Therapeutic effect of Ga-Al-As diode laser irradiation on experimentally induced inflammation in rats.
We produced experimental inflammation models in rats by carrageenin and studied the effect of Ga-Al-As diode laser irradiation (780 nm, continuous wave, 31.8 j/sec/cm2, spot size of 0.2 mm) on inflamed regions compared with those of indomethacin, a potent anti-inflammatory agent. We found that a low-power infrared laser has an anti-inflammatory effect on carrageenin inflammation. A low-power laser inhibits: (1) the increase of vascular permeability during the occurrence of an acute inflammation in the carrageenin-air-pouch model, (2) edema in the acute stage in the carrageenin-paw-edema model, and (3) the granuloma formation in the carrageenin-granuloma model after receiving laser irradiation once daily. In all cases, irradiation for less than 10 min was sufficient to inhibit the inflammation by 20-30%. The inhibitory effect of laser irradiation was not comparable to that of indomethacin (4 mg/kg, i.o.) in the air-pouch model and the paw-edema model, whereas laser irradiation was more potent than that of daily administration of indomethacin (1 mg/kg, i.o.) in the granuloma model. In future studies of the mechanism of laser effect, it should be noted that irradiating a rat twice, before and after the provocation of inflammation, was essential in order to achieve an effective inhibition of paw-edema.
Honmura
A
A
Kanagawa Rehabilitation Research Institute, Atsugi, Japan.
Yanase
M
M
Obata
J
J
Haruki
E
E
D000535:Aluminum; D000818:Animals; D001151:Arsenic; D001798:Blood Proteins / Q000493:pharmacokinetics / Q000528:radiation effects; D001834:Body Water / Q000378:metabolism / Q000528:radiation effects; D002199:Capillary Permeability / Q000187:drug effects / Q000528:radiation effects*; D002351:Carrageenan; D003872:Dermatitis / Q000188:drug therapy / Q000473:pathology / Q000532:radiotherapy*; D004195:Disease Models, Animal; D004487:Edema / Q000188:drug therapy / Q000532:radiotherapy*; D005070:Evans Blue; D005708:Gallium; D006099:Granuloma / Q000188:drug therapy / Q000532:radiotherapy*; D007213:Indomethacin / Q000627:therapeutic use*; D053685:Laser Therapy; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012666:Semiconductors; D012871:Skin Diseases / Q000188:drug therapy / Q000532:radiotherapy*
D001798:Blood Proteins; D005070:Evans Blue; D002351:Carrageenan; D005708:Gallium; D000535:Aluminum; D001151:Arsenic; D007213:Indomethacin