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Biomedical subjects

V A Arefolov

Publications and source records attributed to V A Arefolov.

At least 19 recordsLinked to original sources

[Effect of the N-terminal fragment of substance P1-4 on the somatic manifestations of the stress reaction and on the catecholamine content of the adrenals in rats].

The antistress affect of the substance P1-4 N-terminal fragment (ARG-Pro-Lys-Pro, 100 mkg/kg, i.p.) has been studied on the model of immobilization stress in rats. It was ascertained that the preparation of protective effect is revealed to the greatest extent on the exhaustion stage (48 h of immobilization), which served to prevent the lymphoid organs mass reduction and ulcer development and also accounted for greater adrenaline and noradrenaline content preservation in tissues and chromaffin cells of adrenal glands in stressed animals.

Adrenal Glands

Effect of the N-terminal tetrapeptide of substance P SP (1-4) and tuftsin on the pre- and postsynaptic transmitter outflow in rat adrenal gland slices.

Two structurally related tetrapeptides, the N-terminal tetrapeptide of substance P SP(1-4) and tuftsin, exerted some similarities in modifying immune reactions and normalizing stress-induced disorders in the catecholamine system of adrenals. This paper presents results about the effects of tuftsin and SP(1-4) on the cholinergic-adrenergic interaction in rat adrenal gland slices. Both, tuftsin and SP(1-4) inhibited the nicotine-evoked [3H]noradrenaline outflow (postsynaptic effect), but the effect of SP(1-4) was more pronounced. SP(1-4) also inhibited the electrically stimulated [3H]ACh outflow (presynaptic effect), whereas tuftsin did not affect the ACh outflow. It is suggested that the regulation of the cholinergic-adrenergic interaction in adrenals is mediated by specific receptors, which are different on the pre- and postsynaptic side.

Acetylcholine

[Role of the peripheral catecholaminergic systems in the antistress action of neuropeptides].

The mediator activity of the peripheral catecholaminergic systems (the adrenergic nerves of dura mater and the concentrations of noradrenaline and adrenaline in the adrenals of rats) during dynamic and immobilization stress was investigated with the help of fluorescent microscopy and spectrofluorometry. Neuropeptides--dalargin and another enkephalin analog--were injected intraperitoneally, 150 mg/kg. A visible antistress action of these neuropeptides has been demonstrated, it was more marked after treatment with dalargin. The role of peripheral catecholaminergic system in the mechanism of stress-protective effects of neuropeptides is discussed.

Adrenal Medulla

[Morphometric ultrastructural study of the adreno- and noradrenocytes of the rat adrenal during immobilization stress of varying duration].

The ultrastructural organization of secretory granules, containing adrenaline (A) or noradrenaline (NA) was studied in chromaffin cells of the rat adrenal gland after 3-, 24- and 48-hour immobilization stress. Using cytochemical electron microscopic Tranzer's method and the method of morphometry, the number of normal dense cores, "empty" and "semiempty" vesicles was calculated. It was shown that the total content of vesicles and the ratio of investigated types of both adrenaline- and noradrenaline-accumulating granules were markedly changed during stress. The degree of such stress-induced reorganization depended on the stage of stress reaction and involved first A-cells and then NA-cells.

Adrenal Medulla

[Detection of the pro-opiomelanocortin peptide fragments--beta-endorphin and ACTH--in the adrenals of rats and mice by immunohistochemistry].

Independent peptide fragments of pro-opiomelanocortin molecule, beta-endorphin and ACTH, have been detected immunohistochemically in the adrenal glands of rats and mice. Immunoreactive beta-endorphin and ACTH have been revealed in the adrenal medulla and reticular zone of the adrenal cortex. beta-endorphin and ACTH distribution patterns in adrenal sections were identical, which is indicative of the linked synthesis of these peptides in the adrenal gland. The data obtained suggest the existence of pituitary-independent mechanisms regulating corticosteroidogenesis in the adrenal gland, involving adrenal pro-opiomelanocortin fragments.

Adrenal Glands

[Changes in the opioid peptide content of the adrenals of rats during immobilization stress].

Radioimmunoassay was used to study variation in the content of opioid peptides (leu- and met-enkephalins) in rat adrenal glands at different stages of immobilization stress. The data obtained were correlated to the content of catecholamines (CA). It was discovered that during stress, the content of peptides noticeably increased, being independent of the main pool of CA in adrenal tissue.

