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Ivanova IV, Melnyk MI, Dryn DO, Prokhorov VV, Zholos AV, Soloviev AI. Electrophysiological characterization of the activating action of a novel liposomal nitric oxide carrier on Maxi-K channels in pulmonary artery smooth muscle cells. J Liposome Res 2021; 31:399-408. [PMID: 33319630 DOI: 10.1080/08982104.2020.1863424] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The aim of this study was to establish the mechanisms of action of a novel liposomal nitric oxide (NO) carrier on large-conductance Ca2+-activated channels (BKCa or Maxi-K) expressed in vascular smooth muscle cells (VSMCs) isolated from the rat main pulmonary artery (MPA). Experimental design comprised of both whole-cell and cell-attached single-channel recordings using the patch-clamp techniques. The liposomal form of NO, Lip(NO), increased whole-cell outward K+ currents in a dose dependent manner while shifting the activation curve negatively by about 50 mV with respect to unstimulated cells with the EC50 value of 0.55 ± 0.17 µM. At the single channel level, Lip(NO) increased the probability of the open state (Po) of Maxi-K channels from 0.0020 ± 0.0008 to 0.74 ± 0.02 with half-maximal activation occurring at 4.91 ± 0.01 μM, while sub-maximal activation was achieved at 10-5 M Lip(NO). Channel activation was mainly due to significant decrease in the mean closed dwell time (about 500-fold), rather than an increase in the mean open dwell time, which was comparatively modest (about twofold). There was also a slight decrease in the amplitude of the elementary Maxi-K currents (approximately 15%) accompanied by an increase in current noise, which might indicate some non-specific effects of Lip(NO) on the plasma membrane itself and/or on the phospholipids environment of the channels. In conclusion, the activating action of Lip(NO) on the Maxi-K channel is due to the destabilization of the closed conformation of the channel protein, which causes its more frequent openings and, accordingly, increases the probability of channel transition to its open state.
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Affiliation(s)
- Irina V Ivanova
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
| | - Mariia I Melnyk
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine.,A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine.,Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Dariia O Dryn
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine.,A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine.,Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | | | - Alexander V Zholos
- Institute of Biology and Medicine, Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Anatoly I Soloviev
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences, Kyiv, Ukraine
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Melnyk MI, Ivanova IV, Dryn DO, Prylutskyy YI, Hurmach VV, Platonov M, Al Kury LT, Ritter U, Soloviev AI, Zholos AV. C 60 fullerenes selectively inhibit BK Ca but not K v channels in pulmonary artery smooth muscle cells. Nanomedicine 2019; 19:1-11. [PMID: 30981819 DOI: 10.1016/j.nano.2019.03.018] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Revised: 02/20/2019] [Accepted: 03/19/2019] [Indexed: 01/12/2023]
Abstract
Possessing unique physical and chemical properties, C60 fullerenes are arising as a potential nanotechnological tool that can strongly affect various biological processes. Recent molecular modeling studies have shown that C60 fullerenes can interact with ion channels, but there is lack of data about possible effects of C60 molecule on ion channels expressed in smooth muscle cells (SMC). Here we show both computationally and experimentally that water-soluble pristine C60 fullerene strongly inhibits the large conductance Ca2+-dependent K+ (BKCa), but not voltage-gated K+ (Kv) channels in pulmonary artery SMC. Both molecular docking simulations and analysis of single channel activity indicate that C60 fullerene blocks BKCa channel pore in its open state. In functional tests, C60 fullerene enhanced phenylephrine-induced contraction of pulmonary artery rings by about 25% and reduced endothelium-dependent acetylcholine-induced relaxation by up to 40%. These findings suggest a novel strategy for biomedical application of water-soluble pristine C60 fullerene in vascular dysfunction.
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Affiliation(s)
- Mariia I Melnyk
- O.O. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine; Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, Kyiv, Ukraine
| | - Irina V Ivanova
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, Kyiv, Ukraine
| | - Dariia O Dryn
- O.O. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine; Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, Kyiv, Ukraine; ESC "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Yuriy I Prylutskyy
- ESC "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Vasyl V Hurmach
- ESC "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine
| | - Maxim Platonov
- Institute of Molecular Biology and Genetics, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Lina T Al Kury
- College of Natural and Health Sciences, Zayed University, Abu Dhabi, United Arab Emirates
| | - Uwe Ritter
- Technical University of Ilmenau, Institute of Chemistry and Biotechnology, Ilmenau, Germany
| | - Anatoly I Soloviev
- Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, Kyiv, Ukraine
| | - Alexander V Zholos
- O.O. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine; ESC "Institute of Biology and Medicine", Taras Shevchenko National University of Kyiv, Kyiv, Ukraine.
