[Arp2/3 complex is involved in the effect of glutoxim and molixan on intracellular Ca2+ concentration in macrophages].

The involvement of Arp2/3 complex, which causes actin filament branching, in the effect of drugs glutoxim and molixan was investigated. Using Fura-2AM microfluorimetry it was shown for the first time that Arp2/3 complex inhibitor CK-0944666 almost completely prevents the increase in intracellular Ca2+ concentration, induced by glutoxim or molixan in macrophages. The data suggest the involvement of Arp2/3 complex in the glutoxim and molixan effect on the Ca2+ signalling processes in macrophages.

[Microtubular disrupter nocodazole and vesicular transport inhibitor brefeldin A attenuate the glutoxim effect on Na+ transport in frog skin].

Using the voltage-clamp technique, a possible role of microtubules and vesicular transport in the effect of pharmacological analogue of oxidized glutathione, drug glutoxim, on Na+ transport in the frog Rana temporaria skin was investigated. It was shown for the first time that the disrupter of microtubules nocodazole or inhibitor of vesicular transport brefeldin A similarly modulate (completely inhibit) the stimulatory effect of glutoxim on Na+ transport. The data suggest the involvement of reorganization of microtubules and vesicular transport in the regulatory effect of glutoxim on Na+ transport. .

[The effect of cyclooxygenase and lipoxygenase inhibitors on Ca(2+)-responses induced by glutoxim and molixan in macrophages].

Glutoxim and molixan belong to a new generation of disulfide-containing drugs with immunomodulatory, hepatoprotective and hemopoetic effect. Using Fura-2AM microfluorimetry, the possible involvement of the cyclooxygenase and lipoxygenase pathways of arachidonic acid oxidation in the effect of glutoxim and molixan on the intracellular Ca2+ concentration in rat peritoneal macrophages has been investigated. We have shown for the first time that preincubation of the cells with the cyclooxygenase inhibitors, indomethacin and aspirin, or lipoxygenase inhibitors, nordihydroguaiaretic acid, caffeic acid and baicalein, almost completely prevents the intracellular Ca2+ concentration increase induced by glutoxim or molixan. The obtained data indicate the involvement of products and/or enzymes of the arachidonic acid cyclooxygenase and lipoxygenase metabolism pathways in the effect of glutoxim and molixan on the processes of Ca2+ signaling in macrophages.

[The involvement of actin cytoskeleton in glutoxim and molixan effect on intracellular Ca(2+)-concentration in macrophages].

Glutoxim and molixan belong to new generation of disulfide-containing drugs with immunomodulatory, hepatoprotective and hemopoetic effect on cells. Using Fura-2AM microfluorimetry, two structurally distinct actin filament disrupters, latrunculin B and cytochalasin D, and calyculin A, which causes actin filaments condensation under plasmalemma, we have shown the involvement of actin cytoskeleton in the intracellular Ca(2+)-concentration increase induced by glutoxim or molixan in rat peritoneal macrophages. Morphological data obtained with the use of rhodamine-phalloidine have demonstrated that glutoxim and molixan cause the actin cytoskeleton reorganization in rat peritoneal macrophages.

[The effect of glutoxim on Na+ transport in frog skin: the role of cytoskeleton].

Using voltage-clamp technique, the possible role of the cytoskeleton in the effect of pharmacological analogue of oxidized glutathione (GSSG), drug glutoxim, on Na+ transport in the frog Rana temporaria skin was investigated. It was shown for the first time that preincibation of the skin with the microtubular disrupter, nocodazole, actin filament disrupter, cytochalasin D or protein phosphatase PP1/PP2A inhibitor, calyculin A, significantly decrease the stimulatory effect of glutoxim on Na+ transport. The data suggest the involvement of microtubules and microfilaments in the regulatory effect of glutoxim on Na+ transport in frog skin and that reorganization of actin filaments or microtubules leads to inhibition of stimulatory effect of glutoxim on Na+ transport in frog skin epithelia.

[Superfamily of voltage dependent K+ channels: structure, functions and pathology].

