Maternal nutrient restriction during early to mid gestation alters the relationship between insulin-like growth factor I and bodyweight at term in fetal sheep
Maternal nutrient restriction during early to mid gestation alters the relationship between insulin-like growth factor I and bodyweight at term in fetal sheep
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DOI：
10.1071/rd00115
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发表时间：
2000-01-01
影响因子：
1.9
通讯作者：
Symonds, ME
中科院分区：
文献类型：
--
作者：
Heasman, L;Brameld, J;Symonds, ME
本研究旨在确定绵羊妊娠28至77天母体营养限制导致的胎盘大小改变是否与胎儿体重或尺寸与接近足月时血浆胰岛素样生长因子（IGF） I浓度或肝脏IGF-I和IGF- ii mRNA丰度之间的关系改变有关。单胎母羊消耗1.2倍（对照，n = 19）或0.5倍（营养限制）。n = 28)妊娠28 ~ 77 d的代谢能（ME）需求，之后所有母羊均饲喂以完全满足其维持和妊娠所需的ME。接近足月（145 +/- 1天）各组间血浆IGF-I浓度相似，但仅与对照组羔羊的胎儿体重、胸围、冠臀长和瘦体重呈显著相关（r(2) = 0.38, 0.76, 0.33）。0.42;P < 0.001)，而非营养限制母羊（r(2) = 0.01, 0.11, 0.01, 0.02）。接近足月的两组胎儿肝脏IGF-I和IGF-II mRNA表达无差异。在结论。例如，在妊娠早期到中期母体营养限制，然后喂养到足月，会改变胎儿IGF-I、体重和身高之间的关系。在长时间的营养限制后，妊娠后期增加母亲的营养可以刺激胎儿的营养供应，从而在不增加血浆igf - 1的情况下促进胎儿的生长。因此，在母亲在整个妊娠期得到充分喂养的胎儿中，胎儿体重和血浆IGF-I浓度之间的关系缺失。
The present study was designed to determine whether altered placental size, as a consequence of maternal nutrient restriction in sheep between 28 and 77 days gestation, is associated with a modified relationship between fetal weight or dimensions and plasma insulin-like growth factor (IGF) I concentration or abundance of hepatic IGF-I and IGF-II mRNA close to term. Singleton-bearing ewes consumed either 1.2x (controls, n = 19) or 0.5x (nutrient restricted. n = 28) their metabolizable energy (ME) requirements from 28 to 77 days gestation, after which all ewes were fed in order to fully meet their ME requirements for maintenance and pregnancy. Close to term (145 +/- 1 days) plasma IGF-I concentration in cord blood was similar between groups, but only significantly correlated with fetal bodyweight, thoracic circumference, crown-rump length and lean body mass in lambs born to control (r(2) = 0.38, 0.76, 0.33. 0.42; P < 0.001), and not to nutrient-restricted (r(2) = 0.01, 0.11, 0.01, 0.02) ewes. There were no differences in fetal hepatic expression of IGF-I and IGF-II mRNA between groups close to term. In conclusion., maternal nutrient restriction in early to mid gestation followed by feeding to requirements up to term alters the relationship between fetal IGF-I, bodyweight and length. Increasing maternal nutrition in later gestation after a prolonged period of nutrient restriction may stimulate fetal nutrient supply such that fetal growth is enhanced without an increase in plasma IGF-I. As a result, there is a loss of the relationship between fetal weight and plasma IGF-I concentration observed in fetuses whose mothers are fed adequately throughout gestation.