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Soloviev AI, Kizub IV. Mechanisms of vascular dysfunction evoked by ionizing radiation and possible targets for its pharmacological correction. Biochem Pharmacol 2018; 159:121-139. [PMID: 30508525 DOI: 10.1016/j.bcp.2018.11.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/28/2018] [Indexed: 12/20/2022]
Abstract
Ionizing radiation (IR) leads to a variety of the cardiovascular diseases, including the arterial hypertension. A number of studies have demonstrated that blood vessels represent important target for IR, and the endothelium is one of the most vulnerable components of the vascular wall. IR causes an inhibition of nitric oxide (NO)-mediated endothelium-dependent vasodilatation and generation of reactive oxygen (ROS) and nitrogen (RNS) species trigger this process. Inhibition of NO-mediated vasodilatation could be due to endothelial NO synthase (eNOS) down-regulation, inactivation of endothelium-derived NO, and abnormalities in diffusion of NO from the endothelial cells (ECs) leading to a decrease in NO bioavailability. Beside this, IR suppresses endothelial large conductance Ca2+-activated K+ channels (BKCa) activity, which control NO synthesis. IR also leads to inhibition of the BKCa current in vascular smooth muscle cells (SMCs) which is mediated by protein kinase C (PKC). On the other hand, IR-evoked enhanced vascular contractility may result from PKC-mediated increase in SMCs myofilament Ca2+ sensitivity. Also, IR evokes vascular wall inflammation and atherosclerosis development. Vascular function damaged by IR can be effectively restored by quercetin-filled phosphatidylcholine liposomes and mesenchymal stem cells injection. Using RNA-interference technique targeted to different PKC isoforms can also be a perspective approach for pharmacological treatment of IR-induced vascular dysfunction.
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Affiliation(s)
- Anatoly I Soloviev
- Department of Pharmacology of Cellular Signaling Systems and Experimental Therapy, Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, 14 Eugene Pottier Street, Kiev 03068, Ukraine
| | - Igor V Kizub
- Department of Pharmacology, New York Medical College, 15 Dana Road, Valhalla 10595, NY, United States.
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Melnyk MI, Dryn DO, Al Kury LT, Zholos AV, Soloviev AI. Liposomal quercetin potentiates maxi-K channel openings in smooth muscles and restores its activity after oxidative stress. J Liposome Res 2018; 29:94-101. [DOI: 10.1080/08982104.2018.1458864] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Affiliation(s)
- Mariia I. Melnyk
- Institute of Pharmacology and Toxicology, National Academy of Medical Science, Kyiv, Ukraine
- A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Dariia O. Dryn
- Institute of Pharmacology and Toxicology, National Academy of Medical Science, Kyiv, Ukraine
- A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Lina T. Al Kury
- Department of Health Sciences, Zayed University, Abu Dhabi, United Arab Emirates
| | - Alexander V. Zholos
- A.A. Bogomoletz Institute of Physiology, National Academy of Sciences of Ukraine, Kyiv, Ukraine
- ESC “Institute of Biology and Medicine”, Taras Shevchenko Kyiv National University, Kyiv, Ukraine
| | - Anatoly I. Soloviev
- Institute of Pharmacology and Toxicology, National Academy of Medical Science, Kyiv, Ukraine
- ESC “Institute of Biology and Medicine”, Taras Shevchenko Kyiv National University, Kyiv, Ukraine
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Kizub IV, Strielkov IV, Shaifta Y, Becker S, Prieto-Lloret J, Snetkov VA, Soloviev AI, Aaronson PI, Ward JP. Gap junctions support the sustained phase of hypoxic pulmonary vasoconstriction by facilitating calcium sensitization. Cardiovasc Res 2013; 99:404-11. [PMID: 23708740 PMCID: PMC3718323 DOI: 10.1093/cvr/cvt129] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/16/2013] [Revised: 05/09/2013] [Accepted: 05/18/2013] [Indexed: 01/04/2023] Open
Abstract
AIMS To determine the role of gap junctions (GJs) in hypoxic pulmonary vasoconstriction (HPV). METHODS AND RESULTS Studies were performed in rat isolated intrapulmonary arteries (IPAs) mounted on a myograph and in anaesthetized rats. Hypoxia induced a biphasic HPV response in IPAs preconstricted with prostaglandin F2α (PGF2α, 3 µM) or 20 mM K⁺. The GJ inhibitors 18β-glycyrrhetinic acid (18β-GA, 30 µM), heptanol (3.5 mM), or 2-aminoethoxydiphenyl borate (2-APB) (75 µM) had little effect on the transient Phase 1 of HPV, but abolished the sustained Phase 2 which is associated with Ca²⁺ sensitization. The voltage-dependent Ca²⁺ channel blocker diltiazem (10 µM) had no effect on HPV, and did not alter the inhibitory action of 18β-GA. Sustained HPV is enhanced by high glucose (15 mM) via potentiation of Ca²⁺ sensitization, in the presence of high glucose 18β-GA still abolished sustained HPV. Simultaneous measurement of tension and intracellular Ca²⁺ using Fura PE-3 demonstrated that whilst 18β-GA abolished tension development during sustained HPV, it did not affect the elevation of intracellular Ca²⁺. Consistent with this, 18β-GA abolished hypoxia-induced phosphorylation of the Rho kinase target MYPT-1. In anaesthetized rats hypoxia caused a biphasic increase in systolic right ventricular pressure. Treatment with oral 18β-GA (25 mg/kg) abolished the sustained component of the hypoxic pressor response. CONCLUSION These results imply that GJs are critically involved in the signalling pathways leading to Rho kinase-dependent Ca²⁺ sensitization during sustained HPV, but not elevation of intracellular Ca²⁺, and may explain the dependence of the former on an intact endothelium.
