[The ratio of systemic and coronary fractions of left ventricular output in reflex pressor reactions].

In acute experiments the participation of coronary and systemic fractions was studied during suppression of the carotid sinus baroreceptors by the occlusion of the carotid arteries and stimulation of the tibial nerve afferent fibers. In most tests systemic fraction was reduced in carotid arteries occlusion and increased in tibial nerve stimulation. The coronary fraction was always increased. The cardiac output (the sum of systemic and coronary fractions) was steady with blood pressure increase by 20 to 70%. The role of coronary fraction in the mechanism of homeometric regulation of the heart is discussed.