Neurobehavioral effects of D-glaucine in rats

Adult, male Fischer-344 rats were dosed by gavage with 75 or 150 mg/kg of D-glaucine for six weeks. A battery of neurobehavioral tests was given prior to dosing, after three and six weeks of dosing and three and five weeks after cessation of dosing. Routine histopathological assessment was made five weeks after cessation of exposure. Animals receiving the high dose of glaucine showed a transient decrease in body weight, decreased motor activity after three weeks of dosing, and decreased grip strength after three and six weeks of dosing. The lower dose of glaucine decreased forelimb grip strength after six weeks of dosing. Glaucine had no effects on other measures of motor function (negative geotaxis, hindlimb splay) or reactivity to noxious (hot plate, tail flick) or non-noxious stimuli (sound or air puff). By five weeks postdosing, the neurobehavioral functioning of glaucine-exposed rats was not different than controls. Histopathological examination revealed a brown discoloration of the thyroid, brain, and muscles and the appearance of brown pigments in the cell bodies of neurons located in the brain stem and spinal cord.