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Affiliation(s)
- Igor V. Kizub
- Department of Experimental Therapeutics, Institute of Pharmacology and Toxicology of National Academy of Medical Sciences of Ukraine, Kiev, Ukraine
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
| | - Ievgen V. Strielkov
- Department of Experimental Therapeutics, Institute of Pharmacology and Toxicology of National Academy of Medical Sciences of Ukraine, Kiev, Ukraine
| | - Yasin Shaifta
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
| | - Silke Becker
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
| | - Jesus Prieto-Lloret
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
| | - Vladimir A. Snetkov
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
| | - Anatoly I. Soloviev
- Department of Experimental Therapeutics, Institute of Pharmacology and Toxicology of National Academy of Medical Sciences of Ukraine, Kiev, Ukraine
| | - Philip I. Aaronson
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
| | - Jeremy P.T. Ward
- Division of Asthma, Allergy and Lung Biology, King's College London, 5th Floor Tower Wing, Guy's Campus, London SE1 9RT, UK
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Soloviev AI, Bondarenko AI, Kizub IV. Selective glycolysis blockade in guinea pig pulmonary artery and aorta reverses contractile and electrical responses to acute hypoxia. Vascul Pharmacol 2012; 57:119-23. [PMID: 22706072 DOI: 10.1016/j.vph.2012.06.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 05/31/2012] [Accepted: 06/07/2012] [Indexed: 11/18/2022]
Abstract
The goal of this study was to clarify the mechanisms of hypoxic pulmonary vasoconstriction (HPV) reversal following selective glycolysis blockade and to assess possible contribution of endothelial electrogenesis to this phenomenon as a trigger mechanism. We compared smooth muscle (SM) contractility and endothelial cell (EC) membrane potential (MP) during acute hypoxia before and after glycolysis blockade. MPs were recorded from the endothelium of guinea pig pulmonary artery (GPPA) and thoracic aorta (GPTA) using the patch-clamp technique. Acute hypoxia caused hyperpolarization in GPTA EC, while EC from GPPA were depolarized. Also, acute hypoxia elicited constriction in isolated GPPA and dilatation in GPTA. Selective glycolysis inhibition always reversed both electrical and contractile responses in GPPA to hypoxia, but in GPTA this only occurred in 30% of experiments. It is likely that an unknown glycolysis-driven mechanism in EC mediates vascular tone regulation under hypoxia and underlies the paradoxical difference in the response of pulmonary and systemic arterial SM to hypoxia. Our data suggest that HPV development in GPPA might, at least partially, be driven by EC depolarization spreading to the underlying SM cells.
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Affiliation(s)
- Anatoly I Soloviev
- Department of Experimental Therapeutics, Institute of Pharmacology and Toxicology, 14 E. Pottier Str., 03068, Kiev, Ukraine.
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Kizub IV, Pavlova OO, Ivanova IV, Soloviev AI. Protein kinase C-dependent inhibition of BK(Ca) current in rat aorta smooth muscle cells following gamma-irradiation. Int J Radiat Biol 2010; 86:291-9. [PMID: 20353339 DOI: 10.3109/09553000903564042] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
PURPOSE The aim of this study was to estimate the effects of non-fatal whole-body gamma-irradiation on outward potassium plasma membrane conductivity in rat vascular smooth muscle cells (VSMC), and to identify underlying mechanisms. MATERIALS AND METHODS Rats were exposed to a 6 Gy dose irradiation from a cobalt(60) source. Whole-cell potassium current was measured in freshly isolated rat aorta smooth muscle cells using standard patch-clamp technique. RESULTS We have determined that whole-body ionising irradiation significantly inhibits whole-cell outward K(+) current in rat aortic VSMC obtained from irradiated rats 9 and 30 days after irradiation, and this inhibition appears to be increased throughout post-irradiation period. Using selective inhibitors of small conductance Ca(2+)-activated K(+) channels (SK(Ca)), apamin (1 microM), intermediate conductance Ca(2+)-activated K(+) channels (IK(Ca,)), charybdotoxin (1 microM) and a large conductance Ca(2+)-activated K(+) channels (BK(Ca)), paxilline (500 nM), we established that the main component of whole-cell outward K(+) current in rat aortic VSMC is due to BK(Ca). It is clear that on the 9th day after irradiation paxilline had only a small effect on whole-cell outward K(+) current in VSMC, and was without effect on the 30th day post-irradiation, suggesting complete suppression of the BK(Ca) current. The PKC inhibitor, chelerythrine (100 nM), effectively reversed the suppression of whole-cell outward K(+) current induced by ionising irradiation in the post-irradiation period of 9 and 30 days. CONCLUSIONS The results suggest that irradiation-evoked inhibition of the BK(Ca) current in aortic VSMC is mediated by PKC. Taken together, our data indicate that one of the mechanisms leading to elevation of vascular tone and related arterial hypertension development under ionising irradiation impact is a PKC-mediated inhibition of BK(Ca) channels in VSMC.
