Department of Anatomy, Tokyo Medical University, Tokyo, Japan.
Toxicol Mech Methods. 2021 Feb;31(2):116-125. doi: 10.1080/15376516.2020.1841865. Epub 2020 Nov 16.
Neonatal maternal separation is an experimental model used to evaluate the effects of toxic stress in neonates, or early life stress. Although various physiological and psychological stresses during childhood have been reported, the effects of neonatal maternal separation on the male reproductive system remain unclear. Therefore, the present study evaluated the effects of neonatal maternal separation on the male reproductive system. In neonatal male ICR mice, maternal separation was performed for 0.5, 1, 2, and 4 hours/day, from postnatal day 1 to 10. At 10 weeks of age, the neonatal maternal separation mice exhibited decreases in both testicular weight and epididymal sperm number, along with various testicular morphological changes involving germ cells, Sertoli cells, and interstitial cells. Notably, neonatal maternal separation mice showed decreased numbers of Sertoli cells. Animals subjected to 0.5-, 1-, and 2-h/day neonatal maternal separation exhibited decreases in serum levels of testosterone but not in those of gonadotropin (luteinizing hormone and follicle-stimulating hormone). Together, these data showed that neonatal maternal separation in male mice causes decreased Sertoli cell numbers following puberty, resulting in subsequent decreased spermatogenic activity.
新生期母婴分离是一种用于评估新生儿或生命早期应激毒性作用的实验模型。虽然在儿童时期已经报道了各种生理和心理应激，但新生期母婴分离对男性生殖系统的影响尚不清楚。因此，本研究评估了新生期母婴分离对雄性生殖系统的影响。在新生雄性 ICR 小鼠中，从出生后第 1 天到第 10 天，每天进行 0.5、1、2 和 4 小时的母婴分离。在 10 周龄时，新生期母婴分离的小鼠睾丸重量和附睾精子数量均减少，同时出现各种涉及精原细胞、支持细胞和间质细胞的睾丸形态学变化。值得注意的是，新生期母婴分离的小鼠支持细胞数量减少。每天接受 0.5、1 和 2 小时母婴分离的动物表现出血清睾酮水平降低，但促性腺激素（黄体生成素和卵泡刺激素）水平没有降低。综上所述，这些数据表明，雄性小鼠的新生期母婴分离导致青春期后支持细胞数量减少，从而导致随后的生精活性降低。
