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Biomedical subjects

V V Portugalov

Publications and source records attributed to V V Portugalov.

At least 19 recordsLinked to original sources
PubMed1984

[Aminopeptidase activity in the neurons of the nodose ganglion of the vagus nerve in acute experimental emotional stress].

Histological investigation was carried out to study the activity of aminopeptidase (AMP) in neurons of the nodose ganglion of immobilized rabbits with acute experimental emotional stress induced by electrical stimulation of ventromedial hypothalamic nuclei and skin. On the basis of the pattern of cardiovascular reactions, two groups of animals were distinguished: resistant and susceptible to the stress effects. In control animals, AMP activity was found to vary in neurons of different size. The highest activity was recorded in large cells, whereas small cells showed the minimum activity. In resistant animals AMP activity was found to be on control level in all groups of nerve cells. In susceptible rabbits AMP activity rose significantly, with maximum increase of AMP activity being observed in the large and medium-sized neurons.

Acute Disease↗
PubMed1982

[Tyrosine hydroxylase activity in rabbit autonomic nervous system ganglia in acute experimental emotional stress].

The Zigmond method was made use of to study tyrosine hydroxylase activity in cervical, stellate and nodosal ganglia of rabbits predisposed and resistant to stress. Experimental acute emotional stress was induced by concurrent stimulation of the ventromedial nuclei of the hypothalamus and different skin areas. Experiments have shown that changes in metabolic activity of the sympathetic and parasympathetic systems were phasic in nature throughout 3 hours of the experiment. The changes in tyrosine hydroxylase activity in nodosal and stellate ganglia of rabbits predisposed to stress differs from those in stress-resistant animals. Stress-predisposed rabbits manifested a decrease in the activity of tyrosine hydroxylase in stellate and nodosal ganglia.

Acute Disease↗
PubMed1981

[Mechanism of changes in nerve cells in acute experimental emotional stress].

Neurons of the extramural ganglia (g. cervical superior, g. stellate, g. nodosum) of the autonomous nervous system and sympathetic trunk (L4-L6) of rabbits were studied ultrastructurally under acute experimental emotional stress induced by simultaneous electric stimulation of ventromedial hypothalamic nuclei and by electrodermal stimulation of the hind limbs of the immobilized animals. The neurons of the sympathetic ganglia and sympathetic trunk showed insignificant changes. The greatest changes were discovered in the neurons of g. nodosa where, apart from pronounced changes in the nucleus and cytoplasmic organelles, the number and size of lysosomes were also substantially affected.

Animals↗
PubMed1981

[Structural changes in the soleus muscle of rats on the Kosmos-series biosatellites and in hypokinesia].

Structural changes in the soleus muscle of rats used in flight and synchronous experiments of the Cosmos program and hypokinetic studies have been investigated. It is hypothesized that focal edema and dystrophic changes observed in flight, synchronous and hypokinetic rats can be caused by circulation disorders of different etiology. In flight and synchronous rats they develop two days postflight due to the deconditioning of the muscle tissue and intraorgan vascular system which fail to meet the requirements after transition from 0 g to 1 g. In hypokinetic rats circulation disorders occur on the first experimental day due to mechanical causes (paws are pressed against the cage floor impeding venous outflow) and muscle pump deficiency. In all cases circulation disorders seem to be associated with peculiar features of angioarchitectonics of the soleus muscle.

Animals↗
PubMed1980

[Effect of artificial gravity during space flight on protein and RNA concentration in motoneurons of the anterior horns of the spinal cord in rats].

The content of protein and RNA in motoneurons of anterior horns of the spinal cord of rats flown for 18.5 days aboard the biosatellite Cosmos--936 was measured. Ten rats were exposed to weightlessness and 9 rats to artificial gravity. The RNA content in both rat groups remained at the preflight level 4.5--9.5 hours after recovery. The protein content in the motoneuronal cytoplasm of weightless and centrifuged rats was by 42 and 30% lower than in vivarium control. The protein content in the motoneuronal nuclei of the above rats was by 31 and 24% lower than in the controls. Twenty-five days postflight the RNA content in weightless rats was by 22% higher than and in centrifuged rats similar to that in the controls. The protein content in the cytoplasm returned to normal in both rat groups, whereas that in the nuclei of weightless rats was by 37% higher than in the controls.

Animals↗
PubMed1980

[Protein metabolism in the autonomic nervous system structures in acute experimental emotional stress].

