出生后注射雌二醇诱导隐睾性不育小鼠模型的实验研究

Establishment of cryptorchid infertile models by postnatal injection of estradiol in mice

目的:观察出生后注射雌二醇诱导小鼠隐睾模型的发生率及生精情况。方法:90只雄性新生Balb/C小鼠随机分为实验组(n=60)、溶剂对照组(n=20)和正常对照组(n=10)。实验组进一步随机分为4个亚组,分别于出生后3～28 d(4周组)、3～42 d(6周组)、3～56 d(8周组)、3～70 d(10周组)给予皮下注射17-β雌二醇(5μg/d)。观察停药后2周隐睾发生率及形态学变化。结果:实验组各亚组(4、6、8、10周组)停药后2周隐睾发生率分别为0%、26.7%、60%、60%。而对照组均无隐睾发生。在4周和6周组停药后均出现隐睾自行下降恢复生精的情况,连续注药8周后模型稳定,隐睾生精不恢复。结论:出生后连续注射雌二醇8周能够建立稳定的隐睾性不育小鼠模型。

[ Abstract] Objective： To investigate the incidence and spermatogenesis of cryptorchid testes induced by postnatal injection of estradiol. Methods ： Ninety male newborn Balb/C mice were randomly divided into an experimental （ n = 60）, a solvent control （ n = 20） and a normal control group （n = 10）. The experimental mice were again assigned to a 4-week, a 6-week, an 8-week, and a lO- week subgroup, and injected subcutaneously with 17-beta estradiol （5 Ixg/d） from 3 to 28, 3 to 42, 3 to 56 and 3 to 70 days after birth, respectively. The incidence of cryptorchidism and morphological changes of the testes were observed at 2 weeks after drug with- drawal. Results ： The incidence rates of cryptorchidism in the 4-, 6-, 8- and 10-week groups were 0%, 26.7%, 60% and 60%, re- spectively, but no cryptorchidism occurred in the solvent and normal control groups. The 4- and 6-week groups showed autonomous de- scent of the cryptorchid testes and recovery of spermatogenesis after drug withdrawal. The models became stable and no spermatogenesis recovery was observed after 8 weeks of continuous medication. Conclusion ： Stable crytorchid infertile models can be established in mice by postnatally continuous injection of estradiol for over 8 weeks.