维生素C对烧伤休克犬口服补液时内脏脂质过氧化损伤的影响

Vitamin alleviates visceral lipid peroxidative injury in dogs during oral fluid resuscitation of burn shock

目的研究维生素C（VC）对50％TBSA烧伤口服补液时脏器脂质过氧化损伤的影响。方法成年雄性Beagle犬12只，先期无菌手术行动、静脉插管，24h后采用凝固汽油燃烧法造成50％体表面积（TBSA）Ⅲ度烧伤。随机分为口服补液组和口服补液＋VC组，于伤后30min开始胃内分别输入葡萄糖-电解质溶液（GES）或含VC的GES液（250mg／kg维生素C溶于GES），第1个24h补液量依据Parkland公式为4ml·kg^-1·1％烧伤面积^-1，伤后24h起两组动物均实施静脉补液。所有动物均于伤后72h处死，取心、肺、肝、肾、空肠组织，测定黄嘌呤氧化酶（XOD）活性、丙二醛（MDA）含量和脏器组织含水率；同时测定血浆谷丙转氨酶（ALT）、肌酐（Cr）、磷酸肌酸激酶同工酶（CK—MB）和二胺氧化酶（DAO）的变化。结果伤后72h口服补液＋VC组脏器XOD活性高于口服补液组，其中心、肾和空肠差异有统计学意义（P〈0．01）；脏器MDA含量也显著高于口服补液组，心、肺、肝、肾、空肠组织差异均有统计学意义（均P〈0．01）。L1服补液＋VC组脏器组织含水率显著低于口服补液组，心[（75．4±1．1）％ vs （78．5±0．8）％]，肺[（68．1±0．9）％ vs（73．9±1．0）％]，肝[（75．2±0．8）％ vs （78．3±1．5）％]，肾[（73．8±1．1）％ vs （78．1±0．8）％]和空肠[（76．3±0．8）％ vs（80．4±0．6）％]，差异均有统计学意义（均P〈0．01）。脏器功能指标也显著低于口服补液组（ALT 46．6±2．49 vs 86．9±7．89，P〈0．01；Cr 43．4±7．05 vs 95．2±1．23，P〈0．01；CK—MB 7156±596 vs 8023±384，P〈0．01；DAO 1．86±0．45 vs 2．68±0．61，P〈0．05）。结论维生素C能抑制烧伤休克口服补液时缺血再灌注引起的脏器氧自由基生成，减轻组织水肿和脏器功能损害。

Objective To investigate the effect of vitamin C （VC） on visceral lipid oxidative injury during oral fluid resuscitation of burn shock. Methods Twelve male Beagle dogs were surgically prepared for arterial and venous cannulation, and 24 hours later they were subjected to a 50% TBSA full-thickness flame injury. In the first 24 hours after burn dogs were resuscitated with gastric infusion of either glucoseelectrolyte solution （GES group, n =6） or GES containing 250 mg/kg of VC （GES/VC group, n =6）. The delivery rate and volume of GES was in accordance with that of Parkland formula （4 ml·kg^-1·1% TBSA^-1 in the first 24 hours）. In the second 24 hours all animals received delayed IV fluid resuscitation. At end of 72 hours after injury, animals were sacrificed, and specimens of heart, lung, liver, kidney and jejunum were harvested for evaluation of xanthine oxidase （XOD） , malondialdehyde （MDA） and assessment of the tissue water content （ratio of dry to wet weight ） of organs. The plasma levels of alanine aminotransferase （ ALT）, creatinine （ Cr）, MB isoenzyme of creatine kinase （CK-MB） and diamine oxidase （DAO） were determined at same time. Results At 72 hours after burn it was showed significant higher activities of XOD in GES/CAR than GES group in heart, kidney and jejunum, and lower contents of MDA in heart, lung, liver, kidney and jejunum （P all 〈 0. 01 ）. Tissue water contents were significantly lower in GES/CARthanGES group in heart [（75.4±1.1）% vs （78.5±0.8）%], lung[（68.1 ±0.9）% vs （73.9±1.0）%], liver [（75.2±0.8）% vs （78.3±1.2）%], kidney[（73.8±1. 1）% vs （78.1 ± 0. 8） %]. and jejunum [ （76. 3 ± 0. 8 ） % vs （ 80. 4 ± 0. 6） ] respectively, all P 〈 0. 01. The levels of ALT, CK-MB, Cr and DAO in GES/CAR group were （46. 6 ±2.49） U/L, （43.4 ±7. 05） mol/L, （7156 ±596） U/L and （ 1.86 ±0. 45 ） U/L respectively, all significantly lower than those of the GES group [（ 86. 9 ± 7. 89） U/L, （95.2 ± 1.23） mol/L, （8023 ± 384） U/L and （2. 68 ± 0. 61 ） U/L respectively, all P 〈 0. 05]. Conclusion The results indicated that vitamin C alleviated visceral tissue edema and organ injury by inhibiting free radical production during oral fluid resuscitation of burn shock.