Photothrombotic middle cerebral artery occlusion and reperfusion laser system in spontaneously hypertensive rats.
OBJECTIVE
To establish a less invasive and reproducible focal ischemia model in the rat, we adopted a 2-laser system (ie, photothrombosis and YAG laser-induced reperfusion).


METHODS
The distal middle cerebral artery (MCA) of spontaneously hypertensive rats was occluded by 568-nm krypton laser and intravenous infusion of the photosensitizing dye rose bengal and was recanalized by 355-nm ultraviolet laser irradiation. Cerebral blood flow was determined by laser-Doppler flowmetry at the penumbral cortex. Infarct volume was determined at 3 days after distal MCA occlusion.


RESULTS
Brain temperature determined with infrared thermography was maintained within an acceptable range of approximately 1 degrees C upper shift of the center of brain temperature distribution during krypton or YAG laser irradiation. The average of the values (23 experiments; n=163) of coefficient of variation of infarct volume was 21+/-6%, indicating high reproducibility of this model. After distal MCA occlusion, cerebral blood flow was decreased to 32+/-16% of the control values and was increased to 98+/-21% after YAG laser-induced reperfusion. Infarct volume in these rats was 61+/-18 mm3 (coefficient of variation=30%; n=6).


CONCLUSIONS
We have characterized a highly reproducible focal ischemia model utilizing a 2-laser system, one to induce thrombotic MCA occlusion and the other to facilitate reperfusion.
Yao
Hiroshi
H
Department of Medicine and Clinical Science, Second Department of Internal Medicine, Graduate School of Medical Sciences, Kyushu University, Maidashi 3-1-1, Higashi-ku, Fukuoka 812-8582, Japan. yao-h@hizen2.hosp.go.jp
Sugimori
Hiroshi
H
Fukuda
Kenji
K
Takada
Junichi
J
Ooboshi
Hiroaki
H
Kitazono
Takanari
T
Ibayashi
Setsuro
S
Iida
Mitsuo
M
D000818:Animals; D001783:Blood Flow Velocity / Q000187:drug effects; D001831:Body Temperature / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000528:radiation effects; D004195:Disease Models, Animal; D020244:Infarction, Middle Cerebral Artery / Q000473:pathology* / Q000628:therapy*; D017075:Laser Coagulation; D053685:Laser Therapy; D007834:Lasers / Q000009:adverse effects; D008027:Light; D008297:Male; D051381:Rats; D011918:Rats, Inbred SHR; D011921:Rats, Inbred WKY; D017207:Rats, Sprague-Dawley; D015424:Reperfusion / Q000295:instrumentation*; D015203:Reproducibility of Results; D013314:Stress, Mechanical; D013817:Thermography