Effect of semiconductor GaAs laser irradiation on pain perception in mice.
The influence of subacute exposure (11 exposures within 16 days) of mice to the low power (GaAs) semiconductive laser-stimulated irradiation on pain perception was investigated. The pain perception was determined by the latency of foot-licking or jumping from the surface of a 53 degrees C hot plate. Repeated hot-plate testing resulted in shortening of latencies in both sham- and laser-irradiated mice. Laser treatment (wavelength, 905 nm; frequency, 256 Hz; irradiation time, 50 sec; pulse duration, 100 nsec; distance, 3 cm; peak irradiance, 50 W/cm2 in irradiated area; and total exposure, 0.41 mJ/cm2) induced further shortening of latencies, suggesting its stimulatory influence on pain perception. Administration of morphine (20 mg/kg) prolonged the latency of response to the hot plate in both sham- and laser-irradiated mice. This prolongation tended to be lesser in laser-irradiated animals. Further investigations are required to elucidate the mechanism of the observed effect of laser.
Zarković
N
N
Ruder Bosković Institute, Zagreb, Yugoslavia.
Manev
H
H
Pericić
D
D
Skala
K
K
Jurin
M
M
Persin
A
A
Kubović
M
M
D000818:Animals; D004723:Endorphins / Q000502:physiology; D005260:Female; D007834:Lasers; D051379:Mice; D009020:Morphine / Q000627:therapeutic use; D010146:Pain / Q000503:physiopathology*; D010166:Palliative Care; D012684:Sensory Thresholds / Q000528:radiation effects
D004723:Endorphins; D009020:Morphine