Aspirin eliminates the cutaneous vasodilation caused by electrical stimulation

Abstract

Several studies have demonstrated the effectiveness of electrical stimulation (e-stim) in promoting the healing of ischemic skin ulcers and wounds. It is thought that the improved healing may be due in part to increased dermal blood flow. The purpose of this study was to determine the magnitude of the blood flow response to a clinical e-stim protocol, and to establish the effects of aspirin (an inhibitor of prostaglandin synthesis) on that response. Twelve healthy female subjects ages 20–24 were studied: six subjects were used to determine the vascular response to e-stim without aspirin; the other six subjects had the vascular response examined 24–48 hrs following oral administration of 975 mg of aspirin. A low-frequency clinical e-stim protocol was applied to the lower leg at 2 Hz and 10-45 mA for 10 min. Using laser Doppler flowmetry, microcirculatory dermal blood flow was measured midway between the e-stim electrodes that were placed 5 cm apart. Results showed that estim increased blood flow by 27% (P=0.05) and the vascular response usually occurred within 1-2 min. The vascular response was not present in those subjects who had received aspirin (4% increase in blood flow, P=0.42). Conclusions: e-stim is effective at modestly increasing blood flow to dermal tissues, and prostaglandin inhibition by aspirin prevents this current-induced vasodilation.