Multi-dose crystalloid cardioplegia preserves intracellular sodium homeostasis in myocardium

Citation
Vd. Schepkin et al., Multi-dose crystalloid cardioplegia preserves intracellular sodium homeostasis in myocardium, J MOL CEL C, 31(9), 1999, pp. 1643-1651
Citations number
38
Categorie Soggetti
Cardiovascular & Hematology Research
Journal title
JOURNAL OF MOLECULAR AND CELLULAR CARDIOLOGY
ISSN journal
00222828 → ACNP
Volume
31
Issue
9
Year of publication
1999
Pages
1643 - 1651
Database
ISI
SICI code
0022-2828(199909)31:9<1643:MCCPIS>2.0.ZU;2-C
Abstract
The goal of this study was to assess the effect of multi-dose St Thomas car dioplegia on intracellular sodium homeostasis in a rat heart model. A new m agnetic resonance method was applied which enable us to detect intracellula r Na changes without chemical shift reagents. Three groups of isolated rat hearts were subjected to 51 min of ischemia and 51 min of reperfusion at 37 degrees C: Group 1-three infusions of St Thomas cardioplegia every 17 min for 2 min (n = 7); Group 2-single-dose infusion of cardioplegia at the begi nning of stop-flow ischemia (n = 8); and Group 3-clamp ischemia (n = 3) wit hout cardioplegia administration. Performance of the heart was assessed by rate-pressure product relative to the pre-ischemic level (RPP). An NMR meth od was applied which continuously detects the Na-i concentration in the hea rt, using the ability of bound sodium to exhibit triple-quantum transitions and the growth of the corresponding signal when sodium ions pass from extr acellular to intracellular space. Clamp ischemia without cardioplegia and 5 0 min of reperfusion left the heart dysfunctional. with Na-i growth from th e pre-ischemic level of 13.9 +/- 1.2 mM to 34.9 +/- 1.3 mM and 73,9 +/- 1.9 mM at the end of ischemia and reperfusion. respectively. During single-dos e cardioplegia the corresponding values for Na-i were 30.2 +/- 1 mM and 48. 5 +/- 1.7 mM (RPP = 29%). Multiple infusions of cardioplegic solution resul ted in a remarkable preservation of the heart's intracellular Na concentrat ion with a non-significant increase in Na-i during ischemia and only 16.7 /- 1 mM, (P = 0.01), after subsequent reperfusion (RPP = 85%). The time cou rse of Na-i changes in the rat heart model demonstrates a prominent potenti al of multi-dose St Thomas' cardioplegia in preserving intracellular sodium homeostasis at 37 degrees C. The growth of Na-i concentration during ische mia, as an indicator of the viability of the myocytes, can reperfusion. hav e a prognostic value for the heart's performance during (C) 1999 Academic P ress.