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.
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
Hiroshi
H
Yao
Hiroshi
H
Sugimori
Kenji
K
Fukuda
Junichi
J
Takada
Hiroaki
H
Ooboshi
Takanari
T
Kitazono
Setsuro
S
Ibayashi
Mitsuo
M
Iida
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