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Affiliation(s)
- Igor V Kizub
- Experimental Therapeutics Department, Institute of Pharmacology and Toxicology of Academy of Medical Sciences of Ukraine, Kiev, Ukraine.
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Kizub IV, Pavlova OO, Johnson CD, Soloviev AI, Zholos AV. Rho kinase and protein kinase C involvement in vascular smooth muscle myofilament calcium sensitization in arteries from diabetic rats. Br J Pharmacol 2010; 159:1724-31. [PMID: 20218979 DOI: 10.1111/j.1476-5381.2010.00666.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Diabetes mellitus (DM) causes multiple dysfunctions including circulatory disorders such as cardiomyopathy, angiopathy, atherosclerosis and arterial hypertension. Rho kinase (ROCK) and protein kinase C (PKC) regulate vascular smooth muscle (VSM) Ca(2+) sensitivity, thus enhancing VSM contraction, and up-regulation of both enzymes in DM is well known. We postulated that in DM, Ca(2+) sensitization occurs in diabetic arteries due to increased ROCK and/or PKC activity. EXPERIMENTAL APPROACH Rats were rendered hyperglycaemic by i.p. injection of streptozotocin. Age-matched control tissues were used for comparison. Contractile responses to phenylephrine (Phe) and different Ca(2+) concentrations were recorded, respectively, from intact and chemically permeabilized vascular rings from aorta, tail and mesenteric arteries. KEY RESULTS Diabetic tail and mesenteric arteries demonstrated markedly enhanced sensitivity to Phe while these changes were not observed in aorta. The ROCK inhibitor HA1077, but not the PKC inhibitor chelerythrine, caused significant reduction in sensitivity to agonist in diabetic vessels. Similar changes were observed for myofilament Ca(2+) sensitivity, which was again enhanced in DM in tail and mesenteric arteries, but not in aorta, and could be reduced by both the ROCK and PKC blockers. CONCLUSIONS AND IMPLICATIONS We conclude that in DM enhanced myofilament Ca(2+) sensitivity is mainly manifested in muscular-type blood vessels and thus likely to contribute to the development of hypertension. Both PKC and, in particular, ROCK are involved in this phenomenon. This highlights their potential usefulness as drug targets in the pharmacological management of DM-associated vascular dysfunction.
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Affiliation(s)
- I V Kizub
- Institute of Pharmacology and Toxicology, Academy of Medical Sciences of Ukraine, Kiev, Ukraine
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Tishkin SM, Rekalov VV, Ivanova IV, MoreLand RS, Soloviev AI. Ionizing non-fatal whole-body irradiation inhibits Ca2+-dependent K+channels in endothelial cells of rat coronary artery: Possible contribution to depression of endothelium-dependent vascular relaxation. Int J Radiat Biol 2009; 83:161-9. [PMID: 17378524 DOI: 10.1080/09553000601146931] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE The goal of this study was to evaluate the influence of ionizing irradiation on large conductance Ca2+-dependent potassium (BKCa) channels in rat coronary endothelial cells. MATERIALS AND METHODS Rats were exposed to a 6 Gy dose from a cobalt60 source. Experimental design of this study comprised recording of contractile force using isolated rat aortic rings and whole-cell patch clamp techniques to study whole-cell potassium currents in isolated rat coronary artery endothelial cells. RESULTS It has been shown that outward potassium currents in endothelial cells 9 days after irradiation appear to be suppressed or even totally abolished. The reversal potential for these currents in irradiated cells was shifted to more positive values. Paxilline (500 nM), an inhibitor of BKCa channels, had no or only a negligible effect on irradiated cells. The experiments using isolated aortic rings demonstrated that both paxilline and irradiation significantly shifted the acetylcholine dependent concentration-relaxation response curve to the right. Irradiated tissues were insensitive to paxilline. CONCLUSION The results suggest that non-fatal, whole-body gamma-irradiation suppresses large conductance, calcium-activated potassium channels, which control the driving force for Ca2+ entry and therefore Ca2+ dependent nitric oxide (NO) synthesis in endothelial cells. This may contribute, in part, to radiation-induced endothelium dysfunction and an increase in arterial blood pressure.
