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Is stunning prevented by ischemic preconditioning?
- Source :
-
Molecular and cellular biochemistry [Mol Cell Biochem] 1998 Sep; Vol. 186 (1-2), pp. 123-9. - Publication Year :
- 1998
-
Abstract
- In a model of global ischemia in the isolated perfused rat heart, a 20 min ischemic period followed by 30 min of reperfusion induces a decrease in isovolumic developed pressure (LVDP) and +dP/dtmax to 61+/-6% and 61+/-7% of baseline, respectively. Left ventricular end-diastolic pressure (LVEDP) increases to 36+/-4 mmHg at the end of the reperfusion period. No significant necrotic area as assessed by triphenyltetrazolium chloride (TTC) was detected at the end of the reperfusion period. By an immunohistochemical method using antiactin monoclonal antibodies 10.8+/-1.9% of unstained cells were detected in the stunned hearts and 10.3+/-1.2% in control hearts. Preceding the ischemic episode with a cycle of 5 min of ischemia followed by 10 min of reperfusion (ischemic preconditioning) protected contractile function. LVDP and +dP/dtmax now stabilized at 89+/-5% and 94+/-5% of baseline respectively. LVEDP was 20+/-2 mmHg at the end of the reperfusion period. The protection of contractile dysfunction after 20 min of ischemia was achieved also by early reperfusion of low Ca2+-low pH perfusate. With this intervention LVDP stabilized at 87+/-5% of baseline. LVEDP was 12+/-2 mmHg at the end of the reperfusion period. A positive inotropic intervention induced by a modified postextrasystolic potentiation protocol at the end of the reperfusion period increases LVDP to levels higher than baseline in the stunned hearts. However, these values were less than those obtained in control hearts. Ischemic preconditioning significantly increased the maximal inotropic response. Therefore, ischemic preconditioning diminishes the contractile dysfunction of early stunning.
- Subjects :
- Animals
Blood Pressure
Disease Models, Animal
In Vitro Techniques
Myocardial Contraction
Myocardial Infarction pathology
Myocardial Infarction prevention & control
Myocardial Stunning etiology
Myocardial Stunning physiopathology
Rats
Time Factors
Ventricular Function, Left
Ischemic Preconditioning, Myocardial
Myocardial Stunning prevention & control
Subjects
Details
- Language :
- English
- ISSN :
- 0300-8177
- Volume :
- 186
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- Molecular and cellular biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 9774193