Effect of ischemia on free nucleotides of perfused rabbit heart

EFFECT OF ISCHEMIA ON FREE NUCLEOTIDES OF PERFUSED RABBIT HEART. A. Casti, N.Reali, G. Orlandini, R. Ferrari, 0. Visioli, A. Corti. II Cattedra di Chimica Biologica di Parma e Modena e Cattedra di Cardiologia dell'universith di Par-ma, Facoltl di Medicina e Chirurgia,Parma, Italy. In our experiments myocardial ischemia (MI) (obtained in the isolated and perfused rabbit heart reducing coronary flow from 22 to 2,5 ml/min for 15' or 60') induced dramatic changes of content and labelled precursors in corporation into free nucleotides (FN). Both these parameters were significantly reduced for ATP and ADP, while they were increased for IMP, AMP and adenosine. The same pattern was true for GTP, GDP and GMP. As for the pattern of uridylic FN the results indicate a significant decrease of content and radioactivity, except that an increase of UTP concentration. The cytidylic FN which were unchanged after 15' of ischemia, were significantly reduced when ischemia was prolonged for 60'. There was also an increase of NAD after ischemia but not of the other redox coenzymes (NADP, FAD) Finally, MI induced a 90% decrease of CAMP and HSCoA radioactivity. These data provide evidences that the changes of FN pool during ischemia give useful information on a) energy trasferring processes (as from adenylic FN) b) protein synthesis (as from guanylic FN) c) glycogen and glycoprotein synthesis (as from uridilyc FN) d) phospholipids metabolism (as from cytidylic FN). (Supported by grant from Consiglio Nazionale delle Ricerche, Roma)

OXYGENATED VERSUS LUTION:EXPERIMENTAL

NON OXYGENATED CRISTALLOID CARDIOPLEGIC SOEVALUATION ON ISCHEMIC MYOCARDIUM. Turi-

netto geli

G .+:Qlarnieri

B .fCenacchi A. InstAtute

croscopy

ard

of

Institute

C .,c+oli

G.,Grillone

Cardiosurgery,Institute of Biochemistry,University

of

G.,PieranClinical Miof Bologna,

Bologna,Italy. Some evidences can be obtained

exist using

that,a better myocardial oxygenated cristalloid

cold

protection cardiople-

gic solutions. In order to verify this hypothesis,experiments were undertaken on pigs put oncardiopulmonary by-pass and the aorta was clamped for 3 hours. Subsequently the extracorporeal circulation was prolorqed for '1 hour of reperfusion. Anima 1s were divided in two groups:group A received the pure St. Thomas

solution.Group

hearts

recovered

riod.

Mitochondrial

B the

spontaneously function

same

at (R-C.1

solution

the

oxygenated.

end of

.,Q02,ADP/O)

ischemia or repurfusion was not significantly both groups. The same results were obtained ctural analysis. The Authors conclude that tion do not significantly improved myocardial

the

All

ischemic either

peafter

different in at the ultrastruoxygenated soluprotection.