[Changes in the blood supply and oxygen tension of the brain following afferent somatic stimulation]

Effect of somatic afferent C fibres stimulation on rCBF (H2 - clearance method) and cerebral tissue pO2 was studied in 20 dogs. MABP and partial pressure of the arterial blood gases were stabilized before and during 3 min stimulation of the sciatic nerves. The blood flow was changed by 32% in the thalamus and by 17% in the hypothalamus during ipsilateral stimulation. Contralateral sciatic nerve stimulation caused smaller but still a significant fall of the rCBF and increase of the CVR in both regions. Parallel to these changes, tissue pO2 decreased by 19% in the hypothalamic and by 25% in the thalamic areas as compared with the prestimulation level.