高温复合创伤对兔血一氧化氮及平均动脉压的影响

目的探讨急性热暴露复合创伤后血浆一氧化氮(NO)早期变化及其对血压的可能影响,为急性应激条件下NO的作用机制研究提供理论依据.方法建立兔急性热暴露复合创伤模型,实验动物分为常温无创组、常温创伤组、高温无创组、高温创伤组.于0、1、2 h不同时间点取血测定NO含量,全程监测血压变化.结果急性热暴露创伤后1 h左右,兔血浆NO浓度下降,然后升高,高温创伤组NO浓度在1、2 h时分别为(42.75±8.24)、(59.54±9.05)μmol/L,差异有显著性(P＜0.05),而正常对照组则为(56.63±3.79)、(55.22±7.15)μmol/L,两组于1 h时的差异有显著性(P＜0.05).在高温和创伤条件下,兔平均动脉压(MAP)于60～70 min降至最低点,继之有一个短暂的回升,然后则迅速下降.结论急性热暴露复合创伤兔早期血浆NO浓度先降低后升高,且与MAP的变化有一定关系.

Effect of hyperthermia combined with trauma on serum nitric oxide and mean arterial pressure in rabbits

OBJECTIVE: To study the early change of serum nitric oxide (NO) after acute heat exposure with trauma and the effect of NO on mean arterial pressure (MAP), thus to provide theoretical basis for studying the mechanism of NO effect in acute stress. METHODS: The rabbit model of acute heat exposure combined with trauma was established. The animals were divided into four groups, including control, trauma, hyperthermia and hyperthermia combined with trauma. The levels of NO were measured at different time points: 0 h, 1 h, 2 h and MAP was monitored throughout the whole experiment. RESULTS: The concentration of NO declined at first and then increased at 1 h or so after acute heat exposure and trauma. The levels of NO in hyperthermia with trauma group at 1 h, 2 h were (42.75 +/- 8.24), (59.54 +/- 9.05) micro mol/L respectively (P < 0.05), while those in control group were (56.63 +/- 3.79) and (55.22 +/- 7.15) micro mol/L, the difference at 1h between two groups was significant (P < 0.05). Under the circumstance of hyperthermia and trauma, the level of MAP declined to the lowest point at 60 - 70 min and then showed a transient rise, after that, the level declined rapidly. CONCLUSIONS: At the early stage of acute heat exposure and trauma, the concentration of serum NO declined at first and then increased, and had certain relationship with the change of MAP.