[The effect of ATP-dependent K(+)-channel opener on transmembrane potassium exchange and reactive oxygen species production upon the opening of mitochondrial pore].

The effect of mitochondrial ATP-dependent K(+)-channel (K(+)ATP-channel) opener diazoxide (DZ) on transmembrane potassium exchange and reactive oxygen species (ROS) formation under the opening of mitochondrial permeability transition pore (MPTP) was studied in rat liver mitochondria. The activation of K(+)-cycling (K(+)-uptake and K(+)/H(+)-exchange) by DZ was established with peak effect at < or = 500 nM. It was shown that MPTP opening as well resulted in the activation of K(+)-cycling together with simultaneous activation of Ca(2+)-cycle in mitochondria.

[The effect of ATP-dependent K(+)-channel opener on the functional state and the opening of cyclosporine-sensitive pore in rat liver mitochondria].

The effect of mitochondrial ATP-dependent K(+)-channel (K+(ATP)-channel) opener diazoxide (DZ) on the oxygen consumption, functional state and the opening of cyclosporine-sensitive pore in the rat liver mitochondria has been studied. It has been established that K+(ATP)-channel activation results in the increase of the oxygen consumption rate (V4(s)) and the uncoupling due to the acceleration of K(+)-cycling, the decrease in state 3 respiration rate (V3) and the respiratory control ratio (RCR). Under K+(ATP)-channel activation an inhibition of oxidative phosphorylation takes place which reduces the rate of ATP synthesis and hydrolysis as well as ATP production and consequently results in the seeming increase of P/O ratio.

[Effects of modulators of calcium metabolism on mesenteric artery contractions during activation of P2X receptors in guinea-pig].

ATP evokes changes in the vascular tone through the activation of P2X and P2Y purinoceptors. To evaluate relative contribution of Ca2+ entry through the L-type voltage-gated calcium channels and Ca2+ -induced Ca2+ -release (CICR) mechanisms in initiation of vascular smooth muscle contraction induced by P2XRs activation, we have applied P2X receptor agonist -meATP (10 microM) and measured changes in phasic isometric tension of endothelium-denuded mesenteric artery rings in the presence of antagonists IP3Rs (60 mcmol/l APB) or RyRs (100 mcmol/l tetracaine) combined with on-off modulation of the L-type calcium channels by nicardipine (5 microM). We found that activation of P2XRs results in Ca2+ release from SR through both IP3Rs and RyRs.

[The treatment of neurospastic vascular diseases in Raynaud phenomenon].

The efficacy of proposed methods for cardiovascular diseases with Raynaud phenomenon manifestations treatment was estimated. After application of the author method the patients extremities temperature had raised by 2 .50 degreesC.

[Involvement of voltge dependent potassium channels in rabbit corpus cavernosum responses to oxidative stress].

Previously we have demonstrated that oxidative stress produces a complex response of the rabbit corporal smooth muscle cells consisting of transient relaxation followed by contraction. We used 4-AP and TEA, selective blockers for voltage- and Ca(2+)-dependent K+ channels to investigate possible contribution of these channels in maintaining of basal cavernosal tone as well as in mediating of contractile response caused by oxidative stress. TEA in concentration of 1 mmol/l caused contraction of corporal smooth muscle.

[Role of nitric oxide in the corpus cavernosum reactions evoked by hydrogen peroxide].

Corpus cavernosum smooth muscle spends the majority of its time in the contracted state consisting of tonic and tetanic components. Tetanic component is a result of superposition of phasic contrations ocuring spontaneously with a frequency of 5-27/minute. Hydrogen peroxide (H2O2) in concentration of 10(-3) mol/l causes a transient increase in tetanic contraction lasting 5 to 8 minutes, followed by either recovery of spontaneous activity or inhibition of its frequency and muscle strip relaxation.

[Mechanisms of enhanced vascular contractility in experimental animals and humans in atherosclerosis].

Contractile and electrical responses of muscle strips from rabbit aorta to 5-HT and hyper K solution were compared in controls group of rabbits fed a normal diet, and atherosclerotic animals fed 1% cholesterol diet for 12 weeks (atherosclerotic group). A study of vascular responses of human popliteal artery was also carried out. It was shown that smooth muscle cells from arteriosclerotic vessels of both rabbits and human exhibit an increased sensitivity to contractile action of hyperpotassium solution and 5-HT.

[Cholera in the Far East of Russia. Communication 2. Epidemiological characteristics of the outbreak of cholera El tor in Iuzhno-Sakhalinsk].

The outbreak of cholera eltor in Yuzhno-Sakhalinsk has been analyzed. The fact of the import of this infection from China and its transmission mainly by the water route due to the intensive contamination of environmental objects has been substantiated. The effective purification decontamination of sewage water plays decisive role on the system of anticholera measures.

