Currently, photobiomodulation therapy (PBMT) is gaining space in the scientific and clinical environment. To help elucidate the importance of irradiance, this study evaluated the effect of two different PBMT irradiances (3.5 and 90 mW/cm²), given a fixed wavelength of 630 nm and a dose of 2 J/cm², on mechanical hyperalgesia following Complete Freund's Adjuvant (CFA) intraplantar (i.pl.) injection in mice. Additionally, we investigated the role of peripheral opioid and endothelin-B receptors (ET_B-R), as well as sex differences in treatment outcome. Different groups of male or female mice were evaluated 6 and 96 h after CFA. Mechanical hyperalgesia was evaluated 30 min after treatments. Naloxone or Bq-788 administration, fifteen minutes before PBMT or Sarafotoxin S6c, helped determine the involvement of peripheral opioid and ET_B-Rs on PBMT. Lastly, ET_B-Rs skin immunocontent in both sexes was quantified after PBMT consecutive daily treatments. PBMT at an irradiance of 90 mW/cm², was more effective than 3.5 mW/cm². Bq-788 and naloxone administration prevented the effects of PBMT and SRTX S6c; however, PBMT did not influence peripheral ET_B-Rs immunocontent. The results suggest that irradiance influences PMBT effect; and that activation of ET_B-R play a role in peripheral PBMT opioid induced analgesia. Lastly, PMBT effects do not appear to be sex-dependent.

当前，光生物调节疗法（PBMT）在科学和临床环境中正在获得发展。为了帮助阐明辐照的重要性，本研究评估了两种不同的PBMT辐照（3.5和90 mW / cm ²），在固定波长为630 nm且剂量为2 J / cm ^2的情况下对完全性痛觉过敏的影响小鼠体内的弗氏佐剂（CFA）足底（i.pl.）注射。此外，我们研究了外周阿片和内皮素B受体（ET _B-R）以及治疗结果中的性别差异。CFA后6和96小时评估了不同组的雄性或雌性小鼠。治疗后30分钟评估机械性痛觉过敏。PBMT或Sarafotoxin S6c之前15分钟服用纳洛酮或Bq-788，有助于确定外周阿片类药物和ET _B -R与PBMT的关系。最后，在连续每天进行PBMT治疗后，对男女的ET _B -Rs皮肤免疫含量进行了定量。PBMT在90 mW / cm ²的辐照度下比3.5 mW / cm ²更有效。Bq-788和纳洛酮的使用可防止PBMT和SRTX S6c的作用；但是，PBMT不会影响外围ET _B-Rs免疫含量。结果表明，辐照度会影响PMBT效果。ET _B -R的激活在外周PBMT阿片样物质镇痛中起作用。最后，PMBT效应似乎与性别无关。