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Zsirai L, Kun A, Visolyi GÁ, Svébis MM, Domján BA, Tabák Á. Birthweight trends and their explanatory factors in Hungary between 1999 and 2018: an analysis of the Hungarian Tauffer registry. Reprod Health 2024; 21:52. [PMID: 38609984 PMCID: PMC11015640 DOI: 10.1186/s12978-024-01787-0] [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] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 04/05/2024] [Indexed: 04/14/2024] Open
Abstract
BACKGROUND The increasing birthweight trend stopped and even reversed in several high income countries in the last 20 years, however the reason for these changes is not well characterized. We aimed to describe birthweight trends of term deliveries in Hungary between 1999 and 2018 and to investigate potential maternal and foetal variables that could drive these changes. METHODS We analysed data from the Hungarian Tauffer registry, a compulsory anonymized data collection of each delivery. We included all singleton term deliveries in 1999-2018 (n = 1,591,932). We modelled birthweight trends separately in 1999-2008 and 2008-2018 in hierarchical multiple linear regression models adjusted for calendar year, newborn sex, maternal age, gestational age at delivery, and other important determinants. RESULTS Median birthweights increased from 3250/3400 g (girl/boy) to 3300/3440 g from 1999 to 2008 and decreased to 3260/3400 g in 2018. When we adjusted for gestational age at delivery the increase in the first period became more pronounced (5.4 g/year). During the second period, similar adjustment substantially decreased the rate of decline from 2.5 to 1.4 g/year. Further adjustment for maternal age halved the rate of increase to 2.4 g/year in the first period. During the second period, adjustment for maternal age had little effect on the estimate. CONCLUSIONS Our findings of an increasing birthweight trend (mostly related to the aging of the mothers) in 1999-2008 may forecast an increased risk of cardiometabolic diseases in offsprings born in this period. In contrast, the decreasing birthweight trends after 2008 may reflect some beneficial effects on perinatal morbidity. However, the long-term effect cannot be predicted, as the trend is mostly explained by the shorter pregnancies.
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Affiliation(s)
- László Zsirai
- Department of Gynaecology and Family Planning, Istenhegyi GeneDiagnostic Center, Budapest, Hungary
| | - Attila Kun
- Department of Obstetrics and Gynaecology, Tolna County Balassa János Hospital, Szekszárd, Hungary
- Outpatient Department of Obstetrics and Gynecology, Paks Health Centre, Paks,, Hungary
| | - Gergely Á Visolyi
- Károly Rácz School of PhD Studies, Semmelweis University, Budapest, Hungary
- Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, 26 Üllői Str., Budapest, H-1085, Hungary
- Bajcsy-Zsilinszky Teaching Hospital, Budapest, Hungary
| | - Márk M Svébis
- Károly Rácz School of PhD Studies, Semmelweis University, Budapest, Hungary
- Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, 26 Üllői Str., Budapest, H-1085, Hungary
| | - Beatrix A Domján
- Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, 26 Üllői Str., Budapest, H-1085, Hungary
| | - Ádám Tabák
- Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, 26 Üllői Str., Budapest, H-1085, Hungary.
- UCL Brain Sciences, University College London, London, UK.
- Department of Public Health, Semmelweis University Faculty of Medicine, Budapest, Hungary.
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Comerma-Steffensen S, Kun A, Prat-Duran J, Mogensen S, Alan Albayrak E, Fais R, Munro G, Peters D, Simonsen U. A novel reuptake inhibitor, IP2015, induces erection by increasing central dopamine and peripheral nitric oxide release. Br J Pharmacol 2024. [PMID: 38604613 DOI: 10.1111/bph.16362] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/07/2024] [Accepted: 02/12/2024] [Indexed: 04/13/2024] Open
Abstract
BACKGROUND AND PURPOSE An estimated 40% of patients with erectile dysfunction have a poor prognosis for improvement with currently available treatments. The present study investigated whether a newly developed monoamine transport inhibitor, IP2015, improves erectile function. EXPERIMENTAL APPROACH We investigated the effects of IP2015 on monoamine uptake and binding, erectile function in rats and diabetic mice and the effect on corpus cavernosum contractility. KEY RESULTS IP2015 inhibited the uptake of 5-HT, noradrenaline and dopamine by human monoamine transporters expressed in cells and in rat brain synaptosomes. Intracavernosal pressure measurement in anaesthetized rats revealed that IP2015 dose-dependently increased the number and the duration of spontaneous erections. Whereas pretreatment with the dopamine D2-like receptor antagonists, clozapine and (-)-sulpiride, or cutting the cavernosal nerve inhibited IP2015-induced erectile responses, the phosphodiesterase type 5 inhibitor sildenafil further enhanced the IP2015-mediated increase in intracavernosal pressure. IP2015 also increased the number of erections in type 2 diabetic db/db mice. Direct intracavernosal injection of IP2015 increased penile pressure, and in corpus cavernosum strips, IP2015 induced concentration-dependent relaxations. These relaxations were enhanced by sildenafil and blunted by endothelial cell removal, a nitric oxide synthase inhibitor, NG-nitro-l-arginine and a D1-like receptor antagonist, SCH23390. Quantitative polymerase chain reaction (qPCR) showed the expression of the dopamine transporter in the rat corpus cavernosum. CONCLUSION AND IMPLICATIONS Our findings suggest that IP2015 stimulates erectile function by a central mechanism involving dopamine reuptake inhibition and direct NO-mediated relaxation of the erectile tissue. This novel multi-modal mechanism of action could offer a new treatment approach to erectile dysfunction.
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Affiliation(s)
- Simon Comerma-Steffensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Department of Biomedical Sciences/Animal Physiology, Faculty of Veterinary, Central University of Venezuela, Caracas, Venezuela
- Initiator Pharma A/S, Copenhagen, Denmark
| | - Attila Kun
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Judit Prat-Duran
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Susie Mogensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Elif Alan Albayrak
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Department of Pharmacology, Faculty of Pharmacy, Ege University, Izmir, Türkiye
| | - Rafael Fais
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Division of Pulmonary, Critical Care, Sleep and Occupational Medicine, Indiana University School of Medicine, Indianapolis, Indiana, USA
| | | | - Dan Peters
- Initiator Pharma A/S, Copenhagen, Denmark
- DanPET AB, Malmö, Sweden
| | - Ulf Simonsen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
- Initiator Pharma A/S, Copenhagen, Denmark
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Visolyi GÁ, Kun A, Szalai O, Svébis MM, Domján BA, Zsirai L, Tabák ÁG. Pregnancy outcomes of women with untreated 'mild' gestational diabetes (gestational diabetes by the WHO 2013 but not by the WHO-1999 diagnostic criteria) - A population-based cohort study. Diabetes Res Clin Pract 2023; 203:110874. [PMID: 37579993 DOI: 10.1016/j.diabres.2023.110874] [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] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2023] [Revised: 08/01/2023] [Accepted: 08/11/2023] [Indexed: 08/16/2023]
Abstract
AIMS We compared pregnancy outcomes of untreated 'mild' GDM (GDM by WHO 2013 but not by WHO-1999) to normal glucose tolerant women (NGT). METHODS In a universal screening program 4333 pregnant women had a 3-point 75 g OGTT in Hungary in 2009-2013. By WHO-2013 untreated NGT was diagnosed in n = 3303, 'mild' GDM in n = 336 cases. RESULTS 'Mild' GDM women were older (mean difference, SE: 1.4, 0.3 yrs), had higher fasting (1.0, 0.02), 60-minute (1.0, 0.09), and 120-minute (0.4, 0.06 mmol/l) blood glucose, and blood pressure (2.6, 0.5/2.0, 0.5 mmHg). Weight gain was similar in both groups (-0.3, 0.3 kg). GDM newborns were heavier (142, 50 g) and were more frequently macrosomic (>4000 g, OR 1.85, 95 %CI 1.35-2.54). Hypertension during pregnancy was more prevalent in the GDM group (OR 1.55, 95 %CI 1.05-2.28), as well as induced (OR 1.38, 95 %CI 1.10-1.74) and instrumental delivery (OR 1.34, 95 %CI 1.07-1.68), and acute caesarean section (OR 1.32, 95 %CI 1.04-1.64). Most of these differences substantially attenuated or became non-significant after adjustment for pre-pregnancy BMI. CONCLUSIONS Pregnancy outcomes of 'mild' GDM were worse compared to normal glucose tolerant women however these differences were explained by the pre-pregnancy BMI difference between groups.
