孕期应激对子代雌鼠成年后酒精摄取行为及脑内小白蛋白表达的影响

Effects of prenatal stress on voluntary ethanol intake and brain parvalbumin expression in adult female rat offspring

目的探讨孕期应激对子代雌鼠成年后酒精摄取行为以及脑内小白蛋白表达的影响。方法6只SD孕鼠随机分为孕期应激组（PS组，n=3）和对照组（CON组，n=3）。PS组孕鼠在妊娠晚期接受限制性应激，CON组孕鼠不给予孕期应激。子代成年后，PS组和CON组雌性子代分别随机分为PS-S组（n=6）和PS-NS组（n=6），CON-S组（n=6）和CON-NS组（n=6）。PS-S组和CON—S组动物先后接受限制性应激和冰水应激。所有动物均给予水和酒精溶液进行喂养，比较各组子鼠的基础酒精摄人量和子代应激后的酒精摄人量。用免疫组化方法检测子代海马和前额皮质小白蛋白的表达。结果PS—NS组在第1，4，6周的酒精摄人量明显低于CON—NS组（P〈0．05）。PS—S组在限制性应激后第1周的酒精摄人量[（3．79±0．47）kg·d^-1·g^-1]明显高于CON-S组[（1．68±0．68）kg·d^-1·g^-1]（P〈0．05），而PS—S组动物在冰水应激后第3周的酒精摄人明显小于CON—S组（P〈0．05）。另外，PS—S组子代海马CA2区和前额皮质M1区的小白蛋白表达均明显低于CON-S组（15．82±0．30，26．52±0．12，P〈0．05）。结论孕期应激可影响成年雌性子代的酒精摄取行为，此过程可能与海马和前额皮质小白蛋白表达的减少有关。

Objective To observe the effects of prenatal stress on voluntary ethanol intake（EI） and brain parvalbumin （PV） expression in adult female rat offspring. Methods Six pregnant SD rats were randomly divided into prenatal stress （PS, n = 3） and control group （ CON, n = 3）. During the late gestational periods, rats in PS were subjected to restraint stress for consecutive 3 days. The adult female offspring in PS were randomly divided into PS plus stress group（PS-S, n=6） and Ps without stress group（PS-NS, n=6）. The adult female offspring in CON were randomly divided into stress（ CON-S, n= 6） and no stress group（ CON-NS, n= 6）. The rats in PS-S and CON-S were subjected to restraint stress, and 3 weeks later ice-water stress. All the rats in each group were offered free choice between water and ethanol solution. Then EI of every rat was assessed every day. The PV expression in hippocampus and frontal cortex were detected by immunohistochemistry. Results The basal EI of PS-NS at the 1st, 4th and 6th week were significantly less than that of CON-NS（ P 〈 0.05 ）. The EI of PS-S at the 1st week after restraint stress was significantly higher than that of CON-S （ P〈 0.05 ）. But EI of PS-S at the 3rd week after ice-water stress was much less than that of CON-S （ P 〈 0.05 ）. The PV expression of PS-S offspring in the hippocampal CA2 and frontal cortex M1 were obviously lower than that of CON-S（ P 〈 0.05 ）. Conclusion Prenatal stress could affect on alcohol preference of adult female rat offspring, which possibly is related to the reduction of PV expression in brain.