ラット脳局所虚血モデル—1．手術法，生理学的パラメターの変化

FOCAL CEREBRAL INFARCTION IN THE RAT:I. OPERATIVE TECHNIQUE AND PHYSIOLOGICAL MONITORINGS FOR CHRONIC MODEL

　抄録　ラットにおいて中大脳動脈を閉塞し，局所脳虚血を作製した。さらに慢性実験モデルとして利用するための基礎的実験として，脳血管の分布域の観察，手術法の検討，術後1週間にわたる生理学的パラメターの観察を行った。ハロセン吸入麻酔下に左眼球を剔出し，側頭骨底部に小穿孔をあけ，左中大脳動脈を電気凝固により閉塞した。体血圧は，術中および術後に麻酔の影響により約30％の低下がみられたが30分以内に回復し，その後1週間にわたり変化は認められなかった。体重は，閉塞群では経時的に減少し，1週間後には85％に減少したが，sham手術群では術後数日間の低下の後，回復した。1週間の観察期間中，死亡例はなく，神経症状の観察では，数日間右片麻痺がみられたが，1週間後にはほぼ回復した。本モデルは，慢性実験に適した，小動物における局所脳虚血モデルである。

The purpose of this paper is to develop a new chronic model of focal cerebral infarction by occluding the middle cerebral artery (MCA) in the rat. The operative method and results of physiological monitorings before, during, and after operation are shown. In adult male Sprague-Dawley rats, the left MCA was occluded via trans-retro-orbital approach symply by retracting the temporalis muscle. This method was slightly modified from our original method for chronic experiments.

In a group of rats, systemic arterial pressure and blood gasses were monitored using a femoral arterial cathetor before, during, and after the ope-ration. In the other group, blood pressure by tail--cuff method, neurological findings, and body weight were examined for one week after the MCA occlusion. During the operation under the halothane anesthesia, systemic arterial pressure decreased about 30% comparing with preanesthetic normal value and then quickly returned to normal within 30 minutes after the operation. Body weight progressively decreased in the occluded group during the observation period of one week, although body weight in the sham-operated group decreased only for initial few days and recovered. No animal died during first one week. Slight right hemiparasis was observed only in the MCA occlu-ded group for few days.