In this review the recent studies related to the voltage dependent K+ channels are discussed. During the last 15 years the molecular cloning revealed a large number of alpha-subunits of voltage dependent K+ channels. This approach enabled to elucidate the properties of different types of channels and, in particular, characteristics of such structural elements as auxiliary subunits. These subunits are mainly responsible for the ionic permeability features of alpha-subunits. There are several cytoplasmic and membrane-associated auxiliary subunits such as beta-subunits, minK (minimal K+ channel peptide), MiRP (minK-related peptide), KChAP (K+ channel-associated protein), KChIP (K+ channel-interacting protein) and NCS (neuronal calcium sensor).

[The involvement of tyrosine kinases and phosphatidylinositol kinases in the effect of oxidized glutathione and glutoxim on Na+ transport in frog skin].

Using voltage-clamp technique, the role of tyrosine kinases and phosphatidylinositol kinases in the effect of oxidized glutathione (GSSG) and its pharmacological analogue, drug glutoxim, on Na+ transport in the frog Rana temporaria skin was investigated. It was shown for the first time that preincubation of the skin with tyrosine kinase inhibitor genistein or with two structurally distinct phosphatidylinositol kinase inhibitors, wortmannin and LY294002, significantly decreased the stimulatory effect of GSSG or glutoxim on Na+ transport. The data suggest that GSSG and glutoxim might transactivate insulin receptor in the basolateral membrane of epithelial cells and trigger the signaling cascade, involving tyrosine kinases and phosphatidylinositol kinases, which lead to Na+ transport stimulation in frog skin.

[The effect of phosphatidylinositol kinase inhibitors on store-dependent Ca2(+)-transport in macrophages].

Using Fura-2AM microfluorimetry the role of phosphatidylinositol kinases in the regulation of Ca2+ signals induced by purinergic agonist ATP and endoplasmic Ca2(+)-ATPase inhibitor thapsigargin in rat peritoneal macrophages was investigated. It was shown that two structurally distinct phosphatidylinositol 3- and phosphatidylinositol-4-kinases inhibitors wortmannin and LY294002 showed a dose- dependent effect on store-dependent Ca2(+)-entry, induced by thapsigargin or ATP. The data suggest that phosphatidylinositol 3- and phosphatidylinositol-4-kinases play an important role in the activation of store-dependent Ca2(+)-entry in macrophages and that their effect might be mediated by their influence on actin cytoskeleton. The results are compatible with the "secretion-like coupling model" for store-dependent Ca2(+)-entry in macrophages based on a reversible trafficking and coupling of the Ca2+ store with the plasma membrane which suggests the involvement of microfilaments and phosphatidylinositol kinases.

[Structural and functional organization of Na+ transport in epithelial systems. I. Epithelial Na+ channels].

The review summarizes recent data on the structural and functional organization and regulation mechanisms of Na+ transport in epithelial systems. The review is focused on the structure, function, regulation and pathology of epithelial Na+ channels, which are critical for Na+ homeostasis maintenance and blood pressure control.

[Effect of latrunculin B, jasplakinolide and brefeldin A on the store-dependent Ca2+ entry in macrophages].

Using Fura-2AM microfluorimetry, effect of actin filament modifiers and vesicular trafficking inhibitor on the store-dependent Ca2+ entry induced by purinergic agonists (ATP, UTP) and endoplasmic Ca2+-ATPase inhibitors (thapsigargin, cyclopiazonic acid) in rat peritoneal macrophages was investigated. It was shown that inhibition of actin polymerization by latrunculin B had a biphasic time-dependent effect on Ca2+ entry, showing an initial potentiation followed by inhibition of Ca2+ entry. Moreover, addition of latrunculin B after induction of store-dependent Ca2+ entry inhibited the Ca2+ influx. Jasplakinolide, which reorganizes actin filaments into a tight cortical layer adjacent to the plasma membrane, prevented activation of store-dependent Ca2+ entry but did not modify this process after its activation. Vesicular transport inhibitor brefeldin A, which inactivates arfproteins, inhibited activation of store-dependent Ca2+ entry but did not alter this mechanism once being initiated. These data are compatible with the sectretion-like coupling model for store-dependent Ca2+ entry in macrophages based on a reversible trafficking and coupling of Ca2+ store with the plasma membrane.

[The role of protein kinase C in Na+ transport regulation in the skin of adult frogs and tadpoles of Rana temporaria]. / Rol' proteinkinazy C v reguliatsii transépitelial'nogo transporta Na+ v kozhe vzroslykh osobei i golovastikov liagushki Rana temporaria.