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Affiliation(s)
- Sergey M Tishkin
- Institute of Pharmacology and Toxicology, Academy of Medical Sciences, Kiev, Ukraine
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Soloviev AI, Tishkin SM, Zelensky SN, Ivanova IV, Kizub IV, Pavlova AA, Moreland RS. Ionizing radiation alters myofilament calcium sensitivity in vascular smooth muscle: potential role of protein kinase C. Am J Physiol Regul Integr Comp Physiol 2005; 289:R755-62. [PMID: 15890787 DOI: 10.1152/ajpregu.00748.2004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Radiation exposure increases vascular responsiveness, and this change involves endothelial damage, as well as direct effects on vascular smooth muscle. In this study, we tested the hypothesis that myofilament Ca2+sensitivity in vascular smooth muscle is increased from single whole body gamma irradiation (6 Gy). We measured contractile responses from intact and permeabilized rat thoracic aortic rings combined with cytosolic Ca2+([Ca2+]i) measurements. The sensitivity to KCl and phenylephrine increased significantly in tissues from animals on the 9th and 30th days postirradiation compared with control. Irradiation also significantly increased Ca2+sensitivity in β-escin permeabilized smooth muscle on the 9th and 30th days postirradiation. Inhibitors of protein kinase C, chelerythrine, and staurosporine, had no effect on the pCa-tension curves in control permeabilized tissues but significantly decreased Ca2+sensitivity in permeabilized tissues on the 9th and 30th days postirradiation. Phorbol dibutyrate (PDBu, 10−7M) increased Ca2+sensitivity in control skinned smooth muscle but was without effect in irradiated vascular rings. Simultaneous measurement of contractile force and [Ca2+]ishowed that myofilament Ca2+sensitivity defined as the ratio of force change to [Ca2+]isignificantly increased following γ-irradiation. PDBu (10−6M) stimulation of intact aorta produced a sustained contraction, while the increase in [Ca2+]iwas transient. In irradiated tissues, PDBu-induced contractions were greater than those seen in control tissues but there was no elevation in [Ca2+]i. Taken together, these data strongly support the hypothesis that irradiation increases the sensitivity of vascular smooth muscle myofilaments to Ca2+and this effect is dependent on activation of protein kinase C.
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Affiliation(s)
- Anatoly I Soloviev
- Institute of Pharmacology and Toxicology, Academy of Medical Sciences, 14 Eugene Pottier Street, Kiev 03057, Ukraine.
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Soloviev AI, Tishkin SM, Parshikov AV, Ivanova IV, Goncharov EV, Gurney AM. Mechanisms of endothelial dysfunction after ionized radiation: selective impairment of the nitric oxide component of endothelium-dependent vasodilation. Br J Pharmacol 2003; 138:837-44. [PMID: 12642385 PMCID: PMC1573711 DOI: 10.1038/sj.bjp.0705079] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2002] [Revised: 10/24/2002] [Accepted: 10/30/2002] [Indexed: 11/09/2022] Open
Abstract
(1) Gamma radiation impairs vascular function, leading to the depression of endothelium-dependent vasodilatation. Loss of the nitric oxide (NO) pathway has been implicated, but little is known about radiation effects on other endothelial mediators. (2) This study investigated the mechanisms of endothelial dysfunction in rabbits subjected to whole-body irradiation from a cobalt(60) source. (3) The endothelium-dependent relaxation of rabbit aorta evoked by acetylcholine (ACh) or A23187 was impaired in a dose-dependent manner by irradiation at 2 Gy or above. Inhibition was evident 9 days post-irradiation and persisted over the 30 day experimental period. (4) Endothelium-independent responses to glyceryl trinitrate (GTN), sodium nitroprusside (SNP) and 3-morpholino-sydnonimine (SIN-1) were suppressed over a similar dose range at 7-9 days post-irradiation, but recovered fully by 30 days post-irradiation. (5) In healthy vessels, ACh-induced relaxation was inhibited by L-N(omega)-nitroarginine (L-NA; 3 x 10(-4) M) and charybdotoxin (10(-8) M) plus apamin (10(-6) M) but resistant to indomethacin, indicating the involvement of NO and endothelium-derived hyperpolarizing factor (EDHF). Supporting this, ACh caused smooth muscle hyperpolarization that was reduced by L-NA and charybdotoxin plus apamin. (6) In irradiated vessels, responses to ACh were insensitive to L-NA but abolished by charybdotoxin plus apamin, indicating selective loss of NO-mediated relaxation. (7) In animals treated shortly after irradiation with the antioxidant, alpha-tocopherol acetate, the NO-dependent relaxation was restored without effect on the EDHF-dependent component. (8) The results imply that radiation selectively impairs the NO pathway as a consequence of oxidative stress, while EDHF is able to maintain endothelium-dependent relaxation at a reduced level.