[The results of combined surgical treatment of the occlusive forms of the deep vein thrombosis with the trophic ulcers in the lower extremities].

The results of treatment of 156 patients with occlusion forms of the deep veins thrombosis of the lower extremities and trophic ulcers are adduced. The partial or complete thrombectomy the shunting, Linton and Cockett operations, plastic interventions, the pulmonary artery embolism prophylaxis were conducted, and the late terms--the vibro- and hydromassage.

The action of calcium channel blockers on recombinant L-type calcium channel alpha1-subunits.

1. CHO cells expressing the alpha(1C-a) subunit (cardiac isoform) and the alpha(1C-b) subunit (vascular isoform) of the voltage-dependent L-type Ca2+ channel were used to investigate whether tissue selectivity of Ca2+ channel blockers could be related to different affinities for alpha1C isoforms. 2.

Evidence for a direct interaction of thapsigargin with voltage-dependent Ca2+ channel.

The effect of thapsigargin, an inhibitor of the sarco-endoplasmic reticulum Ca(2+)-ATPase, on voltage-dependent Ca2+ channels has been investigated in the A7r5 cell line and in membrane preparations from rat aorta, heart and brain. Patch-clamp technique showed that, at micromolar concentrations, thapsigargin inhibited the L-type Ca2+ channel current in A7r5 cells. It depressed the current at all voltages without change in the steady state inactivation curve.

[Effects of the membrane potential level on serotonin-induced contraction of the pulmonary artery smooth muscle in rabbits].

The effects of changes in membrane potential level on the electrical and contractile responses induced by serotonin (10(-6) mol/l) were investigated in muscle strips from rabbit main pulmonary artery using sucrose-gap technique. In spite of the fact that serotonin-induced depolarization did not exceed the threshold level for development of contraction, it was followed by a strong tonic contraction. Nearly a half of this contraction could be relaxed by an electrotonic hyperpolarization of the membrane.

[The role of calcium and potassium conductance in electrogenesis of smooth-muscle cells of the basilar artery].

The role of calcium and potassium conductances in electrogenesis of smooth muscle cells of the bovine basilar artery has been investigated using blocking agents of calcium and potassium channels both in the normal Krebs solution and in hyperpotassium solution under anelectrotonic repolarization of the cell membrane. It is shown that both voltage-operated calcium and potassium conductances participate in generation of gradual action potentials evoked by electrical stimulation. A higher contribution of potassium conductance into the total membrane conductance during depolarization is found to be the main factor interfered with development of full-size action potential.

[The role of intra- and extracellular Ca in the activation of contraction of pulmonary artery smooth muscles induced by serotonin].

In Ca-free EGTA-containing solution serotonin induced a transient contraction of rabbit pulmonary artery smooth muscle which decayed to nearly steady-state level accounted for 17.7 +/- 1.6% of original contraction in Krebs solution.

[Membrane mechanisms of the excitatory action of serotonin on the smooth muscles of the rabbit pulmonary artery].

Serotonin induced dose-dependent tonic contractions of the rabbit pulmonary artery smooth muscles with KED50, of 2.7 X 10(-7) mol/l. More than 80% of these contractions were found to be dependent on extracellular calcium.

[Electrophysiological analysis of the action of kavinton on the smooth muscles].

Cavinton at a concentration of 10(-7)-10(-5) M was found to have a dose-dependent relaxing effect on bovine cerebral artery smooth muscles, without changing the resting potential and membrane resistance. Smooth muscles of the rabbit portal vein and guinea-pig taenia coli were insensitive to low cavinton concentrations. The results are consistent with the hypothesis that relaxing action of cavinton is due to the blocking of Ca2+ ions influx into the cells of cerebral artery through receptor-operated calcium channels.

[Electrical properties and transmembrane ion currents of single smooth-muscle cells].

Current and voltage clamp investigations of freshly isolated smooth muscle cells from guinea-pig ileum and taenia coli were performed using single suction micropipette technique. Specific membrane capacity of smooth muscle cells was calculated and accounted for 1.6 microF/cm2, with specific resistance varying from 50 to 150 k omega X cm2.

[Nature of electromechanical connections in the smooth muscle cells of the pulmonary artery].

Depolarization of the rabbit pulmonary artery smooth muscle cells over critical level (5-7 mV) by outward current or high K+ solution application produced contraction proportional to the depolarization. High K+ solution produced an initial spike on the rising phase of depolarization followed by subsequent phasic contraction amplitude of which was lower than that of the tonic one. Anelectrotonic repolarization of smooth muscle cells by means of inward current in high K+ solution was usually followed by spontaneous AP generation and subsequent phasic contractions which were summed and increased total contractile tension.