[Ionic mechanisms of carbon monoxide action on the contractile properties of smooth muscles of the blood vessels].

Carbon monoxide (CO) is one of a family of gas transmitters. In this article we present the results of mechanographic investigations of the mechanisms of CO action on a rat thoracic aorta segments. We found that relaxing effect of CO donor CORM-2 on vascular smooth muscles is mediated mainly by opening of voltage-dependent potassium channels in smooth muscle cells: 4-aminopyridine, blocking these channels, almost completely eliminated the CO-induced vasorelaxation of the segments precontracted by depolarization of the smooth muscle cells membranes with high potassium (30 mM KCl) solution or by phenylephrine (10 microM).

NKCC1 and hypertension: role in the regulation of vascular smooth muscle contractions and myogenic tone.

High-ceiling diuretics (HCD), known potent inhibitors of housekeeping Na(+),K(+),2Cl cotransporter (NKCC1) and renal-specific NKCC2, decrease [Cl(-)](i), hyperpolarize vascular smooth muscle cells (VSMC), and suppress contractions evoked by modest depolarization, phenylephrine, angiotensin II, and UTP. These actions are absent in nkcc1 (/) knock-out mice, indicating that HCD interact with NKCC1 rather than with other potential targets. These findings also suggest that VSMC-specific inhibitors of NKCC1 may be considered potential pharmacological therapeutic tools in treatment of hypertension.

[Myogenic tone of blood vessels in health and disease: role of purinergic signaling system and Na+, K+ 2Cl+ cotransport].

The narrowing of blood vessels evoked by increasing intraluminal pressure and termed as myogenic response plays a key role in the maintenance of the blood flow rate independently of the variation of systemic arterial pressure. Myogenic response MR is accompanied by decreased electrical membrane potential in the vascular smooth muscle cells (VSMC) that, in turn, leads to activation of voltage-gated Ca2+ channels and elevation of [Ca2+]i. Upstream mechanisms underlying VSMC depolarization remain poorly understood.

[Research of cytoskeleton-dependent mechanisms of contractile activity regulation in the smooth muscles].

Influence of modulation of cytoskeleton by colchicine, vinblastine and cytochalasine B on contractile reactions of smooth muscles has been investigated by mechanographical method, by the methods of the double sucrose gup junction. Ratio F/G-actin in smooth muscle cells defined a method of a fluorescent microscopy. Microfilaments in a greater degree than microtubule are involved in regulation of reductions caused by hyperpotassic-induced reductions of membrane of smooth muscle segments of the rat aorta and generation of action potentials and reductions smooth muscle cells from guinea pig urethra.

Specific adrenergic responses of smooth muscles in the vascular wall of guinea pig pulmonary arteries during ovalbumin sensitization.

The adrenergic contractile responses of smooth muscles in the vascular wall of guinea pig pulmonary arteries were studied during ovalbumin sensitization. Sensitization was followed by inhibition of contractile responses to an alpha-adrenoceptor agonist mesatone, prevented endothelium-derived relaxation, and potentiated the contractile response to isoproterenol. Administration of a beta-adrenoceptor agonist isoproterenol potentiated the increase in mechanical strain of smooth muscles in the pulmonary artery precontracted with high-potassium Krebs solution.

Vascular smooth muscle contraction evoked by cell volume modulation: role of the cytoskeleton network.

Previously, we reported that hyposmotic swelling evoked transient vascular smooth muscle cell (SMC) contraction that was completely abolished by L-type Ca(2+) channel blockers. In contrast, sustained contraction revealed in hyper- and isoosmotically-shrunken SMCs was insensitive to L-type channel blockers and was diminished in Ca(2+)-free medium by only 30-50%. Several research groups reported cell volume-dependent cytoskeleton network rearrangements.

[Definition of parameters of the condition of oxidizing stress in smooth muscle cells under influence of exogenous nitroso-glutatyon in vitro].

Influence of exogenous nitroso-glutatyon on intensity of oxidizing processes in smooth muscles of colon and bronchial tubes in intact and atopic sensitised porpoises (guinea pigs) was studied. In sensitised porpoises, antioxidant protection has been initially reduced against the background of increased maintenance of products of oxidizing that reflects a picture of oxidizing damage and can be associated with an inflammatory process. In incubation with nitroso-glutatyon, a decrease in activities of syperoxiddismutase and catalase is marked and, in sensitised animals, this effect has been expressed to a lesser degree.

[Na+,K+,2Cl(-)-cotransport and chloride permeability of the cell membrane in mezaton and histamine regulation of electrical and contractile activity in smooth muscle cells from the guinea pig ureter].

