适于胎龄儿与小于胎龄儿血浆氨基酸浓度的比较

AComparisionofPlasmaAminoAcidConcentrationsbetwenAppropriateandSmalforGestationalAgeFetuses

目的：了解正常胎儿血浆氨基酸谱，探讨小于胎龄（ＳＧＡ）儿的发病机理。方法：用经腹脐静脉穿刺术和剖宫产术采脐静脉血，测定３０例不同胎龄正常胎儿血浆氨基酸浓度，并用配对的方法比较１０对出生后适于胎龄（ＡＧＡ）和ＳＧＡ母、儿血浆氨基酸浓度的差异。结果：ＡＧＡ儿脐血１５种氨基酸浓度高于其母血，脐血与母血血浆氨基酸浓度显著相关；胎儿与母体氨基酸总浓度及其比值均恒定。ＳＧＡ儿必需氨基酸浓度下降，尤以支链氨基酸和赖氨酸下降明显，ＳＧＡ儿与其母体的必需氨基酸和支链氨基酸比值亦下降，差异均有显著性，但ＳＧＡ孕妇必需氨基酸和支链氨基酸浓度无显著变化。结论：胎盘功能和母体营养供给是维持胎儿正常生长发育的重要因素，ＡＧＡ母、儿双方氨基酸维持相对稳定和平衡；ＳＧＡ儿存在氨基酸代谢紊乱，某些ＳＧＡ儿氨基酸浓度降低并不是因其母体氨基酸浓度低所致。

Objective:Toinvestigatetheroleofaminoacidplayedinpathogenesisofsmalforgestationalage(SGA)fetuses.Methods:Plasmaaminoacids′concentrations(PAAC)ofumbilicalvenoussamplesobtainedbycordocentesisbeforelabororatcesareansectionweremeasuredin30casesofappropriateforgestationalage(AGA)fetusesatdiferentgestationalage.PAACofbothmotherandfetusesweremeasuredandcomparedin10casesofSGAand10casesofAGA.Results:IncasesofAGA,thePAACinfetuses(3.11±0.41mmol/L)werefoundtobehigherthanthatinmothers.ThereweresignificantcorrelationsbetweenfetalandmaternalPAAC.ThetotalPAACinmothersandfetuses,anditsratioswerenotchangedwithgestationalage.IncasesofSGA,essentialaminoacids′concentration(EAA),especialybranchchainaminoacid(BCAA)andlysine,decreasedsignificantly.Thefeto-maternalratiosofEAAandBCAAwerereducedsignificantly,whereasconcentrationsofEAAandBCAAinmothersdidnotchangesignificantly.Conclusions:Theresultsindicatedthatplacentalfunctionandmaternalnutrientsupplementwereimportantfactorsformaintainingfetalgrowthanddevelopment.InAGAcases,relationshipofPAACbetweenmothersandfetuseswerekeptinastablebalance.InSGAfetusescertainaminoacidmetabolicdisturbancesexisted.ThereductionofsomePAACwasnotduetotheirdecreaseinmothers.