[The effect of the ventral structures of the medulla oblongata on systemic arterial pressure and on the resistance and capacitance of the skeletal muscle vessels].

Following the isolation of ventral portions of the medulla oblongata from the dorsal ones and from the upper parts of the c. n. s. in cats, no changes were found in the initial level of systemic blood pressure, in perfusion pressure or in venous outflow in the m. gastrocnemius, vessels. Electrical stimulation of ventral portions of the lateral paragigantocellular nucleus under these conditions increased the systemic AP, regional vascular resistance and decreased the capacitance of the n. gastrocnemius' vessels, whereas after bilateral electrical coagulation of the nucleus the stimulation led to a stable and obvious decrease in the systemic AP and perfusion pressure in the muscle vessels. No changes of the regional vascular capacitance were noted. The significance of ventral structures of medulla oblongata in maintaining of initial AP level, formation of tonic neurogenic messages to arterial vessels of m. gastrocnemius and in actualization of the reflex neurogenic effects upon arterial and venous vessels of skeletal muscles, is discussed.