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Biomedical subjects

N A Mezhiborskaia

Publications and source records attributed to N A Mezhiborskaia.

10 recordsLinked to original sources
PubMed1990

[Ultrastructural manifestations of blood-tissue barrier reactions to acute hypoxia in old animals].

Readjustments occurring in different blood-tissue barriers (the brain, endocrine glands, heart, liver, jejunum) in response to acute hypoxia in old animals develop against the background of the preceding age-specific changes, including the adaptive ones. This results, first, in a significant narrowing of the adaptive reaction range and, second, acceleration and deepening of destructive processes in tissues and prolongation of the restoration period.

Acute Disease↗
PubMed1989

[Age-related ultrastructural characteristics of various cells in acute hypoxia].

Ultrastructural peculiarities, concerning reaction of cells in various populations brain-sensorimotor cortex, mammillary nuclei, vascular plexus; myocardium; liver; jejunum) in mature (6-8 months) and old (24-30 months) male white Wistar rats have been studied at an experimental acute hypobaric hypoxic hypoxia. Both general changes, that are manifested in various degree in different cell groups and organo-specific ones are noted. The manifestation degree of the reactive changes is evidently connected with certain metabolic and functional peculiarities, as well as with the character of cell restoration. In the old animals hypoxic hypoxia produces more profound destructive processes in all cell populations studied. This is accompanied with a restriction in ability to adaptation.

Acute Disease↗
PubMed1987

[Intranuclear inclusions in the cells of different tissues of the aging rat].

Ultrastructure of neuronal and glial nuclei has been studied in various parts of the CNS, in parenchymatous cells of internal organs, in endotheliocytes and pericytes of their blood capillaries in intact rats--mature (6-8-month-old) and old (26-28-month-old), as well as at certain experimental influences. In all the cellular populations studied (most often in neurons), various in their structure, intranuclear inclusions (INI) have been revealed, that are considered as five main types. The number of INI increases sharply at ageing, that is especially noticeable under experimental conditions. Some INI are situated in morphologically preserved, actively working cells, being normal components of the nucleus, others--reflect profound rearrangements of nuclear proteins, disturbances in lipid metabolism up to irreversible destructive processes in the nucleus.

Aging↗
PubMed1981

[Reactive changes in the capillaries of the mammillary bodies of the brains of aging animals].

As electron microscopic investigation of the capillary wall in the mammillary bodies has demonstrated, in old animals the number of organells in the endothelial cells decreases; discomplexion and reduction of mitochondrial crists occur, their matrix becomes cleared; myelin-like structures are formed. In pericytes pigment inclusions are accumulating. Noncellular component of the basal layer loses its regular structure and foci of hydratation appear in it. When pharmacological loadings (adrenaline, aminazine) are applied to old animals, distrophic processes in the vascular wall increase; that results in disturbance of permeability, sharp hydratation of the basal layer, edema of the tissue elements around the brain and, hence, in a more prolonged restorative period.

Aging↗
PubMed1981

[Ultrastructural characteristics of the cerebral capillaries of aging animals subjected to hypoxic hypoxia].

The ultrastructure of capillary walls of the mamillary bodies was studied in rats distributed in two age groups: adult (6-8-month-old) and old (28-30-month-old) animals under hypoxic hypoxia. It was found that age-related differences in the response of brain capillary walls to the injuring agent were reduced to a rapid increase in dystrophic phenomena and less conspicuous compensatory processes seen in the old animals. More profound injuries to other brain tissues adjacent to the vessels were also indicative of less efficacy of the adaptive reactions in the old animals.

Age Factors↗
PubMedDate not supplied

[The age-related characteristics of autophagocytosis in different tissues of laboratory animals].

To elucidate the role of autophagy in age-related lipofuscinogenesis, the accumulation of autophagic vacuoles (AV) caused by the blockade of their fusion with lysosomes under the effect of vinblastine was studied in cells of various tissues (hepatocytes, pinealocytes, epitheliocytes of choroid plexus, cardiomyocytes, neurons) in mice and rats of different ages. The degree of AV accumulation in cells of old animals did not exceed that in adult ones. The results suggest that the accumulation of lipofuscin (LF) in aging cells is mainly due to the disturbance of lysosomal degradation or removal of LF out of cells rather than to the increase in autophagy.

Aging↗