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Affiliation(s)
- Gergely Á Visolyi
- Károly Rácz School of PhD Studies, Semmelweis University, Budapest, Hungary; Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, Budapest, Hungary.
| | - Attila Kun
- Tolna County Balassa János Hospital, Department of Obstetrics and Gynaecology, Szekszárd, Hungary
| | | | - Márk M Svébis
- Károly Rácz School of PhD Studies, Semmelweis University, Budapest, Hungary; Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, Budapest, Hungary
| | - Beatrix A Domján
- Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, Budapest, Hungary
| | - László Zsirai
- Department of Gynecology and Family Planning, Istenhegyi GeneDiagnostic Center, Hungary
| | - Ádám G Tabák
- Department of Internal Medicine and Oncology, Semmelweis University Faculty of Medicine, Budapest, Hungary; UCL Brain Sciences, University College London, London, United Kingdom; Department of Public Health, Semmelweis University Faculty of Medicine, Budapest, Hungary.
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Comerma-Steffensen S, Kun A, Hedegaard ER, Mogensen S, Aalkjaer C, Köhler R, Mønster Christensen B, Simonsen U. Down-regulation of K Ca2.3 channels causes erectile dysfunction in mice. Sci Rep 2017. [PMID: 28630432 PMCID: PMC5476588 DOI: 10.1038/s41598-017-04188-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
Modulation of endothelial calcium-activated K+ channels has been proposed as an approach to restore arterial endothelial cell function in disease. We hypothesized that small-conductance calcium-activated K+ channels (KCa2.3 or SK3) contributes to erectile function. The research was performed in transgenic mice with overexpression (KCa2.3T/T(−Dox)) or down-regulation (KCa2.3T/T(+Dox)) of the KCa2.3 channels and wild-type C57BL/6-mice (WT). QPCR revealed that KCa2.3 and KCa1.1 channels were the most abundant in mouse corpus cavernosum. KCa2.3 channels were found by immunoreactivity and electron microscopy in the apical-lateral membrane of endothelial cells in the corpus cavernosum. Norepinephrine contraction was enhanced in the corpus cavernosum of KCa2.3T/T(+Dox)versus KCa2.3T/T(−Dox) mice, while acetylcholine relaxation was only reduced at 0.3 µM and relaxations in response to the nitric oxide donor sodium nitroprusside were unaltered. An opener of KCa2 channels, NS309 induced concentration-dependent relaxations of corpus cavernosum. Mean arterial pressure was lower in KCa2.3T/T(−Dox) mice compared with WT and KCa2.3T/T(+Dox) mice. In anesthetized mice, cavernous nerve stimulation augmented in frequency/voltage dependent manner erectile function being lower in KCa2.3T/T(+Dox) mice at low frequencies. Our findings suggest that down-regulation of KCa2.3 channels contributes to erectile dysfunction, and that pharmacological activation of KCa2.3 channels may have the potential to restore erectile function.
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Affiliation(s)
- Simon Comerma-Steffensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark.
| | - Attila Kun
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Elise R Hedegaard
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | - Susie Mogensen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
| | | | - Ralf Köhler
- Aragon Agency for Investigation and Development (ARAID), Translational Research Unit, Miguel Servet University Hospital, Zaragoza, Spain
| | | | - Ulf Simonsen
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, Aarhus University, Aarhus, Denmark
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Kun A, Tornóczky J. [The myo-inositol is beneficial in the therapy of pregnancy with insulin-dependent type 2 diabetes and polycystic ovary syndrome]. Orv Hetil 2017; 158:541-545. [PMID: 28366078 DOI: 10.1556/650.2017.30595] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Authors would like to demonstrate the beneficial effect of myo-inositol supplementation in a pregnant woman with insulin-dependent type 2 diabetes mellitus and polycystic ovary syndrome. Insulin and metformin treatment could not achieve normalization of glucose homeostasis for 3 years, and hypoglycemic episodes were frequent. Myo-inositol and folic acid supplementation added to the basic treatment resulted in improved glucose levels in 2 months. At this time she became pregnant. During pregnancy serum glucose levels still improved in the next 2 months. The amniotic membrane ruptured at the 19th gestational week, and pregnancy had to be finished. Developmental disturbances were excluded by the pathologist. She became pregnant again and gave birth to a premature male neonate at the 29th gestational week. The aim of the report was to demonstrate that myo-inositol supplementation may improve the efficacy of the therapy in type 2 diabetes mellitus. Orv. Hetil., 2017, 158(14), 541-545.
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Affiliation(s)
- Attila Kun
- Szülészet-Nőgyógyászat Osztály, Tolna Megyei Balassa János Kórház Szekszárd, Béri B. Á. u. 5-7., 7100
| | - János Tornóczky
- Megyei Diabétesz Gondozó, Tolna Megyei Balassa János Kórház Szekszárd
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Kun A, Tornóczky J. The importance of determining C-peptide level for forecasting the therapy of gestational diabetes mellitus. Eur J Obstet Gynecol Reprod Biol 2016. [DOI: 10.1016/j.ejogrb.2016.07.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Hedegaard ER, Nielsen BD, Kun A, Hughes AD, Krøigaard C, Mogensen S, Matchkov VV, Fröbert O, Simonsen U. KV 7 channels are involved in hypoxia-induced vasodilatation of porcine coronary arteries. Br J Pharmacol 2014; 171:69-82. [PMID: 24111896 DOI: 10.1111/bph.12424] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2013] [Revised: 07/08/2013] [Accepted: 09/04/2013] [Indexed: 12/14/2022] Open
Abstract
BACKGROUND AND PURPOSE Hypoxia causes vasodilatation of coronary arteries, but the underlying mechanisms are poorly understood. We hypothesized that hypoxia reduces intracellular Ca(2+) concentration ([Ca(2+)](i)) by opening of K channels and release of H₂S. EXPERIMENTAL APPROACH Porcine coronary arteries without endothelium were mounted for measurement of isometric tension and [Ca(2+)](i), and the expression of voltage-gated K channels K(V)7 channels (encoded by KCNQ genes) and large-conductance calcium-activated K channels (K(Ca)1.1) was examined. Voltage clamp assessed the role of K(V)7 channels in hypoxia. KEY RESULTS Gradual reduction of oxygen concentration from 95 to 1% dilated the precontracted coronary arteries and this was associated with reduced [Ca(2+)](i) in PGF(2α) (10 μM)-contracted arteries whereas no fall in [Ca(2+)](i) was observed in 30 mM K-contracted arteries. Blockers of ATP-sensitive voltage-gated potassium channels and K(Ca)1.1 inhibited hypoxia-induced dilatation in PGF2α -contracted arteries; this inhibition was more marked in the presence of the K(v)7 channel blockers, XE991 and linopirdine, while a K(V)7.1 blocker, failed to change hypoxic vasodilatation. XE991 also inhibited H₂S- and adenosine-induced vasodilatation. PCR revealed the expression of K(V)7.1, K(V)7.4, K(V)7.5 and K(Ca)1.1 channels, and K(Ca)1.1, K(V)7.4 and K(V)7.5 were also identified by immunoblotting. Voltage clamp studies showed the XE991-sensitive current was more marked in hypoxic conditions. CONCLUSION The K(V)7.4 and K(V)7.5 channels, which we identified in the coronary arteries, appear to have a major role in hypoxia-induced vasodilatation. The voltage clamp results further support the involvement of K(V)7 channels in this vasodilatation. Activation of these K(V)7 channels may be induced by H₂S and adenosine.
