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Biomedical subjects

G V Maksimov

Publications and source records attributed to G V Maksimov.

At least 19 recordsLinked to original sources
PubMed2002

Role of ionic transport in regulation of hemoglobin affinity for oxygen in diabetes mellitus.

The rate of Na(+)/H(+) exchange is increased by 24%, activities of Ca-dependent K+ channels is increased by 13%, and activity of erythrocyte Ca(2+)-ATPase decreased by 17% in patients with diabetes mellitus concomitant with essential hypertension in comparison with patients with essential hypertension without disorders of carbohydrate metabolism. Changes in activity of Na(+)/H(+) exchange, Ca-dependent K(+) channels, and erythrocyte Ca(2+)-ATPase and increased oxygen affinity of hemoglobin are due to increased glucose concentration in the plasma and are leveled by olifen.

Calcium-Transporting ATPases↗
PubMed2001

Study on conformational changes in hemoglobin protoporphyrin in essential hypertension.

Changes in protoporphyrin conformation, partial pressures of O2 and CO2, and the mechanisms responsible for regulation of pCa and pH in erythrocytes were studied in essential hypertension (EH). Changes in protoporphyrin conformation in EH were accompanied by a decrease in the partial pressure of O2 and an increase in the partial pressure of CO2. This was associated with increased activities of Na+/H+-exchange and Ca2+-dependent K+-channels and with a decreased activity of Ca2+-ATPase. The changes in protoporphyrin conformation in EH are suggested to decrease the efficiency of O2 metabolism in hemoglobin and increase the values of intracellular pCa and pH of erythrocytes.

Calcium-Transporting ATPases↗
PubMed2001

A study of demyelination of nerve fibers using dynamic phase contrast microscopy.

Dynamic phase microscopy was used for evaluation of changes in myelinated axon segment in the paranodal region of nerve fibers during demyelination. Normally paranodal myelin sheath is characterized by regular oscillations of the optical path difference with frequences of 4.2 and 6.7 Hz. Demyelination decreased the amplitude and conduction velocity in nerve fibers and shifted the characteristic frequencies of optical path difference oscillations to 2.8, 3.2, and 11 Hz. These shifts of optical path difference frequencies probably resulted from disturbances in the state of charged phospholipids and a decrease in the level of bound Ca(2+)during demyelination of nerve fiber.

Animals↗
PubMed1992

[The mechanisms of the porphyrin conformation of normal blood hemoglobin and in pathology].

The spectra of resonance Raman scattering of blood in norm and under pathology (myocardial infarction and sepsis), as well after artificial hemotransfusion or UV photomodification have been studied. It has been shown that under heart pathology the structure of hemoglobin porphyrin macrocycle of erythrocytes changes, the size of porphyrin "nucleus" increases. The opposite conditions are observed at blood sepsis. It has been found that the traditional methods in tissue restoration, hemotransfusion and UV photomodification of blood don't result in complete restoration of hemoporphyrin molecule.

Blood↗
PubMed1989

[Molecular mechanisms of the action of local anesthetics].

Raman spectroscopy revealed a suppression of the polyene chain of C40-carotenoids in membrane of the frog nerve during local action of an anesthetic agent in resting and excitation. The phosphatidylcholine binding decreased during rhythmic excitation and local anesthetic action. A mechanism of potential-dependent changes of the carotenoid conformation during local anesthetic action, was discussed.

Action Potentials↗
PubMed1986

[Binding of 3H-bungarotoxin by nerve trunks of the frog during excitatory conduction].

In the frog nerve, 3H-bungarotoxin and 3H-acetylcholine binding increased whereas the acetylcholinesterase activity decreased in rhythmic stimulation. The enhancement of 3H-bungarotoxin binding to nerve during the rhythmic stimulation seems to stem from transformation of "inactive" forms of acetylcholine receptor of glial membrane to "active" ones.

Acetylcholine↗
PubMed1984

[Calcium ion binding in somatic nerves during conduction of rhythmic excitation].

Increase of Ca entry upon excitation depended on stimulation frequency and the types of nerves in crab, frog and squid. The amount of absorbed Ca was high in myelinated nerves whereas the velocity of absorption was higher in nonmyelinated nerves. The maximal level of Ca entry during rhythmic excitation was observed in the frog nerve. The data obtained suggest a mechanism of Ca entry in somatic nerves during rhythmic excitation.

Animals↗
PubMed1983

[Raman spectra of somatic nerves under different functional conditions].

The light scattering spectra (LS) of different kind of somatic nerves during excitation and its block has been investigated. In the LS spectra of frog nerves the spectra of C40-carotenoids was dominated by the following bands at 1008 cm-1, 1160 cm-1 and 1526 cm-1. The peaks of LS were decreased during the excitation and under the action of ouabain and increased under the action of ether. The changes of LS spectra can be explained by shift of maximum of light intensity of C40-carotenoids uptake and positions of side CH3-radical in polyene chain.

Action Potentials↗
PubMed1979

[Regulation of Na, K-ATPase activity in nerves during propagation of rhythmic excitation].

The changes of Na, K-ATPase activity of the isolated squid, crab, frog, and rat nerves depended on the stimulation frequency: at the frequency specific for each nerve the maximum deviation from initial resting level occurred. During a certain stimulation the maximum deviation of SH-group content and Na/K ratio as well as of Na, K-ATPase activity developed while the level of acetylcholine esterase activity (AEA) remained at its minimum. The data obtained suggest the mechanism of Na, K-ATPase activity in nerve under rhythmic propagation of excitation. In the resting nerve the minimum level of the acetylcholine concentration is kept because of the AEA. Under stimulation the membrane depolarization induces changes of the protein conformation suppressing the AEA. This results in an increase of the acetylcholine concentration in the nerve which leads to an increase of Na+ influx and K+ efflux. The changes of Na/K ratio in the nerve activate the transport ATPase.

Acetylcholinesterase↗