[Inhibitors of mitochondrial permeability transition pore prevent apoptosis of dopaminergic neurons in the mesencephalon].

In the study the role of apoptosis in development of dopaminergic neuronal cell death within substantia nigra (parts compacta) and ventral tegmental area induced by 6-OHDA was investigated. It was found that intermittent hypoxia and the water-soluble vitamine E (Trolox) and melatonin, as antioxidants and inhibitors of mitochondrial permeability transition pore protect dopaminergic cells from cytotoxic effect of 6-OHDA. It is supposed that mitochondrial permeability transition pore plays an important role in apoptosis of neurons in the brain.

[The nitric oxide system in a chronic deficiency of mesostriatal dopamine: the action of nitroglycerin].

Unilateral chronic deficiency in dopamine was induced by injection of the neurotoxin 6-hydroxydopamine into the mesostriatum of male Wistar rats (n = 15). The content of the nitric oxide metabolite--NO2- was three time less than in controls in the neostriatum on the operated side only, whereas, in the heart, aorta and plasma it was reduced by 1.9, 1.

[The nitrous oxide system under conditions of chronic cerebral dopamine deficiency and hypoxia].

Acute experiments were conducted on adult Wistar rats two months after unilateral microinjection of the 6-hydroxydopamine into the medial forebrain bundle. This led to a greater than 90% decrease of dopamine, fell by 70% of the content of the stable metabolite of nitric oxide-nitrite anion and by up to 80% of nitric oxide synthase activity in the lesioned neostriatum. Nitric oxide synthase activity fell by 30% in the heart, by 60% in the aorta, while nitrite anion decreased in the heart and aorta, in blood plasma and erythrocytes by 45%, 40%, 70%, 30% compared with controls rats, respectively.