CORRELATIVE STUDIES ON SARCOLEMMAL ULTRASTRUCTURE, PERMEABILITY, AND LOSS OF INTRACELLULAR ENZYMES IN THE ISOLATED HEART PERFUSED WITH CALCIUM-FREE MEDIUM

  • 1 January 1979
    • journal article
    • research article
    • Vol. 97  (2) , 411-+
Abstract
Effects of Ca2+-free perfusion and Ca-free perfusion followed by reperfusion with Ca2+ on sarcolemmal structure, sarcolemmal permeability and creatine phosphokinase loss were investigated in isolated perfused rat hearts. Release of creatine phosphikinase was significant (P < 0.0002) after 4-5 min of perfusion with Ca2+-free medium, but later releases in comparison to their immediately preceding periods became significant only after more than 20 min perfusion. Poor correlation betwee enzyme loss and La3+ permeability prior to 20 min of Ca2+-free perfusion was noted. After 20 minutes of Ca2+-free perfusion, the basal lamina was separated from the plasma membrane and La3+ was seen in the cytoplasm. The intramembranous particles began to aggregate at that time. The morphologic and enzymatic changes were dramatic following reperfusion of Ca2+-free perfused hearts. Morphologic changes in these hearts included separation of basal lamina, cellular separation at the intercalated disk, dissolution of actin filaments at the region of I band, contraction bands, cell swelling and staining or filling of mitochondrial membranes with La3+. Increased sacrolemmal permeability was associated with tears and aggregation of intramembranous particles in the sarcolemmal lipid bilayers. Apparently reperfusion of Ca2+-free perfused cells causes irreversible damage to the sarcolemmal lipid bilayer, and the degree of alterations induced in the cells in dependent upon the initial duration of Ca2+-free perfusion.