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Biomedical subjects

L Z Pevzner

Publications and source records attributed to L Z Pevzner.

At least 37 records · Page 2Linked to original sources
PubMed1977

[Trace changes in the quantity of RNA in neurons and neuroglia of the hypothalamic nuclei of the brain following short-term intermittent exposure to cold].

Adult albino rats were kept for 2 minutes at --20 degrees C, then for 5 minutes at 25 degrees C, this intermittent cooling being repeated 15 times. One hour after the end of the cooling, the RNA quantity per cell was determined by means of visible cytospectrophotometry to find the increase in the cytoplasm of medial preoptic area neurons and in the nuclei of their glial satellite cells as well as in the nuclei of the perineuronal glial cells of mammillary bodies. Two days after the rats had stayed at the room temperature, these RNA changey bodies the RNA content decreased. 3 days later, the RNA content in the whole neuron--neuroglia unit of the preoptic area returned to normal, while in the neurons and neuroglia of mammillary bodies augmented markedly: this augmentation was found as late as 15 days after the cessation of the cooling. 30 days after the end of the cooling, the RNA quantity in the mammillary body neurons returned to normal, whiel in the neuroglia of this hypothalamic nucleus decreased even lower than the normal level. The authors discuss the problem of a so-called "vegetative memory" and of the involvement of hypothalamic neuron--neuroglia units in the metabolism tranformation dealing with a consolidation of this memory.

Adaptation, Physiological↗
PubMed1976

Cytospectrometric studies on the lactate dehydrogenase isoenzymes in functionally different neuron-neuroglia units. II. Species and strain differences and effects of histotoxic hypoxia and audiogenic convulsions.

Cytospectrophotometric determination of H- and M-forms of LDH has shown that in white mice as compared with Wistar rats the activity ratio of H- to M-forms is lower in cerebral cortex neurons but higher in spinal cord motoneurons. No statistically significant species difference has been found in cerebellum PURKINJE cells as well as in the perineuronal glia of all the areas studied. Rats of KRUSHINSKY-MOLODKINA strain with hereditary high sensitivity to audiogenic convulsions differed from Wistar rats only with higher H- to M-form activity ratio in cerebellum PURKINJE cells and in their glial satellite cells. Histotoxic hypoxia in mice due to KCN injection gave rise in 15 min 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 cerebellum PURKINJE neurons. Audiogenic convulsions in KRUSHINSKY-MOLODKINA rats induced an increase of H-form activity of LDH in the perineuronal glia of spinal cord anterior horns and of M-form activity in cerebellum PURKINJE cells while decrease of M-forms of cerebellum neuroglia. An importance of multiple forms of enzymes for the fine functional regulation of the cell biochemical pattern is discussed.

Animals↗
PubMed1976

[RNA concentration in neuron-neuroglia systems of the retina and visual zones of the cerebral cortex during light deprivation and light stimulation].

A two-wave-length cytophotometry of the gallocyanin-chromium alum-stained preparations showed that in adult rats kept for 30 days in complete darkness there was a decrease in the RNA content in the perineuronal neuroglia of the retinal ganglion cell layer only, with no changes in the corresponding neurons. No changes were found in the neurons and in the perineuronal glia of the layer II---III of the visual cerebral cortex. After the end of light deprivation a 2-hour stimulation with a constant or flickering light did not influence the RNA content in the neurons of both regions of the visual analyzer studied, whereas in control rats this stimulation induced a marked increase in the RNA content in these neurons. Qualitative changes in the metabolism of the cellular RNA in the nervous system of adult animals under the effect of light deprivation are emphasized. Differences in the biochemical peculiarities of various neuron-neuroglia systems, depending on their localization in the visual analyzer, are discussed.

Animals↗
PubMed1976

[Cytospectrophotometric analysis of various color reactions for acid and basis proteins in nerve tissue cells].

