Department of Obstetrics and Gynecology, China-Japan Friendship Hospital, Beijing 100029, China.
State Key Laboratory of Animal Nutrition, College of Animal Science and Technology, China Agricultural University, Beijing 100193, China.
Biomed Res Int. 2020 Jan 8;2020:1630890. doi: 10.1155/2020/1630890. eCollection 2020.
Within-litter birth weight variation in multiparous animals has become a big issue due to high incidence of low birth weight neonates, which gives rise to high preweaning mortality and morbidity. Foetus with various birth weights is the outcome of diverse embryos competence which is affected by oocyte quality. Glucosamine (GlcN) has been reported to be involved in oocyte maturation; however, its effect on pregnant outcomes remains unknown. The present study was conducted to investigate the effects of premating GlcN supplementation via drinking water on within-litter birth weight variation and its underlying mechanism. Fifty eight Sprague-Dawley female rats were randomly assigned to one of two groups with normal drinking water or drinking water supplemented with 0.5 mM GlcN from six to eight weeks old. Variation of within-litter birth weight in the GlcN group was 5.55%, significantly lower compared with 8.17% in the control group. Birth weight was significantly increased in the GlcN group (2.27 ± 0.06) compared with the control group (2.08 ± 0.04). Both absolute and relative weights of the ovary at the end of GlcN treatment were higher in the GlcN group than in the control group ( < 0.05). In the GlcN group, there were more successfully implanted blastocysts (13.38 ± 0.63 and 15.75 ± 0.59 in the control and treatment group, respectively) with more uniform distribution along the two uterine horns compared with the control group. Besides, gene expressions of Alk3 and Bmp2 were increased in the implantation sites, while IGF-1 and Mucin-1 were decreased significantly in rats administrated with GlcN. Maternal progesterone, estradiol, and IGF-1 concentrations on D 19.5 were significantly increased, while insulin and total cholesterol levels were significantly decreased in contrast with control dams. In summary, the administration of 0.5 mM GlcN solution before mating reduced within-litter birth weight variation, accompanied with increased fetal weight. Further investigation indicated that the improved outcome of pregnancy results at least partly from the increased ovary weights of the rats, the homogeneous embryo developmental competence, the enhanced receptivity of the uterine environment, and the adjusted maternal hormone levels.
多胎动物中每窝内的出生体重差异已成为一个大问题，因为低出生体重的新生儿发病率很高，这导致了较高的断奶前死亡率和发病率。具有不同出生体重的胎儿是胚胎能力不同的结果，而胚胎能力受卵母细胞质量的影响。已报道氨基葡萄糖（GlcN）参与卵母细胞成熟；然而，其对妊娠结局的影响尚不清楚。本研究旨在探讨通过饮用水在交配前补充氨基葡萄糖对每窝内出生体重变化的影响及其潜在机制。58 只 Sprague-Dawley 雌性大鼠被随机分为两组，一组饮用普通水，另一组从 6 至 8 周龄起饮用添加 0.5mM GlcN 的水。GlcN 组的每窝内出生体重变化为 5.55%，明显低于对照组的 8.17%。GlcN 组的出生体重（2.27±0.06）明显高于对照组（2.08±0.04）。GlcN 处理结束时，卵巢的绝对重量和相对重量在 GlcN 组均高于对照组（<0.05）。在 GlcN 组中，成功着床的胚泡数量更多（对照组和治疗组分别为 13.38±0.63 和 15.75±0.59），且在两个子宫角中的分布更均匀。此外，在 GlcN 处理的大鼠中，植入部位的 Alk3 和 Bmp2 基因表达增加，而 IGF-1 和 Mucin-1 的表达明显降低。与对照组母鼠相比，D19.5 时母鼠孕激素、雌二醇和 IGF-1 浓度显著升高，而胰岛素和总胆固醇水平显著降低。总之，在交配前给予 0.5mM GlcN 溶液可减少每窝内的出生体重差异，并伴有胎儿体重增加。进一步的研究表明，妊娠结局的改善至少部分归因于大鼠卵巢重量的增加、胚胎发育能力的均匀性、子宫环境的接受能力的增强以及母体激素水平的调整。
