目的 探讨脑源性神经营养因子（BDNF）对正常和热应激条件下小鼠着床前胚胎发育和凋亡的影响。 方法 150只雌性昆明小鼠用于实验，2细胞期胚胎添加或不添加10μg/L BDNF进行体外培养，早期囊胚37 ℃条件下或41 ℃热处理2 h，观察胚胎发育情况，TUNEL法和Hoechst 33342分析囊胚细胞数量和凋亡情况，荧光技术分析Caspase-9的活力。 结果 在37 ℃条件下BDNF能够促进早期囊胚发育，增加囊胚细胞数量，降低凋亡率及Caspase-9的活力，热应激能够降低早期囊胚的发育能力，减少囊胚细胞数量而增加凋亡率，且中等和高Caspase-9活力囊胚的比例热处理后明显增加，当培养基中添加10μg/L BDNF时，能够明显缓解热应激对早期囊胚发育和质量的不利影响。 结论 BDNF对37 ℃或41 ℃热应激条件下小鼠着床前胚胎发育、细胞数量、凋亡和Caspase-9活力起到一定的调控作用。

Objective To investigate the effect of brain derived neurotrophic factor (BDNF) on the development and apoptosis of mouse early blastocyst either cultured continuously at 37 ℃ or treated with heat shock at 41 ℃ for 2 hours. Methods A total of 150 female Kunming mice were used. The early blastocysts were cultured continuously at 37 ℃ or subjected to heat shock for 2 hours at 41 ℃ while being cultured with or without 10μg/L BDNF. The development of early blastocysts was recorded. The TUNEL reaction and Hoechst 33342 method were used to observe the apoptosis cells of blastocysts. The Caspase-9 activity of mouse blastocyst was analysed by fluorescent technique. Results Treatment with BDNF at 37 ℃ promoted the development of early blastocysts. The normal developmental blastocyst cells were increased while apoptosis cells and Caspase-9 activities were decreased in early blastocyst in BDNF treatment group. The development of early blastocyst was inhibited in heat shock treatment group, and TUNEL positive cells number and Caspase-9 activities were increased. There were normal developmental blastocyst in 10μg/L BDNF treatment group. Conclusion Our findings suggest that BDNF signaling plays important roles during mouse early blastocyst development, blastocyst cell numbers, blastocyst apoptosis and the Caspase-9 activity.