Polyvinyl formal films soaked with various concentrations of proteins as well as Carnoy-fixed paraffin sections of rat brain were stained with various colour reactions for acidic and basic proteins. Sufficient specificity, reproductivity, sensitivity and applicability for cytospectrophotometric determinations have been shown for the staining of acidic proteins with Toluidine blue 0 (pH 9.0) or with Fast green FCF (pH 2.6), and for the staining of basic proteins with Alcian blue (pH 10.0), or with Fast green FCF (pH 8.2). Importance of cytophotometric analysis of individual protein fractions is outlined for the functional cytochemistry of the nervous system.

Albumins↗
PubMed1976

[Scanning intergrating cytospectophotometry of tightly apposed micro-objects (as an example, a study of the circadian rhythm of RNA and protein concentrations in different neuron--neuroglia systems)].

A scheme of electron aperture is described which permits a scanning intergrating cytospectrophotometry of adjacent microobjects. Results are presented of such cytophotometry to determine RNA and protein content in various neuron--neuroglia units of the rats studied every 4 hours during 24 hours period. Contraphase character of circadian fluctuations has been shown for RNA level in cerebllum Purkinje cells, hypothalamus supraoptic neurons and spinal cord motoneurons as compared with the fluctuations in corresponding glial satellite cells. Protein content fluctuations were of contraphase character only in the spinal motoneurons and in their perineuronal glia, whereas in all the other neuron-neuroglia units the period of fluctuations was rather similar in the neurons and in the glial cells. A great value of quantitative cytochemical methods is outlined to carry out a functional biochemical analysis of nervous tissue cells.

Animals↗
PubMed1976

[Cytophotometric correlation of changes in the RNA and protein concentrations of perineuronal oligodendrogliocytes and ependymal cells of the spinal cord under different experimental conditions].

By means of ultraviolet and visible cytospectrophotometry, RNA and total protein content per cell was determined in perineuronal oligodendrogliocytes of spinal cord anterior horns and in ependyma cells of spinal cord central canal in Wistar rats under various experimental conditions. It was only in one experimental series that the cell kinds compared were characterized by a similar metabolic response: daily adrenaline injections for two weeks resulted in RNA accumulation both in the oligodendroglia and in the ependyma: besides, in both the kinds of spinal cord cells, no changes in RNA amount was found due to acute hypoxic hypoxia and to 6-mercaptopurine administration. In all the other experimental series (aurantin adminstraion: adrenalectomy and hydrocortison treatment; posthypoxic reparation), changes in RNA content markedly differed in the oligodendroglia and in the ependyma. The data are presented concerning the changes in protein content in the cytoplasm of spinal cord ependyma cells under the experimental conditions applied. Importance of topochemical analysis of nervous tissue structures by means of quantitative cytochemical methods is outlined.

Adrenalectomy↗
PubMed1975

[Circadian rhythm of total histone concentration in noradrenalinergic and serotoninergic neurons and their glial satellite cells].

By means of photoelectric aperture cytospectrophotometry of fast green FCF strain sections the total histone content was determined in the nuclei and whole bodies of the neurons of the reticular formation, as well as in the nuclei of their glial satellite cells during various periods of the 24-hour cycle. In the noradrenalinergic neurons of the reticular formation of the lateral nucleus ther was revealed a circadian rhythm of the changes in the total histone content with the two maxima and the two minima per 24 hours in the neuronal bodies, but with only one period of fluctuations per 24 hours in their nuclei. On the contrary, in the 5-hydroxytryptaminergic (serotoninergic) neurons of the paragiant-cell nucleus of the reticular formation the total histone content changes once in 24 hours in the cell bodies, but twice within the same period in the neuronal nuclei. The amplitude of fluctuations was markedly lower than in the corresponding neurons in the cells of the perineuronal neuroganglia,

Animals↗
PubMed1975

[Cytoplasmic RNA content in the brain and spinal cord neurons of red-cheeked susliks during the hibernation period and on arousal].

