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Reduced free radical generation during reperfusion of hypothermically arrested heart
J Mol Cell Cardiol 22 (Supplement V) (1990) pi9
ROLE OF GRANULOOYTEELASTASE (GE) IN HYOCARDIAL REF'ERFUSION INJURY (RI). Piero Ceriana, Daniele Bertollo, Andrea Pagnin, Roberto De Ponti*, Tiziana Bosoni**. Servizio di Anestesia e Rianimazione 1 ",*Divisione di Cardiologia,**Servizio di Analisi Chimico-Cliniche. IRCCS Policlinico San Matteo, 27100 Pavia, Italy. It is well known that neutrophil granulocyte (NG) play a key role in the myocardial RI, hence we have investigated the reliability of GE as a marker of RI. We have studied, with the informed consent, 7 patients (5 males, 2 females, mean age 57+8.3 fraction 60+5.8%). GE has time 55.3+11.4 min., mean ejection years, mean cross-clamp been sampled from both radial artery (RA) and coronary sinus (CS) after induction of anaesthesia and 5',15',30',60' and 120' after the release of the aortic cross-clamp. We have found the following values: CS= baseline:52+12; 5':520+43, 15':550+23, 30': 630+38, 60':707+27, 120':640+36. RA= baseline:47+8,-5':260+U8,-15':460+42,-30':510+ 24,-60':432+18, 120':440+26. Chi square test has been used-for statistical analysis. All the values are greatly increased (normal val. 22210 mcg/l) since during extracorporeal circulation massive degranulation of NG takes place; nevertheless, GE values from the CS are significantly higher (pt0.05) compared to the values of the RA. From in all cases, meaning a clinical point of view, weaning from bypass was uneventful that a significant degree of stunned myocardium was never found. Anyway, our data demonstrate that a significant sequestration and degranulation of NG take place in the coronary vasculature when the myocardium is reperfused after a period of ischemia.
P20 REDUCED FREE RADICAL GENERATION DURING REPERFUSION OF HYPOTHERMICALLY ARRESTED HEART. M. Renuka Prasad, John k Rwsou, Richard M. Engelman, Xuekun Liu, Devarshi Nath and Dipak K. Das. University of Connecticut School of Medicine, Farmington, CT, 06032 and Baystate Medical Center, Springfield, MA, 01199, U.S.A. Several studies indicate the presence of hydroxyl radical (OH.) as well as its involvement in the myocardial reperfusion injury. A transition metal like iron is necessary for the conversion of superoxide anion (O,-) to a highly reactive and cytotoxic hydroxyl radii (OH.). In the present study, we have examined the generation of OH’ and free iron in the reperfused hearts following either normothermic (37%) or hypothermic ischemia (5~). Employing the Langendorff technique, the isolated rat hearts were subjected to global ischemia for 30 min at 3PC or 5°C and then reperfused for 15 min at 37°C. The results of the study suggest that both the OH. generation in myocardium and free iron release into perfusate were significantly lower in hearts made ischemic at VC, as compared to 37%. The release of myoglobin and lactic acid dehydrogenase into perfusate also followed a similar pattern. Furthermore, in $ yi& studies, chemically generated O,- at 5°C caused signWantty lower rate of oxidation of oxymyoglobin as well as generation of OH. and free iron, as compared to 37°C. These results suggest: (1) reperfusion of hypothermic ischemic heart is associated with a reduction in the generation of OH’ and cellular damage compared to that of normothermic ischemic heart; (2) myoglobin, an intracellular protein is a source of free iron and plays a role in the reperfusion injury mediated by free radicals.
P21 'E-E RXEOFOXY~
FREE RADICALS INTHE PATXGENESIS OF POST-I-C INCOMPETENCE INTH!Z,MYKARDIUM. LindaMaxwell and John BGavin. Department of Pathology, University New Zealand.
VASCULAR of Auckland,
Oxygenated Krebs Henseleit buffer with or without the free radical scavengers superoxide dismutase (SOD 60,000 U/l) plus catalase (Cat 60,000 U/l) or desferrioxamine (Des 0.60 mnl/l) was administered to groups (n=5) of isolated perfused rat hearts inmediately prior to and for 5 or 60 minutes after 0, 15 or 45 min of global is&a&a. After fixation the hearts were perfused with nuclear track emulsion to identify c-tent vascular pathways in electron micrographs. Whereas 45 min of ischaemia followed by 5 ti reperfusion without the scavengers was associated with a 95% reduction in c-tent capillaries fran 2450+425 to 121+208/m in the subendocardial third of the left ventricular myocardim, the presence of either SOD plus Cat or Des was associated with an increase in the
number of c-tent capillaries in all 100% of the capillaries were c-tent. play a major role Research supported
hearts.
