Changes in cardiac cathepsin B activity in response to interventions that alter heart size or protein metabolism: Comparison with cathepsin D

J. Stanley Crie, Phyllis Morton, Kern Wildenthal

Research output: Contribution to journalArticle

7 Scopus citations

Abstract

The specific activity of cardiac cathepsin B is significantly decreased by starvation and corticosteroid treatment in vivo, and by exposure of the heart in vitro to insulin, hydrocortisone and cycloheximide. Increases in cathepsin B activity occur following isoproterenol-induced cardiac damage in vivo and exposure in vitro to sucrose. Cathepsin B activity in heart is not changed during normal aging or in thyrotoxicosis. These responses are different from simultaneous changes in cardiac cathepsin D activity in several instances (starvation, corticosteroid treatment, aging and thyrotoxicosis). In the past, measurements of cathepsin D activity in heart have sometimes been considered to be representative of lysosomal proteinase activity in general and used as an index of cardiac lysosomal proteolytic capacity. The present results suggest that changes in cathepsin D do not necessarily reflect alterations in other lysosomal proteinases and may not serve as a valid indicator of overall lysosomal proteolytic capacity under all conditions.

Original languageEnglish (US)
Pages (from-to)487-494
Number of pages8
JournalJournal of Molecular and Cellular Cardiology
Volume15
Issue number8
DOIs
StatePublished - Aug 1983

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Keywords

  • Ageing
  • Cathepsin B
  • Cathepsin D
  • Lysosomes
  • Proteolysis
  • Starvation
  • Thyratoxicosis

ASJC Scopus subject areas

  • Molecular Biology
  • Cardiology and Cardiovascular Medicine

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