犬の急性閉塞性水頭症におけるNIK−242注（20％erythritol）の頭蓋内圧降下作用

EFFECT OF NIK-242 INJ. (20% ERYTHRITOL) ON INTRACRANIAL PRESSURE IN DOGS WITH ACUTE OBSTRUCTIVE HYDROCEPHALUS

　NIK−242注は四炭糖アルコールであるerythritolの20％溶液で，本剤の頭蓋内圧降下作用について，犬の急性閉塞性水頭症モデルを用いて調べ，mannitolおよびglycero1と比較した。投与方法は10分間の点滴静注で・投与薬剤および投与量によって，NIK−242注（erythritolとして0.5，1.0，2.0g／kg）投与群，mannitol 1.0g／kg投与群，glycerol O.5g／kg投与群の計5群（各群n＝6）に分けた。投与開始から150分間にわたり平均頭蓋内圧，平均大動脈圧，血清浸透圧を測定し，また最大圧降下率，最大圧降下到達時間，圧降下持続時間，反跳現象の発生頻度について検討した。

　その結果，NIK−242注は頭蓋内圧を降下させる作用があり，その作用は用量依存性で，血清浸透圧の上昇にほぼ相関していた。最適投与量は1.0g／kgで，平均頭蓋内圧は投与120分後まで統計学的に有意に低下し（P＜O.05），最大圧降下率83.6±10.6％，最大圧降下到達時岡22.7±3.0分であった。反眺現象は150分の観察期間中1例も認めなかった。NIK−242注（erythritolとして1.0g／kg）はmannitol（1.0g／kg）よりも圧降下作用の大きさで若干優れ，glycerol（0.59／kg）よりも圧降下作用の大きさ，持続時間，反跳現象の発生頻度で優れていた。

The effects of NIK-242 inj. (20% erythritol) on intracranial pressure (ICP) and serum osmotic pressure (Osm. P) were investigated in dogs with acute obstructive hydrocephalus, and they werecompared with those of 20% mannitol or 10% glycerol in 5% fructose and 0.9% saline. Animals were divided into 5 groups (n= 6 in each group) and treated with either NIK-242 inj. (0.5 g/kg, 1.0 g/kg, 2.0 g/kg), mannitol (1.0 g/kg) or gly-cerol (0.5 g/kg). These drugs were administrated intravenously for 10 min. NIK-242 inj. rapidly reduced ICP and increased Osm. P. There was correlation between changes of ICP and Osm. P. The regression equation was Y= -6.489 X + 726.206 (n=104, p＜0.00001, R= -0.665). The effects were dose-dependent, but there were no signifi-cant differences between the effects of NIK-242 inj. 1.0 g/kg infusion and 2.0 g/kg infusion. The most appropriate dose of NIK-242 inj. was 1.0 g/kg, in which group ICP was significantly lowerthan the initial pressure until 120 minutes after administration (p＜0.05). The maximum reduction rate of ICP {(initial ICP-minimum ICP)/initial ICP× 100} was 83.6 ± 10.6% at 22.7 ± 3.0 min. after administration. It was 61.6±6.9% at 19.3± 1.6 min. in mannitol group and 77.1± 7.4% at 15.0±0.8 min. in glycerol group. There was no rebound phenomenon on ICP during 150 min., but there was one in mannitol gruop and five in glycerol group. NIK-242 inj. (1.0 g/kg) was slightly effective compared with mannitol in the degree of ICP reduction, and more effective than glycerol in the degree of ICP reduction and the duration with a low incidence of rebound pheno-menon.