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1.

001-es BibID:BIBFORM027559
Első szerző:Bak István (vegyész, analitikus, farmakológus)
Cím:The role of heme oxygenase-related carbon monoxide and ventricular fibrillation in ischemic/reperfused hearts / Istvan Bak, Gabor Papp, Tibor Turoczi, Edit Varga, Levente Szendrei, Miklos Vecsernyes, Ferenc Joo, Arpad Tosaki
Dátum:2002
Megjegyzések:Reperfusion-induced ventricular fibrillation (VF) and heme oxygenase (HO)-related carbon monoxide (CO) production in isolated ischemic/reperfused rat hearts were studied by gas chromatography. Hearts were subjected to 30 min ischemia followed by 2 h reperfusion, and the expression of HO-1 mRNA (about 4-fold) was observed in ischemic/reperfused-nonfibrillated hearts. In fibrillated hearts, the reduction (about 75%) in HO-1 mRNA expression was detected. These changes in HO-1 mRNA expression were reflected in tissue CO production. Thus, in the absence of VF, CO production was increased about 3.5-fold, while in the presence of VF, CO production was under the detectable level in comparison with the control group. Our results suggest that the stimulation of HO-1 mRNA expression may lead to the prevention of reperfusion VF via an increase in endogenous CO production. To prove this, hearts were treated with 1 microM of N-tert-butyl-alpha-phenylnitrone (PBN) as an inducer of HO-1. PBN treatment resulted in about 20 times increase in HO-1 mRNA expression, and even a higher production rate in endogenous CO. HO protein level and enzyme activity followed the same pattern, as it was observed in HO-1 mRNA expression, in fibrillated and nonfibrillated myocardium. Five mM/l of zinc-protoporphyrin IX (ZnPPIX) significantly blocked HO enzyme activity and increased the incidence of VF, therefore the application of ZnPPIX led to a significant reduction in HO-1 mRNA and protein expression. Our data provide direct evidence of an inverse relationship between the development of reperfusion-induced VF and endogenous CO production. Thus, interventions that are able to increase tissue CO content may prevent the development of reperfusion-induced VF.
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
egyetemen (Magyarországon) készült közlemény
Megjelenés:Free Radical Biology & Medicine. - 33 : 5 (2002), p. 639-648. -
További szerzők:Papp Gábor (1976-) (vegyész, kémikus) Turóczi Tibor (1976-) (molekuláris biológus) Varga Edit (gyógyszerész) Szendrei Levente Vecsernyés Miklós (1959-) (gyógyszertechnológus, endokrinológus) Joó Ferenc (1949-) (vegyész) Tósaki Árpád (1958-) (kísérletes farmakológus, gyógyszerész)
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2.

001-es BibID:BIBFORM041210
035-os BibID:PMID:11033413
Első szerző:Csonka Csaba
Cím:Effects of oxidative stress on the expression of antioxidative defense enzymes in spontaneously hypertensive rat hearts / Csaba Csonka, Tunde Pataki, Peter Kovacs, Sebastian L. Müller, Matthias L. Schroeter, Arpad Tosaki, Ingolf E. Blasig
Dátum:2000
Megjegyzések:Little is known concerning the effect of oxidative stress on the expression of antioxidative enzymes in the decompensated cardiac hypertrophy of spontaneously hypertensive rats (SHR), considered as a model of dilative cardiomyopathy in man. Superoxide dismutase (SOD), catalase, and glutathione peroxidase (GPx) were characterized in isolated perfused hearts of 18 month old SHR and the age-matched normotensive control Wistar-Kyoto (WKY) rats, before and after 30 min infusion of 25 microM H(2)O(2). After infusion of H(2)O(2), aortic flow decreased in WKY from 26.2 +/- 2.2 to 16.0 +/- 0.8 ml/min (p <.05) but not in SHR (18.2 +/- 1.9 vs. 20.7 +/- 2.2 ml/min). This protection was related to the higher myocardial activities of GPx, MnSOD and CuZnSOD in SHR, compared with those of the WKY group. Although total SOD activity in the SHR fell after H(2)O(2) exposure (to 1.81 +/- 0.13 from 3.56 +/- 0.49 U/mg of protein), catalase activity increased (to 2.46 +/- 0.34 from 1.56 +/- 0.29 k min(-1)mg(-1)protein), compared with the pre-infusion period (p <.05 in each case). In additional studies, hearts were subjected to 30 min of global ischemia followed by 30 min of reperfusion. The results obtained in ischemic/reperfused hearts show the same changes in enzyme activities measured as it was observed in H(2)O(2) perfused hearts, indicating that oxidative stress is independent of the way it was induced. The higher catalase activity derived from elevated mRNA synthesis. The antioxidative system in dilative cardiomyopathic hearts of SHR is induced, probably due to episodes of oxidative stress, during the process of decompensation. This conditioning of the antioxidative potential may help overcome acute stress situations caused by reactive oxygen species in the failing myocardium.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Free Radical Biology & Medicine 29 : 7 (2000), p. 612-619. -
További szerzők:Pataki Tünde (1971-) (farmakológus, klinikai farmakológus) Kovács Péter (1939-) (farmakológus) Müller, Sebastian L. Schroeter, Matthias L. Tósaki Árpád (1958-) (kísérletes farmakológus, gyógyszerész) Blasig, Ingolf E.
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3.

