TY - GEN
T1 - Low-level light therapy for zymosan induced arthritis in rats
AU - Castano, Ana P.
AU - Tianhong, Dai
AU - Demidova-Rice, Tatiana N.
AU - Salomatina, Elena V.
AU - Yaroslavsky, Anna N.
AU - Yaroslavsky, Ilya
AU - Cohen, Richard
AU - Apruzzese, William A.
AU - Smotrich, Michael H.
AU - Hamblin, Michael R.
PY - 2007
Y1 - 2007
N2 - It has been known for many years that low level laser (or light) therapy (LLLT) can ameliorate the pain, swelling and inflammation associated with various forms of arthritis. Light is absorbed by mitochondrial chromophores leading to an increase in ATP, reactive oxygen species and/or cyclic AMP production and consequent gene transcription via activation of transcription factors. However, despite many reports about the positive effects of LLLT in medicine, its use remains controversial. Our laboratory has developed animal models designed to objectively quantify response to LLLT and compare different light delivery regimens. In the arthritis model we inject zymosan into rat knee joints to induce inflammatory arthritis. We have compared illumination regimens consisting of a high and low fluence (3 J/cm2 and 30 J/cm 2), delivered at a high and low irradiance (5 mW/cm2 and 50 mW/cm2) using 810-nm laser light daily for 5 days, with the effect of conventional corticosteroid (dexamethasone) therapy. Results indicated that illumination with 810-nm laser is highly effective (almost as good as dexamethasone) at reducing swelling and that longer illumination time was more important in determining effectiveness than either total fluence delivered or irradiance. Experiments carried out using 810-nm LLLT on excisional wound healing in mice also confirmed the importance of longer illumination times. These data will be of value in designing clinical trials of LLLT.
AB - It has been known for many years that low level laser (or light) therapy (LLLT) can ameliorate the pain, swelling and inflammation associated with various forms of arthritis. Light is absorbed by mitochondrial chromophores leading to an increase in ATP, reactive oxygen species and/or cyclic AMP production and consequent gene transcription via activation of transcription factors. However, despite many reports about the positive effects of LLLT in medicine, its use remains controversial. Our laboratory has developed animal models designed to objectively quantify response to LLLT and compare different light delivery regimens. In the arthritis model we inject zymosan into rat knee joints to induce inflammatory arthritis. We have compared illumination regimens consisting of a high and low fluence (3 J/cm2 and 30 J/cm 2), delivered at a high and low irradiance (5 mW/cm2 and 50 mW/cm2) using 810-nm laser light daily for 5 days, with the effect of conventional corticosteroid (dexamethasone) therapy. Results indicated that illumination with 810-nm laser is highly effective (almost as good as dexamethasone) at reducing swelling and that longer illumination time was more important in determining effectiveness than either total fluence delivered or irradiance. Experiments carried out using 810-nm LLLT on excisional wound healing in mice also confirmed the importance of longer illumination times. These data will be of value in designing clinical trials of LLLT.
KW - Biomodulation
KW - Biostimulation
KW - Cold laser
KW - Low-level light therapy
KW - Wound healing
KW - Zymosan-induced arthritis
UR - http://www.scopus.com/inward/record.url?scp=34548259260&partnerID=8YFLogxK
U2 - 10.1117/12.698193
DO - 10.1117/12.698193
M3 - Conference contribution
AN - SCOPUS:34548259260
SN - 0819465410
SN - 9780819465412
T3 - Progress in Biomedical Optics and Imaging - Proceedings of SPIE
BT - Mechanisms for Low-Light Therapy II
T2 - Mechanisms for Low-Light Therapy II
Y2 - 21 January 2007 through 21 January 2007
ER -