Leonid Luksha

Karolinska University Hospital, Tukholma, Stockholm, Sweden

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Publications (9)31.98 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Statins are believed to exert beneficial effects against cardiovascular disease beyond correction of dyslipidemia. There are however still very sparse data on how individual statins interact with the production of vasoactive eicosanoids and nitric oxide (NO) in human vascular endothelial cells. Here we have determined how fluvastatin affects the mRNA expression of genes associated with vascular reactivity as well as the formation of two major vasodilators, prostacyclin (PGI2) and NO, in human endothelial cells. Also, the influence of fluvastatin on arterial resistance was assessed in isolated small arteries. We show that the promoter activity of prostacyclin synthase (PTGIS), the mRNA expression of PTGIS and endothelial nitric oxide synthase (eNOS), and the production of PGI2 and NO are significantly induced by fluvastatin. Also, strong rapid dilatation ex vivo was observed, with the equal contribution of PGI2 and NO. Our findings in cell culture experiments and in isolated human arteries indicate that fluvastatin-evoked endothelium-derived vasodilator production may confer protection of the endothelial cells via both acute and long-term effects of fluvastatin treatment. If these effects take place in vivo, we suggest a protective pleiotropic role of fluvastatin on the cardiovascular system, particularly at the level of the vascular endothelium, to ameliorate the process of atherogenesis and in the acute manner to reduce vascular tone.
    Heart and Vessels 01/2011; 26(6):628-36. · 2.13 Impact Factor
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    ABSTRACT: This study was undertaken to study vascular reactivity of small myometrial arteries in women with idiopathic menorrhagia. Small myometrial arteries were isolated from 6 patients with idiopathic menorrhagia and 4 controls. The contractile responses to thromboxane mimetic (U46619) and endothelin-1 were assessed before and after incubation with N(w)-nitro-L arginine methyl ester alone or in combination with indomethacin (Indo). Endothelium-dependent dilation to bradykinin and basal tension were compared before and after incubation with N(w)-nitro-L arginine methyl ester alone, or with N(w)-nitro-L arginine methyl ester in combination with indomethacin. Constriction to endothelin-1 was enhanced in idiopathic menorrhagia arteries (P < .05). Idiopathic menorrhagia arteries demonstrated enhanced basal tension after incubation with N(w)-nitro-L arginine methyl ester, which was further exaggerated by indomethacin. NOS inhibition had no effect on basal tension in controls, but basal tension was enhanced after inhibition of cyclooxygenase-derived products (P < .05). Bradykinin-mediated dilation was significantly increased in idiopathic menorrhagia (P < .05). The presence of functional alterations in small myometrial arteries could contribute to idiopathic menorrhagia.
    American journal of obstetrics and gynecology 08/2008; 199(6):646.e1-5. · 3.28 Impact Factor
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    ABSTRACT: The objectives of this study were to determine whether placental growth factor (PlGF) exerts a vasodilatory effect on rat uterine vessels (arcuate arteries and veins) and to examine regional differences in reactivity by comparing these responses to those of comparably sized mesenteric vessels. We also sought to examine and compare its effects on human uterine and subcutaneous vessels. All vessels were studied in vitro, under pressurized (rat) or isometric wire-mounted (human) conditions, and exposed to a range of PlGF concentrations. Inhibitors of nitric oxide and prostaglandin synthesis were included in an effort to understand the causal mechanism(s). In rat uterine arteries, the effects of receptor inhibition and activation using selective ligands for VEGFR-1 (PlGF) vs. VEGFR-2 (VEGF-E) were determined, and real-time RT-PCR was performed to evaluate the effect of pregnancy on relative abundance of VEGFR-1 and VEGFR-2 message in the vascular wall. PlGF was a potent vasodilator of all vessels studied, with greatest sensitivity observed in rat uterine arteries. Pregnancy significantly augmented dilator sensitivity to PlGF, and this effect was associated with selective upregulation of VEGFR-1 message in the pregnant state. The contribution of nitric oxide was appreciable in rat and human uterine arteries, with lesser effects in rat uterine veins and mesenteric arteries, and with no observable effect in human subcutaneous vessels. Based on these results, we conclude that PlGF is a potent vasodilator of several vessel types in both humans and rats. Its potency and mechanism vary with physiological state and vessel location and are mediated solely by the VEGFR-1 receptor subtype. Gestational changes in the uterine circulation suggest that this factor may play a role in modulating uterine vascular remodeling and blood flow during the pregnant state.
    AJP Heart and Circulatory Physiology 04/2008; 294(3):H1381-7. · 4.01 Impact Factor