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Affiliation(s)
- E R Hedegaard
- Department of Biomedicine, Pulmonary and Cardiovascular Pharmacology, University of Aarhus, Aarhus, Denmark
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Kun A, Seprényi G, Varró A, Papp JG, Pataricza J. Neurogenic contraction induced by the antiarrhythmic compound, AVE 0118, in rat small mesenteric arteries. Basic Clin Pharmacol Toxicol 2014; 115:315-20. [PMID: 24629214 DOI: 10.1111/bcpt.12225] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2013] [Accepted: 02/21/2014] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to investigate the vasoactivity of two inhibitors of potassium ion (K(+) ) channels, a potential antiarrhythmic compound, AVE 0118, and 4-aminopyridine (4-AP). Basal and stimulated tones of rat small mesenteric arteries as well as the possible involvement of KV 1.5 ion channel in the mechanism of vascular effect induced by the compounds were analysed. The standard organ bath technique for vascular tone and immunohistochemistry for the localization of ion channels in the arterial tissue were performed. Third- or fourth-order branch of arterial segments was mounted in myographs for recording the isometric tension. AVE 0118 (10(-5) M) and 4-AP (10(-5) M) modulated neither the basal tone nor the contraction induced by noradrenaline but increased the contraction evoked by electrical field stimulation, sensitive to the block of alpha-1 adrenergic receptors. KV 1.5 ion channel-specific immunostaining demonstrated the presence of immunoreactive nerves, and Schwann-cell-specific (S100) immunostaining confirmed the presence of myelin sheath in rat small mesenteric arteries. The study supports an indirect, sympathetic effect of AVE 0118 similar to that of 4-AP, which is mediated, at least in part, by blocking neuronal KV 1.5 type potassium ion channels in the medio-adventitial layer of rat small mesenteric artery.
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Affiliation(s)
- Attila Kun
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
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Killyeni A, Nicoara A, Canpean V, Kun A, Astilean S, Popescu I. S-acetyl-calix[8]arene adsorption on polycrystalline Au surface: A kinetic study. Electrochim Acta 2013. [DOI: 10.1016/j.electacta.2013.04.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Király I, Pataricza J, Bajory Z, Simonsen U, Varro A, Papp JG, Pajor L, Kun A. Involvement of large-conductance Ca(2+) -activated K(+) channels in both nitric oxide and endothelium-derived hyperpolarization-type relaxation in human penile small arteries. Basic Clin Pharmacol Toxicol 2013; 113:19-24. [PMID: 23414060 DOI: 10.1111/bcpt.12059] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 01/28/2013] [Indexed: 12/01/2022]
Abstract
Large-conductance Ca(2+) -activated K(+) channels (BKC a ), located on the vascular smooth muscle, play an important role in regulation of vascular tone. In penile corpus cavernosum tissue, opening of BKC a channels leads to relaxation of corporal smooth muscle, which is essential during erection; however, there is little information on the role of BKC a channels located in penile vascular smooth muscle. This study was designed to investigate the involvement of BKC a channels in endothelium-dependent and endothelium-independent relaxation of human intracavernous penile arteries. In human intracavernous arteries obtained in connection with transsexual operations, change in isometric force was recorded in microvascular myographs, and endothelium-dependent [nitric oxide (NO) and endothelium-derived hyperpolarization (EDH)-type] and endothelium-independent (NO-donor) relaxations were measured in contracted arteries. In penile small arteries contracted with phenylephrine, acetylcholine evoked NO- and EDH-type relaxations, which were sensitive to iberiotoxin (IbTX), a selective blocker of BKC a channels. Iberiotoxin also inhibited relaxations induced by a NO-donor, sodium nitroprusside. NS11021, a selective opener of BKC a channels, evoked pronounced relaxations that were inhibited in the presence of IbTX. NS13558, a BKC a -inactive analogue of NS11021, failed to relax human penile small arteries. Our results show that BKC a channels are involved in both NO- and EDH-type relaxation of intracavernous penile arteries obtained from healthy men. The effect of a selective opener of BKC a channels also suggests that direct activation of the channel may be an advantageous approach for treatment of impaired endothelium-dependent relaxation often associated with erectile dysfunction.
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Affiliation(s)
- István Király
- Department of Urology, University of Szeged, Szeged, Hungary
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Buki K, Kirsten E, Bauer P, Vidair C, Kun A, Mendeleyev J, Kun E. Inhibition of migration of MDA-MB-231 cells by methyl-3,5-diiodo-4-(4'-methoxyphenoxy)benzoate (DIME). Int J Oncol 2012; 11:1247-50. [PMID: 21528330 DOI: 10.3892/ijo.11.6.1247] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The GTPase activity of purified dimeric tubulin (alpha+beta) at 5 mu M was insensitive to methyl-3,5-diiodo-4-(4'-methoxyphenoxy) benzoate (DIME), in contrast to nocodazole which activated GTPase. Cellular motility of MDA-MB-231 (human mammary cancer) cells migrating through 12-mu m pores was inhibited by DIME similar to nocodazole in a drug concentration-and DIME structure-dependent manner. An increase of cytoplasmic ATPase activity of DIME-treated cells without a decrease in ATP contents of intact cells suggests that DIME may also influence additional as yet unidentified ATP-dependent system(s) probably also involved in cell motility. These results show that DIME not only arrests cells in M phase but also inhibits cell motility in interphase. However the cellular mode of action of DIME is different from the action of other toxic tubulin-targeted drugs, despite the fact that DIME in a concentration-dependent manner disrupts microtubule structures in intact cells.
