腹腔注射法建立一氧化碳中毒迟发性脑病大鼠模型

The building of delayed neuropsychologic sequelae rat model by carbon monoxide peritoneum injection

目的探索建立一氧化碳(CO)中毒迟发性脑病(DNS)大鼠模型的可靠方法。方法成年Wistar大鼠随机分成4个实验组(每组n=10)和1个对照组(n=4),实验组分别按50、100、150和200 mL/kg腹腔内注射CO,对照组按200 mL/kg腹腔内注射空气。中毒后不同时间断尾取血,分光光度法检测碳氧血红蛋白(HbCO)变化。迷宫实验评估动物的智力状态,以正确上安全岛少于3次为DNS。TUNEL法原位检测大脑皮质、海马区细胞凋亡情况。结果各实验组注射CO后,大鼠呈现典型CO中毒表现,HbCO与CO注射剂量呈显著正相关(r=0.77,P<0.05)。50 mL/kg组和对照组无明显DNS表现;100 mL/kg组和150 mL/kg组大多数动物中毒后存活,约半数存活动物出现DNS表现,脑组织细胞凋亡率显著高于对照组。200 mL/kg组大多数动物中毒后死亡,存活动物DNS发生率和脑细胞凋亡数与100 mL/kg组和150 mL/kg组无显著差异。结论按100～150 mL/kg腹腔注射CO可有效建立DNS大鼠模型,具有简便、可靠、重复性好的特点,是一种非常理想的造模方法。

Objective To explore a reliable method for building the animal model of delayed neuropsychologic sequelae （DNSI after acute carbon monoxide （COl poisoning. Methods Adult Wistar rats were selected and randomly divided into 4 treatment groups （ n =10 each groupl and 1 control group （n =4）. In treatment groups, different doses of CO （50 mL/kg, 100 mL/kg, 150 mL/kg and 200 mL/ kg） were administrated by peritoneum injection, and in control group, CO was replaced by air （200 mL/ kg） to peritoneum inject. Carboxyhemoglobin （HbCO） levels in blood were detected after administration. Morris maze test was adopted to identify DNS occurring. In different time points after treatment, brain cortex and hippocampus were isolated, embedded into paraffin and sliced into 5μm sections. Apoptosis of brain cells was measured by TUNEL staining. Result The rats of each treatment group showed typical acute CO poisoning symptoms after CO infusion. There was positive correlation between HbCO and injected CO doses（r =0. 77,P 〈 0.05）. In 50 mL/kg group and control group, neither DNS nor dead was occurred. The apoptosis in 50 mL/kg group was not signifieantly different with those in control group. In 100 mL/kg group and 150 mL/kg, most rats were surviving （8 in 100 mL/kg group and 7 in 150 mL/kg） after poisoning and more than half of survived rats （62.50% in 50 mL/kg group and 71.43% in 100 mL/ kg） developed into DNS identified by Morris maze testing. The apoptosis of brain cells in both 50 mL/kg group and 100 mL/kg group were significantly higher than those in control group. In 200 mL/kg group, the majority of 7 eases were dead within 30 min after poisoning, and in 4 survived rats, 3 of them developed DNS. However, neither apoptosis nor DNS rates in 200 mL/kg group were significantly different with those in 100 mL/kg group and in 150 mL/kg group. Conclusion CO peritoneum injection is a effective, convenient, and reliable way to build the animal model of DNS by acute CO poisoning.