Rapid diminution of calcium in the myocardium by transfer to pericardial solutions. Myocardial dialysis.
A new method is described for the controlled and specific depletion of calcium from the vascularly perfused heart of experimental animals by means of dialysis, using a pericardial solution. A 30-40 ml isotonic phosphate buffer pH 7.3 with a low Ca2+ and high Mg2+ concentration (0.2 and 2.7 mM respectively) was inserted into the pericardial cavity of anaesthetized dogs and kept there for 10 or 60 min. The calcium content of the subendocardial and subepicardial halves of the left ventricular wall was similarly decreased to about 70% (P < 0.01) within 10 min and to 62% (P < 0.001) at 60 min, compared to that of hearts dialysed for 60 min in a standard solution of Ca2+ 1.2 mM and Mg2+ 1 mM. Calcium content of the myocardium dialysed with low Ca2+ and a standard Mg2+ solution decreased to only 75% (P < 0.01) at 60 min. Similar changes of calcium were measured in other parts of the heart. An increase in Ca2+ concentration in the pericardial solution was observed at the same time as a decrease in calcium in the myocardium. The increase in Ca2+ reached about 0.7 mM at 60 min, but decreased slightly, and finally, fell to 85% of pre-dialysis values at 60 min. It is concluded that this method of myocardial dialysis is effective in reducing myocardial calcium and is influenced by the duration of dialysis and the Mg2+ content of dialysate.
Darsinos
J T
JT
University of Athens, School of Medicine, Department of Clinical Therapeutics, Greece.
Samouilidou
E C
EC
Karli
J N
JN
Pistevos
A C
AC
Theodorakis
M G
MG
Papoutsis
C P
CP
Levis
G M
GM
Moulopoulos
S D
SD
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002314:Cardioplegic Solutions; D003956:Dialysis; D004285:Dogs; D008274:Magnesium / Q000378:metabolism; D008955:Models, Cardiovascular; D009206:Myocardium / Q000378:metabolism*; D010477:Perfusion; D010496:Pericardium
D002314:Cardioplegic Solutions; D008274:Magnesium; D002118:Calcium