Abstract |
We investigated the efficacy of histidine in reducing ischemia-reperfusion (I/R)-induced myocardial injury in isolated perfused rat hearts. In I/R hearts, the contractile function and coronary flow were 59 +/- 10 and 78 +/- 6% of control. Perfusion with histidine resulted in significant increase in contractility (94 +/- 4%) and coronary flow (92 +/- 4%). The incidence of arrhythmias during reperfusion was 100% (10 out of 10) in the I/R hearts with an average duration of 12.22 +/- 1.55 (SE) min. The duration of arrhythmias was shortened to 8.24 +/- 1.46, 2.15 +/- 0.9, and 2.49 +/- 1.50 min with 10, 25, and 50 mM histidine, respectively. The duration of sinus rhythm increased from 6.26 +/- 1.56 min in I/R hearts to 10.66 +/- 1.55, 14.99 +/- 1.61, and 17.18 +/- 0.95, and 11.73 +/- 0.93 min after perfusion with 10, 25, and 50 mM histidine, and superoxide dismutase (SOD)- catalase- mannitol, respectively. Electron microscopy revealed significant ultrastructural damage of myocytes in I/R hearts, which included swelling of the mitochondria and disruption of both the sarcolemma and the myofibrils. Histidine reduced the ultrastructural damage in a dose-dependent fashion. In general, the protective effect of histidine was superior than SOD- catalase- mannitol. We conclude that histidine protects myocardium against I/R damage most likely by a singlet oxygen scavenging mechanism.
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Authors | R C Kukreja, K E Loesser, A A Kearns, S A Naseem, M L Hess |
Journal | The American journal of physiology
(Am J Physiol)
Vol. 264
Issue 5 Pt 2
Pg. H1370-81
(May 1993)
ISSN: 0002-9513 [Print] United States |
PMID | 8498550
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't, Research Support, U.S. Gov't, P.H.S.)
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Chemical References |
- Reactive Oxygen Species
- Histidine
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Topics |
- Animals
- Arrhythmias, Cardiac
(etiology)
- Heart
(drug effects)
- Histidine
(pharmacology)
- In Vitro Techniques
- Male
- Microscopy, Electron
- Myocardial Ischemia
(complications, pathology, physiopathology)
- Myocardial Reperfusion
- Myocardial Reperfusion Injury
(prevention & control)
- Myocardium
(ultrastructure)
- Perfusion
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species
(metabolism)
- Time Factors
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