Protein metabolism of extramural ganglia neurons of the rabbit autonomic nervous system (superior cervical, stellate, nodular) and the sympathetic chain at the level of the 4th--6th thoracic segment has been studied at an acute emotional stress produced by simultaneous electric stimulation of the hypothalamic ventro-medial nuclei and various parts of the body skin. It has been found out that in rabbits "predisposed to the development of stress, metabolic activity of the sympathetic nervous system structures and that of the vagus nerve change during the experimental emotional stress. In the stellate sympathetic node and in the sympathetic chain anabolic processes intensify, while in the nodular ganglion and, to a less degree, in the superior cervical node, catabolic processes intensify. Under the effect of a modulated electromagnetic field (voltage 30 v/m, frequency 39 MHz, modulation rate 7 Hz, depth of modulation 80%) the rabbits demonstrate an increased stability to the stress effect. It is possible that one of the factors determining functional stability of the cardio-vascular system to the stress effect could be certain changes in the nodular ganglion reactivity. In adapting rabbits, the anabolic processes predominate over the catabolic ones in the nodular ganglion.

Acute Disease↗
PubMed1980

[LDH isoenzyme spectrum of the extramural ganglia of the autonomic nervous system, the working heart, and cardiac conduction system of rabbits during acute experimental emotional stress].

The content of LDH isozymes was studied in extramural ganglions (superior cervical ganglion, stellate ganglion and symphathetic chain at the level of the 4th--6th thoracic segments) of the sympathetic nervous system, of the nodosal ganglion of the vagus nerve, working myocardium and conductive system of the heart of rabbits with acute experimental emotional stress provoked by simultaneous electric stimulation of the negative emotiogenic area of the hypothalamus, ventromedial nuclei, and skin. Under conditions of emotional stress no changes could be recorded in the ratio of LDH isozymic fractions in the ganglions as compared with control. No changes were found in LDH content of the working myocardium in rabbits exposed to stress. The conductive system of the heart (atrioventricular node and His' bundle) demonstrated a certain sensitivity to stress, manifesting in the increased activity of fast-moving fractions in the spectrum of LDH isozymes. The modulated electromagnetic field that exerts a protective action against an adverse effect of emotional stress produced significant shifts in LDH spectrum in the ganglions of the autonomous nervous system. No changes were detected in the spectrum of LDH isozymes in the conductive system. The results obtained suggest that the above structures of the autonomous nervous system are an important link in the bodily response to the concomitant action of the two stressors.

Acute Disease↗
PubMed1979

[Effect of artificial gravitation on the skeletal musculature of rats during space flights].

Comparative morphological and histochemical investigation of the rat skeletal muscles after a 18.5 days flight in the space ship "Cosmos-936" under conditions of weightlessness and artificial gravitation created by means of a centrifuge has demonstrated that weightlessness creates muscular atrophy, with fibres of different types affected in different muscles. The greatest changes take place in the soleus muscle. Metabolic disorders in the muscular tissue are manifested as an excessive deposition of glycogen and an increased content of phospholipids in it. The artificial gravitation favourably affects the state of the skeletal musculature preventing the development of metabolic disorders, though it does not completely avert the appearance of atrophic processes in it.

Animals↗
PubMed1979

[Hematopoietic organs in mice following a single administration of hydrocortisone].

Kinetics of the number and direction of CFU differentiating in mice after a single infusion of hydrocortisone in a dose of 5 mg per mouse was studied using the method of an exogenous cloning of the stem cells in the spleen and the bone marrow of the irradiated recipients. Against the background of the long-term involution of the thymicolymphoid apparatus a change of the number and direction of the CFU differentiating occurred. Along with this, CFU concentration in the spleen and bone marrow of mice remained constant. Under the hormone action CFU differentiating capacity in the spleen and bone marrow in the direction of erythro- and myelopoiesis sharply changes; CFU of the bone marrow behaves as CFU of the spleen, and CFU of the spleen behaves as CFU of the bone marrow of normal mice. It is suggested that the described effects of the CFU of the spleen and bone marrow of mice given hydrocortisone were due to the redistribution of T-lymphocytes and not to direct cytotoxic effect of hydrocortisone on the CFU population.

Animals↗
PubMed1978

[Mechanisms of development of histological and cytochemical changes in mammals (rats) during orbital flights].

The review surveys the publications on morphological and cytological changes in different functional systems of mammals (rats) flown on board the biological satellites of the Cosmos series. The paper gives an evidence that major changes in rats during orbital flights are induced by motor deprivation resulting in distinct metabolic disorders which histologically are represented as osteoporosis of the spongy segments of the long tubular skeletal bones, their periosteocytic osteolysis and atrophic developments in skeletal muscles. The paper discusses neurotrophic nature of these changes and emphasizes the contribution of stress reactions at different flight stages, especially on return to 1 g.

