Infrared laser diode irradiation has no behavioral or biochemical effect on pain in the sciatic nerve ligation-induced mononeuropathy in rat.

摘要: Abstract The aim of this study was to evaluate the effect acute and repeated (5 days) treatment with various types infrared (IR) diode lasers probes (single- vs cluster-beam) on pain response in rats peripheral mononeuropathy produced by sciatic nerve ligation. Male Sprague-Dawley were anesthetized sodium pentobarbital, mid-thigh surgically exposed reveal nerve, around which four ligatures loosely tied. On postoperative day 5, skin over lesion subjected a 30-min daily local exposure from 904-nm IR laser (700 Hz, average output power 10 mW) single-beam probe, 830-nm Hz) either (average 50 or cluster-beam probe 15 mW), placebo for 5 consecutive days. Two responses (foot-withdrawal time hind-paw elevation time) measured both sides using radiant heat method days 9. In addition, cold allodynia 9 placing chilled metal plate (4 degrees C) measuring duration hind paws. 9, animals sacrificed collection samples brain lumbar spinal cord determination tissue concentrations dynorphin A1-8-like immunoactivity (DYN) specific radioimmunoassay (RIA). The withdrawal times right side all groups methods irradiation did not differ significantly as compared placebo-treated group when after surgery. No statistically significant differences unaffected left paw noted either. measurement similarly failed any laser-treated versus placebo. RIA analysis found that DYN elevated ipsilaterally ligation side, contralateral All modalities produce difference level groups. It is concluded reduce hyperalgesia induced rats.