THE SODIUM-POTASSIUM ATPASE INHIBITOR OUABAIN IS NEUROTOXIC IN THE RAT SUBSTANTIA-NIGRA AND STRIATUM

Injection of ouabain, a potent and selective inhibitor of Na+/K+ ATPas e, into the rat striatum and substantia nigra caused a selective neuro nal loss in up to 70% of the lesioned area. However, there was a glial cell/macrophage proliferation in the core of the lesion. Neuronal los s was demonstrated by staining in vivo with Trypan Blue, a marker for dead cells. Cholinesterase staining was also lost, but in the striatum this was revealed only after pre-existing enzyme was irreversibly inh ibited in vivo.