Influence of Na+,K+,2Cl(-)-cotransport and chloride permeability of the cell membrane on electrically-induced action potential and contraction of smooth muscle cells from guinea pig ureter was examined with the methods of the double sucrose gap junction. Mesatone (10 microM) and histamine (10 microM) induced prolongation of the action potential and elevation of smooth muscle cell contraction, whereas hyperosmic medium (+150 mM sucrose), and recovery of solution osmolality in hyposmic condition (70 mM NaCl) after a single contraction. Inhibitor Na+,K+,2Cl(-)-cotransport bumetanide (10 microM) and chloride permeability blockers niflumic acid (10-100 microM) and SITS (10-500 microM) attenuated stimulating effects of mesatone, histamine and hyperosmic medium.

[Features of the pharmacosensitivity of smooth muscles of the lesser circulation circle artery walls in rabbits].

Features of the pharmacological sensitivity of smooth muscles in the walls of arteries of the lesser circulation circle in rabbits with respect to cholinergic, histaminergic, and adrenergic agents, as well as the influence of endothelium on the realization of contractile response to these agents have been investigated in rabbits. A special feature in the cholinergic relaxation of smooth muscles of a pulmonary artery is a two-componential character of the dose dependence. The low-threshold component of the relaxant action of pilocarpine exhibits the endothelium-dependent character.

[Physiological characteristics of the smooth muscles vessels of the small circle of blood circulation].

Now sireos problem of pulmonology there are the diseases connected with infringement of coordinated regulation of a tone of smooth muscles of vessels and airways of ways that conducts to dissociation of parameters haemodinamyc and ventilation of lungs and as consequence, to infringement airwave-perfusion attitudes. In the review features humoral regulation contractile activity of smooth muscles of vessels of a small circle of blood circulation, a role of endocellular alarm systems in these mechanisms, and endothelium, as the local modulator endocrine functions are considered. Disgusting muscles of a small circle are distinguished from the main vessels of the big circle of blood circulation with predisposition to the raised mechanical pressure.

[The mechanisms in NO-dependent regulation of electrical and mechanical activity in smooth muscles].

The role of nitric oxide (NO) and its implication in intracellular and intercellular signaling pathways attract an attention of many research teams up to now. Away of its signaling functions. NO is considered as one of the key molecules in maintenance of balance between the physiological and pathological processes due to cytoprotective and cytotoxic functions of this molecule.

Cell-volume-dependent vascular smooth muscle contraction: role of Na+, K+, 2Cl- cotransport, intracellular Cl- and L-type Ca2+ channels.

This study elucidates the role of cell volume in contractions of endothelium-denuded vascular smooth muscle rings (VSMR) from the rat aorta. We observed that hyposmotic swelling as well as hyper- and isosmotic shrinkage led to VSMR contractions. Swelling-induced contractions were accompanied by activation of Ca2+ influx and were abolished by nifedipine and verapamil.

Effect of Na+,K+,2Cl- cotransport inhibitor bumetanide on electrical and contractile activity of smooth muscle cells in guinea pig ureter.

The effect of Na(+),K(+),2Cl(-) cotransport inhibitor bumetanide on action potentials and contractions of smooth muscle cells in the ureter of guinea pigs evoked by electrical stimulation was studied by the method of double sucrose bridge. Bumetanide (10-100 microM) dose-dependently suppressed action potential and contractions of smooth muscle cells induced by 1-10 microM histamine, 10 microM mesatone, 5 mM tetraethylammonium, and 100 microM sodium nitroprusside. Our findings suggest that test substances modulate Na(+),K(+),2Cl(-) cotransport in smooth muscle cells.

[Studying cGMP-dependent mechanisms of vinpocetine effect on smooth muscle cells].

The results of the membrane potential measurements (by the double sucrose gap junction technique) and the smooth muscle tension determination (by the mechanical force measurements) in the rat aorta showed that vinpocetine potentiates the effect of sodium nitroprusside and nitroglycerin on the smooth muscle cells. In the concentration range of 2-20 microM, vinpocetine produced a dose-dependent inhibition of the Ca2+ conductivity of the membrane and decreased the smooth muscle contractility response. At a concentration of 1 microM, the drug acted as an inhibitor of the phosphodiestherase (PDE) activity and produced the effects similar top those of dibutyryl-cGMP (rather than dibutyryl-cAMP).

[Myogenic effects of cyclic guanosine monophosphate in smooth muscle cells. Role of protein kinase C].

Heterogeneity of the cGMP-dependent contractility effects of the smooth cells (SMC) was shown in guinea pig ureter by the methods of the double sucrose gap junction. Sodium nitroprusside (SN, 0.1-100 microM) relaxed the high-K+ depolarisationprecontracted SMC but strengthened the SMC constriction triggered by electrical stimulation.

Role of cyclic nucleotides in regulation of pulmonary artery tone in rabbits.

The involvement of cAMP- and cGMP-dependent signal systems into the regulation of the contractile reaction of smooth muscles of the rabbit pulmonary arteries was studied using a mechanographic method. For modulation of intracellular level of cyclic nucleotides we used adenylate cyclase activators beta-adrenoceptor agonist isadrin, guanylate cyclase inhibitor methylene blue, penetrating analog dibutyryl-cAMP, and phosphodiesterase inhibitors. The mechanisms of cAMP- and cGMP-dependent regulation of smooth muscle contractile activity were realized in close interrelationship, and the key component of this was cyclic nucleotide phosphodiesterases.

