Laser photobiostimulation-induced hypoalgesia in rats is not naloxone reversible.
Laser photobiostimulation (LPBS) at the pulsing frequency of 4 Hz applied to the low resistance point located at the base of the tail of the rat, (Governing Vessel Meridian 1), produced a hypoalgesic effect, measured by tail-flick and hot-plate techniques. Pre-treatment with low dose naloxone (2 mg/kg) did not reverse the hypoalgesic effect of LPBS. High dose naloxone (20 mg/kg) reversed only partially, but significantly, the hypoalgesic effect of LPBS measured by hot-plate, but not that measured by the tail-flick technique. These data suggest that mechanisms other than endogenous opioids may be involved in LPBS-induced hypoalgesia.
Ponnudurai
R N
RN
UMD-New Jersey Medical School, Department of Anesthesiology, Newark 07103.
Zbuzek
V K
VK
Niu
H L
HL
Wu
W H
WH
D000698:Analgesia; D000818:Animals; D053685:Laser Therapy; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D009619:Nociceptors / Q000187:drug effects / Q000528:radiation effects; D010146:Pain / Q000503:physiopathology*; D010147:Pain Measurement; D051381:Rats; D011919:Rats, Inbred Strains; D011930:Reaction Time / Q000187:drug effects / Q000528:radiation effects; D011957:Receptors, Opioid / Q000187:drug effects* / Q000528:radiation effects
D011957:Receptors, Opioid; D009270:Naloxone