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Affiliation(s)
- Anatoly I Soloviev
- Department for Experimental Therapeutics, Institute of Pharmacology and Toxicology, Academy of Medical Sciences, 14, Eugene Pottier Street, Kiev, 03057 Ukraine
| | - Sergey M Tishkin
- Department for Experimental Therapeutics, Institute of Pharmacology and Toxicology, Academy of Medical Sciences, 14, Eugene Pottier Street, Kiev, 03057 Ukraine
| | - Alexander V Parshikov
- Department for Experimental Therapeutics, Institute of Pharmacology and Toxicology, Academy of Medical Sciences, 14, Eugene Pottier Street, Kiev, 03057 Ukraine
| | - Irina V Ivanova
- Department for Experimental Therapeutics, Institute of Pharmacology and Toxicology, Academy of Medical Sciences, 14, Eugene Pottier Street, Kiev, 03057 Ukraine
| | - Eugene V Goncharov
- Department for Experimental Therapeutics, Institute of Pharmacology and Toxicology, Academy of Medical Sciences, 14, Eugene Pottier Street, Kiev, 03057 Ukraine
| | - Alison M Gurney
- Department of Physiology and Pharmacology, Strathclyde Institute for Biomedical Sciences, University of Strathclyde, 27, Taylor Street, Glasgow G4 ONR
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Soloviev AI, Stefanov AV, Tishkin SM, Khromov AS, Parshikov AV, Ivanova IV, Gurney AM. Saline containing phosphatidylcholine liposomes possess the ability to restore endothelial function damaged resulting from gamma-irradiation. J Physiol Pharmacol 2002; 53:701-12. [PMID: 12512704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
The protective action of passive saline filled ("empty") phosphatidylcholine liposomes (PCL) on endothelial function was examined in thoracic aortas obtained from gamma irradiated (6 Gy) Chinchilla rabbits, and then verified in experiments on non-anesthetized and anesthetized rats. Acetylcholine (ACh)-induced vascular relaxant responses in isolated vascular tissues rats were used as the test of endothelial integrity and its functional ability. It was shown that when added to the bath solution (100 microg/ml), PCL effectively restored endothelium-dependent ACh relaxations of isolated vascular rings damaged resulting from gamma-irradiation but had no effect on endothelium-independent vascular responses to therapeutic nitric oxide (NO) donors. The liposomes were also without protective effect when injected to the rabbits intraperitoneally (30 mg/kg) 1 hour before irradiation. In contrast, PCL, being injected at the same dose 1 hour after radiation impact, promote normalization of both endothelium-dependent vascular responses to ACh and nitric oxide (NO) donors. PCL restored also the sensitivity of vascular tissues to authentic NO (aqueous NO solution) that was surprisingly increased after irradiation, and normalized relationship between ACh-stimulated NO release and relaxant response amplitudes in irradiated aortas. Experiments on non-anesthetized and anesthetized rats demonstrated that irradiation led to significant elevation in the level of arterial blood pressure without any changes in cardiac contractility. PCL administration (25 mg/kg, i.v.) effectively normalized an increased arterial blood pressure in irradiated animals. In conclusion, it appears that PCL due to its ability to normalize NO-dependent vascular tone control mechanisms might be worthwhile therapeutic approach in case of ionizing irradiation accident. These result support the concept that the depression of endothelium-dependent vascular responses after irradiation may be result of decreased NO bioavailability due to its conversion to less potent vasodilators during irradiation-induced oxidative attack.
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Affiliation(s)
- A I Soloviev
- Department for Experimental Therapeutics, Institute of Pharmacology and Toxicology, Academy of Medical Sciences, Kiev, Ukraine.
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Lehen'kyi VV, Zelensky SN, Stefanov AV, Soloviev AI. Effects of Nitric Oxide Donors on Vascular Smooth Muscles Depend on a Type of Vascular Smooth-Muscle Preactivation. Cardiovasc Toxicol 2002; 2:151-60. [PMID: 12271158 DOI: 10.1385/ct:2:2:151] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The abilities of such therapeutic nitrovasodilators as sodium nitroprusside (SNP) and glyceryl trinitrate (GTN) to dilate vascular smooth muscles (VSM) and affect intracellular calcium concentration level ([Ca2+]i) in a rat tail artery were tested under different types of preactivation. To shed light on mechanisms underlying possible differences in the action of these two nitric oxide (NO) donors, simultaneous measurements of [Ca2+]i and contractile force were done. All vascular rings were precontracted either using a high-K+-Krebs solution or phenylephrine (PE). It was shown that the effect of both NO donors strongly depended on a type of VSM preactivation. The EC50 for GTN under K+ stimulation of VSM comprised (2.48 +/- 1.6) x 10(-5) M, whereas the mean EC50 under PE stimulation was (3.05 +/- 2.3) x 10(-4) M (p < 0.05, n = 9). The EC50 for SNP under K+ stimulation of VSM comprised (1.09 +/- 0.47) x 10(-7) M, whereas the EC(50) under PE stimulation was (8.01 +/- 2.4) x 10(-6) M (p < 0.05, n = 9). GTN demonstrated a significant discrepancy in the magnitude of changes in [Ca2+]i and related VSM relaxant responses, indicating the ability of GTN to relax VSM in the absence of a proportional decrease in [Ca2+]i. The main peculiarity of SNP action under K+ stimulation as compared to PE stimulation was the transient decrease in [Ca2+]i while relaxation was sustained. Therefore, both NO donors demonstrated their ability to produce vasorelaxation as a result of an alteration in myofilament calcium sensitivity. These data clearly indicate that the sensitivity of VSM to NO donors is higher under K+ depolarization than that seen under PE stimulation, indicating that Ca2+ entry through voltage-operated calcium channels is more sensitive to NO as compared to calcium mobilization by means of Ca2+ entry through receptor- operated calcium channels or intracellular Ca2+ release, or both.
