FOLATE STATUS IN INTRAUTERINE GROWTH RETARDED INFANTS

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得主要资金， 因此可以在其他CRISP条目中表示。列出的机构是 中心，不一定是研究者的机构。 叶酸缺乏在IUGR中的作用尚不确定。 本研究为叶酸、叶酸辅助因子及叶酸调节酶在胎儿宫内生长受限中的作用提供了初步证据。 据推测，IUGR新生儿与正常生长的新生儿相比，叶酸和维生素B12代谢异常。 将收集30名IUGR新生儿和90名对照新生儿的脐带血。 分娩后，将5-15 cc脐带血收集在预冷的EDTA管（5-15 cc）中，分离，加入（体积/重量）1%抗坏血酸，快速冷冻并储存在-20 ℃下，直至分析叶酸辅因子。将5cc置于预冷的红盖中，使其凝结，分离血清，等分至750 μ l，快速冷冻并储存在-20 ℃下直至分析代谢物。我们将使用我们实验室开发的新颖和灵敏的测定法来证实在IUGR胎羊模型中观察到的结果。 代谢物含量测定：血清蛋氨酸、SAM和SAH将在Dr. Stabler 13的实验室通过稳定同位素稀释法测定。此外，该方法产生叶酸和维生素B12的其他代谢物的浓度，其有助于区分叶酸和维生素B12缺乏：二甲基甘氨酸、甲基甘氨酸、高半胱氨酸、丝氨酸、甘氨酸、半胱氨酸、甲基丙二酸、色氨酸和胱硫醚。 叶酸辅酶测定：将使用我们在Dr. Kolhouse实验室12开发的技术，通过直接探针MS测定血浆中的总叶酸、5-甲基-THF、5，10亚甲基-THF和THF的甲酰基（5-甲酰基-THF、10-甲酰基-THF、5，10亚甲基-THF）。我们假设IUGR婴儿与对照组相比有叶酸缺乏的证据。我们预计，我们将产生叶酸和代谢物值的规范性数据，并使用这些新的更灵敏的检测方法直接确定叶酸缺乏症和IUGR之间的潜在关联。 代谢物测定已在动物和人体试验中得到验证，并且具有很好的重现性。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The role of folate deficiency in IUGR is uncertain. This study will provide preliminary evidence for the roles of folate, folate cofactors and the enzymes of folate regulation in human intrauterine growth restricted neonates. It is hypothesized that IUGR newborns will have abnormalities of folate and vitamin B12 metabolism compared to appropriately grown newborns. Cord blood will be collected on 30 IUGR newborns and 90 control newborns. After delivery, 5-15 cc of cord blood will be collected in prechilled EDTA tubes (5-15 cc) separated, brought to (vol/wt) 1% ascorbic acid, snap frozen and stored at -20 C until analysis for folate cofactors. 5 cc will be placed in a prechilled red top, allowed to clot and serum separated, aliquoted to 750 l aliquots, snap frozen and stored at -20 C until analysis for metabolites.We will use novel and sensitive assays developed in our laboratories to confirm observations made in a fetal sheep model of IUGR. Metabolite assay: Serum methionine, SAM and SAH will be determined by the stable isotope dilution method in the laboratory of Dr. Stabler 13. In addition, this method yields the concentrations for other metabolites of folate and vitamin B12 that aid in distinguishing folate from vitamin B12 deficiency: dimethylglycine, methylglycine, homocysteine, serine, glycine, cysteine, methyl- malonic acid, tryptophan, and cystathionine. Folate coenzyme assay: Plasma will be assayed for total folate, 5-methyl-THF, 5,10 methylene THF and the formyl groups of THF (5-formyl-THF, 10-formyl-THF, 5,10 methenyl-THF) by direct probe MS using a technique that we have developed in Dr. Kolhouse's laboratory 12. We hypothesize that IUGR infants will have evidence for folate deficiency compared to controls. We anticipate that we will generate normative data for folate and metabolite values and using these new more sensitive assays directly determine the potential association between folate deficiency and IUGR. The metabolite assays have been validated in animal and human testing and are very reproducible.