RESISTANCE TO ISCHEMIC DAMAGE IN HEARTS OF STARVED RABBITS - CORRELATION WITH LYSOSOMAL ALTERATIONS AND DELAYED RELEASE OF CATHEPSIN-D

  • 1 January 1980
    • journal article
    • research article
    • Vol. 43  (3) , 197-207
Abstract
Prolonged starvation produces dramatic changes in the lysosomal properties of the heart and in its energy stores and might be expected to alter some of the characteristic cardiac responses to ischemia. To test this possibility, the circumflex coronary artery of rabbits, fed normally or starved for 6 days, was ligated. Ultrastructural evidence of myocytic damage following 30-120 min of ischemia was much less severe in the starved animals than in the normally fed group. The development of signs of irreversible injury (e.g., osmiophilic densities in mitochondria) was delayed for 1 h or more by starvation. A similar delay occurred in the biochemical redistribution of cathepsin D activity and in the cytoplasmic release of acid hydrolases from lysosomes and sarcoplasmic reticulum. A marked protective effect of starvation against myocardial ischemia may occur. In starved and fed animals ischemically induced release of lysosomal enzymes was closely linked temporally to the development of subcellular damage.