THE EFFECTS OF ELECTRICAL ACUPUNCTURE TO PATELLAR TENDON AND ELECTRICAL STIMULATION TO FEMORAL NERVE ON THE BLOOD FLOW OF THE PATELLAR TENDON IN RAT

Abstract

The effects of electrical acupuncture at the patellar tendon and electrical stimulation of the femoral nerve on patellar tendon blood flow were evaluated using laser Doppler flowmetry in anesthetized rats. In most subjects the blood flow in the patellar tendon rapidly decreased for 30 seconds after the start of local electrical acupuncture and then increased above baseline. Changes in blood flow did not necessarily follow changes in arterial blood pressure. Changes in tendon blood flow induced by electrical stimulation of the femoral nerve were similar to those induced by electrical acupuncture at the patellar tendon. Arterial blood pressure and heart rate were not affected by electrical stimulation of the femoral nerve. Phentolamine administration abolished the decreased patellar tendon blood flow seen after initiating electrical acupuncture at the patellar tendon, whereas atropine abolished the increased patellar tendon blood flow seen after terminating electrical acupuncture at the patellar tendon. Furthermore, atropine did not evoke increased blood flow following electrical stimulation of the femoral nerve. These results suggest that the decrease of blood flow seen after initiating electrical acupuncture may be controlled by sympathetic vasoconstrictor nerves and the increase of blood flow following electrical acupuncture may be controlled by cholinergic vasodilator nerves.