Animals↗
PubMed1978

[Effect of artificial gravitational force in space flight on the concentration of water soluble proteins in nerve tissue structures].

The content of water-soluble proteins in the grey and white matter of the spinal cord, spinal ganglia, and the sensory-motor area of the large hemispheres of the brain of rats after a 18.5-day space flight was measured. The content of water-soluble proteins in the grey and white matter of the spinal cord and spinal ganglia of rats exposed to weightlessness showed a significant decrease 4.5--9.5 hours postflight. The water-soluble protein content in the white matter of the spinal cord diminished in rats exposed to artificial gravity inflight. The water-soluble proteins content in the grey matter of the spinal cord of rats exposed to weightlessness increased significantly 25 days postflight. The content of water-soluble proteins in the grey matter of the cortex of the sensory-motor area of the large hemispheres of the brain of rats exposed to weightlessness and artificial gravity remained unchanged in comparison with the vivarium controls both 4.5--9.5 hours and 25 days postflight.

Animals↗
PubMed1978

[Determination of "settling factor" (f) by the hematopoietic stem cell cloning test in mouse spleen and bone marrow].

The effect of distribution of injected colony-forming units (CFU) in the recipient's organism was studied. The distribution was assessed by the "sedimentation factor" (f) criterion. This factor was found by the number of colonies revealed on histological sections of the spleen and femoral bone marrow in comparison with the number of colonies visible on the surface of the spleen. Macroscopic count of the colonies on the spleen permits, to assess the f value both in the whole spleen volume and in the femoral bone marrow. In this case f value was independent of the character of CFU differentiation. f value could change depending on the physiological condition of CFU population. In irradiation of the bone marrow CFU in a dose of 200, 400 and 600 R f value in the spleen decreased in comparison with control, but remained unchanged in the bone marrow.

Animals↗
PubMed1977

[Morphologic and cytochemical research aboard the biosatellite "Cosmos-782"].

Organs of rats flown for 19.5 days on board the Cosmos-782 biosatellite were investigated morphologically and cytochemically. After flight, as a result of drastic decrease or loss of static load on the musculeskeletal system in zero-g, the rats developed mineral metabolism changes that morphologically appeared as osteoporosis of spongy bones, their periosteocytic osteolysis, as well as inhibition of red blood cell precursors in bone marrow, atrophy and dystrophy of skeletal muscles. The development of stress-reaction which seemed to increase at certain flight stages (launch and re-entry) and weightlessness--1 g transition brought about changes in the structure and cell composition of lymph organs, changes in the hypothalamic-pituitary-neurosecretory system, adrenals, gastro-intestinal tract and other organs and systems. Changes in the receptor system of the inner ear resulted, evidently, from weightlessness and acceleration effects, whereas retinal lesions were due to heavy charged particles of cosmic radiation. The changes noted were reversible and 25 days after flight returned, completely or partly, to the normal.

Adrenal Glands↗
PubMed1977

[Experiments with cultures of mammalian cells aboard the biosatellite "Cosmos-782"].

A considerable contribution to the investigation on biological importance of weightlessness was made by the experiments with animals in the artificial Earth satelites (AES) of "Cosmos" type. Cell cultures can serve as an ideal model to get a direct cell response to the effect of external factors. For the experiment in the AES "Cosmos-782", two thoroughly examined cell strains (L and 237) were chosen, which differed in a number of parameters (for example, duration of their mitotic cycles). Density of cell seeding and temperature of their cultivation in the laboratory experiment were calculated in such a way that the whole cycle of the culture development should take place under the conditions of weightlessness: the beginning of lag-phase--before launching and the stationary phase--after landing. The weightlessness was not shown to result in any genetical shifts revealed at chromosomal level. When cultivated after the flight, the cells do not change their mitotic cycle parameters, mitotic course and structural organization. The data obtained in the experiments with AES "Cosmos-368" and "Cosmos-782" (increase of mitotic index, some forms of mitotic pathology during the first terms of cultivation after the flight and enlargement of cellular nuclei) demonstrate the changes in the cell population which have formed under the conditions of weightlessness. Similar changes are observed while the cells propagate in the laboratory conditions. Indirect data on an earlier cell culture aging during the flight do not exclued the possibility that under weightlessness the rate of cell propagation could differ from that under gravitation.

Animals↗