Objective: The aim was to study the contractility of the conduit coronary artery to vasoactive agents in developing and established volume overload cardiac hypertrophy and to compare it with structural alterations in the artery.
Methods: Aortic valve insufficiency in rabbits was used to produce a volume overloaded heart. One month (developing hypertrophy), and four months (stabilised hypertrophy) after inducing aortic insufficiency, the isometric contraction of the coronary artery to acetylcholine, serotonin, and potassium chloride was recorded.
In the course of adaptation of the rabbit heart to volume load passive diastolic properties of the hypertrophic ventricle and myocardium were changing significantly. On day 30 following perforation of the aortic valve stiffness of the ventricle was reduced, yet normalized ventricular stiffness and myocardial stiffness were increased. These changes were prevented by beta adrenergic blockade during development of adaptation of the heart to volume load.
View Article and Find Full Text PDFStereological morphometry was used to determine ultrastructural changes of the myocardium in the course of well defined chronic hemodynamic overload. Overload was induced in the hearts of rabbits by perforation of aortic valves. Relative volumes of mitochondria, myofibrils were measured in tissue samples taken from subendocardial and subepicardial region of the left ventricle.
View Article and Find Full Text PDFBratisl Lek Listy
February 1989
Induced insufficiency of the aortal valve in rabbits is followed by gradual adaptation of the heart to volume load. In the period of developing hypertrophy, we studied the changes in the passive diastolic properties of the ventricle. By analyzing the passive relationship between the volume of the ventricular cavity and the intraventricular pressure, the stiffness of the ventricle, normalized ventricular stiffness, and myocardial stiffness were determined.
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