Hypoalgesic effect of laser photobiostimulation shown by rat tail flick test.
We demonstrated a 50% increase in pain threshold following laser photobiostimulation (LPBS), employing rat tail-flick test. Helium-neon laser (1 mW) of three different pulsing frequencies (4, 60, and 200 Hz) was applied on tail low resistance point for 15 seconds and tail-flick latencies were measured 30 minutes, 1 hour, 24 hours, 48 hours and 7 days later. LPBS of 4 Hz produced hypoalgesia of rapid onset and short duration while the response to 60 Hz was delayed and lasted longer. LPBS of 200 Hz did not produce any hypoalgesia.
D000818:Animals; D053685:Laser Therapy; D008297:Male; D010146:Pain / Q000532:radiotherapy*; D010775:Photic Stimulation; D051381:Rats; D011919:Rats, Inbred Strains