In suns treatedhearts
aInK&
Thus oxygen free radicals appear to in the pathogenesis of post-ischaemic microvascular inccxnpetence. by the Medical Research Council of New Zealand. s.7
ROLE OF GRANULOOYTEELASTASE (GE) IN HYOCARDIAL REF'ERFUSION INJURY (RI). Piero Ceriana, Daniele Bertollo, Andrea Pagnin, Roberto De Ponti*, Tiziana Bosoni**. Servizio di Anestesia e Rianimazione 1 ",*Divisione di Cardiologia,**Servizio di Analisi Chimico-Cliniche. IRCCS Policlinico San Matteo, 27100 Pavia, Italy. It is well known that neutrophil granulocyte (NG) play a key role in the myocardial RI, hence we have investigated the reliability of GE as a marker of RI. We have studied, with the informed consent, 7 patients (5 males, 2 females, mean age 57+8.3 fraction 60+5.8%). GE has time 55.3+11.4 min., mean ejection years, mean cross-clamp been sampled from both radial artery (RA) and coronary sinus (CS) after induction of anaesthesia and 5',15',30',60' and 120' after the release of the aortic cross-clamp. We have found the following values: CS= baseline:52+12; 5':520+43, 15':550+23, 30': 630+38, 60':707+27, 120':640+36. RA= baseline:47+8,-5':260+U8,-15':460+42,-30':510+ 24,-60':432+18, 120':440+26. Chi square test has been used-for statistical analysis. All the values are greatly increased (normal val. 22210 mcg/l) since during extracorporeal circulation massive degranulation of NG takes place; nevertheless, GE values from the CS are significantly higher (pt0.05) compared to the values of the RA. From in all cases, meaning a clinical point of view, weaning from bypass was uneventful that a significant degree of stunned myocardium was never found. Anyway, our data demonstrate that a significant sequestration and degranulation of NG take place in the coronary vasculature when the myocardium is reperfused after a period of ischemia.
P20 REDUCED FREE RADICAL GENERATION DURING REPERFUSION OF HYPOTHERMICALLY ARRESTED HEART. M. Renuka Prasad, John k Rwsou, Richard M. Engelman, Xuekun Liu, Devarshi Nath and Dipak K. Das. University of Connecticut School of Medicine, Farmington, CT, 06032 and Baystate Medical Center, Springfield, MA, 01199, U.S.A. Several studies indicate the presence of hydroxyl radical (OH.) as well as its involvement in the myocardial reperfusion injury. A transition metal like iron is necessary for the conversion of superoxide anion (O,-) to a highly reactive and cytotoxic hydroxyl radii (OH.). In the present study, we have examined the generation of OH’ and free iron in the reperfused hearts following either normothermic (37%) or hypothermic ischemia (5~). Employing the Langendorff technique, the isolated rat hearts were subjected to global ischemia for 30 min at 3PC or 5°C and then reperfused for 15 min at 37°C. The results of the study suggest that both the OH. generation in myocardium and free iron release into perfusate were significantly lower in hearts made ischemic at VC, as compared to 37%. The release of myoglobin and lactic acid dehydrogenase into perfusate also followed a similar pattern. Furthermore, in $ yi& studies, chemically generated O,- at 5°C caused signWantty lower rate of oxidation of oxymyoglobin as well as generation of OH. and free iron, as compared to 37°C. These results suggest: (1) reperfusion of hypothermic ischemic heart is associated with a reduction in the generation of OH’ and cellular damage compared to that of normothermic ischemic heart; (2) myoglobin, an intracellular protein is a source of free iron and plays a role in the reperfusion injury mediated by free radicals.
P21 'E-E RXEOFOXY~
FREE RADICALS INTHE PATXGENESIS OF POST-I-C INCOMPETENCE INTH!Z,MYKARDIUM. LindaMaxwell and John BGavin. Department of Pathology, University New Zealand.
VASCULAR of Auckland,
Oxygenated Krebs Henseleit buffer with or without the free radical scavengers superoxide dismutase (SOD 60,000 U/l) plus catalase (Cat 60,000 U/l) or desferrioxamine (Des 0.60 mnl/l) was administered to groups (n=5) of isolated perfused rat hearts inmediately prior to and for 5 or 60 minutes after 0, 15 or 45 min of global is&a&a. After fixation the hearts were perfused with nuclear track emulsion to identify c-tent vascular pathways in electron micrographs. Whereas 45 min of ischaemia followed by 5 ti reperfusion without the scavengers was associated with a 95% reduction in c-tent capillaries fran 2450+425 to 121+208/m in the subendocardial third of the left ventricular myocardim, the presence of either SOD plus Cat or Des was associated with an increase in the
number of c-tent capillaries in all 100% of the capillaries were c-tent. play a major role Research supported
hearts.
In suns treatedhearts
aInK&
Thus oxygen free radicals appear to in the pathogenesis of post-ischaemic microvascular inccxnpetence. by the Medical Research Council of New Zealand. s.7