001-es BibID:BIBFORM020511
Első szerző:Csonka Csaba
Cím:Heme oxygenase and cardiac function in ischemic/reperfused rat hearts / Csaba Csonka, Edit Varga, Peter Kovacs, Peter Ferdinandy, Ingolf E. Blasig, Zoltan Szilvassy Árpád Tosaki
Dátum:1999
Megjegyzések:AbstractWe investigated whether the expression of heme oxygenase (HO) isozymes was related to the occurrence of ventricular fibrillation (VF) induced by ischemia/reperfusion in nondiabetic and diabetic myocardium. To study the role of HO-1 and HO-2 mRNA expression in VF, isolated hearts obtained from nondiabetic and 8-week diabetic rats were subjected to 30 min of ischemia followed by 2 h of reperfusion. Expression of HO-1 and HO-2 mRNA was studied in fibrillated and nonfibrillated myocardium using Northern blotting and reverse transcription polymerase chain reaction (RT-PCR). The effect of zinc protoporphyrin IX (Zn-PPIX), a potent inhibitor of HO activity, on HO activity was also studied in ischemic/reperfused hearts. Upon reperfusion, an expression of HO-1 was observed in nonfibrillated myocardium. HO-1 mRNA expression was significantly reduced in hearts showed VF. Zn-PPIX (5 microM) treatment reduced HO activity from its control values of 398+/-27 (in nondiabetics) and 370+/-20 pmol bilirubin/h (in diabetics) to 69+/-14 (in nondiabetics, p<.05) and 60+/-11 pmol bilirubin/h (in diabetics, p<.05), respectively, and all hearts, upon reperfusion, showed VF in both nondiabetic and diabetic subjects. HO-2 expression was unchanged in nonfibrillated and fibrillated myocardium. Postischemic function showed no correlation with the expression of these genes. Our data show that the mechanism(s) of ischemia/reperfusion-induced VF involves the downregulation of HO-1 mRNA and a reduction in HO activity. Furthermore, the mechanism(s) of VF at molecular level involving HO isozymes does not show a significant difference between nondiabetics and diabetics.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
heme oxygenase
cardiac function
ischemic heart
reperfused heart
Megjelenés:Free Radical Biology and Medicine 27 : 1-2 (1999), p. 119-126. -
További szerzők:Varga Edit (gyógyszerész) Kovács Péter (1947-) (belgyógyász, kardiológus, klinikai farmakológus) Ferdinándy Péter Blasig, Ingolf E. Szilvássy Zoltán (1957-) (belgyógyász, farmakológus, klinikai farmakológus) Tósaki Árpád (1958-) (kísérletes farmakológus, gyógyszerész)
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4.