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Affiliation(s)
- K Buki
- SAN FRANCISCO STATE UNIV,LAB ENVIRONM TOXICOL & CHEM,OCTAMER RES FDN,ROMBERG TIBURON CTR,TIBURON,CA 94920
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Schjørring O, Kun A, Flyvbjerg A, Kirkeby HJ, Jensen JB, Simonsen U. Flow‐Evoked Vasodilation Is Blunted in Penile Arteries from Zucker Diabetic Fatty Rats. J Sex Med 2012; 9:1789-800. [DOI: 10.1111/j.1743-6109.2012.02743.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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Ambrus N, Szolnoky J, Pollesello P, Kun A, Varró A, Papp JG, Pataricza J. Prolonged Antispasmodic Effect in Isolated Radial Artery Graft and Pronounced Platelet Inhibition Induced by the Inodilator Drug, Levosimendan. Basic Clin Pharmacol Toxicol 2011; 110:269-74. [DOI: 10.1111/j.1742-7843.2011.00801.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Abstract
There are conflicting results regarding the frequency of gestational diabetes (GDM) in Hungary. The aim of this study was to estimate the prevalence of GDM and to clarify the association between selected maternal characteristics and GDM risk. In a population-based screening program of GDM in Tolna County, Hungary, 75 g OGTTs were offered to all pregnant women between 24-28 weeks of gestation and evaluated according to WHO criteria in 2000 (WHO GDM). Women were also classified based on the IADPSG criteria (IADPSG GDM). Selected risk factors were recorded by district nurses. OGTT results were available for 1,835 (81.2%) pregnancies out of 2,261. Altogether 159 (8.7%) were diagnosed as WHO GDM and 304 (16.6%) as IADPSG GDM. Gestational diabetes was related to older age, higher BMI, and an increasing number of deliveries (all p<0.005). The risk of IADPSG GDM monotonously increased with age, -pre-pregnancy BMI and number of deliveries. The risk of WHO GDM increased linearly with age, however, women with the highest BMI (≥ 29.2 kg/m2) had decreased risk compared to women with a BMI of 26.1-29.1 kg/m2 (p<0.05). There was an inverse U-shaped association between GDM risk and number of deliveries with the highest risk observed in those with 3 deliveries (p quadratic term=0.008). We found a high prevalence of GDM in this Caucasian Hungarian population. Our results suggest that pre-pregnancy BMI and previous deliveries elevate the risk of WHO GDM only to a certain level, above which the risk decreases.
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Affiliation(s)
- A Kun
- Tolna County Balassa János Hospital, Department of Obstetrics and Gynaecology, Szekszárd, Hungary.
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Kun A. Insulin resistance is associated with gestational hypertension and not with preeclampsia: a population-based screening study. Gynecol Obstet Invest 2010; 71:256-61. [PMID: 21160156 DOI: 10.1159/000320326] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Accepted: 08/11/2010] [Indexed: 12/25/2022]
Abstract
AIMS To investigate the relationship between insulin resistance (IR) and subsequent gestational hypertension (GH) or preeclampsia (PE) in normoglycemic and in gestational diabetic pregnant women. Furthermore, we tested whether this association was independent of the prepregnancy body mass index (BMI). METHODS Each participant underwent a 75-gram oral glucose tolerance test (OGTT) according to World Health Organization recommendation criteria with determination of serum glucose and C-peptide concentrations. IR was determined as a C-peptide-to-glucose ratio at the fasting (FCGR) state and at 2 h (2CGR) after load. RESULTS A total of 2,954 women were included with a singleton pregnancy, delivery at term, no chronic hypertension, and data on both glucose and C-peptide. Of these women, 183 (6.2%) developed GH and 49 (1.7%) PE. Gestational diabetes mellitus (GDM) was diagnosed in 6.0% of the participants. The FCGR and 2CGR were significantly higher in all women with GH, irrespective of their BMI, compared to the normotensive group; however, the PE and the normotensive groups had similar FCGR and 2CGR values. CONCLUSIONS The present study suggests that IR at the OGTT is associated with the later development of GH; on the other hand, it is not associated with PE. These relationships are independent of the maternal BMI.
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Affiliation(s)
- Attila Kun
- Department of Obstetrics and Gynecology, Tolna County Balassa János Hospital, Szekszárd, Hungary. drkun.attila @ gmail.com
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Pataricza J, Szolnoky J, Krassói I, Hegedus Z, Kun A, Varró A, Papp JG. Vasorelaxing effect of levosimendan against 5-hydroxytryptamine-induced contractions in isolated human conduit bypass grafts. J Pharm Pharmacol 2010; 58:1107-12. [PMID: 16872558 DOI: 10.1211/jpp.58.8.0012] [Citation(s) in RCA: 6] [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] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
Abstract
Levosimendan is a novel inodilator drug developed for the treatment of heart failure. The possible vasodilating property of the drug in human coronary artery bypass grafts was investigated. Isometric tensions of the left internal thoracic artery (LITA, n = 8) as well as the proximal and distal segments of the radial artery (RA, n = 8 and 8) were measured in isolated organ baths. Concentration-relaxation curves for levosimendan (0.009-1.14 μmol L−1) were obtained against 5-hydroxytryptamine (5-HT; serotonin, 0.002–9.3 μmol L 1)-induced contractions. 5-HT-induced contraction of LITA was considerably smaller than that of the proximal and distal RAs. Levosimendan relaxed the grafts in the following order of calculated maximum efficacies (Emax): LITA > proximal RA > distal RA (LITA 100.3 ±16.2% of 5-HT-induced maximum tension, proximal RA 86.9 ±8.6%, distal RA 59.4 ± 17.5%, P < 0.05 LITA vs distal RA). The potency values of levosimendan, expressed as the negative logarithm of 50% effective concentrations (pD2), were comparable in the three bypass grafts (LITA −6.52 ± 0.44 log mol L−1, proximal RA −6.60 ± 0.49 log mol L−1, distal RA −6.85 ± 0.45 log mol L−1). The results suggest that levosimendan is an effective vasorelaxant of conduit bypass grafts and may serve as a new therapeutic tool, especially in the case of LITA and proximal RA grafts, for relieving perioperative spasm and subsequent graft failure.
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Affiliation(s)
- János Pataricza
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary
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Biró LP, Kertész K, Horváth E, Márk GI, Molnár G, Vértesy Z, Tsai JF, Kun A, Bálint Z, Vigneron JP. Bioinspired artificial photonic nanoarchitecture using the elytron of the beetle Trigonophorus rothschildi varians as a 'blueprint'. J R Soc Interface 2009; 7:887-94. [PMID: 19933221 DOI: 10.1098/rsif.2009.0438] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
An unusual, intercalated photonic nanoarchitecture was discovered in the elytra of Taiwanese Trigonophorus rothschildi varians beetles. It consists of a multilayer structure intercalated with a random distribution of cylindrical holes normal to the plane of the multilayer. The nanoarchitectures were characterized structurally by scanning electron microscopy and optically by normal incidence, integrated and goniometric reflectance measurements. They exhibit an unsaturated specular and saturated non-specular component of the reflected light. Bioinspired, artificial nanoarchitectures of similar structure and with similar properties were realized by drilling holes of submicron size in a multilayer structure, showing that such photonic nanoarchitectures of biological origin may constitute valuable blueprints for artificial photonic materials.
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Affiliation(s)
- L P Biró
- Research Institute for Technical Physics and Materials Science, PO Box 49, H-1525 Budapest, Hungary.
