Effect of estrogen on global myocardial ischemia-reperfusion injury in female rats

Peiyong Zhai, Thomas E. Eurell, Robert Cotthaus, Elizabeth H. Jeffery, Janice M. Bahr, David R. Gross

Research output: Contribution to journalArticlepeer-review

Abstract

We investigated the effects of estrogen on global myocardial ischemia-reperfusion injury in rats that were ovariectomized (Ovx), sham-operated, or ovariectomized and then given 17β-estradiol (E2β) supplementation (Ovx+E2β). Hearts were excised, cannulated, perfused with and then immersed in chilled (4°C) cardioplegia solution for 30 min, and then retrogradely perfused with warm (37°C), oxygenated Krebs-Henseleit bicarbonate buffer for 120 min. The coronary flow rate, first derivative of left ventricular pressure, and nitrite production were all significantly lower in Ovx than in sham-operated or Ovx+E2β hearts. However, coronary flow rates or nitrate production were not consistently different throughout the entire reperfusion period. Ca2+ accumulated more in Ovx rat hearts than in sham-operated or Ovx+E2β hearts, and mitochondrial respiratory function was lower in Ovx hearts than in hearts from the other two groups. Marked interstitial edema and contraction bands were seen in hematoxylineosin-stained sections of Ovx rat hearts but not in hearts from either of the other groups. Hematoxylin-basic fuchsinpicric acid-stained sections revealed fewer viable myocytes in hearts from the Ovx group than from the sham or Ovx+E2β group. Transmission electron microscopy demonstrated more severely damaged mitochondria and ultrastructural damage to myocytes in Ovx rat hearts. Our results indicate that estrogen plays a cardioprotective role in global myocardial ischemia-reperfusion injury in female rats.

Original languageEnglish (US)
Pages (from-to)H2766-H2775
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Volume279
Issue number6 48-6
DOIs
StatePublished - 2000

Keywords

  • Calcium
  • Mitochondrial function
  • Myocardial ultrastructure
  • Nitric oxide

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)

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