001-es BibID:BIBFORM041211
035-os BibID:PMID:11557310
Első szerző:Sato, Motoaki
Cím:Grape seed proanthocyanidin reduces cardiomyocyte apoptosis by inhibiting ischemia/reperfusion-induced activation of JNK-1 and C-JUN / Motoaki Sato, Debasis Bagchi, Arpad Tosaki, Dipak K. Das
Dátum:2001
Megjegyzések:The mechanism of cardioprotection with red wine consumption was studied by examining the antideath signaling cascade of one of the principle components of red wine, proanthocyanidins. Grape seed proanthocyanidin extract (GSPE) was administered orally (100 mg/kg/d) supplemented with regular diet for 3 weeks to a group of rats while the other group was given the regular diet only for the same period of time. After 3 weeks, rats were sacrificed, hearts excised, and perfused via Langendorff mode. After stabilization, hearts were perfused in the working mode for baseline measurement of contractile function. Hearts were then made globally ischemic for 30 min followed by 2 h of reperfusion. Contractile function was continuously monitored during reperfusion, and free radical production was examined by electron spin resonance (ESR) technique. Cardiomyocyte apoptosis was examined by TUNEL staining in conjunction with an antibody against myocin heavy chain to specifically detect myocytes. Induction of JNK-1 and c-fos proteins was studied by Western blot analysis using respective antibodies followed by densitometric scanning. The results indicated significant induction of JNK-1 and c-fos proteins in the ischemic/reperfused myocardium, which was inhibited by the proanthocyanidin extract. In concert, GSPE significantly reduced the appearance of apoptotic cardiomyocytes in the ischemic/reperfused hearts. GSPE also significantly reduced the appearance of the reactive oxygen species in the hearts. Improved postischemic contractile recovery was achieved with GSPE suggesting its cardioprotective action. The results of this study indicated that GSPE functioned as an in vivo antioxidant, and its cardioprotective properties may be at least partially attributed to its ability to block antideath signal through the inhibition of proapoptotic transcription factor and gene, JNK-1 and c-Jun.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Free Radical Biology & Medicine 31 : 6 (2001), p. 729-737. -
További szerzők:Bagchi, Debasis Tósaki Árpád (1958-) (kísérletes farmakológus, gyógyszerész) Das, Dipak Kumar
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5.

001-es BibID:BIBFORM002216
Első szerző:Thirunavukkarasu, Mahesh
Cím:VEGFR1 (Flt-1+/-) gene knockout leads to the disruption of VEGF-mediated signaling through the nitric oxide/heme oxygenase pathway in ischemic preconditioned myocardium / Mahesh Thirunavukkarasu, Bela Juhasz, Lijun Zhan, Venugopal P. Menon, Arpad Tosaki, Hajime Otani, Nilanjana Maulik
Dátum:2007
Tárgyszavak:Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Free Radical Biology and Medicine 42 : 10 (2007), p. 1487-1495. -
További szerzők:Juhász Béla (1978-) (kísérletes farmakológus) Zhan, Lijun Menon, Venugopal P. Tósaki Árpád (1958-) (kísérletes farmakológus, gyógyszerész) Otani, Hajime Maulik, Nilanjana
Internet cím:elektronikus változat
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6.

001-es BibID:BIBFORM041697
Első szerző:Tósaki Árpád (kísérletes farmakológus, gyógyszerész)
Cím:Effects of SOD, catalase, and a novel antiarrhythmic drug, EGB 761, on reperfusion-induced arrhythmias in isolated rat hearts / Tosaki A., Droy-Lefaix M. T., Pali T., Das D. K.
Dátum:1993
Megjegyzések:Effects of superoxide dismutase (SOD), catalase, EGB 761 (Tanakan), and their combination on reperfusion-induced ventricular fibrillation (VF), tachycardia (VT), and the formation of oxygen free radicals were studied after 30 min of global ischemia followed by reperfusion in isolated rat hearts. In the first series of studies, rats received a daily dose of 10(4), 2 x 10(4), or 5 x 10(4) U/kg of SOD (i.v.); 2.5 x 10(4), 5 x 10(4), or 10(5) U/kg of catalase (i.v.); and 25, 50, 100, or 200 mg/kg of EGB 761 (per os), respectively, for 10 d (chronic administration). Neither SOD nor catalase alone reduced the incidence of reperfusion arrhythmias, but EGB 761 dose-dependently reduced the incidence of such arrhythmias. The coadministration of SOD (5 x 10(4) U/kg) with catalase (5 x 10(4) U/kg) significantly reduced the incidence of VF and VT. The same reduction in the incidence of VF and VT was observed when SOD (5 x 10(4) U/kg) was given in combination with EGB 761 (50 mg/kg). In the second series of studies, hearts were isolated and perfused with 5 x 10(4) U/l of SOD plus 5 x 10(4) U/l of catalase (acute treatment), and the incidence of reperfusion-induced VF and VT was significantly reduced. The combination of SOD (5 x 10(4) U/l) with EGB 761 (50 mg/l) also reduced the incidence of VF and VT. In these experiments, we studied the time course of oxygen radical formation using 5,5-dimethyl-pyrroline-N-oxide (DMPO), a spin trap, and it was found that EGB 761 (200 mg/l) or the coadministration of EGB 761 (50 mg/l) with SOD (5 x 10(4) U/l) almost completely abolished the formation of oxygen radicals during reperfusion measured by electron spin resonance (ESR) spectroscopy. Although SOD or catalase alone significantly reduced the formation of oxygen radicals, these drugs failed to prevent the development of reperfusion arrhythmias, while their combination significantly attenuated both the formation of free radicals and the incidence of reperfusion-induced arrhythmias. Our results indicate that the combination therapy may synergistically reduce the formation of free radicals and the incidence of reperfusion-induced VF and VT.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Free radical biology and medicine. - 14 : 4 (1993), p. 361-370. -
További szerzők:Droy-Lefaix, Marie-Thérèse Pali Tibor Das, Dipak Kumar
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7.

