Myocardial ischemic contracture. Metabolites affect rigor tension development and stiffness.
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منابع مشابه
Myocardial ischemic contracture. Metabolites affect rigor tension development and stiffness.
Myocardial ischemia is characterized by a decrease in phosphocreatine (PCr) and Mg(2+)-ATP contents as well as an accumulation of myosin ATPase reaction products (inorganic phosphate [P(i)], protons, and Mg(2+)-ADP). The possibility that these metabolites play a role in rigor tension development was checked in rat ventricular Triton X-100-skinned fibers. Rigor tension was induced by stepwise de...
متن کاملContracture During Myocardial Ischemia
The effects of inosine (INO) on substrate metabolism and rigor formation in ischemic myocardium were examined in isolated rabbit hearts. Metabolite content was assessed in tissue extracts by chemical analysis and in the whole heart by `C and 31P nuclear magnetic resonance spectroscopy. In ischemic hearts metabolizing either [3-'3Clpyruvate or [1-13C glucose, 1 mM INO increased both total and D3...
متن کاملMyocardial contracture and accumulation of mitochondrial calcium in ischemic rabbit heart.
The relationship between myocardial contracture and cell calcium was studied in electrically paced, isolated perfused rabbit hearts. Isovolumic left ventricular dP/dt and end-diastolic pressure were utilized as indexes of contractility and ventricular stiffness. After 60 min of low flow (ischemia) without or with reperfusion at high flow for 10 min, calcium was measured in the mitochondrial fra...
متن کاملIncreased diastolic chamber stiffness during demand ischemia: response to quick length change differentiates rigor-activated from calcium-activated tension.
BACKGROUND Increased diastolic chamber stiffness (increased DCS) during angina (demand ischemia) has been postulated to be generated by increased diastolic myocyte calcium concentration. METHODS AND RESULTS We reproduced demand ischemia in isolated isovolumically contracting red-cell-perfused rabbit hearts by imposing pacing tachycardia during global low coronary blood flow (32% of baseline)....
متن کاملThe influence of the rate of rigor state development on its tension in single muscle fibre.
The rigor tension and stiffness of glycerinated fibres from rabbit psoas muscle were found to vary markedly in dependence on the rate of substitution of the solutions in the experimental chamber. The maximum value of rigor tension, which is close to that activated by Ca2+ with pCa4, was obtained at the slow development of rigor in the absence of Ca2+ ions. The observed dependence is assumed to ...
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ژورنال
عنوان ژورنال: Circulation Research
سال: 1994
ISSN: 0009-7330,1524-4571
DOI: 10.1161/01.res.74.5.920