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Biomedical subjects

V V Kupriianov

Publications and source records attributed to V V Kupriianov.

At least 19 recordsLinked to original sources
PubMed1996

[Neurovasal relations in the human neocortex].

Different types of interneurons producing nitric oxide in human brain motor cortex were studied by means of histochemical reaction to NADPH diaphorase--the marker of nitric oxide synthase. Non-synaptic dendrito-, axo- and somatovasal contacts between typical smooth and spinous checking interneurons were shown. A hypothetic scheme of local blood circulation control is represented, after which these cells, exerting inhibitory synaptic action on pyramidal neuron at the same time cause vasodilatation by secreting nitric oxide near to the capillary. Scientific Research laboratory of Biological Mechanisms of Structural Maintenance of Homeostasis, Russian Medical University, Moscow.

Adult↗
PubMed1992

[Metabolic and functional consequences of complete inhibition of creatine kinase by iodoacetamide in the perfused heart].

Treatment of perfused rat hearts with 0.5 mM iodoacetamide (IAAm) for 15 min at different workloads resulting in a nearly complete inhibition of creatine kinase (CK, 99%) was followed by a rapid decline of the phosphocreatine (PCr) level (30%) and a 2-fold increase of the P(i) level which then stabilized. Conversely, the ATP content started to drop monotonously at the beginning of the IAAm washout and reached 30% 90 min after the IAAm removal under medium load. Under low workload the ATP decay occurred at later periods. Neither the ADP-stimulated mitochondrial respiration in skinned fibers, nor the Ca(2+)-stimulated ATPase activity of myofibrils was affected by IAAm treatment. The sensitivity of the resting tension of skinned fibers to Ca2+ tended to a slight increase. The cardiac work index (PRP-pressure-rate product) decreased by 25%, while the end diastolic pressure (EDP) rose by 15 mm Hg when IAAm acted under medium load. In contrast, under low work these parameters were practically stable. The hearts poisoned with IAAm performed a two times lower maximal work and had reduced (by 35%) oxygen consumption rates. The efficiency of energy utilization for mechanical work decreased by 40%. The changes in PRP and EDP correlated with the cytosolic [ATP]/[ADP] ratio in such a way that the decrease in the latter was associated with a decrease in PRP and the elevation of EDP. These data suggest that the creatine kinase system is necessary for the effective translation of a high [ATP]/[ADP] ratio from the intermembrane space of mitochondria to the cytoplasm, myofibrils and ionic pumps. This provides a high level of mechanical work and good relaxation of the left ventricle and protects cytosolic adenine nucleotides from the breakdown.

Adenine Nucleotides↗
PubMed1992

[Functional significance of 2 pathways of energy transport in cardiomyocytes].

To study the relative roles of creatine kinase (CK) and adenylate systems in cardiac energy turnover, the effect of CK inhibitor, iodoacetamide- (IAA, 0.5 mM), and 2-deoxyglucose-(DOG, 2 mM) induced) 65% depletion of adenine nucleotides at slightly decreased CK flux was determined in isolated rat heart. Both substances did not substantially affect contractile parameters of the isovolumic heart. However, an augmentation of cardiac work induced by isoproterenol addition was feeble and transient in IAA-treated hearts while the response of DOG-treated hearts was well preserved. The cardiac failure after IAA treatment was associated with irreversible fall in myocardial ATP content as evidenced by 31P-NMR technique. Furthermore, these hearts were unable to perform cardiac pump function due to insufficient cardiac filling and distensibility. The DOG-treated hearts exhibited 50% reduction in the pump function and were able to increase their work in elevated resistance. The results suggest that CK pathway is extremely important for both full cardiac relaxation and maximal contractile function.

Adenosine Triphosphate↗
PubMed1991

[The pavement lining of the vessels in the earthworm (Lumbricus terrestris)].

Effect of some preparatory methods to make ready earthworm tissues for electron microscopical investigation has been studied in order to reveal structural components of the vascular wall. The method for an immediate fixation of the earthworm tissues in liquid nitrogen with a subsequent additional fixation in cooled 2.5% glutar aldehyde, applied in combination with OsO4-thiocarbohydroside-OsO4 method is optimal. This method of samples preparation gives a reliable information concerning existence of an internal--endothelial--lining in the earthworm vessels. A conclusion is made on a qualitatively new level of cell differentiation of the internal vascular lining in the earthworm, which is called phase of blast transformation of endotheliocytes.