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    ABSTRACT: The role of gap junctions in endothelium-derived hyperpolarizing factor (EDHF)-mediated relaxation of human arteries was assessed using connexin mimetic peptides (CMPs) designated (37,43)Gap27, (40)Gap27, and (43)Gap26 according to homology with the major vascular connexins (Cx37, Cx40, and Cx43). Resistance arteries were obtained from subcutaneous fat biopsies of healthy pregnant women undergoing elective cesarean section. Endothelium-dependent vasodilatation to bradykinin (BK) was assessed using wire myography. N(omega)-nitro-l-arginine methyl ester (l-NAME) and indomethacin (nitric oxide synthase and cyclooxygenase inhibitors, respectively) attenuated maximal relaxation to BK (R(max)) by approximately 50%. Coincubation with l-NAME, indomethacin, and the combined CMPs ((37,43)Gap27, (40)Gap27, and (43)Gap26) almost abolished relaxation to BK (R(max) = 12.2 +/- 3.7%). In arteries incubated with l-NAME and indomethacin, the addition of either (37,43)Gap27 or (40)Gap27 had no significant effect on R(max), whereas (43)Gap26 caused marked inhibition (R(max) = 21 +/- 6.4%, P = 0.005 vs. l-NAME plus indomethacin alone) that was similar to that of the triple combination. Endothelium-independent vasorelaxation was unaffected by CMPs, l-NAME, or indomethacin. Immunohistochemistry demonstrated Cx37, Cx40, and Cx43 expression in the endothelium and vascular smooth muscle. In pregnant women, EDHF-mediated vasorelaxation of subcutaneous resistance arteries is dependent on Cx43 and gap junctions.
    AJP Heart and Circulatory Physiology 03/2007; 292(2):H1026-32. · 4.01 Impact Factor
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    ABSTRACT: Sex related differences in cardiovascular function have been reported in oestrogen receptor beta knockout (ERbetaKO) mice. In this study we examined the role of endothelium-derived hyperpolarizing factor (EDHF) in differences in small artery endothelial function between ERbetaKO and wild-type (WT) mice. Small femoral arteries were isolated from ERbetaKO and WT mice and mounted on a wire myograph. Concentration-response curves to ACh were compared before and after incubation with inhibitors of nitric oxide (NO) and prostacyclin (PGI2) synthesis. Comparison of the expression of the principal vascular connexins (Cx37, 40 and 43), implicated in EDHF-mediated dilatation were undertaken by immunohistochemistry. Vascular ultrastructure was studied by transmission and scanning electron microscopy. ACh-induced relaxation of arteries (< 200 microm internal diameter) was greater in WT females versus males and was attributable to a greater EDHF component of relaxation. This sex difference was absent in ERbetaKO mice. Arteries from ERbetaKO males (but not females) were more sensitive to ACh compared to WT. The pharmacological evidence and morphological prerequisite for involvement of gap junctions in EDHF-mediated responses was confirmed in male arteries. The absence of ERbeta had no influence on expression of main Cx subtypes within vascular wall or on ultrastructure and morphology of the endothelium. The data suggest that in WT male mice, ERbeta reduces EDHF-mediated relaxation through gap junction communication.
    The Journal of Physiology 01/2007; 577(Pt 3):945-55. · 4.38 Impact Factor
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    ABSTRACT: The aim of this study was to investigate acute vasodilator responses to phytoestrogens and selective estrogen receptor-alpha (ERalpha) agonist in isolated small arteries from men with established coronary heart disease (CHD) and with a history of myocardial infarction versus healthy male control subjects. As to methodology, small arteries obtained from subcutaneous fat biopsies and mounted on a wire myograph were preconstricted with norepinephrine, and dilator responses to increasing nanomolar-micromolar concentrations of the phytoestrogens resveratrol and genistein (predominantly ERbeta agonists) and to propyl-[1H]-pyrazole-1,3,5-triyl-trisplenol (PPT, a selective ERalpha agonist) were determined. These were compared with responses to reference compound 17beta-estradiol (17beta-E2). Concentration-response curves were constructed before and after nitric oxide (NO) synthase inhibition with Nomega-nitro-L-arginine methyl ester. As a result, relaxation induced by the investigated compounds was similar in men with CHD and control men, but in both groups PPT and genistein-induced relaxation was greater than that of resveratrol and 17beta-E2. NO contributed to both phytoestrogens and PPT-induced relaxation but not to 17beta-E2 responses in arteries from control men. This NO-mediated component of relaxation was absent in arteries from men with established CHD. In conclusion, phytoestrogens, at concentrations achievable by ingestion of phytoestrogen-rich food products, evoke dilatation ex vivo of small peripheral arteries from normal men and those with established CHD. The contribution of NO to dilatory responses by these compounds is pertinent to arteries from control males, whereas other NO-independent dilatory mechanism(s) are involved in arteries from CHD.
    AJP Heart and Circulatory Physiology 06/2006; 290(5):H1969-75. · 4.01 Impact Factor
