H. Korb

Changes in myocardial substrate utilisation and protection of ischemic stressed myocardium by oxfenicine [(S)-4-hydroxyphenylglycine]

SummaryPotential protective effects of oxfenicine [(S)-4-hydroxyphenylglycine] in ischemic stressed canine myocardium have been studied. This compound is characterized as a drug leading to metabolic inhibition of free fatty acid (FFA) metabolism.The drug (0.06 mmol·kg−1 body weight) caused no changes in hemodynamics or energy demand (Et) but depressed myocardial oxygen consumption (MVO2) by 11% (P<0.02). Significant changes in FFA and lactate metabolism were observed: lactate extraction (EX) increased from 22.5–37.1 μmol/min, extraction ratio (EXR) from 16.5–30% and oxygen extraction ratio (OER) from 24.8–38%; EX of FFA decreased from 6900–5000 nmol/min, EXR from 48.2–31.4% and OER from 59.7–46.6%. Arterial concentrations of FFA and lactate remained unchanged. EX, EXR and OER of glucose were not affected under basic conditions.In the same collective, repeated ischemia (3 min) was produced by proximal occlusion of the left anterior descending artery (LAD). The efficiency of the drug was examined by (a) the amounts of ischemia metabolites released in the early reperfusion and (b) quantification of O2-debt and O2-repayment in the occlusion- and reperfusion periods. Compared to control occlusions, premedication led to a reduced O2-debt (P<0.01) combined with a reduced amount of oxygen additionally taken up in the early reperfusion (P<0.05). Furthermore, release of potassium increased (+7.1%; P<0.05); release of lactate (-32%, P<0.001) and inorganic phosphate (-34%, P<0.01) decreased.These data give support to the concept that a pharmacologically induced shift of cardiac metabolism with reduction of FFA utilisation may be favourable in circumstances with limited oxygen supply.

Increase of myocardial oxygen consumption due to active diastolic wall tension.

SummaryA marked increase in left ventricular diastolic pressuren

Preservation of myocardium in transient ischemia by the thromboxane synthetase inhibitor UK 38.485.

(bar P_{LVD} )

Estimation of myocardial blood flow heterogeneity by transorgan helium transport functions.

n relative to volume is regularly observed during angina pectoris and may contribute to further deteriorations of myocardial perfusion in the ischemic myocardium and to pulmonary congestion as well. A possible simultaneous increase in myocardial oxygen consumption (MVO2) due to a reversible diastolic tone during transient ischemia has not been taken into consideration in previous studies on alterations in ventricular diastolic properties.13 closed-chest experiments were carried out in clinical catheterization technique with situations of highn

A new model for testing therapeutic interventions during myocardial ischemia

(Mdot VO_2 )

Protective effects of hypothermia on ischemic stressed myocardium during short-term, repeated coronary artery occlusion

n (18–50 mm Hg) relative to volume induced by right ventricular pacing (n=19; 172±5 beats/min) and catecholamine-induced reversible diastolic tone (n=17) in moderate hypothermia (31°C).n