Adrenal Glands

[State of the peripheral catecholaminergic systems during pharmacologic correction of immobilization stress using sodium oxybutyrate].

Fluorescent microscopy and spectrofluorometry of biogenic amines were employed to study the peripheral catecholaminergic systems in immobilized rats which received sodium hydroxybutyrate. The content of catecholamines was measured in the adrenergic nerves of dura mater, vas deferens and chromaffin tissue of the adrenals. It was established that sodium hydroxybutyrate in a dose of 40 mg/kg intraperitoneally promoted returning to normal of the adrenergic mediator activity during alarm and resistance stages. The role of the peripheral catecholaminergic systems in the mechanism of the stress-protective effect of sodium hydroxybutyrate is discussed.

Adrenal Glands

[Effect of sodium hydroxybutyrate on the ultrastructure of cross-striated muscle tissue myocytes during physical exercise].

The ultrastructure of myocytes of the rat myocardium and skeletal muscles was studied in the control during physical exercise and under conditions of two-week sodium hydroxybutyrate pretreatment. It was shown that single maximum physical exercise caused significant changes in the fine structure of cardiomyocytes and somewhat less changes in a pronounced intermyofibrillar edema, the swelling of mitochondria and an acute fall of the glycogen level. A two-week sodium hydroxybutyrate pretreatment prevented the changes in the myocytes. The observed structure normalization induced by the drug is likely to be due to the specific nature of its metabolic transformation and to the effect on the energy exchange.

Animals

[A pharmacologic analysis of several adrenomimetic effects of serotonin].

Contractions of the isolated rat vas deferens in response to the addition of serotonin could be explained by the release of catecholamines from the nerve endings. As shown by the use of D-, M- and T-antagonists of serotonin (LSD-25, indocarb, typindole), symatholytic--bretilium, alpha-adrenolytic--droperidol and imipramine, this effect was not associated with the direct activation of serotonin- and adrenoreactive receptors.

Animals

[Adrenergic component in the mechanism of action of sodium oxybutyrate].

The influence of sodium oxybutyrate on the adrenergic neurotransmitter content in the nerve fibers and the synaptic vesicles and the uptake of exogenous noradrenaline (NA) by the sympathetic nerves of rat Vas deferens was studied by spectrofluorimetry, fluorescent-histochemistry and cytochemical electron microscopy. Sodium oxybutirate failed to influence the stores of the adrenergic mediator, but was capable of blocking the uptake and accumulation of the exogenous NA.

Animals

[Effect of carbidine on the process of adrenergic neurotransmission].

Methods of physiological analysis were applied to a study of the effect of an original psychotropic agent--carbidine--on the process of adrenergic neurotransmission on a model of an isolated rat Vas deferens. The noradrenaline (NA) content was determined in the same ductus spectrofluorimetrically; the capacity of the neuroleptic to block the consumption of the exogenous NA by the tissue was also investigated. Carbidine proved to possess an adrenomimetic effect caused by it capacity to release NA, leading to a reduction of endogenous neuromediator stores.

Animals

[Influence of nonakhlazin on adrenergic neurotransmission in the vas deferens of rats].

The effect of a new antianginal drug--nonachlazine on the adrenergic neurotransmission in the isolated rat vas deferens was studied by examining the vas deferens contractions in response to the transmural electric stimulation of the postganglionic sympathetic nerves and addition of noradrenaline (NA) or BaCl2. After the nonachlazine treatment the NA content in the vas deferens was also studied by the spectrofluorometric method. Besides, the effect of the drug on the uptake of the exogenous NA was investigated. Nonachlazine was found to possess some sympatholytic and spasmolytic effect and could block the uptake of the exogenous NA greatly.

Animals

[Effect of carbidine on the content and storage of adrenergic neurotransmitter in the synaptic vesicles].

The influence of carbidine, an original psychotropic drug, on the adrenergic neurotransmitter content and storage in the sympathetic nerves was studied with the use of cytochemical electron microscopy. The influence of carbidine on the uptake of the exogenous noradrenaline (NA) in the synaptic vesicles was also studied. Carbidine was found to be capable to decreasing the NA storage in the synaptic vesicles and failed to block the accumulation of the exogenous NA in the synaptic vesicles.

Amines