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    ABSTRACT: Estrogen receptor-beta knockout mice become hypertensive as they age, and males have a higher blood pressure than females. We hypothesized that the absence of estrogen receptor-beta may contribute to development of cardiovascular dysfunction by modification of adrenergic responsiveness in the peripheral vasculature. Small femoral arteries (internal diameter <200 microm) were isolated from estrogen receptor-beta knockout and wild-type mice and mounted on a wire myograph. Concentration-response curves to phenylephrine and norepinephrine were compared and the contribution of adrenoceptor subtypes established using specific agonists and antagonists. The involvement of endothelial factors in the modulation of resting tone was also investigated and immunohistochemical analysis used to confirm the presence or absence of estrogen receptor expression. Compared with wild type, arteries from estrogen receptor-beta knockout male, but not female, mice demonstrated gender-specific enhancement of the response to phenylephrine (alpha1-adrenoceptor agonist), which was accompanied by elevated basal tension attributable to endothelial factors. Contractile responses to the mixed adrenoceptor agonist norepinephrine did not differ significantly between estrogen receptor-beta knockout and wild type; however, beta-adrenoceptor inhibition unmasked an enhanced underlying alpha1-adrenoceptor responsiveness in estrogen receptor-beta knockout males. beta-adrenoceptor-mediated dilatation was also enhanced in estrogen receptor-beta knockout versus wild-type males. We suggest that estrogen receptor-beta modifies the adrenergic control of small artery tone in males but not in females.
    Hypertension 12/2005; 46(5):1163-8. · 6.87 Impact Factor
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    Leonid Luksha, Karolina Kublickiene
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    ABSTRACT: Several clinical conditions related to women's cardiovascular health strongly correlates with endothelial dysfunction, which is conventionally associated with alterations in synthesis, release or bioavailability of endothelium-derived nitric oxide (NO). Current review pays attention to rapidly growing evidence about the importance of Endothelium-Derived Hyperpolarizing Factor (EDHF). EDHF-mediated action is pertinent to resistance circulation where EDHF overcomes NO contribution, while in large conduit vessels endothelium-dependent dilatation is predominantly conferred by NO. This indicates that changes in synthesis, release, or pharmacological manipulation of EDHF is of critical importance in the maintenance of organ perfusion, peripheral resistance and blood pressure, the disturbances in which distinctively predispose the development of cardiovascular disorders. This review describes current knowledge about EDHF, including nature and characterization of its action, alterations in the mechanisms of EDHF contribution to endothelium-dependent relaxation with particular focus on preeclampsia, gender differences and cardiovascular complications after menopause. The distinction in the relative contribution of NO versus EDHF and estrogen-related regulation of EDHF-mediated responses are highlighted. The indications that EDHF-mediated response accounts for different chemical mediator or electrical transmission depending on species, vascular bed and healthy or diseased condition are discussed paying attention to women's cardiovascular health and future therapeutic implications.
    Current Women's Health Reviews. 01/2005; 1(1).
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    ABSTRACT: We studied the importance of endothelium-derived hyperpolarizing factor (EDHF) vs. nitric oxide (NO) and prostacyclin (PGI(2)) in bradykinin (BK)-induced relaxation in isolated small subcutaneous arteries from normal pregnant women. We also explored the contribution of cytochrome P-450 (CYP450) product of arachidonic acid (AA) metabolism, hydrogen peroxide (H(2)O(2)), and gap junctions that have been suggested to be involved in EDHF-mediated responses. Isolated arteries obtained from subcutaneous fat biopsies of normal pregnant women (n = 30) undergoing planned cesarean section were mounted in a wire-myography system. In norepinephrine-constricted vessels, incubation with N(G)-nitro-L-arginine methyl ester (L-NAME) resulted in a significant reduction in relaxation to BK. Simultaneous incubation with L-NAME and indomethacin failed to modify this response further. BK-mediated dilatation in the presence of K(+)-modified solution was decreased to similar level as obtained after incubation with L-NAME. Incubation with L-NAME abolished BK-induced responses in K(+)-modified solution. Sulfaphenazole, a specific inhibitor of CYP450 epoxygenase, and catalase (an enzyme that decomposes H(2)O(2)) did not affect the EDHF-mediated relaxation because concentration-response curves to BK were similar in arteries after incubation with L-NAME vs. L-NAME + sulfaphenazole and L-NAME + catalase. The inhibitor of gap junctions, 18 alpha-glycyrrhetinic acid, significantly reduced BK-mediated relaxation both without and with incubation with L-NAME. We found that both NO and EDHF, but not PGI(2), are involved in the endothelium-dependent dilatation to BK. BK-induced relaxation is almost equally mediated by NO and EDHF. CYP450 epoxygenase metabolites of AA or H(2)O(2) do not account for EDHF-mediated response; however, gap junctions are involved in the EDHF-mediated responses to BK in subcutaneous small arteries in normal pregnancy.
    AJP Regulatory Integrative and Comparative Physiology 07/2004; 286(6):R1102-9. · 3.28 Impact Factor

Publication Stats

146 Citations
31.98 Total Impact Points

Institutions

  • 2005–2011
    • Karolinska University Hospital
      • Department of Obstetrics and Gynecology
      Tukholma, Stockholm, Sweden
  • 2008
    • University of Vermont
      Burlington, Vermont, United States
  • 2007
    • Karolinska Institutet
      • Institutionen för klinisk vetenskap, intervention och teknik
      Solna, Stockholm, Sweden
    • The University of Edinburgh
      • Centre for Cardiovascular Science
      Edinburgh, SCT, United Kingdom
  • 2004
    • Akademiska Sjukhuset
      Uppsala, Uppsala, Sweden