Distribution of glycogen in the rat heart

The total and trichloroacetic acid soluble fractions of glycogen were determined in various portions of the rat heart. The amount in each portion was compared on the basis of the nitrogen content of the same sample. The total glycogen concentration was highest in the atria, lowest in the left ventricle and intermediate in the septum and right ventricle. A similar distribution was found for TCA soluble glycogen. The possible role of glycogen in cardiac energetics and structure is discussed.

Effect of acute mitral insufficiency of various degrees on mean arterial blood pressure, coronary blood flow cardiac output and oxygen consumption

In anesthetized dog, acute mitral insufficiency of variable severity results in an increase in coronary blood flow and myocardial oxygen consumption. The increase in oxygen consumption is interpreted as meaning either that the left ventricle expends a significant amount of energy in regurgitating blood into the left atrium during mitral insufficiency, or that mitral insufficiency induces a decrease of the efficiency of the left ventricle or both.

Studies of the effect of antiarrhythmic drugs on carbohydrate metabolism of rat heart muscle in vitro

The effect of antiarrhythmic drugs on the oxidation of glucose by heart tissue was studied. Quinine and quinidine inhibited oxygen consumption and glucose utilization by rat heart slices and homogenates, while chloroquine and procaine amide had little effect.

Effect of catecholamines, l-epinephrine and l-norepinephrine on coronary flow and oxygen metabolism of the myocardium

The effect of continuously infused intravenous l-epinephrine and l-norepinephrine (0.1–2.5 gamma/kg/min.) was determined in the open-chest, anesthetized dog prepared for measurement of total coronary flow. Coronary blood flow, myocardial oxygen availability and coronary venous oxygen content consistently increased after catecholamine administration despite wide fluctuations, above and below control values, in heart rate and mean aortic pressure at constant cardiac output. Thus, there was a significant decrease in the coronary arteriovenous oxygen difference after catecholamine administration. The increase in coronary flow and decrease in the coronary A-V oxygen difference were seen even when blood pressure and heart rate were lowered. It is concluded that the departure from the usual relationship between coronary flow and myocardial oxygen consumption is attributable to coronary vasodilatation. However, myocardial oxygen consumption is still the primary factor controlling coronary flow during catecholamine action.