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Nagy N, Szűts V, Horváth Z, Seprényi G, Farkas AS, Acsai K, Prorok J, Bitay M, Kun A, Pataricza J, Papp JG, Nánási PP, Varró A, Tóth A. Does small-conductance calcium-activated potassium channel contribute to cardiac repolarization? J Mol Cell Cardiol 2009; 47:656-63. [DOI: 10.1016/j.yjmcc.2009.07.019] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2009] [Revised: 06/19/2009] [Accepted: 07/16/2009] [Indexed: 11/27/2022]
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Kun A, Matchkov VV, Stankevicius E, Nardi A, Hughes AD, Kirkeby HJ, Demnitz J, Simonsen U. NS11021, a novel opener of large-conductance Ca(2+)-activated K(+) channels, enhances erectile responses in rats. Br J Pharmacol 2009; 158:1465-76. [PMID: 19845682 DOI: 10.1111/j.1476-5381.2009.00404.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
BACKGROUND AND PURPOSE Large-conductance Ca(2+)-activated K(+) channels (BK(Ca)), located on the arterial and corporal smooth muscle, are potential targets for treatment of erectile dysfunction (ED). This study investigated whether NS11021 (1-(3,5-Bis-trifluoromethyl-phenyl)-3-[4-bromo-2-(1H-tetrazol-5-yl)-phenyl]-thiourea), a novel opener of BK(Ca) channels, relaxes erectile tissue in vitro and enhances erectile responses in intact rats. The effects were compared with sildenafil, an inhibitor of phosphodiesterase type 5. EXPERIMENTAL APPROACH Patch clamp was used to record whole cell current in rat isolated corpus cavernosum smooth muscle cells (SMCs) and human umbilical vein endothelial cells (HUVECs). Isometric tension was measured in intracavernous arterial rings and corpus cavernosum strips isolated from rats and men, and simultaneous measurements of intracellular Ca(2+) concentration ([Ca(2+)](i)) and tension were performed in intracavernous arteries. Erectile response was measured in anaesthetized rats. KEY RESULTS In patch clamp recordings, NS11021 increased currents sensitive to the selective BK(Ca) channel blocker, iberiotoxin (IbTX) in SMCs, but did not modulate K(+) current in HUVECs. NS11021 reduced [Ca(2+)](i) and tension in penile arteries. IbTX inhibited the vasorelaxation induced by NS11021 and sildenafil in human erectile tissue. NS11021 and sildenafil but not vehicle increased erectile responses in anaesthetized rats, an effect which was abolished after pretreatment with tetraethylammonium. CONCLUSIONS AND IMPLICATIONS NS11021 leads to relaxation of both intracavernous arteries and corpus cavernosum strips primarily through opening of BK(Ca) channels. It is also effective in facilitating erectile responses in anaesthetized rats. These results suggest a potential for use of BK(Ca) openers in the treatment of ED.
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Affiliation(s)
- A Kun
- Department of Pharmacology, University of Aarhus, Denmark
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Pataricza J, Márton Z, Lengyel C, Tóth M, Papp JG, Varró A, Kun A. Potassium channels sensitive to combination of charybdotoxin and apamin regulate the tone of diabetic isolated canine coronary arteries. Acta Physiol (Oxf) 2008; 194:35-43. [PMID: 18394024 DOI: 10.1111/j.1748-1716.2008.01859.x] [Citation(s) in RCA: 4] [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: 11/28/2022]
Abstract
AIMS Functional roles of calcium-activated potassium channels on the mechanical activity of epicardial coronary arteries obtained from a canine model of diabetes were investigated. METHODS Coronary arteries were isolated from healthy, alloxan-diabetic and insulin-treated diabetic dogs. Basal tensions, contractions induced by the prostaglandin (PG) analogue, U46619, and endothelium-dependent relaxations to acetylcholine (ACh) were modified with charybdotoxin (CHTX) + apamin (APA), inhibitors of calcium-activated potassium channels, as well as with N(omega)-nitro-l-arginine (LNA) + indomethacin (INDO) to suppress the synthesis of nitric oxide (NO) and PGs. The relaxing effect of nitroprusside-sodium (SNP), an NO donor, was also determined. RESULTS In diabetic coronary arteries, CHTX + APA did not change while LNA + INDO elevated the basal tension. PG-induced contractions were enhanced by CHTX + APA and by LNA + INDO in all the three groups of animals. CHTX + APA decreased the maximal relaxations to ACh in a partly insulin-dependent manner. LNA + INDO abolished the endothelium-dependent relaxations to ACh. In diabetic coronary arteries, the sensitivity to SNP-induced relaxation was enhanced, insulin independently, suggesting that NO could be partly responsible for maintaining intact ACh-induced vasorelaxation. CONCLUSION In diabetic canine coronary artery, the vasomotor responses reflect up-regulation of calcium-activated potassium channels. This endothelial mechanism of the canine epicardial coronary artery may oppose vasoconstrictions in diabetic vascular tissue.
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Affiliation(s)
- J Pataricza
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Szeged, Hungary.
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Bartha S, Campetella G, Ruprecht E, Kun A, Házi J, Horváth A, Virágh K, Molnár Z. Will interannual variability in sand grassland communities increase with climate change? COMMUNITY ECOL 2008. [DOI: 10.1556/comec.9.2008.s.4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Kun A, Kiraly I, Pataricza J, Marton Z, Krassoi I, Varro A, Simonsen U, Papp JG, Pajor L. C-Type Natriuretic Peptide Hyperpolarizes and Relaxes Human Penile Resistance Arteries. J Sex Med 2008; 5:1114-1125. [DOI: 10.1111/j.1743-6109.2008.00775.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Acsai K, Kun A, Farkas AS, Fülöp F, Nagy N, Balázs M, Szentandrássy N, Nánási PP, Papp JG, Varró A, Tóth A. Effect of partial blockade of the Na(+)/Ca(2+)-exchanger on Ca(2+) handling in isolated rat ventricular myocytes. Eur J Pharmacol 2007; 576:1-6. [PMID: 17727839 DOI: 10.1016/j.ejphar.2007.07.047] [Citation(s) in RCA: 19] [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] [Received: 04/27/2007] [Revised: 07/19/2007] [Accepted: 07/23/2007] [Indexed: 11/30/2022]
Abstract
SEA0400 is a selective inhibitor of the Na(+)/Ca(2+) exchanger having equal potencies to suppress both the forward and reverse mode operation of the Na(+)/Ca(2+) exchanger. Present experiments were designed to study the effect of partial blockade of Na(+)/Ca(2+) exchanger on Ca(2+) handling in isolated rat ventricular myocytes. Intracellular Ca(2+) transient and cell shortening were measured in ventricular myocytes loaded with Fura-2-AM fluorescent dye. Partial blockade of Na(+)/Ca(2+) exchanger was induced by superfusion of the cells with SEA0400 at a concentration of 0.3 microM. Amplitude of the intracellular Ca(2+) transient and cell shortening was significantly increased by SEA0400 in both field stimulated and voltage clamped myocytes, without significant elevation of diastolic Ca(2+) level and the decay time constant of the Ca(2+) transient. In patch clamped myocytes the SEA0400 induced increase in the Ca(2+) transient and cell shortening was accompanied by significant reduction of peak L-type Ca(2+) current. These effects can be explained by the autoregulative nature of cardiac Ca(2+) handling, as the reduced Ca(2+) efflux from the cell results in an increased Ca(2+) load to the sarcoplasmic reticulum leading to increased Ca(2+) release, which in turn may decrease the L-type Ca(2+) current by accelaration of Ca(2+) dependent inactivation of L-type Ca(2+) current. Our results suggest that complex changes in the Ca(2+) cycling can occur after selective pharmacological inhibition of the Na(+)/Ca(2+) exchanger.
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Affiliation(s)
- Károly Acsai
- Division of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary.
