쥐에 대한 레이저 자극시 진통효과

Abstract

Laser photobiostimulation (LPBS) is one of the recent additions to therapeuticprocedures used in chronic pain management. Though widely used, a clear understandingof its mechanìsm of actìon was not disclosed. In additìon, the energy density thatproduces maximal benefìt has not yet been estab!ished. The purposes of thìs study wereto determine the effects of LPBS on pain relief in rat and to determìne treatment dosage. Eight, 8-week old female, Sprague-Dawley rats were employed. All subjects wereassigned to one of four groups: a sham laser group, a 0.4 J/crri‘ laser group, a 2.0 J/cm'laser group, and a 6.0 J/cm' laser group. Ga-As laser (904 nm wavelength) of threedifferent energy densities <0.4, 2.0, 6.0 J/cm') was applied on a tail acupuncture point andtail-flick latencies were measured five times pre-and post-treatment as followingschedules: 30 minutes, 1 hour. 24 hours. 48 hours, and 7 davs later. An increase in pain threshold was demonstrated following LPBS, emp!oying rat tail-flick test. LPBS of 2.0 J/cm' produced hypoalgesia of rapid onset and short duration (1 hour, 24 hours) while theresponse to 6.0 J/cm2 was delayed and lasted longer (48 hours, 7 days). LPBS of 0.4 J/crn'did not produce any hypoalgesia.