卷烟烟气暴露对大鼠学习记忆功能及海马组织病理和BDNF表达的影响

设对照组(未染毒)、低剂量组(约2.5支烟,每天染毒10 min)、中剂量组(约5支烟,每天染毒20 min)及高剂量组(约10支烟,每天染毒40 min)4个处理,将雄性SD大鼠置于气体染毒箱内行被动吸烟,研究卷烟烟气暴露对大鼠学习记忆功能及海马病理和脑源性神经营养因子(brain-derived neurotrophicfactor,BDNF)的影响。结果表明:染毒30 d,染毒组大鼠潜伏时间均显著短于对照组,BDNF表达显著高于对照组;染毒60 d,中剂量组大鼠潜伏时间显著短于对照组,BDNF表达显著高于对照组;染毒180 d,染毒组大鼠潜伏时间显著长于对照组,BDNF表达显著高于对照组;不同剂量处理大鼠的海马HE染色均无明显变化,大鼠的海马组织均无器质性损伤;短期烟气暴露可提高大鼠学习记忆功能,随染毒时间的延长,大鼠学习记忆功能下降,该作用与海马BDNF的表达密切相关。

TInfluence of cigarette smoke exposure on learning and memory function,histologic changes and brain-derived neurotrophic factor in rats

Male SD rats were randomly divided into normal control group and cigarette smoke group(CS group).Rats in CS group were exposed to cigarette smoke in ventilated smoking chambers and divided into low-dose group(about 2.5 cigarettes,exposed for 10 minutes a day),medium-dose group(about 5 cigarettes,exposed for 20 minutes a day) and high-dose group(about 10 cigarettes,exposed for 40 minutes a day).The influence of cigarette smoke exposure on learning and memory function of rats,on pathological changes of hippocampus and on the expression of brain-derived neurotrophicfactor(BDNF) was explored by Morris water maze,H-E staining and immunohistochemistry staining,respectively.The results showed that the escape latency of CS group was significantly decreased and the expression of BDNF was significantly increased compared to normal control group 30 d after exposure;the escape latency of medium-dose group was shorter than that of the normal control group and the expression of BDNF of CS group was significantly increased 60 d after exposure;the escape latency of CS group was significantly increased and the expression of BDNF was significantly increased compared to normal control group 180 d after exposure.The hippocampus of rats in each group showed no significant change in H-E staining.The results showed that the function of learning and memory of rats was increased after short-term cigarette smoke exposure but decreased gradually with increased exposure time.This effect was closely related to the expression of BDNF in hippocampus.