The effect of lumbar sympathetic stimulation on the vasculature of bone.
1 The nutrient artery to the tibia of anaesthetized dogs was perfused at a constant rate by blood from the femoral artery and the perfusion pressure in the artery, the intramedullary pressure of the bone and the pressure in the nutrient vein recorded. 2 Low frequency stimulation (1 to 5 HZ) of the lumbar sympathetic chain always increased the perfusion pressure but the intramedullary pressure sometimes increased, sometimes decreased and sometimes remained unchanged. 3 The alpha-adrenoceptor blocking agents, phentolamine (1 mg/kg i.v.) and dihydroergotamine (0.5 mg/kg i.v.) reduced or abolished these effects whereas the beta-adrenoceptor blocking agent, propranolol (1 mg/kg i.v.) did not modify them. 4 The nutrient vein end pressure did not differ significantly from the intramedullary pressure and underwent similar variations during stimulation of the lumbar sympathetic chain.
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D001842:Bone and Bones / Q000098:blood supply*; D004285:Dogs; D004558:Electric Stimulation; D012039:Regional Blood Flow / Q000187:drug effects; D013564:Sympathetic Nervous System / Q000502:physiology*; D014690:Venous Pressure / Q000187:drug effects
D000317:Adrenergic alpha-Antagonists; D000319:Adrenergic beta-Antagonists