Animals↗
PubMed1989

[Structure and function of lymphatic postcapillaries (coordinating mechanism of the processes of interstitial transport and lymphatic resorption].

Investigation performed on topography, structure and resorptive function of lymphatic microvessels in the serous membranes gives possibilities to work out a model on formation and transport of lymph. Lymphatic postcapillaries (LP) - thin-walled endothelial channels with valves make an important link of the lymphatic system. The LP structure is similar to that of capillaries. These microvessels are situated in the interstitial space area, that are characterized with their high content of plasma proteins and water. Interrelation in concentrations of protein in the LP lumen and in the tissue ensures the existence of the osmotic gradient pressure through the wall and contributes liquor resorption into the lumen of microvessels. Peritoneal lymphatic capillaries are situated in the areas of a higher hydrotation level of the interstitial space. They can control the rate of the liquor filtration from plasma into tissue and regulate the resorption level in the whole lymphatic network. The model provides a differentiated participation of the LP and capillaries in performing resorption of proteins and liquor from the interstitium. The resorption mechanisms are closely connected with processes of the lymph movement along the vessels.

Animals↗
PubMed1988

[Ultrastructural organization of vessels of the slug (Agriolimax agrestis)].

Ultrastructural analysis on organization of the slug microvessel walls (arterioles, capillaries and venules) has been performed. Transport canals of endothelial cells in the capillaries and venules have been estimated. A conclusion is made that in the evolutionary process of development the vascular endothelium becomes more specialized.

Animals↗
PubMed1988

[Biomechanics of the spiral arrangement of muscle elements in the vessels and mechanism of its regulation during hemodynamics].

On the basis of a previously proposed hypothesis about a spiral orientation of muscle elements in the walls of muscular arteries, terminal arteries and arterioles, as a universal regularity, concrete mechanisms of vascular biomechanics and bioregulation at hemodynamics are analyzed. The latter come to a cyclic change of the vasodilator phase into the vasoconstrictory one and vice versa, accompanying with a change of pressures in the local areas of the vessel from the lower to the higher and vice versa along the vascular length. Movement of the pulsed wave with the muscle elements is ensured by a consecutive change of pressures in successive local areas. This is performed under the influence of the blood stream pulsed wave and ensured by a multicontour regulatory system, including terminal and central, cholinergic and adrenergic reflectory arches, interacting in accordance with the principle of double reciprocal innervation and regulation.

Biomechanical Phenomena↗
PubMed1988

[Structural characteristics of the mediastinal pleura and its blood vessels].

By means of impregnation of the microcirculatory bed vessels after V. V. Kupriyanov and transmissive electron microscopy, topological picture of hemomicrovessels has been estimated in the glomerular constructions of the dog mediastinal pleura. The composition of cell elements and peculiarities in distribution of the latter in the zone of the milk spots are examined. Their structural characteristics are manifested as presence of mesothelium of a decomplexated type accumulation of macrophagal and lymphocyto-plasma cells, glomerular organization of the capillary network and postcapillary venules, two types of endothelial lining of the metabolic microvessels. The role of the milk spots in ensuring immune protection, in migration of macrophages and in filtration of the pleural liquid is discussed.

Animals↗
PubMed1987

[Angiogenic effect of colchicine].

The effect of colchicine on the microcirculatory vessels of eye perilimbal area was revealed in 2 groups of experimental rabbits. Colchicine was found to promote the growth of capillaries both during intravenous injections of colchicine solution and during local colchicine application as an ointment. The proper substance of cornea was also changed under the influence of colchicine. Changes in the ultrastructure of the capillary wall and endothelial cells forming the capillaries have been noted.

Animals↗
PubMed1987

[Morphofunctional characteristics of the vascular endothelium in the common leech (Clepsina complanta)].

The electron microscopic investigation has revealed in the body of the leech two types of vessels, that together with common signs possess a number of peculiarities in composition of endothelial cells. These vessels have different level of organization: the vessels of the first type, concerning the parenchyma of the leech, are nutritive, and the vessels of the second type combine capacitance and transport functions and are the place of hemolymph renovation at the expense of an active metabolic and synthetic activity of the endothelial cells. A fact is stated concerning a specific position of mitochondria in the endotheliocytes of the second type vessels: from the vessel's lumen they are not covered with plasmolemma along their whole extent and come into an immediate contact with hemolymph. Therefore, a hypothesis is suggested on functional activity of the endothelial cell mitochondria in the second type vessels. Presumptive differentiation of the two major vessels of the leech body makes it possible to suppose that there exist functional predecessors of the vessels of branchial and pulmonary type, that is vessels of lesser and greater circulation.

