CCL

Összesen 6 találat.
#/oldal:
Részletezés:
Rendezés:

1.

001-es BibID:BIBFORM041657
Első szerző:Blasig, Ingolf E.
Cím:Inverse relationship between ESR spin trapping of oxyradicals and degree of functional recovery during myocardial reperfusion in isolated working rat heart / Blasig I. E., Ebert B., Hennig C., Pali T., Tosaki A.
Dátum:1990
Megjegyzések:STUDY OBJECTIVE: The aim of the study was to investigate the generation of free oxyradicals as factors in myocardial ischaemia-reperfusion pathology. DESIGN: Isolated perfused rat hearts were subjected to 30 min global ischaemia followed by reperfusion. The spin trap 5,5-dimethyl-1-pyrroline-1-oxide was added to the effluent of the heart to avoid pharmacological interaction with the heart. The effluent was then analysed by electron spin resonance spectroscopy. MATERIALS: Studies were performed on hearts of 51 male Sprague-Dawley rats, weight 300-350 g. MEASUREMENTS AND RESULTS: During reperfusion, the formation of hydroxyl radical adducts of the trap was observed, with a maximal value after 3 min. The initial amount of radicals trapped during the first 3 min of reperfusion showed an inverse correlation with the degree of heart function restored within 30 min of reperfusion. Spearman's rank correlation coefficients were calculated to be -0.734 for heart rate, -0.825 for left ventricular developed pressure, -0.787 for the maximum of its first derivative, -0.787 for coronary flow, and -0.796 for aortic flow (p less than 0.05, n = 10, in each instance). No statistically significant correlation was found between the cumulative amount of radicals trapped in the effluent during the initial phase of reperfusion and the duration of ventricular fibrillation, duration of ventricular tachycardia, or number of ventricular ectopic beats (registered during 30 min reperfusion). CONCLUSIONS: The application of spin trapping to the effluent of isolated perfused hearts allows the generation of oxyradicals to be characterised without interaction of the trap with the heart. It also allows the time course of radical production to be investigated, and can detect relative changes in their intensity. These are important factors in the study of the pathogenic role of free radicals generated during reperfusion of an ischaemic heart.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Cardioscular Research. - 24 : 4 (1990), p. 263-270. -
További szerzők:Ebert, Berndt Hennig, Christian Pali Tibor Tósaki Árpád (1958-) (kísérletes farmakológus, gyógyszerész)
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
DOI
Borító:

2.

001-es BibID:BIBFORM041704
035-os BibID:PMID:7921376
Első szerző:Tósaki Árpád (kísérletes farmakológus, gyógyszerész)
Cím:Ginkgo biloba extract (EGb 761) improves postischemic function in isolated preconditioned working rat hearts / Arpad Tosaki, Daniel T. Engelman, Tibor Pali, Richard M. Engelman, Marie-Therese Droy-Lefaix
Dátum:1994
ISSN:0954-6928
Megjegyzések:We studied the effect of preconditioning and Gikgo biloba extract (EGb 761) in relation to the recovery of contractile function after global ischemia in the isolated working rat heart. METHODS: Hearts (n = 12 in each group) were randomly divided into five groups: In group I, hearts were subjected to 30 min of normothermic global ischemia followed by 30 min of reperfusion; in group II, they were subjected to one cycle of preconditioning consisting of 5 min ischemia and 10 min reperfusion before the induction of 30 min of ischemia and 30 min of reperfusion; group III hearts underwent two cycles of preconditioning; group IV hearts underwent three cycles of preconditioning; and group hearts underwent four cycles of preconditioning before the onset of 30 min ischemia followed by 30 min of reperfusion. RESULTS: Ventricular fibrillation (total) and ventricular tachycardia (no preconditioning) both fell from 100% to 50% (P < 0.05) after four cycles of preconditioning. In relation to ventricular fibrillation, preconditioning significantly reduced the formation of oxygen free radicals, measured by electron spin resonance spectroscopy (ESR), but recovery of cardiac function was low in all preconditioned groups. Because of the relatively low incidence of arrhythmias (50% ventricular fibrillation and 50% ventricular tachycardia) and relatively low cardiac function in Group V, EGb 761, a free-radical scavenger, was chosen to improve myocardial contractile function in preconditioned hearts. Fifty and 100 mg/kg of EGb 761 (per os) significantly improved coronary flow, aortic flow, left ventricular developed pressure (LVDP), and the first derivative of LVDP (LVDdP/dtmax) in the four-cycle preconditioned group. Thus, after 30 min of reperfusion, aortic flow was improved from 11.6 +/- 0.9 ml/min to 19.7 +/- 1.2 ml/min (P < 0.05) with a dose of 50 mg/kg of EGb 761 and to 22.0 +/- 1.5 ml/min (P < 0.05) with a dose 100 mg/kg of EGb 761, in the four-cycle preconditioned group. During reperfusion, the formation of free radicals was reduced by approximately 50 and 60% using 50 mg/kg and 100 mg/kg of EGb 761, respectively, when compared with the four-cycle preconditioned drug-free control group. CONCLUSION: We have demonstrated that EGb 761 can improve contractile function after global ischemia in the isolated working rat heart by reducing the formation of oxygen free radicals, and we have shown that this protection is additive to that of ischemia-induced preconditioning.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Coronary Artery Disease 5 : 5 (1994), p. 443-450. -
További szerzők:Engelman, Daniel T. Pali Tibor Engelman, Richard M. Droy-Lefaix, Marie-Thérèse
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
DOI
Borító:

3.

