Characterisation of the calcium paradox in the isolated perfused pigeon heart: protection by hypothermia, acidosis and alkalosis.

The aim of the present investigation was to examine the conditions inducing a calcium paradox in the isolated perfused pigeon heart. Loss of mechanical and electrical activity, creatine phosphokinase and total protein release were used to define cell damage. Perfusion was performed at 36, 38, 40 and 42 degrees C and calcium deprivation lasted 5, 10, 20 or 40 min.