[Morphological picture of lesions to substantia nigra of rats following intracardial administration of quinolinic acid].

Quinolinic acid is tryptophan metabolite and one of the known endogenous substance of selective neurotoxic properties. Morphological studies on noxious effect of quinolinic acid on the black substance of the brain of rats following intracardial administration of this acid were carried out. Dependence of the lesions on the dose and time of use were analysed. No lesions to the black substance were noted following a series of everyday injections of quinolinic acid in the dose of 30 mol/ml for 4 and 8 days. Degenerative changes in the neurons of black substance appeared after a dose of 60 mol/ml injected everyday for 4 days. These changes exacerbated significantly after 8 days. Generalized neuronal defects and intensive degenerative lesions in the preserved neurons with signs of decomposition of fibrous elements of tissular basis followed an administration of quinolinic acid in the dose of 100 mol/ml for 4 and 8 consecutive days.