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Márton Z, Pataricza J, Krassói I, Kun A, Varró A, Papp J. Effect of NEP enzyme inhibitor thiorphan on isolated systemic and coronary blood vessels. J Mol Cell Cardiol 2006. [DOI: 10.1016/j.yjmcc.2006.03.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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King RB, Silaghi-Dumitrescu I, Lupan A, Kun A. The shapes of hypoelectronic six-vertex anionic bare boron clusters: Effects of the countercations. Main Group Chemistry 2005. [DOI: 10.1080/10241220600798435] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Pataricza J, Márton Z, Hegedus Z, Krassói I, Kun A, Varró A, Papp JG. Role of calcium-activated potassium channels in the regulation of basal and agonist-elevated tones in isolated conduit arteries. ACTA ACUST UNITED AC 2004; 91:263-5. [PMID: 16438119 DOI: 10.1556/aphysiol.91.2004.3-4.9] [Citation(s) in RCA: 3] [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: 11/19/2022]
Abstract
Functional role of calcium-activated potassium (KCa) channels on the basal and agonist-elevated arterial tones was investigated in isolated rabbit aorta, porcine and canine coronary arteries as well as in human internal mammary artery. The vascular tones enhanced by contractile agents were increased further by preincubation of these conduit blood vessels with selective (charybdotoxin or iberiotoxin) or nonselective (tetraethylammonium) inhibitors of KCa channels. The basal tone (without an agonist) was increased only in the canine coronary artery. The results indicate a feed-back regulatory role of KCa channels counteracting the vasospasm of conduit arteries.
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Affiliation(s)
- J Pataricza
- Department of Pharmacology and Pharmacotherapy, University of Szeged, Hungary
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Kun A, Martinez AC, Tankó LB, Pataricza J, Papp JG, Simonsen U. Ca2+-activated K+ channels in the endothelial cell layer involved in modulation of neurogenic contractions in rat penile arteries. Eur J Pharmacol 2003; 474:103-15. [PMID: 12909201 DOI: 10.1016/s0014-2999(03)02004-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [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: 12/01/2022]
Abstract
The present study was designed to investigate the functional K+ channels involved in contractions induced by electrical field stimulation in isolated rat penile arteries. Blockers of Ca2+-activated K+ channels (KCa), tetraethylammonium, and of large-conductance KCa channels, charybdotoxin and iberiotoxin, as well as a blocker of voltage-dependent K+ channels (KV), 4-aminopyridine, increased resting tension in penile small arteries. In the presence of propranolol and NG-nitro-L-arginine (L-NOARG), electrical field stimulation evoked prazosin-sensitive contractions. In endothelium-intact preparations, these latter contractions were enhanced in the presence of tetraethylammonium and charybdotoxin. However, these blockers did not enhance contractions evoked by exogenously added noradrenaline. Endothelial cell removal increased the neurogenic contractions but tetraethylammonium had no further potentiating effect in these preparations. In the presence of an inhibitor of cyclooxygenase, indomethacin, and inhibitor of nitric oxide (NO) synthase, L-NOARG, acetylcholine evoked relaxations, which were abolished in the presence of either tetraethylammonium or charybdotoxin. In phenylephrine-contracted arteries treated with guanethidine and atropine, electrical field stimulation evoked relaxations, which were partially inhibited by L-NOARG and tetraethylammonium, without any additive effect of these drugs. These observations suggest that both large-conductance KCa channels and KV channels sensitive to iberiotoxin/tetraethylammonium and 4-aminopyridine, respectively, are directly involved in the modulation of myogenic tone of rat penile arteries. Furthermore, activation of endothelial intermediate-conductance KCa channels sensitive to tetraethylammonium and charybdotoxin leads to release of a non-NO nonprostanoid factor, which inhibits release of the neurotransmitter, noradrenaline, but these channels do not appear to be involved in inhibition of contraction evoked by exogenously applied noradrenaline in rat penile arteries.
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Affiliation(s)
- Attila Kun
- Department of Pharmacology, University of Aarhus, 8000 Aarhus C, Denmark
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Pataricza J, Krassói I, Höhn J, Kun A, Papp JG. Functional role of potassium channels in the vasodilating mechanism of levosimendan in porcine isolated coronary artery. Cardiovasc Drugs Ther 2003; 17:115-21. [PMID: 12975592 DOI: 10.1023/a:1025331617233] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.2] [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: 01/30/2023]
Abstract
Levosimendan, a new type of inodilator drugs, is known to activate membrane adenosine 3',5'-triphosphate-sensitive potassium (KATP) channels in some vascular smooth muscles and causes vasorelaxation. The involvement of potassium channels in the mechanism of the coronary artery relaxing effect of the drug has not been established. In the present study performed in the porcine epicardial coronary artery, the effect of levosimendan (0.009-3.2 microM) was compared to cromakalim (0.0125-5 microM), the known activator of ATP-sensitive potassium (KATP) channels, in the presence of glibenclamide (GLI), an inhibitor of KATP channels and tetraethylammonium (TEA), the non-selective inhibitor of potassium channels. The interaction of levosimendan with the specific calcium-activated potassium channel (KCa) blocker, iberiotoxin (IBTX), and the voltage-sensitive potassium channel (KV) blocker, 4-aminopyridine (4-AP), was also studied. All the experiments were performed in the isometric tension of endothelium denuded porcine isolated epicardial coronary arteries precontracted with 20 mM potassium chloride. 1 microM GLI decreased the maximum of cromakalim-induced relaxation by 60% but did not affect the action of levosimendan. In contrast, 2 mM TEA decreased only the coronary artery relaxing effect of levosimendan. 100 nM IBTX suppressed the maximum effect of levosimendan by only 15% while 0.5 mM 4-AP significantly shifted the concentration-response curve of the inodilator to the right. 5 mM 4-AP caused a maximum of 33% decrease of levosimendan-induced relaxation. These results indicate that, in porcine isolated epicardial coronary artery, the vasorelaxing mechanism of levosimendan involves the activation of voltage-sensitive and, at large concentrations, calcium-activated potassium channels.
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Affiliation(s)
- János Pataricza
- Department of Pharmacology and Pharmacotherapy, University of Szeged, H-6701, Szeged, Dóm tér 12., Hungary
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King RB, Silaghi-Dumitrescu I, Kun A. A density functional theory study of five-, six- and seven-atom germanium clusters: distortions from ideal bipyramidal deltahedra in hypoelectronic structures. ACTA ACUST UNITED AC 2002. [DOI: 10.1039/b206345j] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Kun A, Pataricza J, Krassói I, Szécsi M, Hohn J, Varró A, Papp JG. Low 4-aminopyridine concentration-induced contraction is mediated by neuronal noradrenaline in canine saphenous vein. Vascul Pharmacol 2002; 39:7-11. [PMID: 12616985 DOI: 10.1016/s1537-1891(02)00278-1] [Citation(s) in RCA: 4] [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: 10/27/2022]
Abstract
4-Aminopyridine (4-AP), a known inhibitor of the voltage-dependent potassium channels, is able to increase the basal tone of different types of blood vessel preparations. In order to determine the efficiency of 4-AP in veins and to clarify its possible mechanism of action, the aim of the present study was to determine the basal tone and release of radio-labelled tissue noradrenaline (NA) after administration of low 4-AP concentrations. Experiments were performed in canine saphenous vein in the absence and presence of functional endothelium. 4-AP (0.012-5 microM) enhanced the basal tone of venous rings without and with endothelium (maximum tone at 5 microM 4-AP: 2.20 +/- 1.29 and 1.3 +/- 0.57 mN, respectively). NA stores of the venous tissue were loaded by adding 1 mM NA to the tissue for 10 min and then washed out. After loading the NA-stores of venous tissue, 4-AP-induced contractions were significantly increased both in the absence and presence of endothelium (maximum tone at 5 microM 4-AP after loading with NA: 10.51 +/- 3.64 and 10.52 +/- 4.69 mN, respectively). Following NA loading, chemical denervation of the endothelium denuded venous preparations by 0.5 mM 6-hydroxydopamine (6-OHDA) completely abolished the contractions evoked by 4-AP. After incubation of the saphenous preparations with 3H-NA, 5 microM 4-AP significantly increased tritium-efflux from the tissue. These results provide evidence for the efficiency of 4-AP on the basal tone of isolated canine saphenous vein when applied in low concentrations. Furthermore, it is suggested that this action of 4-AP may considerably depend on the release of NA from the perivascular nerve endings.