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Affiliation(s)
- V V Lehen'kyi
- Department of Experimental Therapy, Institute of Pharmacology and Toxicology, Kiev 03057, Ukraine
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Soloviev AI, Parshikov AV, Stefanov AV. Evidence for the involvement of protein kinase C in depression of endothelium-dependent vascular responses in spontaneously hypertensive rats. J Vasc Res 1998; 35:325-31. [PMID: 9789113 DOI: 10.1159/000025602] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
The goal of the present study was to evaluate the role of protein kinase C (PKC) in the depression of endothelium-dependent vacular response in spontaneously hypertensive Okamoto rats (SHR). Aortae from SHR demonstrated a decreased relaxant response to acetylcholine (Ach) as compared to aortae from normotensive Wistar-Kyoto (WKY) rats, while papaverine lowered the force of aorta to a similar degree in both strains of rats. PKC inhibitors, H-7 (5 x 10(-6) M) and chelerythrine chloride (10(-6) M), produced a greater decrease in the force developed by the aortae from SHR vs. WKY rats both in intact and chemically permeabilized tissues. In SHR aortae PKC inhibitors enhanced relaxation to Ach to a greater extent as compared to WKY aortae. Furthermore, in the presence of PKC inhibitors, the constrictor responses of SHR aortae to Ach were transformed into relaxant responses, and the concentration-response curve to Ach was shifted to the left. The sensitivity of aortae from SHR to authentic nitric oxide (NO) was lowere compared to WKY rats. EC50s for authentic NO in SHR and WKY rat aortae were different: -2.9 +/- 0.15 x 10(-6) M and 4.58 +/- 0.1 x 10(-7) M (n = 15, p < 0. 001), respectively. Bioassay experiments using SHR aortae showed that the addition of chelerythrine (10(-6) M) to the detector superfusate caused relaxation during treatment of the donor segment with Ach, indicating that the sensitivity of the aortae to NO had been restored. When SHR detector ring was substituted for denuded aortae from WKY rats and PKC inhibitors were not added to the detector superfusate, the relaxation of the detector aortae was also close to the normal Ach-induced relaxation. WKY aortae demonstrated a positive relationship between Ach-stimulated NO release and relaxant response amplitudes (correlation coefficient r = 0.905, p < 0.001, n = 10). In contrast, there was a significant negative correlation in SHR aortae (r = -0.712, p < 0.05, n = 10). Detection of NO release by chemiluminescence showed no significant difference in NO release in SHR and WKY aortae. Taken together, these data suggest that the blunted endothelium-dependent relaxations seen in SHR aortae are mainly due to a decreased sensitivity of vascular smooth muscle to EDRF/NO resulting from an increased PKC activity.
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Affiliation(s)
- A I Soloviev
- Institute of Pharmacology and Toxicology, Academy of Medical Sciences, Kiev, Ukraine.
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Soloviev AI, Stefanov AV, Bazilyuk OV, Sagach VF. Phospholipid vesicles (liposomes) restore endothelium-dependent cholinergic relaxation in thoracic aorta from spontaneously hypertensive rats. J Hypertens 1993; 11:623-7. [PMID: 8397241 DOI: 10.1097/00004872-199306000-00006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
OBJECTIVE The present study was designed to examine, using isolated preparations of thoracic aorta, the effects of artificial phosphatidylcholine vesicles (liposomes) on vascular endothelium-dependent responses in spontaneously hypertensive rats (SHR) compared with those in Wistar-Kyoto (WKY) normotensive rats. DESIGN Phosphatidylcholine liposomes, which possess the ability to repair the plasma membrane of living cells, were used in these experiments. METHODS Liposomes were prepared from egg phosphatidylcholine. A suspension of lipid was subjected to ultrasound treatment at 20 degrees C at a frequency of 44 kHz for 45 s. The contraction of vascular smooth muscle was recorded using a force-displacement transducer coupled with a physiograph. RESULTS It was shown that aortic smooth muscle from SHR demonstrated a loss of endothelium-dependent relaxation in acetylcholine (10(-6) mol/l) compared with WKY rat aortic smooth muscle. Liposomes in a concentration of 100-125 micrograms/ml restored these endothelium-dependent responses more effectively than L-arginine (10(-5) to 10(-4) mol/l), which is known to be a precursor of endothelium-derived relaxing factor (EDRF). This effect was not observed in denuded aortic rings, and liposomes lost their ability of repairing endothelium-dependent vascular relaxant responses in the presence of methylene blue (5 x 10(-5) mol/l), which inhibits soluble guanylyl cyclase activation by nitric oxide (NO), and N omega-nitro-L-arginine (L-NNA, 5 x 10(-5) to 10(-4) mol/l), a potent and selective inhibitor of NO synthase. CONCLUSION The present results suggest that the loss of vascular endothelium-dependent responses in SHR may be, at least partly, due to endothelial cells membrane damage, and that the phosphatidylcholine liposomes can repair the function of endothelial cells and restore synthesis or release, or both, of EDRF in hypertension.
