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Characterization of postischemic myocardial viable mass by NMR
J Mol Cell Cardiol 24 (Supplement
II)
(1992)
MANNlWL DECEXXRATE DERNERGIZATION OF GUINEA-PIG MYOCARDWM CAUSED BY TERTURY BUTYLHYD ROPEROXIDE mH,O& N MUKOHARA AND R B@IGER Dept. PbysioL, USUHS, Beth&a. MD 20814
P-28 PmwATE,
Pymvatc, io-ofgl~.napmdtoeorpcenhslimdeperde~trrcovcri*rofenergy~~venhicularpress~devclopme~ in postis&emic isolated workiag guinea pig heart (Eur. I. Ei&tem. 160.. 2X-233, 1989). To teat the Possibility that pyruvate might pot03 againct oxygmdedved iliac radbkwhich have been itnpIIcate$ie isckemia.n~rfusion damage, normoxic Laagenchxff hearts were pcrfmcd for 12 min whh escess 03 mM TBHaOa in presence of 2 mM pyruvate as sole substrate. Hearts wet-e also tesled with normal and elevated glucax (5 o&f. 2.5 I& (5 U/l insulin)) as sole substrates as well as with non-meIabolir.ablc mannitol (20 &I) plus 5 m&f gIumse. I~tmcelluIar pH, lactate (Lx), inorganic phosphate (P,), adeoylalu. creatiae (0) and Cr hcspbate (CkP) wem measured. Perfusion medium was a Kre&Henselcit bicarhoaate buffer @H 7.4; 95% Oa:5% CO5 Ca*+, M 8 , pdusim ~SSIZC at physiological Ievels). M&aboIites were measumd emymaficahy, esnacellularspaoa by [t’C]cottosylioinulio. TBiIsOs increased conmary flow (50 - lOG%) at constant pHt. With 5 mM ghxoae as substrate, total creatine and adenylate pools (AIPiADPtAh4P) were depleted by - 22% and 14%. resp.. P, and Iaoacoumulated (100 - lKJ%, 300 %) due to TBH,O,. Pymvate markedly alteau.Med these changes @ < 0.05). Also manaitol diminished P, and Lac accumulations but did not prevent creatine and adenylate pool depletions. In addition, pysuvate, tnannitol, and also 2.5 mM glucose, but not 5 o&I ghicose, prevented a hll in the CrPiCr ratio. However.only pyruvatc ormannitol stabilized Ibc phosphorylation state of CrP ([CrP]/(]Cr][Pi]), but nucleosidc release dala oxtfirmal increased net adcnylate degradation during peroxide application. After 30 min T13H20, infusion all hearts exhibited energetic failure regatdlm of s&&rate. Thus pyruvate and mannitol maintained the phoaphorylation state of CrP for at least 12 min despite the overdose of gtoplasmic oxygen-derived free radicals; in contrast, with normal gluawe as substrale dephosphotylstion of CrP was evident after 12 mia exposure to TBHaO, It is pmposed that pyruvate or q annitol cart decelerate. but not prevent myocardiai deeoergizatiw due to toxic oxygenderived & radicab. (NIH HL-3GO67)
P-29 CHARACTERIZATION
OF POSTlSCHEMIC MYOCARDIAL VIABLE MASS BY NMR. JA Bianco, L Rayner, and A Thomas. University of Wisconsin, Madison, USA Postischemic cardiac damage was assessed in perchloric acid extract of rabbits by NMR (9.4 Group II (n=5) were perfused with University of Tesla, 400 MHz). Group I (n=5) were controls. Wisconsin solution (UWS) at 4°C for 24 hours. Group III (n=2) were stored for 24 hours at 4°C in UWS. After 24 hours, Groups II and III were reperfused for 30 minuets at 37°C. Perfusion was assessed with Tl-201 autoradiography and viability with light microscopy. Mean * SEM values for creatine-phosphocreatine/lactate were: Group I: 7.82k1.5 g; Group II: 5.9L1.43; Group 111: 3.3kO.9. Gradual build-up of lactate and inorganic phosphate indicated progressive myocardial damage. There was no correlation between the Cr/PCr over lactate ratio and the PCr/&ATP ratio. In summary, NMR spectroscopy yields useful information on viable and nonviable postischemic cardiac mass.
P-30 n1cRovAiTcuLm fsxmmmm IN ISCHAI@lIC BEARTS ARl@STED WITH OXYGENATlKl CRYSTALLOID CARDIOpLEGIC SOWMDN. Choong YS, Cottier D and Porster K. Department of Pathology, School of Hedicine. University of Auckland, Auckland. Her Zealand.
