A phosphorus-31 nuclear magnetic resonance study of myocardial ATP content during postischemic low calcium reperfusion.
Postischemic reperfusion injury can be modified by transient low calcium (Ca2+) reperfusion, although the data on the optimal [Ca2+] are controversial. High-energy phosphates and contractile function of isolated perfused rat hearts (37 degrees C, 300 beats/min) were studied simultaneously during global ischemia (30 min) and reperfusion (10 min at [Ca2+] = 1.3, 0.05, 0.1, 0.3, 0.5 and 0.7 mmol/l, followed by 20 min at [Ca2+] = 1.3 mmol/l), using phosphorus-31 nuclear magnetic resonance (31P NMR) spectroscopy. Reperfusion with 1.3 mmol/l Ca2+ after 0.05 or 0.1 mmol/l Ca2+ largely abolished the recovery of ATP obtained during initial low Ca2+ reperfusion (calcium paradox effect). A [Ca2+] of 0.3 mmol/l was sufficiently high to prevent this detrimental effect; at the same time this concentration was sufficiently low to cause a substantial recovery of ATP, which was maintained upon switching to 1.3 mmol/l Ca2+. Recovery of ATP did not correlate with recovery of contractile function.
Ruigrok
T J
TJ
Department of Cardiology, University Hospital, Utrecht, The Netherlands.
Kirkels
J H
JH
Schreur
J H
JH
van Echteld
C J
CJ
D000255:Adenosine Triphosphate / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000008:administration & dosage* / Q000378:metabolism; D003326:Coronary Circulation; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains
D000255:Adenosine Triphosphate; D002118:Calcium