7.5%氯化钠溶液对失血性低血压狗升压作用的中枢机制

９对狗作头部交叉循环，４对狗作脑交叉循环后，股动脉失血使平均动脉压（ＭＡＰ）降至５．３３ｋＰａ左右，维持３０ｍｉｎ。从其中一只狗（Ａ狗）股静脉输入占总失血量１０％的７．５％ＮａＣｌ溶液（实验组），或生理盐水（对照组）；另一只狗（Ｂ狗）不作任何处理。结果：实验组Ａ，Ｂ两狗动脉血压（ＡＰ）均显著回升，并维持至输液后６０ｍｉｎ，其中收缩压（ＳＰ）回升幅度大于舒张压（ＤＰ），脉压（ＰＰ）加大。对照组ＡＰ回升值无统计学意义。实验组及对照组心率（ＨＲ）均无明显变化。动脉血红细胞比容皆下降，但其下降值组间比较，Ｐ＞０．０５。实验组Ａ狗血浆钠有意义地增高，Ｐ＜０．０１；Ｂ狗变化同对照组。结果提示：在７．５％ＮａＣｌ溶液恢复失血性低血压的作用机制中，中枢神经系统起重要作用。

THE CENTRAL MECHANISM OF PRESSOR RESPONSE INDUCED BY INFUSING 7. 5% SODIUM CHLORIDE SOLUTION IN HEMORRHAGIC HYPOTENSION DOG

Nine pairs of dogs were operated with head cross circulation and four pairs of dogs with brain cross circulation. Bleeding of formoral artery decreased the mean arterial pressure to 5. 33 kPa and maintained for 30 min. In each pair of A dog 10% of total blood lose was infused intravenously by 7. 5% NaCl solution (as test) or normal saline (as control),but B dog was not treated. The results showed that in the test group the arterial blood pressure recovered immediately in both A and B dogs and lasted for more than 60 min after infusion. The recovery value of systolic pressure was higher than diastolic pressure and pulse pressure increased. In the control group the blood pressure recovered slightly but of no statistical significance. There was no remarkable difference in heart rate between the two groups. A marked decrease in hematocrit appeared after bleeding and infusion, but there was no significant difference between the two groups (P>0. 05). Plasma sodium increased significantly after infusion in A dogs of the test group (P<0. 01 ), but the change in B dogs was the same in the control group.These results mentioned above indicate that the central nervous system plays important role on the mechanism of pressor response induced by infusing 7. 5% NaCl solution in the hemorrhagic hypotension dog.