[Aminopeptidase activity in the neurons of the nodose ganglion of the vagus nerve in acute experimental emotional stress]. / Aktivnost' aminopeptidazy v neironakh uzlovatogo gangliia bluzhdaiushchego nerva pri ostrom éksperimental'nom émotsional'nom stresse.

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.

[Tyrosine hydroxylase activity in rabbit autonomic nervous system ganglia in acute experimental emotional stress]. / Aktivnost'tirozingidroksilazy v uzlakh vegetativnoi nervnoi sistemy krolikov pri ostrom éksperimental'nom émotsional'nom stresse.

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.

[Mechanism of changes in nerve cells in acute experimental emotional stress]. / O mekhanizme izmenenii nervnykh kletok pri ostrom éksperimental'nom émotsional'nom stresse.

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.

[Structural changes in the soleus muscle of rats on the Kosmos-series biosatellites and in hypokinesia]. / Strukturnye izmeneniia kambalovidnoi myshtsy krys, éksponirovannykh na biosputnikakh serii "Kosmos" i pri gipokinezii.

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.

Acute experimental emotional stress in rabbits (physiological and cytochemical aspects).

The influence of acute experimental emotional stress, induced by electrical stimulation of the hypothalamus and skin in immobilized adult male rabbits of the Chinchilla breed, was determined in complex physiological and cytochemical investigations. Three groups of animals were distinguished according to the nature of the cardiovascular responses: resistance, adaptable, and predisposed to the development of stress. In animals predisposed to the development of emotional stress, different metabolic changes are induced in different extraneural nodes of the autonomic nervous system and sympathetic chain. The most pronounced changes occur in the nodose ganglion of the vagus nerve; in this case changes of a catabolic nature predominate over anabolic changes in it. In the stellate ganglion and nodes of the sympathetic chain there is an intensification of anabolic processes. The upper cervical sympathetic node occupies an intermediate position with respect to the nature of the metabolic changes. The presence of a tendency for an increase in the activity of the "fast" isoenzymes of lactate dehydrogenase was demonstrated in the conducting system of the heart.

[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]. / Spektr izofermentov LDG ékstramural'nykh uzlov avtonomnoi nervnoi sistemy, rabochego miokarda i provodiashchei sistemy serdtsa krolika pri ostrom éksperimental'nom émotsional'nom stresse.

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.

[Effect of artificial gravity during space flight on protein and RNA concentration in motoneurons of the anterior horns of the spinal cord in rats]. / Vliianie iskusstvennoi sily tiazhesti v kosmicheskom polete na soderzhanie belkov i RNK v motoneironakh perednikh rogov spinnogo mozga krysy.

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.

[Protein metabolism in the autonomic nervous system structures in acute experimental emotional stress]. / Obmen belkov v strukturakh avtonomnoi nervnoi pri ostrom éksperimental'nom émotsional'nom stresse.

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.

[Combined action of space flight and radiation factors on the skeletal musculature of rats]. / Sochetannoe deistvie faktorov kosmicheskogo poleta i radiatsii na skeletnuiu muskulaturu krys.

A prolonged irradiation of rats at a dose of 800 rad on their 10th day of flight aboard the biosatellite Cosmos-690 aggravated the severity of weightlessness- and hypokinesia-induced atrophic and dystrophic processes in the soleus muscle and the atrophic process in the gastrocnemius muscle. These space flight factors did not influence the muscles (biceps brachii, extensor digitorum longus), in which no flight-associated pathologies occurred. Radiation exposure altered the pattern of reparation in the areas of the soleus muscle that developed pathological changes, and delayed resorption which occurred during the pathological process of the connective tissue, which resulted in an inhibition of the reparation process.

[Effect of artificial gravitation on the skeletal musculature of rats during space flights]. / Vliiani iskusstvennoi sily tiazhesti na skeletnuiu muskulaturu krys v usloviiakh kosmicheskogo poleta.

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.

Development of metabolic shifts in structures of the spinal reflex arc in rats after space flight.

The stage of structures of the spinal reflex arc was studied by methods of quantitative cytochemistry in rats after orbital space flights lasting 19.5 and 22.5 days; the RNA and cytoplasmic protein content was determined in spinal motoneurons and sensory neurons of the spinal ganglia, the composition of soluble proteins of the gray and white matter of the spinal cord and spinal ganglia was determined; the lactate dehydrogenase (LD) isozyme spectrum also was investigated in the spinal ganglia and muscles of the hind limbs. A decrease in the content of cytoplasmic proteins in the spinal motoneurons and neurons of the spinal ganglia and a decrease in the content of water-soluble proteins in the gray and white matter of the spinal cord were found 5-11 h after space flight lasting 19.5 days and during the first day after a space flight lasting 22.5 days. Significant changes in the activity of isozyme fractions LD1 and LD2 were found in homogenates of the spinal ganglia. On the 1st and 2nd days after flight the LD isozyme spectrum of the soleus muscle changed from "cardiac" to "intermediate" type. The changes discovered were evidently the result of functional underactivity of the skeletal muscles under conditions of weightlessness. An increase in the RNA content in the sensory and motor neurons and an increase in the content of water-soluble proteins in the gray matter of the spinal cord were found 25-27 days after the end of the space flights, probably a manifestation of readaptation of the animals to terrestrial conditions.

[Hematopoietic organs in mice following a single administration of hydrocortisone]. / Organy krovetvoreniia myshei posle odnokratnogo vvedeniia gidrokortizona.

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.