001-es BibID:BIBFORM041698
Első szerző:Tósaki Árpád (kísérletes farmakológus, gyógyszerész)
Cím:Comparisons of ESR and HPLC methods for the detection of OH. radicals in ischemic/reperfused hearts. A relationship between the genesis of free radicals and reperfusion arrhythmias / Tosaki A., Bagchi D., Pali T., Cordis G. A., Das D. K.
Dátum:1993
Megjegyzések:In this study we compared two methods, electron spin resonance (ESR) spectroscopy and high performance liquid chromatography (HPLC), which are currently used to detect directly hydroxyl radical (OH.) formation in the ischemic and reperfused heart. Isolated buffer-perfused rat hearts were subjected to 30 min of normothermic global ischemia followed by 30 min of reperfusion. 5,5-Dimethyl-pyrroline-N-oxide (DMPO) was used as a spin-trap agent to detect OH. radicals by ESR and HPLC. In additional HPLC studies, salicylic acid was infused into the heart for the detection of OH. radicals. In all studies, the effects of superoxide dismutase (SOD) and catalase (CAT) on the OH. generation were examined. The results of our studies indicate that, irrespective of the method, OH. was always detected when an ischemic heart was reperfused and showed ventricular fibrillation. The OH. concentration increased dramatically between 60 and 90 sec of reperfusion, peaked between 180 and 210 sec, and then progressively decreased. In all cases, both SOD and CAT were able to reduce the formation of OH. radicals, with SOD being relatively more effective. Our results indicate that OH. was produced only in the fibrillating hearts that peaked between 180 and 210 sec (1.64 +/- 0.09 nmol/mL measured by ESR), but not in the non-fibrillating hearts. Although SOD or CAT reduced the OH. formation, they had no effects on the incidence of reperfusion-induced ventricular fibrillation (VF) and ventricular tachycardia (VT). However, when SOD (5 x 10(4) IU/L) was coadministered with CAT (5 x 10(4) IU +/- L), the incidence of reperfusion-induced VF (total) and VT was reduced from their control value of 92 and 100 to 33 (P < 0.05) and 50% (P < 0.05), respectively. The results of this study indicate that the HPLC method, as well as ESR, can be used to detect OH. formation in ischemic/reperfused hearts. Because of the convenience, reproducibility and greater sensitivity, the HPLC technique may be more suitable for OH. detection. Our results further suggest the potential therapeutic value of the combination therapy of SOD and CAT for the reduction of reperfusion-induced VF and VT.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
Megjelenés:Biochemical Pharmacology. - 45 : 4 (1993), p. 961-969. -
További szerzők:Bagchi, Debasis Pali Tibor Cordis, Gerald A. Das, Dipak Kumar
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
DOI
Borító:

4.

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
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
Borító:

5.

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
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
DOI
Borító:

6.

001-es BibID:BIBFORM041158
035-os BibID:PMID:8932989
Első szerző:Tósaki Árpád (kísérletes farmakológus, gyógyszerész)
Cím:Effects of Ginkgo biloba extract and preconditioning on the diabetic rat myocardium / A. Tosaki, T. Pali, Marie-Thérèse Droy-Lefaix
Dátum:1996
ISSN:0012-186X
Megjegyzések:Effects of preconditioning and Ginkgo biloba extract (EGb 761) were studied in isolated nondiabetic and diabetic ischaemic and re-perfused rat hearts. Hearts were randomly divided into five groups in both the age-matched non-diabetic and the 8-week streptozotocin-induced diabetic groups: Group I, hearts were subjected to 30 min of global ischaemia followed by 30 min of re-perfusion; Group II, one cycle of preconditioning consisting of 5 min ischaemia and 10 min re-perfusion before the induction of 30 min of ischaemia and 30 min of re-perfusion; Group III, two cycles of preconditioning; Group IV, three cycles; and Group V, four cycles before the onset of 30 min ischaemia followed by 30 min of re-perfusion. Four cycles of ischaemic preconditioning resulted in a reduction of arrhythmias in non-diabetic rats. Thus, in non-diabetics, the incidence of ventricular fibrillation and tachycardia fell from 92% and 100% (no preconditioning) to 33% (p < 0.05) and 42% (p < 0.05), respectively. Four cycles of preconditioning failed to reduce the incidence of re-perfusion arrhythmias in diabetic subjects. Preconditioning reduced the formation of oxygen free radicals measured by electron spin resonance spectroscopy, but the recovery of cardiac function was low in all non-diabetic and diabetic preconditioned groups. EGb 761 at 25 and 50 mg/kg improved cardiac function in non-preconditioned and preconditioned non-diabetic and diabetic hearts. During re-perfusion in the four-cycle preconditioned non-diabetic and diabetic groups, the amount of free radicals was reduced approximately by 50 and 70% using 25 and 50 mg/kg of EGb 761, respectively. EGb 761 improved cardiac function after ischaemia in both non-preconditioned and preconditioned non-diabetic and diabetic rats. Our data suggest that diabetes could abolish the precondition-induced protection.
Tárgyszavak:Orvostudományok Gyógyszerészeti tudományok idegen nyelvű folyóiratközlemény külföldi lapban
külföldön készült közlemény
Megjelenés:Diabetologia 39 : 11 (1996), p. 1255-1262. -
További szerzők:Pali Tibor Droy-Lefaix, Marie-Thérèse
Internet cím:Intézményi repozitóriumban (DEA) tárolt változat
DOI
Borító:
Rekordok letöltése1 
Corvina könyvtári katalógus v8.2.27 © 2023 Monguz kft. Minden jog fenntartva.