Using the voltage-clamp technique, a possible role of protein kinase C in regulation of Na+ transport in the skin of the frog Rana temporaria was investigated. It was shown that protein kinase C activator phorbol ester 12-myristate 13-acetate (PMA), applied to the apical surface of the skin, stimulated transepithelial Na+ transport, measured as amiloride-sensitive short-circuit current, and also increased such electrical characteristics of frog skin as the open-circuit potential and transepithelial conductance. PMA exerts a similar stimulation effect on Na+ transport across the tadpole skin. Specific inhibitors of protein kinase C, chelerythryne or H-7, almost fully prevented the PMA-induced stimulation of Na+ transport. These data support a concept that the response to PMA was indeed mediated by PKC activation. The results are compatible with the important role played by protein kinase C in regulation of transepithelial Na+ transport in the skin of R. temporaria.

[Mechanisms of Ca2+ signalling in cells]. / Mekhanizmy Ca2+ signalizatsii v kletkakh.

The review summarizes recent data and current opinions of the Ca2+ signal formation in cells. Mechanisms of Ca2+ mobilization from the intracellular Ca2+ stores are discussed along with the pathways of Ca2+ entry from the external medium.

[The role of cytoskeleton structures in regulation of Ca2+ responses in macrophages]. / Rol' struktur tsitoskeleta v reguliatsii Ca2+-otvetov v makrofagakh.

The role of the cytoskeleton in regulation of purinergic agonist- and endoplasmic Ca(2+)-ATPase inhibitors-induced Ca2+ signals in rat peritoneal macrophages was investigated. It has been shown that in cells pretreated with agents that disrupt microtubules (vinblastine, colchicine, colcemid) or actin microfilaments (cytochalasins, phalloidin), the ability of thapsigargin or cyclopiazonic acid to empty Ca2+ stores and activate store-dependent Ca2+ influx was significantly attenuated. On the contrary, microfilaments and microtubule disrupters did not affect ATP- or UTP-induced Ca2+ mobilization, indicating that release of Ca2+ from intracellular stores through the inositol phosphate pathway was intact. The results suggested that an intact cytoskeleton is required for capacitative Ca2+ entry but not for agonist-induced Ca2+ mobilization.

[Effect of arachidonic and other fatty acids on the intracellular calcium concentration and calcium signaling in peritoneal macrophages]. / Vliianie arakhidonovoi i drugikh zhirnykh kislot na vnutrikletochnuiu kontsntratsiiu Ca2+ i formirovanie Ca2+-signalov v peritoneal'nykh makrofagakh.

Effects of arachidonic and other fatty acids on the intracellular Ca2+ concentration ([Ca2+]i) in rat peritoneal macrophages was investigated. It has been shown that cis-polyunsaturated arachidonic and linoleic induce a significant and dose-dependent increase in [Ca2+]i, which is due to depletion of thapsigargin-sensitive Ca2+ store and to stimulation of Ca2+ entry from the extracellular medium. Pharmacological characteristics of Ca2+ entry induced by arachidonic acid appeared to be similar to those of store-dependent Ca2+ entry activated by thapsigargin or cyclopiazonic acid; Ca2+ entry is attenuated by the same Ca2+ channel inhibitors, by tyrosine kinase inhibitor genistein and epoxygenase inhibitor proadifen. Cis-monounsaturated oleic and saturated myristic acids appeared to be less effective and induced only a slight increase in [Ca2+]i at much higher concentrations. Arachidonic and other fatty acids can also stimulate Ca(2+)-ATPase in the macrophage plasma membrane. The data are compatible with the important role played by arachidonic and other free fatty acids in the regulation of [Ca2+]i in peritoneal macrophages.

[Ca(2+)-signaling in peritoneal macrophages]. / Mekhanizmy Ca(2+)-signalizatsii v peritoneal'nykh makrofagakh.

Mechanisms of the Ca2+ signal generation and regulation in peritoneal macrophages activated with purinergic agonists (ATP, UTP), as well as endoplasmic Ca(2+)-ATPase inhibitors, were investigated. Using a wide range of drugs affecting the intracellular signaling systems' components, an important role of second messenger systems and other key functional cellular systems in Ca2+ signals regulation in the macrophages, was shown.

