ショックの病態生理Ⅳ—動脈遮断による腸管阻血犬に対する薬剤の延命効果

A Study on Shock:Ⅳ. Effect of Drugs on the Survival Time of Drugs that Were Clamped the Celiac and Superior Mesenteric Arteries

緒言

　大動脈または腹腔動脈および上腸間膜動脈を遮断することによって，腸管領域を高度に阻血状態にした場合の門脈血には，肝を中心とする網内系の貪食能を著しく低下させる物質が含まれていることが分った^1）。また，動脈遮断時には下腿等では，catecholamineが高度に分泌されることが明らかである。この場合の門脈血は特異的な血管作働性を示すが，catecholamine以外の，特異的な血管拡張作用を持つ物質の存在が考えられる^2）。このような血液性状の解析は緒についたばかりであるが，一方薬剤の投与によって，腸管領域阻血時の重篤な経過を緩和できないかを検討した。薬剤は，α—recepto_rblocking agentのphenoxybenzamine，蛋白酵素阻害剤のtrasylol，作用機序は明確にされていないが，大量のステロイドホルモンを用い，前二者で著効が得られた。

In our previous report, it was obviously demonstrated that a large amount of vaso-constrictive substances which seemed to be catecholamine or catecholamine related sys-temic blood of animals with aortic occlusion, although further analysis of the vasodilating factor of portal blood was not performed. Therefore, the present study was designed to evaluate the effect of phenoxybenzamine (α-blockade) to the survival time of the dogs with occlusion of the celiac and superior mesenteric arteries. Two other drugs, tra-sylol and hydrocortisone were evaluated in the same manner.

The drugs were injected intravenously about 10 minutes prior to arterial clamping. Dose of the drugs were mg/kg of phenoxy-benzamine, 20,000 unit/kg of trasylol, 50mg/kg of hydrocortisone respectively. No addi-tional treatments were performed to the ex-perimental animals until death.

The blood samples for measurement of lactate, pyruvate and gas analysis were serially removed. the mean survival time was as follows.

Control: 6.75 hours, phenoxybenzamine tr-eated: 21 hours, trasylol treated: 14 hours, and hydrocortisone treated: 11 hours.

The animals treated with phenoxybenza-mine or trasylol demonstrated the significant prologation of survival time. The effect of hydrocortisone was not significant. The development of metabolic acidosis and accu-mulation of lactate were closely related to the survival time and they were considerably prevented by phenoxybenzamine or trasylol.