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Affiliation(s)
- Attila Kun
- Division of Cardiovascular Pharmacology, Hungarian Academy of Sciences, Szeged, Hungary.
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Calliari A, Sotelo-Silveira J, Costa MC, Nogueira J, Cameron LC, Kun A, Benech J, Sotelo JR. Myosin Va is locally synthesized following nerve injury. Cell Motil Cytoskeleton 2002; 51:169-76. [PMID: 11977091 DOI: 10.1002/cm.10017] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The presence of Myosin Va (an actin-based molecular motor) in the peripheral nervous system was examined and its subcellular distribution within the axons of the sciatic nerve was demonstrated via immunocytochemistry. Myosin Va (M-Va) in the nerve was detected by using SDS-PAGE and Western blot techniques with a polyclonal antibody specifically raised against the M-Va globular tail domain. In addition, purification of M-Va from the rat sciatic nerve prior to immunoblotting yielded a M-Va standard band. Likewise, optical immunocytochemical procedures revealed the presence of M-Va, particularly in the cortical axoplasmic territory, but also in the Schwann cell soma. The above experiments were carried out both on intact as well as on severed sciatic nerves with similar results. The proximal stumps of severed sciatic nerves (from 0 to 72 h after injury) were labelled in vivo with (35)S-methionine. SDS-PAGE autoradiography of the immunoabsorbed M-Va from the radiolabelled homogenized nerve tissue showed a significant increment of the radioactive intensity of M-Va heavy chain band through time. Moreover, a significant increment of transcripts coding for M-Va heavy chain was detected through time using RT-PCR after nerve injury and compared to intact nerves. This data suggest that M-Va is up-regulated in a time-dependent manner. The latter suggests a possible involvement of M-Va in nerve regeneration processes.
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Affiliation(s)
- A Calliari
- Departament of Molecular and Cell Biology, Facultad de Veterinaria, Universidad de la República, Montevideo, Uruguay
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King RB, Silaghi-Dumitrescu I, Kun A. Distortions from octahedral symmetry in hypoelectronic six-vertex polyhedral clusters of the group 13 elements boron, indium, and thallium as studied by density functional theory. Inorg Chem 2001; 40:2450-2. [PMID: 11327931 DOI: 10.1021/ic0009932] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- R B King
- Department of Chemistry, University of Georgia, Athens 30602, USA
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Krassói I, Pataricza J, Kun A, Papp JG. Calcium-dependent vasorelaxant capacity of levosimendan in porcine and human epicardial coronary artery preparations. Cardiovasc Drugs Ther 2000; 14:691-3. [PMID: 11300371 DOI: 10.1023/a:1007883402379] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Abstract
Local protein synthesis within axons has been studied on a limited scale. In the present study, several techniques were used to investigate this synthesis in sciatic nerve, and to show that it increases after damage to the axon. Neurofilament (NF) mRNAs were probed by RT-PCR, Northern blot and in situ hybridization in axons of intact rat sciatic nerve, and in proximal or distal stumps after sciatic nerve transection. RT-PCR demonstrated the presence of NF-L, NF-M and NF-H mRNAs in intact sciatic nerve, as well as in proximal and distal stumps of severed nerves. Northern blot analysis of severed nerve detected NF-L and NF-M, but not NF-H. This technique did not detect the three NFs mRNAs in intact nerve. Detection of NF-L and NF-M mRNA in injured nerve, however, indicated that there was an up-regulation in response to nerve injury. In situ hybridization showed that NF-L mRNA was localized in the Schwann cell perinuclear area, in the myelin sheath, and at the boundary between myelin sheath and cortical axoplasm. RNA and protein synthesizing activities were always greater in proximal as compared to distal stumps. NF triplet proteins were also shown to be synthesized de novo in the proximal stump. The detection of neurofilament mRNAs in nerves, their possible upregulation during injury and the synthesis of neurofilament protein triplet in the proximal stumps, suggest that these mRNAs may be involved in nerve regeneration, providing a novel point of view of this phenomenon.
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Affiliation(s)
- J R Sotelo-Silveira
- Departamento de Biofísica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay.
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39
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Abstract
BACKGROUND The bradykinin (BK)-induced endothelium-dependent relaxation is impaired in the presence of elevated potassium concentration enhancing the vasospastic tendency of large coronary arteries. Inhibition of the angiotensin-converting enzyme responsible for bradykinin degradation was found to enhance the endothelium-dependent relaxation by BK. The aim of the present study was to investigate the effect of phosphoramidon, known to inhibit a BK-metabolizing neutral endopeptidase enzyme, on relaxation of porcine-isolated coronary artery in depolarizing solution. METHODS Endothelium intact porcine coronary artery rings were studied in organ chambers. The rings were isometrically contracted with potassium chloride (30 mmol/L) and the response to BK (1 to 1,000 nmol/L)-induced relaxation was investigated in the presence of nitric oxide synthase inhibitor Nomega-nitro-L-arginine (300 micromol/L) alone and in combination with the cyclooxygenase inhibitor indomethacin (10 micromol/L), and that of the inhibitor of calcium-dependent potassium channels tetraethylammonium (7 mmol/L). Under these conditions, phosphoramidon (10 micromol/L), an inhibitor of a neutral endopeptidase enzyme (EC.3.4.24.11.), which is responsible for the degradation of BK, was used to enhance the endothelium-dependent relaxation. RESULTS Phosphoramidon potentiated the maximum vasorelaxant effect of BK in Nomega-nitro-L-arginine (control 26.6%+/-10.86% versus phosphoramidon 49.05%+/-4.52%; n = 6, p < 0.05) or in Nomega-nitro-L-arginine + indomethacin-pretreated rings (control 20.7%+/-9.92% versus phosphoramidon 42.0%+/-12.26%; n = 5, p < 0.05) and this increased vasodilation was not modified by tetraethylammonium. CONCLUSIONS In the present study phosphoramidon potentiated the effect of BK in the absence of nitric oxide and prostaglandins in porcine-isolated coronary artery. This effect did not depend on tetraethylammonium-sensitive potassium channels. Phosphoramidon may be a useful pharmacologic tool for preserving the vasorelaxing capacity of coronary arteries after cardioplegia.