[Structural-functional organization of cellular signal transduction systems]. / Strukturno-funktsional'naia organizatsiia signal'nykh sistem v kletkakh

The review summarizes recent data and current opinions of the structural and functional organization of the known signalling systems and their functional elements. A possible role of adenylate cyclase, phosphoinositide, guanylate cyclase, tyrosine kinase systems and also of arachidonic acid, its oxygenated derivatives and of other fatty acids in intracellular signalling processes is discussed.

[Role of protein kinase C in the regulation of Ca-responses induced by purinergic agonists and thapsigargin in rat peritoneal macrophages]. / Rol' proteinkinazy C v reguliatsii Ca-otvetov, indutsirovannykh purinergicheskimi agonistami i tapsigarginom v peritoneal'nykh makrofagakh krysy.

The effect of protein kinase C activating phorbol ester, phorbol-12-myristate-13-acetate (PMA), on purinergic agonists- and thapsigargin-induced Ca2+ signals in Fura-2 loaded rat peritoneal macrophages was investigated. PMA (100 ng/ml) was shown to inhibit 200 muM ATP- or 200 microM UTP-evoked Ca2+ entry in macrophages. Protein kinase C activation by PMA also inhibits the store-dependent or "capacitative" Ca2+ influx stimulated by emptying the intracellular Ca2+ stores with endoplasmic Ca(2+)-ATPase inhibitor thapsigargin (0.5 microM). Inhibition of entry by PMA was fully prevented by protein kinase C inhibitor 50 microM H-7. These data are compatible with the important role played by protein kinase C in the control of Ca2+ entry in rat peritoneal macrophages.

[Effect of inhibitors of mitochondrial oxidative metabolism on Ca-responses induced by purinergic agonists and thapsigargin in rat peritoneal macrophages]. / Vliianie ingibitorov okislitel'nogo metabolizma mitokhondrii na Ca-otvety, indutsirovannye purinergicheskimi agonistami i tapsigarginom v peritoneal'nykh makrofagakh krysy.

Effects of two metabolic inhibitors, oligomycin and carbonyl cyanide m-fluorophenylhydrazone (FCCP), on Ca2+ signals induced by purinergic agonists and thapsigargin in Fura-2-loaded rat peritoneal macrophages was investigated. 1 microgram/ml oligomycin or 1 microM FCCP were shown to inhibit 200 microM ATP or 200 microM UTP-evoked Ca2+ entry in macrophages. Independently of their chemical structure and site of inhibition, both metabolic poisons also inhibit the store-dependent or "capacitative" Ca2+ influx stimulated by emptying the intracellular Ca2+ stores with endoplasmic Ca(2+)-ATPase inhibitor thapsigargin (0.5 microM). These data are compatible with the important role the energy level of the cell plays in the control of Ca2+ entry in rat peritoneal macrophages.

[Effect of tyrosine kinase and tyrosine phosphatase inhibitors on ATP- and thapsigargin-induced CA2+ entry in rat peritoneal macrophages]. / Vliianie ingibitorov tirozinkinaz i tirozinfosfataz na vkhod Ca2+ indutsiruemyl ATF i tapsigarginom v peritoneal'nykh makrofagakh krysy.

The effect of two structurally distinct tyrosine kinase inhibitors, genistein (100 microM) and methyl-2, 5-dihydroxycinnamate (25 microM) on ATP- and thapsigargin-induced Ca2+ signals in Fura-2-loaded rat peritoneal macrophages was investigated. Both compounds were shown to inhibit ATP-evoked Ca2+ entry but not to release from internal stores. Both compounds also inhibit the store-dependent or "capacitative" Ca2+ influx stimulated by emptying the intracellular Ca2+ stores with endoplasmic Ca(2+)-ATPase inhibitor thapsigargin (100 nM). Genistein and methyl-2, 5-dihydroxycinnamate have no effect on Ca2+ release from intracellular stores. Tyrosine phosphatase inhibitor orthovanadate Na (50 microM) increases ATP-induced Ca2+ entry but does not prevent the inhibitory effect of genistein. These data are compatible with the role played by tyrosine phosphorylation in the control of Ca2+ entry in rat peritoneal macrophages.