RESUMO
Eleven male rabbits were divided into 2 groups. Normal saline(NS) group consisted of 5 animals and was treated with 0.9% NaCl solution, and hyperosmotic saline (HS) group consisted of 6 rabbits and was treated with 7.5% NaCl. The animals were exposed to hypobaric hypoxia at a simulated altitude of 4000 m and hemorrhagic shock was inflicted to them through femoral artery bleeding. The mean arterial pressure (MAP) was brought to 6.0 kPa over 10 minutes and kept at that level for 70 minutes. A certain amount of 0.9% NaCl (300 mmol/L) or 7.5% NaCl (2400 mmol/L) was intravenously infused over a 10-minute interval. The volume infused was equivalent to 10% of the total blood shed. It was found that MAP, left ventricular systolic pressure, and LV dp/dt were significantly higher in HS group than in NS group (from 3rd to 20th minute after infusion). Sodium ion concentration was significantly higher in HS (145.8?3.16 mmol/L) than in NS (135.6?2.87 mmol/L) (P