Ghrelin与胎儿及新生儿生长发育和能量代谢的关系

Ghrelin是生长激素释放激素受体的内源性配体,在胎儿及新生儿生长发育和能量代谢过程中发挥重要作用.胎儿期血循环中ghrelin来源于自身分泌(主要是胰腺,胃分泌较少)和胎盘,既有辛酰基化又有去酰基化ghrelin存在,可直接刺激细胞增殖、骨生长,诱导神经管发生.脐血ghrelin水平明显高于母血,并与胎盘重量、胰岛素样生长因子-1、出生体重及身长呈负相关.新生儿期ghrelin主要由胃黏膜细胞分泌,新生儿肠内营养物质的摄入促进胃肠ghrelin分泌细胞的成熟和分泌.新生儿血清总ghrelin水平高于脐血,并与出生体重、身长呈负相关,小于胎龄儿血ghrelin水平高于正常胎龄儿和大于胎龄儿.

Relationship between ghrelin,growth and energy balance of fetus and neonate

Ghrelin is an endogenous ligand for growth hormone secretngogne receptor. It plays an important role in fetal and neonatal development, and regulate energy balance. In fetus,the major source of circulating ghrelin in blood comes from pancreas and placenta. Both acyl ghrelin and des-acyl ghrelin bind to fetal tissues. They stimulate proliferation of fetal skin cells, bone formation and induce neurogenesis in the dorsal motor nucleus. The level of ghrelin is significantly higher in the umbilical cord blood than in the maternal, and is negatively correlated with placental weight, IGF-1 concentration, birth weight and birth length. In neonate, the source of circulating ghrelin comes from the neuroendocrine cells in the fundus of the stomach. Enteral nutritional intake in neonates contribute to the maturation of ghrelin production in stomach and increased the secretion of ghrelin. The plasma ghrelin level in infants is higher than in cord blood, and is negatively correlated with birth weight and birth length. The total ghrelin level of small-for-gestational age infants is greater than that of appropriate and large-for-gestational age infants.