Mongolian gerbilを用いた虚血性脳浮腫に対する nizofenone （Y−9179）の効果

EFFECTS OF NIZOFENONE ON ISCHEMIC CEREBRAL EDEMA IN MONGOLIAN GERBILS

　抄録　Mongolian gerbilを用い，脳虚血後に発生する脳浮腫に対する　nizofenoneの作用をpentobar—bital （PBT）と比較検討した。脳浮腫の指標とした脳水分量は，湿および乾燥重量差より算出した。右総頸動脈永久結紮後，異常症状を呈した動物（陽性動物）の右大脳半球の水分量は，24時間までに約6％経時的に増加した。Nizofenone （30 mg／kg i．　P．）は結紮後24時問，PBT （60 mg／kg i．　P．）は結紮後1.5〜24時間の脳水分量を対照群に較べ有意に減少させた。右総頸動脈を60分間閉塞して再開通後，陽性動物の右大脳半球の水分量は72時間までに約5％経時的に増加した。　Nizofenone （30 mg／kg i．p．）は再開通後24〜72時間，PBT （60 mg／kg i．　p．）は再開通後1.5〜72時間までの脳水分量を対照群に較べ有意に誠少させた。以上，nizofenoneは脳虚血後，早期から効果を示したPBTとは異なり，24時間以降の脳水分量の増加に対し有効であった。脳虚血初期にはcytotoxic edemaが生じ，時問の経過とともにvasogenic edemaに移行すると考えられているところから，nizofenoneは虚血性脳浮腫，とくにvasogenic edemaに対し抑制作用を有することが示唆された。

The effects of nizofenone on ischemic cerebral edema in Mongolian gerbils were compared with those of pentobarbital (PBT). Water content, used as an index of cerebral edema, was calculated from the wet and dry weights of each hemisphere.

In the sensitive gerbils subjected to permanent occlusion of the right common carotid artery, water content of the right hemisphere increased by about 6% at 24 hr after ischemia. In the ani-mals treated with nizofenone (30 mg/kg i. p.) and PBT (60 mg/kg i. p.), water content was significant-ly lower than that of the control group at 24 hr and 1. hr after ischemia, respectively.

In the sensitive gerbils subjected to temporary occlusion of the right common carotid artery for 60 min, water content of the right hemisphere increased gradually by about 5% at 72 hr after recirculation. In the animals treated with nizofe-none (30 mg/kg i. p.) and PBT (60 mg/kg i. p.), water content was significantly lower than that of the control group at 24,-72 hr and 1. 5-72 hr after recirculation, respectively.

Nizofenone became effective in lowering brain water content after 24 hr following ischemia. On the other hand, PBT was effective from an early stage of ischemic cerebral edema. Brain edema following an ischemic injury is considered to beinitially of the cytotoxic type, subsequently chang-ing into the vasogenic type. The above results suggest that nizofenone may be effective in amel-iorating ischemic cerebral edema, particularlyvasogenic edema, and that this may be partially related to its cerebral protective action.