He have showu that oxygeuated St. Xlmms llospital solution (STll) improves post-ischaemic recovery of cardiac function and metabolism while minimizing the To examine the elevation of coronary vascular resistance during ischaelia. pathogeuesis of capillmy incompetence , isolated working rat hearts were arrested (2 min at 4oC) rlth either Sill or fully oxygeuated STll. Bearts were then subjected to global ischaemia fmultidose cardioplegia every 40rin)for 5 hours at 2ooc. They were then perfused fixed and injected with nuclear track emulsion (NTE) to identify corpeteut vessels in full transmu-al resin e8bedded sections by light microscopy. In SlYI + 4 hearte, pester than 90% of vessels remained patent and RTfi was distributed across the full thickness of the LV. In contrast, STB hearts showed more than WX reduction of competent capillaries psed omiuautly in the subendo-ryocardium of LV with ischaemic myocytes. This result has important implications for myocardial protection duriug cardiac surgery. (Bupported by the National Beart Foundation of New Zealand). S.20
II)
(1992)
MANNlWL DECEXXRATE DERNERGIZATION OF GUINEA-PIG MYOCARDWM CAUSED BY TERTURY BUTYLHYD ROPEROXIDE mH,O& N MUKOHARA AND R B@IGER Dept. PbysioL, USUHS, Beth&a. MD 20814
P-28 PmwATE,
Pymvatc, io-ofgl~.napmdtoeorpcenhslimdeperde~trrcovcri*rofenergy~~venhicularpress~devclopme~ in postis&emic isolated workiag guinea pig heart (Eur. I. Ei&tem. 160.. 2X-233, 1989). To teat the Possibility that pyruvate might pot03 againct oxygmdedved iliac radbkwhich have been itnpIIcate$ie isckemia.n~rfusion damage, normoxic Laagenchxff hearts were pcrfmcd for 12 min whh escess 03 mM TBHaOa in presence of 2 mM pyruvate as sole substrate. Hearts wet-e also tesled with normal and elevated glucax (5 o&f. 2.5 I& (5 U/l insulin)) as sole substrates as well as with non-meIabolir.ablc mannitol (20 &I) plus 5 m&f gIumse. I~tmcelluIar pH, lactate (Lx), inorganic phosphate (P,), adeoylalu. creatiae (0) and Cr hcspbate (CkP) wem measured. Perfusion medium was a Kre&Henselcit bicarhoaate buffer @H 7.4; 95% Oa:5% CO5 Ca*+, M 8 , pdusim ~SSIZC at physiological Ievels). M&aboIites were measumd emymaficahy, esnacellularspaoa by [t’C]cottosylioinulio. TBiIsOs increased conmary flow (50 - lOG%) at constant pHt. With 5 mM ghxoae as substrate, total creatine and adenylate pools (AIPiADPtAh4P) were depleted by - 22% and 14%. resp.. P, and Iaoacoumulated (100 - lKJ%, 300 %) due to TBH,O,. Pymvate markedly alteau.Med these changes @ < 0.05). Also manaitol diminished P, and Lac accumulations but did not prevent creatine and adenylate pool depletions. In addition, pysuvate, tnannitol, and also 2.5 mM glucose, but not 5 o&I ghicose, prevented a hll in the CrPiCr ratio. However.only pyruvatc ormannitol stabilized Ibc phosphorylation state of CrP ([CrP]/(]Cr][Pi]), but nucleosidc release dala oxtfirmal increased net adcnylate degradation during peroxide application. After 30 min T13H20, infusion all hearts exhibited energetic failure regatdlm of s&&rate. Thus pyruvate and mannitol maintained the phoaphorylation state of CrP for at least 12 min despite the overdose of gtoplasmic oxygen-derived free radicals; in contrast, with normal gluawe as substrale dephosphotylstion of CrP was evident after 12 mia exposure to TBHaO, It is pmposed that pyruvate or q annitol cart decelerate. but not prevent myocardiai deeoergizatiw due to toxic oxygenderived & radicab. (NIH HL-3GO67)
P-29 CHARACTERIZATION
OF POSTlSCHEMIC MYOCARDIAL VIABLE MASS BY NMR. JA Bianco, L Rayner, and A Thomas. University of Wisconsin, Madison, USA Postischemic cardiac damage was assessed in perchloric acid extract of rabbits by NMR (9.4 Group II (n=5) were perfused with University of Tesla, 400 MHz). Group I (n=5) were controls. Wisconsin solution (UWS) at 4°C for 24 hours. Group III (n=2) were stored for 24 hours at 4°C in UWS. After 24 hours, Groups II and III were reperfused for 30 minuets at 37°C. Perfusion was assessed with Tl-201 autoradiography and viability with light microscopy. Mean * SEM values for creatine-phosphocreatine/lactate were: Group I: 7.82k1.5 g; Group II: 5.9L1.43; Group 111: 3.3kO.9. Gradual build-up of lactate and inorganic phosphate indicated progressive myocardial damage. There was no correlation between the Cr/PCr over lactate ratio and the PCr/&ATP ratio. In summary, NMR spectroscopy yields useful information on viable and nonviable postischemic cardiac mass.
P-30 n1cRovAiTcuLm fsxmmmm IN ISCHAI@lIC BEARTS ARl@STED WITH OXYGENATlKl CRYSTALLOID CARDIOpLEGIC SOWMDN. Choong YS, Cottier D and Porster K. Department of Pathology, School of Hedicine. University of Auckland, Auckland. Her Zealand.
He have showu that oxygeuated St. Xlmms llospital solution (STll) improves post-ischaemic recovery of cardiac function and metabolism while minimizing the To examine the elevation of coronary vascular resistance during ischaelia. pathogeuesis of capillmy incompetence , isolated working rat hearts were arrested (2 min at 4oC) rlth either Sill or fully oxygeuated STll. Bearts were then subjected to global ischaemia fmultidose cardioplegia every 40rin)for 5 hours at 2ooc. They were then perfused fixed and injected with nuclear track emulsion (NTE) to identify corpeteut vessels in full transmu-al resin e8bedded sections by light microscopy. In SlYI + 4 hearte, pester than 90% of vessels remained patent and RTfi was distributed across the full thickness of the LV. In contrast, STB hearts showed more than WX reduction of competent capillaries psed omiuautly in the subendo-ryocardium of LV with ischaemic myocytes. This result has important implications for myocardial protection duriug cardiac surgery. (Bupported by the National Beart Foundation of New Zealand). S.20