Animals↗
PubMed1987

[Metabolism of exogenous phosphocreatine and 3-phosphono-2-imino-1-methyl-4-hydroxy-imidazoline in the perfused rat heart during ischemia].

Exogenous phosphocreatine (PCr) and its cyclic analog, 3-phosphono-2-imino-1-methyl-4-oxoimidazolidine (PIMOI) were used as protectors of ischemic myocardium. PCr was insignificantly metabolized, whereas its analog was rapidly split, resulting in the formation of creatinine and inorganic phosphate as well as of minor amounts of PCr and creatine. Exogenous AMP and ATP accelerated PCr breakdown; in contrast, PIMOI hydrolysis slowed down in the presence of AMP. A similar inhibitory effect was observed after treatment of hearts with 2,4-dinitrofluorobenzene. These data together with those obtained for heart homogenates point to the enzymatic nature of PIMOI hydrolysis in ischemic heart. Acidic phosphatases and 5'-nucleotidases of the heart are supposed to be involved in this process.

Adenosine Monophosphate↗
PubMed1987

[ATP-phosphocreatine metabolism catalyzed by creatine kinase. Comparison of saturation transfer (NMR) and isotope labeling technics].

Unidirectional fluxes from ATP to phosphocreatine (PCr) catalyzed by MM-isoenzyme of creatine kinase (CK) were measured by using 31P-NMR saturation transfer technique and by means of radioactively labeled [gamma-32P]ATP. At 30-37 degrees C and pH 7.4 in a wide range of [PCr]/[creatine] ([PCr]/[Cr]) ratios (0.2 to 3.0) both of these methods gave similar results, thus showing that magnetization (saturation) transfer allows to determine fluxes close to real ones under "physiological" conditions. However, at [PCr]/[Cr] ratio higher than 5 ([ADP] less than 30 microM) or at decreased temperatures (7-15 degrees C, [PCr]/[Cr] approximately 1) fluxes determined by saturation transfer substantially exceeded those measured with the radioactive label. These data imply that under "physiological" conditions phosphoryl group transfer is actually rate-determining step of the CK reaction. On the contrary, at high [PCr]/[Cr] values or at low temperature the control step could be shifted from the phosphoryl group transfer or distributed among other steps of the reaction.

Adenosine Triphosphate↗
PubMed1987

[3-Phosphono-2-imino-4-oxoimidazoline--a competitive substrate of AMP-dephosphorylating enzymes from the cytosol fraction of the rat heart].

3-Phosphono-2-imino-1-methyl-4-oxoimidazolidine (PIMOI), AMP and p-nitrophenyl phosphate (pNPP) were dephosphorylated in the presence of rat heart cytosol at 37 degrees C pH 6.3 at the rates of 0.71, 0.45 and 1.07 mumol/mg X h, respectively. When mixed together, these compounds inhibited the hydrolysis of each other, which points to the participation of common enzyme(s) in this process. The inhibitor of 5'-nucleotidase (alpha,beta-methylene)-ADP, did not affect PIMOI cleavage and moderately inhibited AMP hydrolysis (by ADP, did not affect PIMOI cleavage and moderately inhibited AMP hydrolysis (by 30-50%), thus suggesting that acidic phosphatases are responsible for PIMOI and AMP hydrolysis under these conditions (pH 6.3). Phosphocreatine (PCr) and phosphocyclocreatine (PcCr) were stable to hydrolysis by the cytosolic fraction. However, addition of AMP to the medium containing PCr or PcCr resulted in AMP phosphorylation down to ATP due to the effects of these phosphagens and, probably, of microcontaminations of ATP. This was followed by gradual disappearance of PCr or PcCr and by accumulation of Pi as a result of the "ATPase" activity in the cytosol. The hydrolysis of AMP, PIMOI and p-NPP was sensitive to sulfhydryl reagents [5,5'-dithio-bis-(2-nitrobenzoate) and, in part, 2,4-dinitro-fluorobenzene] and fluoride ion. Thus, PIMOI is a competitive substrate of acidic phosphatases in heart cytosol with respect to AMP and p-NPP. This may partly explain the protective effect of PIMOI on ischemic myocardium.

Adenosine Diphosphate↗