases grip strength may be related to the observation that it induces myotonia, a condition characterized by difficulty in relaxation of skeletal musculature following forceful contraction.
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity*; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D005121:Extremities; D008297:Male; D009043:Motor Activity / Q000187:drug effects*; D009132:Muscles / Q000187:drug effects / Q000294:innervation; D051381:Rats; D011916:Rats, Inbred F344; D013216:Reflex, Startle / Q000187:drug effects
chemical_list: D015084:2,4-Dichlorophenoxyacetic Acid