Relation of sympathetic nervous system to blood pressure of bone marrow

Abstract

Pressures in the femoral artery and in the marrow of the femur of adult cats anesthetized with Nembutal were measured, using 16 gauge needles and Stratham strain gauge transducers. Records were obtained by means of a Sanborn twin viso, model 60. Bone marrow pressures varied between 24 and 114 mm Hg in different animals. Occlusion of the arterial supply caused a fall in marrow pressure. Stimulation of the cut peripheral end of either vagus reduced both systemic and marrow pressures. Stimulation of the cut peripheral end of the splanchnic nerve, or intravenous injection of epinephrine or norepinephrine, increased systemic arterial pressure and decreased marrow pressure. Stimulation of the peripheral end of the abdominal sympathetic trunk reduced marrow pressure. The increase in systemic arterial pressure produced by occlusion of both carotid arteries is associated with an increase in marrow pressure. Marrow pressures are decreased after a large hemorrhage or when amyl nitrite is inhaled. Unilateral denervation of the blood vessels supplying the femur of a decerebrate cat produces a higher marrow pressure as compared with that present in the contralateral innervated femur.