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Affiliation(s)
- I Krassói
- Hungarian Academy of Sciences and Department of Pharmacology and Pharmacotherapy, Albert Szent-Györgyi Medical Center, University of Szeged
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Silaghi-Dumitrescu L, Kun A, Haiduc I. Stable Isomers of Sila - and Germadodecahedrane. a Semiempirical (Am1) Investigation of the Structure of 4/6 and 4/5/6 Ring Containing E20(E=SI, GE) Systems. ACTA ACUST UNITED AC 1999. [DOI: 10.1080/10641229909351382] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Sotelo JR, Kun A, Benech JC, Giuditta A, Morillas J, Benech CR. Ribosomes and polyribosomes are present in the squid giant axon: an immunocytochemical study. Neuroscience 1999; 90:705-15. [PMID: 10215172 DOI: 10.1016/s0306-4522(98)00587-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [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: 11/28/2022]
Abstract
Ribosomes and polyribosomes were detected by immuno-electron microscopy in the giant axon and small axons of the squid using a polyclonal antibody against rat brain ribosomes. The ribosomal fraction used as antigen was purified by ultracentrifugation on a sucrose density gradient and shown to contain ribosomal RNAs and native ribosomes. The polyclonal antibody raised in rabbits reacted with at least ten proteins on immunoblots of purified rat brain ribosomes as well as with a set of multiple ribosomal proteins prepared from the squid giant fiber lobe. Immunoreactions were performed on cryostat sections of the stellate nerve cut at a distance of more than 3 cm from the stellate ganglion, using pre-embedding techniques. Ribosomes and polyribosomes were identified within the giant axon and small axons using electron microscopic methods, following binding of peroxidase-conjugated anti-rabbit IgG secondary antibody. Polysomes were more frequently localized in peripheral axoplasm, including the cortical layer of the giant axon, and were generally associated with unidentified cytoskeletal filaments or with dense matrix material. The immunochemical demonstration of ribosomes and polyribosomes in the giant axon and small axons of the squid confirms similar observations in the squid and the goldfish obtained with the method of electron spectroscopic imaging, and strongly supports the view that a local system of protein synthesis is present in axons. The immunochemical method here described offers an alternative tool for the selective identification of ribosomes, and is likely to prove of value in the analyses of other axonal systems.
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Affiliation(s)
- J R Sotelo
- División Biofísica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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42
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Mirel S, Roman L, Forizs E, Kun A. Conductometric method for the quantitative analysis of Pb(II) and Cd(II) with 2-mercapto-5-R-amino-1, 3, 4-thiadiazole derivatives. J Pharm Biomed Anal 1998; 18:83-91. [PMID: 9863946 DOI: 10.1016/s0731-7085(98)00152-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [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: 10/18/2022]
Abstract
The reactions of the cations with 2-mercapto-5-R-amino-1,3,4-thiadiazole derivatives were studied conductometrically with the purpose of establishing a new conductometric method for the quantitative analysis of Pb(II) and Cd(II). Aqueous solutions of Pb(NO3)2 and Cd(CH3COO)2 were titrated with hidroalcoholic solutions of 2-mercapto-5-amino-1,3,4-thiadiazole (MATD), 2-mercapto-5-allylamino-1,3,4-thiadiazole (MA1ATD) and 2-mercapto-5-acetylamino-1,3,4-thiadiazole (MAcATD) and 2-mercapto-5-phenilamino-1,3,4-thiadiazole (MFATD) in different concentrations. The reactions takes place at pH 6.5 (realised with acetate buffer). A linear classical titration curves was obtained. In solutions more concentrated than 10(-2) M just one equivalence point can be noticed, corresponding to 1:2 Me:R stoechiometries. For concentration less than 10(-2) M two equivalence point were observed at 1:1 and 2:1 ratio of Me:R, indicating the step formation of the complex. Accurate conductometric determinations can be made using the second break points of the titration curves as equivalence points. The amounts of Cd(II) and Pb(II) taken and recovered are good, with an error less than 1%.
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Affiliation(s)
- S Mirel
- Analytical Chemistry Department, Faculty of Pharmacy, University of Medicine and Pharmacy, Cluj-Napoca, Romania.
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43
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Kirsten E, Buki KG, Mendeleyev J, Vidair CA, Kun A, Kun E. Unusual potentiation by vinca alkaloids of the cytostatic and cytocidal action of methyl-3,5-diiodo-4-(4'-methoxyphenoxy) benzoate (DIME) and its nonhydrolyzable ethanone analog (DIPE) on MDA-MB-231 human mammary cancer cells. Int J Oncol 1998; 13:49-55. [PMID: 9625802 DOI: 10.3892/ijo.13.1.49] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
Drug interaction between DIME or DIPE ¿1-[3, 5-diiodo-4-(4'-methoxyphenoxy)-phenyl]-ethanone¿ with vincristine and vinblastine on the growth rate of MDA-MB-231 human mammary cancer cells was determined by the median effect kinetic method. Mutually exclusive cellular binding sites were identified kinetically and isobologram analyses showed potentiation. The combind effect of 0.75 MICROM DIME and 2 nM vincristine demonstrated a nearly type of mutual activation. It was shown that the nonhydrolyzable DIME derivative DIPE is equivalent to DIME, but because of its biological stability is a preferred drug candidate. Vinblastine-DIME cooperative action is similar to that of vincristine-DIME (or DIPE). Activation of caspase 3 by both DIME and vincristine is greatly potentiated when both drugs are added simultaneously in a given proportion. We propose that following a primary binding of DIME and vinca alkaloids to microtubules, an as yet unrecognized mutual activation of caspase 3 apoptotic path is initiated, explaining DNA fragmentation and cell death. A subpopulation of cancer cells, capable of slow growth at 1.5 microM DIME was identified. This cell type was also killed by the DIME-vincristine drug combination.
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Affiliation(s)
- E Kirsten
- Octamer Inc. and Octamer Research Foundation, 2840 Eighth Street, Berkeley, CA 94710, USA
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44
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Buki K, Mendeleyev J, Kun A, Comstock J, Kun E. Inhibition of the GTP-dependent polymerization of tubulin by methyl-3,5-diiodo-4-(4'-methoxyphenoxy) benzoate (DIME). Int J Oncol 1997; 10:911-3. [PMID: 21533462 DOI: 10.3892/ijo.10.5.911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The hormonally inactive thyroid hormone analog methyl-3,5-diiodo-4-(4'-methoxyphenoxy) benzoate (DIME) at 1-5 mu M concentrations inhibits the GTP-dependent polymerization of MTP as determined by an optical test. This inhibition is critically dependent on the concentration of GTP. The quantitative correlation between the concentrations of DIME and GTP, under conditions of a linear rat of MTP polymerization, follows Michaelis-Menten kinetics and the inhibition portrays a 'mixed' type, where k(m) for GTP and V-max are altered simultaneously. Chemical analogs of DIME inhibit MTP polymerization parallel to their antitumorigenic action in vivo. The MTP site is one of the early cellular response sites of DIME.
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Affiliation(s)
- K Buki
- SAN FRANCISCO STATE UNIV,OCTAMER RES FDN,ROMBERG TIBURON CTR,LAB ENVIRONM TOXICOL & CHEM,TIBURON,CA 94920
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45
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Abstract
Rat sciatic nerve segments, 4.5 cm distal to the dorsal root ganglion (DRG), were incubated in vivo with [35S]methionine. Fluorography of 2-D polyacrylamide gels of the nerve proteins demonstrated the labeling of the 68-kDa neurofilament protein, which was identified by immunoblotting. This experimental design excludes the dorsal root ganglion as the source of the radiolabeled neurofilament protein and suggests that this neuron-specific protein may be synthesized in axons.
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Affiliation(s)
- J R Sotelo
- División Biofisica, Instituto de Investigaciones Biológicas Clemente Estable, Montevideo, Uruguay
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46
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Makó Z, Kun A. [Changes in respiratory and circulatory parameters provoked by crying in respiratory distress syndrome]. Orv Hetil 1981; 122:1763-4. [PMID: 6793955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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47
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Csépányi A, Kun A, Márkus E. [A new type of emergency care for hospitalized patients]. Cesk Zdrav 1977; 25:36-8. [PMID: 832331] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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48
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Holló J, Szejtli J, Tóth M, Gantner GS, Kun A. Studien über die saure Hydrolyse von Glykosidbindungen. VII. Mitt.) Die Hydrolyse des Inulins. STARCH-STARKE 1962. [DOI: 10.1002/star.19620141103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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