|Budget Amount *help
¥2,100,000 (Direct Cost : ¥2,100,000)
Fiscal Year 1994 : ¥600,000 (Direct Cost : ¥600,000)
Fiscal Year 1993 : ¥1,500,000 (Direct Cost : ¥1,500,000)
The aim of this study is to make a model of ishemic heart disease by constricting coronary artery, and to examine the change of cardiac function following hypothalamic stimulation and vasodilators administration. Coronary stenosis cats were made by constricting left anterior descending branch(LAD). For the evaluation of hemodynamics and cardiac function, following parameters were measured ; arterial blood pressure, heart rate, cardiac output, blood flow of LAD,dp/dt, oxygen tesion of cardiac muscle. Anterior hypothalamus was electrically stimulated to make the situation of psychological stress the same as during dental treatment. Blood pressure, heart rate, cardiac output, coronary blood flow, dp/dt were increased during hypothalamus stimulation and returned to the control value after the end of stimulation. Oxygen tension of cardiac muscle was not changed significantly. In coronary stenosis cats, the changes of these parameters following hypothalamus stimulation were smaller than in non-stenosis cats. This suggests that the contractility of cardiac muscle is decreased by constricting coronary artery, and reserve capasity of cardiac function for psychological stress is decreased. We are now investigating the influence of vasodilators, such as nitroglycerine and calsium channel blockers, on the hemodynamic changes and cardiac function following hypothalamus stimulation.