严重烧伤后早期肝细胞内外钠离子分布的研究

目的　深入了解严重烧伤后体内钠离子分布的特点 ,为进一步改良复苏方案、提高复苏疗效提供实验依据。方法　成年Sprague Dawley大鼠随机分为假伤组 (12只 )和烧伤组 (7只 ) ,烧伤组动物造成体表面积 4 0 %Ⅲ度烫伤 (以下称烧伤 ) ,按Parkland公式通过颈静脉插管进行液体复苏治疗。假伤组动物行颈静脉插管但不予补液 ,并用 37℃温水模拟烫伤过程。伤后 2 4h用2 3 Na 磁共振波谱技术在活体上直接检测肝细胞内区域和肝细胞外区域钠离子含量的变化 ,并通过测定2 3 Na 磁共振横向弛豫时间 (T2 )了解细胞内、外钠离子的存在状态。　结果　烧伤后 2 4h烧伤组大鼠肝细胞外的钠离子含量较假伤组减少 17%。烧伤组大鼠肝细胞外的2 3 Na 磁共振横向快弛豫时间 (T2f)不变 ,但在总横向弛豫时间中所占比值增加 ,提示细胞外基质中钠的结合位点相对增加 ;细胞内钠离子含量增加 5 7% ,但磁共振横向弛豫时间和快、慢T2 成分相对比值不变 ,提示细胞内分解代谢产物增加 ,以至细胞内基质中钠离子结合位点与钠离子含量成比率增长。　结论　严重烧伤早期 ,远隔部位肝脏器官的细胞外钠离子可因部分丢失于细胞内区域和钠离子结合位点增多而至相对不足

Study on the intra- and extra-hepatocyte distribution of sodium ions in scalded rats during early postburn stage

OBJECTIVE: To investigate the characteristics of the intra- and extra-hepatocyte sodium ions distribution in scalded rats during early postburn stage,with the aim of improving burn shock resuscitation regime and the resuscitation effects. METHODS: Adult Sprague-Dawley rats were randomly divided into sham scalding (C, n = 12) and scalding (S, n = 7) groups. The rats in S group were subjected to 40% TBSA III degree scalding on the back and were catheterized via jugular vein for fluid resuscitation. The rats in C group were catheterized via jugular vein without fluid infusion and were sham scalded by warm water in temperature of 37 degrees. The changes in the intra- and extra-hepatocyte sodium ion contents were determined in vivo by (23)Na-magnetic resonance spectrum technology, while the existing state of the intra- and extra-hepatocyte sodium ion was determined by detecting (23)Na-magnetic resonance horizontal delaying time (T(2)). RESULTS: The extra-hepatocyte sodium content in S group at 24 postburn hours (PBHs) was 17% less than that in C group. In addition, the T(2f) (fast T(2)) in S group remained stable but maintained a higher ratio during the observation time. This suggested that the sodium binding sites in extra-hepatocyte matrix increased relatively and that intra-hepatocyte sodium content increased by 57%. But the T(2) and the fast and slow parts of the T(2) kept stable, which implied that intra-hepatocyte catabolizing products were increased. This led to an increase in the sodium ion binding sites within intra-hepatocyte matrix in proportion to the sodium ion content. CONCLUSION: During early postburn stage, the extra-hepatocyte sodium in a remote organ such as the liver exhibited relative deficiency due to its ingress into hepatocyte cytoplasm and to the increase of sodium combining sites.