Effect of lipid matrix and cytoskeleton proteins on Ca2+-activated K+ channels in erythrocytes of alcoholic and II type diabetes mellitus patients.

We studied the effect of changes in erythrocyte volume and irreversible thermal denaturation of cytoskeleton proteins and lipid matrix on activity of Ca(2+)-activated K+ channels in erythrocytes of alcoholic and patients with II type diabetes mellitus. Changes in Ca(2+)-dependent potassium permeability of erythrocyte membrane in alcoholic patients and patients with II type diabetes mellitus are related to modification of cytoskeleton, rather than to changes in lipid matrix.

Peculiarities of adrenergic regulation of smooth muscles in rabbit pulmonary arteries.

Muscle tension recording was used to study adrenergic contractile reactions of pulmonary artery smooth muscles in rabbits. Stimulation of alpha-adrenoceptors induced contraction of pulmonary artery smooth muscle cells. Endothelium partially inhibited the contractile effect of alpha-adrenoceptor agonists.

Effect of inhibitors of cyclic nucleotide phosphodiesterases on electrical and contractile activity of smooth muscle cells.

Double sucrose gap experiments were carried out to study the effect of phosphodiesterase inhibitors and penetrating analogs of cyclic nucleotides on action potential and contraction of guinea pig ureteral smooth muscle cells. 3-Isobutyl-1-methylxanthine (10 microM) and dibutyryl-cAMP (20 microM) shortened the plateau of action potential and inhibited contraction of smooth muscle cells by increasing potassium permeability of their membrane. Vinpocetine (1 microM) and dibutyryl-cAMP (100 microM) strengthened contraction of smooth muscle cells and shortened action potentials by decreasing sodium permeability of their membrane.

[Regulation of smooth muscles of the vascular wall in the rabbit pulmonary artery].

The cholinergic, histaminergic and adrenergic features of regulation of the small muscles contractile activity in a vascular wall of a pulmonary artery in rabbits and involvement of an endothelium in these processes, were investigated. The cholinergic release phenomenon of small muscles of the rabbit pulmonary artery has a two-component character of dose dependence. The low-threshold components of Pilocarpinum relaxing effect has an endothelium-dependent nature.

Histaminergic regulation of smooth muscles in rabbit pulmonary arteries.

Histaminergic contractile reactions of smooth muscles in rabbit lobar pulmonary arteries were studied using in vitro mechanographic technique. Histamine via activation of H-receptors induced a dose-dependent constriction of smooth muscle segments, while endothelium inhibited histamine-induced contractile reactions. Histamine increased sensitivity of smooth muscle cells in pulmonary artery to sodium nitroprusside.

[Mechanisms of NO-dependent relaxation in smooth muscles of the rat aorta with nitro compounds].

The membrane potential and smooth muscle tension in rat aorta were studied by the method of sucrose gap junction. It was found that sodium nitroprusside and nitroglycerin produced a dose-dependent membrane repolarization and smooth muscle cell relaxation in rat aorta preliminarily contracted and depolarized by hyperpotassium (40 mM) or phenylephrine solutions. The relaxation effect of sodium nitroprusside was more pronounced on the phenylephrine background.

[Intracellular signal systems in the epithelium- and endothelium-dependent relaxation of smooth muscles].

The research of mechanisms of a regulation electrical and contractile of properties of unstriated muscles of an internals remains by an actual problem of modern physiology and medicine. Already now it is possible to state that the efficacy of means of correction of distresses of an internals depends on a degree of a level of scrutiny of these mechanisms. Among physiologically active substances effecting on smooth muscle cells (SM), the special relaxing factor synthesized by endotheliocytes, epithelial cells and SM.

Peculiarities of cholinergic regulation of smooth muscles in rabbit pulmonary arteries.

Cholinergic contractile reactions of smooth muscles in rabbit pulmonary arteries were studied by mechanography. The muscarinic receptor agonist pilocarpine induced biphasic relaxation of mesatone- or potassium-precontracted segments from lobar pulmonary arteries with intact endothelium. The low-threshold endothelium-dependent component of pilocarpine-induced relaxation was suppressed by denudation or nitric oxide synthase blocker L-NAME.

Effect of nitro derivatives on electromechanical coupling in ureteral smooth muscle cells.

Double sucrose gap experiments revealed differences in the effect of nitroglycerin and sodium nitroprusside on action potential and contraction of ureteral smooth muscle cells. Unlike sodium nitroprusside, nitroglycerin inhibited voltage-dependent Ca(2+) membrane permeability. It was concluded that cGMP-independent mechanisms of the effects of nitro derivative reflect the peculiarities of excitation-contraction coupling in smooth muscles.