By means of scanning cytospectrophotometry of gallocyanin chrome alum stained sections, cytoplasmic RNA content per cell in the neurons of the ground squirrel hippocampus, hypothalamic supraoptic nucleus, and spinal cord anterior horns, was shown to decrease as far as the hibernation went on. Before the arousal the RNA amount increased, the increase being the greatest in the hypothalamic neurons. First days after the arousal, the cytoplasmic RNA content in all the neurons was significantly higher than in the same neurons before the hibernation. Changes of RNA content in the neurons and in the homogenates of corresponding brain areas were compared; important role of the hypothalamus in metabolic reconstruction of the nervous system at various stages of hibernation, was outlined.

Animals↗
PubMed1975

[Effect of audiogenic convulsions on the activity of n- and m-forms of lactate dehydrogenase in the neurons and neuroglia of different sections of central nervous system].

It was shown spectrophotometrically that in Krushinsky-Molodkina and Wistar rats the ratio of the activity of the aerobic H-forms of lactic dehydrogenase (LDH) to the activity of the anaerobic M-forms was higher in the neurons of the cerebral cortex and the Purkinje's cells of the cerebellum and in their glial cells-satellites than in the motor neurons of the anterior horns of the spinal cord and their perineuronal glia. In Krushinsky-Molodkina rats (with genetically-determined high sensitivity to audiogenic convulsions) epileptiform attacks under the effect of sound were accompanied by a marked activation of both the H- and the M-forms of LDH in the cortical neurons in the absence of any shifts in the perineuronal glia. On the contrary, the activity of all the forms of LDH was unchanged in the spinal motor neurons, whereas in the neuroglia cells surrounding these neurons there was a distinct increase in the activity of the H-forms of LDH. In the Purkinje's cells of the cerebellum an increase and in the glial cells- satellites -- a reduction of the activity of the M-forms of LDH in case of convulsions was seen.

Acoustic Stimulation↗
PubMed1975

[Biochemical and cytospectrophotometric analysis of the extraction of RNA from spinal cord cell structures].

By means of two-wavelength spectrophotometry, according to Tsanev and Markov, a stability of RNA content has been demonstrated in rabbit spinal cord sections treated with cold perchloric acid: it was only after 18 and particularly 48 hr incubation of the section in a 16% perchloric acid solution that the total tissue RNA began to be extracted. Cytospectrophotometrical study of the motoneurons of spinal cord anterior horns and perineuronal glial cells in gallocyanin -- chrome alum stained sections has shown a rapid loss of RNA under effect of the cold perchloric acid: as early as after a 2 hr treatment, about 2/3 of the whole cellular RNA was extracted from the motoneurons, while about 1/2 from their glial satellite cells. Hydrolysis of the rest of RNA was found out in the neurons and in the neuroglia only after a 18 hr extraction with the perchloric acid. Similarities and differences in the features of neuronal and glial RNA are discussed.

Animals↗
PubMed1975

Cytospectrophotometric studies on the lactate dehydrogenase isoenzymes in functionally different neuron-neuroglia units. I. Optimal procedure conditions and topochemical comparisons in normal mice.

Optimal conditions are described to reveal quantitatively the total activity of lactate dehydrogenase (LDH) and the activity of its H- and M-form in the nervous tissue sections when applying Brody and Engel's tetrazolium method modified by Gerebtzoff. This histochemical reaction has been shown to obey Bouger-Lambert-Beer's law which confirms the possibility of the quantitative determination of the activity of LDH and its isoenzymes by means of cytospectrophotometric method. In the neurons of different areas of the mouse nervous system (cerebral cortex, cerebellar cortex, spinal cord anterior horns, spinal ganglia), both the total LDH activity and the activities of its H- and M-forms were localized in the cytoplasm. Within the limits of the sensitivity and correctness of the cytospectrophotometric method, the ratio of H- 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.

Animals↗