001-es BibID:BIBFORM041658
Első szerző:Tósaki Árpád (kísérletes farmakológus, gyógyszerész)
Cím:Heart protection and radical trapping by DMPO during reperfusion in isolated working rat hearts / Tosaki A., Blasig I. E., Pali T., Ebert B.
Dátum:1990
Megjegyzések:The purpose of this study was to use a direct method, that of electron spin resonance (ESR) spectroscopy, to demonstrate that reperfusion after a period of ischemia results in a sudden increase in the production of free radicals in the myocardium. Furthermore, the role of free radicals in the development of reperfusion arrhythmias and functional disturbances also was investigated using a 30-min period of global ischemia followed by 30 min of reperfusion in the isolated working rat heart. The spin trapping agent 5,5-dimethyl-1-pyrroline-1-oxide (DMPO) when it perfused the heart, 100 mumoles/liter, during the first 10 min of reperfusion attenuated the development of reperfusion arrhythmias and improved the functional recovery of the heart during reperfusion. Without treatment, 55% of hearts showed irreversible ventricular fibrillation, and this was completely prevented by DMPO. In DMPO-treated hearts, the recovery of heart function was improved; thus, coronary flow, aortic flow, left ventricular developed pressure, and first derivative of left ventricular developed pressure were significantly increased from their maximal control values of 16.2 +/- 1.9 ml/min, 12.7 +/- 0.9 ml/min, 11.1 +/- 0.5 kPa, and 426 +/- 31 kPa/s to 21.8 +/- 1.3 ml/min (p less than 0.05), 28.4 +/- 3.0 ml/min (p less than 0.001), 14.5 +/- 1.0 kPa (p less than 0.01), and 584 +/- 41 kPa/s (p less than 0.01), respectively. Left ventricular end-diastolic pressure was also significantly reduced from its control value of 2.8 +/- 0.2 kPa to 2.1 +/- 0.2 kPa (p less than 0.05), while the recovery of heart rate was not improved by DMPO treatment. Parallel ESR studies using DMPO as spin trap demonstrated the formation of .OH radicals in the effluent of the reperfused hearts. ESR signals of the formed DMPO-OH, alpha N = alpha beta H = 1.48 mT, were observed within the first seconds of reperfusion with peak concentrations after about 3 min. In the first series of ESR studies, DMPO (200 mmol/liter) was mixed up effluent and ESR signals were recorded, while in the second series of studies, DMPO was directly infused into the heart. Both methods were appropriate to demonstrate the radical formation that peaked at 3 min of reperfusion after 30 min of global ischemia. Cardiotoxic effects of DMPO can be excluded by using of the "mix-up" method (DMPO is added to effluent) because relatively high DMPO concentration (20-200 mmol/liter) is important for demonstration of free radical production
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Free Radical Biology and Medicine. - 8 : 4 (1990), p. 363-372. -
További szerzők:Blasig, Ingolf E. Pali Tibor Ebert, Berndt
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