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Affiliation(s)
- A I Soloviev
- Institute of Pharmacology and Toxicology, Academy of Medical Sciences, Kiev, Ukraine
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Soloviev AI, Basilyuk OV. Evidence for decrease in myofilament responsiveness to Ca2+ during hypoxia in spontaneously active vascular smooth muscle in rats. Exp Physiol 1993; 78:395-402. [PMID: 8392358 DOI: 10.1113/expphysiol.1993.sp003693] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
The cellular mechanisms underlying smooth muscle hypoxic relaxation were examined in experiments on isolated chemically skinned muscle strips of rat portal vein. Low PO2 (3.9 kPa) shifted the pCa-tension relation to the right by 0.29 +/- 0.01 pCa units as compared to control curves (PO2, 18.8 kPa). Thus the Ca2+ sensitivity of the filaments had decreased. Addition of cyclic AMP (30 mumol l-1) with theophylline (5 mmol l-1) to the buffer solution produced a similar shift to low PO2. Low PO2 also decreased the maximal force to 40-50% of control. Inclusion of sodium fluoride (10 mmol l-1) and aluminium chloride (10 mumol l-1) in a bath solution caused partial (25-30%) relaxation of skinned smooth muscle preconstricted with 10 mumol l-1 Ca2+. The rate and amplitude of smooth muscle relaxation at low PO2 were significantly decreased by tolbutamide (5 mmol l-1), which is known to inhibit cyclic AMP-dependent protein kinases. We suggest that PO2 changes can alter myofilament responsiveness to Ca2+ and this effect may be related to cyclic AMP-dependent phosphorylation of myosin light chain kinase, its inactivation and subsequent uncoupling between Ca2+ and contractile machinery in smooth muscle.
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Affiliation(s)
- A I Soloviev
- A.A. Bogomoletz Institute of Physiology, Academy of Sciences, Kiev, Ukraine
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Soloviev AI, Braquet P. Platelet-Activating Factor - A Potent Endogenous Mediator Responsible for Coronary Vasospasm. Physiology (Bethesda) 1992. [DOI: 10.1152/physiologyonline.1992.7.4.166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Biological properties and experimental evidence suggest an important role for platelet-activating factor (PAF) as an endogenous mediator responsible for coronary vasospasm. PAF can produce both phasic (transient) and tonic (sustained) contractions in coronary arteries in different physiopathological conditions including hypoxia.
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Soloviev AI, Bershtein SA. The contractile apparatus in vascular smooth muscle cells of spontaneously hypertensive rats possess increased calcium sensitivity: the possible role of protein kinase C. J Hypertens 1992; 10:131-6. [PMID: 1313475 DOI: 10.1097/00004872-199202000-00004] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
OBJECTIVE The purpose of the present investigation was to compare calcium sensitivity of contractile machinery in aorta and portal vein smooth muscle cells (SMC) in normotensive Wistar-Kyoto (WKY) rats and spontaneously hypertensive Okamoto rats (SHR), and to shed light upon the mechanisms of possible differences. DESIGN Investigations into calcium sensitivity of SMC myofilaments can only be made on skinned muscular strips. METHODS The vascular strips were made hyperpermeable by detergent skinning with saponin. The isometric calcium-induced contractions of SMC were recorded using a force displacement transducer coupled to a physiograph. RESULTS It was shown that the pCa-tension (negative logarithm of calcium concentration versus tension) relationship for aorta and portal vein SMC in SHR shifted to the left in comparison with WKY rats. Putative protein kinase C inhibitors 1-(S-isoquionolinyl-sulfonyll)-2-methylpiperasine (H-7) and polymyxin B shifted the pCa-tension relationship more significantly to the right in the SMC of SHR than in WKY rats. It has also been shown that H-7 and polymyxin B sharply reduced the maximum tension developed by SMC in SHR whilst causing a non-significant decrease in maximum tension of SMC from WKY rats. These results are consistent with higher protein kinase C activity in SMC of SHR. CONCLUSION These results indicate that the increase in calcium sensitivity of vascular SMC contractile machinery in SHR may be linked with the increase in their protein kinase C activity.
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Affiliation(s)
- A I Soloviev
- A.A. Bogomoletz Institute of Physiology, Ukrainian Academy of Sciences, Kiev
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Abstract
The effect of platelet-activating factor (PAF) on the development of isometric tension by saponin-skinned coronary artery was studied. PAF caused two types of contractions of coronary smooth muscle cells (SMC): (i) rapid, transient (phasic) contractions of SMC were induced by inositol 1,4,5-trisphosphate dependent Ca2+ release from sarcoplasmic reticulum (SR); (ii) slow sustained (tonic) contractions were induced by increase in Ca(2+)-sensitivity of the contractile apparatus of SMC by protein kinase C activation. The present results support the hypothesis that, in SMC of coronary artery, PAF receptors are located not only on the plasma membrane, but also on the SR membranes.
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Affiliation(s)
- A I Soloviev
- A.A. Bogomoletz Institute of Physiology, Kiev, Ukraine, U.S.S.R
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