The phosphate pool of isolated dog heart during global ischaemia: comparison of two cardioplegic solutions with 31P NMR spectroscopy.
31P NMR spectroscopy was used to study the time course of changes in the concentration of high-energy metabolites and intracellular pH in the dog myocardium during hypothermic ischaemia at 9 degrees C in Bretschneider (HTK-B) and St. Thomas' Hospital (StTH) cardioplegic solutions. It was found that ATP and phosphocreatine degrade slowlier in HTK-B than in StTH, with phosphocreatine depletion occurring within 7.9 +/- 1.4 h in HTK-B and within 6.2 +/- 1.4 h in StTH. The values are virtually identical with the time intervals at which ATP concentration falls below the critical level (60% of initial ATP concentration). In agreement with biochemical analysis, a higher concentration of phosphomonoesters was noted until the 180th minute of ischaemia in HTK-B, a finding suggesting more rapid glycogen degradation in HTK-B. Even though HTK-B contains a high concentration of histidine buffer, higher values of intracellular pH were found during ischaemia in StTH. The effect of extracellular concentration of sodium ions on intracellular pH is discussed.
Horská
A
A
Department of Magnetic Resonance, Institute for Clinical and Experimental Medicine, Prague.
Vavrínková
H
H
Hájek
M
M
Tutterová
M
M
Böhm
F
F
Kolc
J
J
Suchánek
M
M
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D001639:Bicarbonates / Q000494:pharmacology; D002122:Calcium Chloride / Q000494:pharmacology; D004285:Dogs; D005260:Female; D005947:Glucose / Q000494:pharmacology; D006003:Glycogen / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008274:Magnesium / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D008353:Mannitol / Q000494:pharmacology; D009206:Myocardium / Q000378:metabolism*; D010100:Oxygen / Q000378:metabolism*; D010710:Phosphates / Q000378:metabolism*; D011189:Potassium Chloride / Q000494:pharmacology; D011343:Procaine / Q000494:pharmacology; D012965:Sodium Chloride / Q000494:pharmacology
D001639:Bicarbonates; C039984:Bretschneider cardioplegic solution; D010710:Phosphates; C041711:St. Thomas' Hospital cardioplegic solution; D008353:Mannitol; D012965:Sodium Chloride; D011343:Procaine; D011189:Potassium Chloride; D000255:Adenosine Triphosphate; D006003:Glycogen; D008274:Magnesium; D005947:Glucose; D002122:Calcium Chloride; D010100:Oxygen