Attenuation of isoproterenol-mediated myocardial injury in rat by an inhibitor of polyamine synthesis

Ulka R. Tipnis, Gui Ying He, Suzhen Li, Gerald Campbell, Paul J. Boor

Research output: Contribution to journalArticle

23 Scopus citations

Abstract

Objective: Ornithine decarboxylase (ODC) is an initial rate-limiting enzyme in the synthesis of polyamines (putrescine, spermidine, and spermine) that play a role in cell growth and differentiation. Recent studies have shown that spermidine and spermine cause injury to a variety of cells including myocytes in vitro. In this investigation, we used α-difluoromethylornithine (DFMO), a specific and irreversible inhibitor of ODC activity and polyamine synthesis to test the hypothesis that polyamines contribute to myocardial injury in rat. Methods: Male Sprague Dawley rats were treated with (i) saline (0.2 ml/day, s.c.), (ii) isoproterenol (ISO) (5 mg/kg/day for 8 days, s.c.) to produce necrotizing myocardial injury, or with (iii) DFMO + ISO. DFMO was started 2 days before the initiation of ISO and both ISO and DFMO were continued until the end of the experimental period. Myocardial injury was assessed by determining the increased release of creatine phosphokinase (CPK) and lactate dehydrogenase (LDH) into the plasma, and by morphometric analysis of the lesion area in heart sections stained with Gomori trichrome. Results: ISO induced the release of CPK and LDH by 6 hr and 24 hr, respectively, and produced subendocardial necrosis, which was both acute and resolving following 8 days of ISO. DFMO treatment inhibited ISO-induced increases in (i) ODC activity and putrescine and spermidine levels in heart, (ii) CPK and LDH activity in plasma, and (iii) the area of subendocardial lesions. Conclusions: These observations suggest that polyamines are one of the intracellular factors that contribute to ISO-mediated cardiac injury in the rat. (C) 2000 by Elsevier Science Inc.

Original languageEnglish (US)
Pages (from-to)273-280
Number of pages8
JournalCardiovascular Pathology
Volume9
Issue number5
DOIs
StatePublished - Nov 15 2000

ASJC Scopus subject areas

  • Pathology and Forensic Medicine
  • Cardiology and Cardiovascular Medicine

Fingerprint Dive into the research topics of 'Attenuation of isoproterenol-mediated myocardial injury in rat by an inhibitor of polyamine synthesis'. Together they form a unique fingerprint.

  • Cite this