Activity of alkaline phospholipase A in lysosomes and mitochondria in damaged rabbit myocardium

: Alkaline phospholipases A were studied in rabbit myocardium under normal conditions and in heart impairment of various etiology. In mitochondrial fraction activity of phospholipase A was increased with elevation of Ca2+ concentration, while the enzyme was Ca2(+)-independent in lysosomes. Hemodynamic overloading of heart, acute local myocardial ischemia and diphtheritic intoxication led to an increase (2-4-fold) of mitochondrial phospholipases A activity with simultaneous decrease of the enzymatic activity in lysosomal membranes.