[Cytophotometric determination of the relationship between the chief isoenzyme forms of lactate dehydrogenase in the neuron--neuroglia system in different fuctional states of the nervous system].

In white mice, unlike the Wistar rats, the ratio of activities of H- and M-forms of lactate dehydrogenase (LDH) is lower in the cerebral cortex neurons but higher in the spinal cord motoneurons within the limits of sensitivity and correctness of the cytospectro-photometric method. No statistically significant species differences in the activity ratios of H- to M-forms of LDH were found in the Purkinje cells of the cerebellum, as well as in the perineuronal glia of all the areas studied. Rats of the Krushinsky--Molodkina strain with a hereditary high sensitivity to audiogenic convulsions differed from the Wistar rats only with a higher H- to M-form activity ratio in the Purkinje cells and in their glial satellite cells. The ratio of H-forms to M-forms of LDH did not differ significantly in the majority of the neuron types studied as well as in the neurons as compared with their glial satellite cells. Histotoxic hypoxia in mice due to KCN injection gave rise to activation of M-forms of LDH in spinal cord motoneurons and spinal ganglia neurons, of H-forms in cerebral and cerebellar cortex neurons and of both forms in the neuroglial cells adjacent to the cerebellum Purkinje neurons. Audiogenic convulsions in the Krushinsky--Molodkina rats induced an increase of the H-form activity of LDH in perineuronal glia of spinal cord anterior horns, and of the M-form activity in the cerebellum Purkinje cells with a decrease in the M-forms of the cerebellum neuroglia. An importance of multiple forms of enzymes for the functional regulation of the cell biochemical pattern is discussed.