Contractile and vascular consequences of blood versus crystalloid cardioplegia in the isolated blood-perfused rat heart.
The protective effects of sanguineous and asanguineous St. Thomas' cardioplegia (SCP and ACP) on post-ischemic vasodilator responsiveness, left ventricular developed pressure and end-diastolic pressure (LVDP and LVEDP), tissue adenosine triphosphate (ATP) and creatine phosphate (CP) contents were compared in the isolated blood-perfused rat heart. Five groups of hearts were studied: the controls (n = 8) perfused with blood (from a support rat) for 50 min (37 degrees C), versus hearts (n = 14/group) arrested by a single infusion of either cardioplegic solution (15 degrees C) prior to global ischemia (15 degrees C) and blood reperfusion (37 degrees C). After 2 or 4 h of ischemia and 50 min of reperfusion, endothelium-dependent vasodilator acetylcholine (1 microgram) induced a 10 +/- 0.5 and 8.5 +/- 0.5% reduction, respectively, in coronary resistance, in the SCP groups, but only a 6.5 +/- 0.6 and 4.5 +/- 0.5% reduction (P < 0.05), respectively, in the ACP groups. However, there were no significant differences in LVDP, LVEDP, tissue ATP and CP contents, and endothelium-independent vasodilator response to nitroglycerin between the two cardioplegic groups. In a further study, rat hearts (n = 8/group) were arrested with SCP (magnesium concentration < 0.5, 5.0 or 16.0 mmol/l, in groups 1, 2 and 3) and subjected to 4 h of global ischemia (15 degrees C) followed by 50 min of blood reperfusion (37 degrees C). At the end of reperfusion, LVDP (at a ventricular volume of 180 microliters) was 60 +/- 3.4, 72 +/- 3.5 and 70 +/- 3.2 in groups 1, 2 and 3, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)
Qiu
Y
Y
Cardiovascular Research, Rayne Institute, St. Thomas' Hospital, London, UK.
Manché
A
A
Hearse
D J
DJ
D000109:Acetylcholine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000032:analysis; D000704:Analysis of Variance; D000818:Animals; D001794:Blood Pressure; D002314:Cardioplegic Solutions / Q000494:pharmacology*; D004730:Endothelium, Vascular / Q000502:physiology; D005260:Female; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects*; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000503:physiopathology; D015425:Myocardial Reperfusion / Q000379:methods; D005996:Nitroglycerin / Q000494:pharmacology; D010725:Phosphocreatine / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014664:Vasodilation / Q000187:drug effects*
D002314:Cardioplegic Solutions; D010725:Phosphocreatine; D000255:Adenosine Triphosphate; D005996:Nitroglycerin; D008274:Magnesium; D000109:Acetylcholine