[Differentiated interaction of hypothalamic and bulbar mechanisms in regulating blood flow in skeletal muscles]

Acute experiments on dogs anesthetized with chloralose and numbutal were made to examine the changes in the blood flow in the muscles of hind limbs in response to stimulation of different parts of the hypothalamus before and after elimination of the effects of the main reflexogenic zones. Vasodilatation in leg muscles evoked by stimulation of the anterior hypothalamus (supraoptic dorso- and ventro-medial nuclei) increased after elimination of baroceptor effects. Qualitatively, the same response evoked by stimulation of the mamillary nuclei diminished. A conclusion has been made about differential interaction of the hypothalamic and bulbar mechanisms in muscle circulation control. It is assumed that vasodilatation of the skeletal muscles evoked by stimulation of the posterior hypothalamus might be determined by reflex inhibition of the vascular tone.