Urinary excretion of 5-L-oxoproline (pyroglutamic acid) during early life in term and preterm infants
Urinary excretion of 5-L-oxoproline (pyroglutamic acid) during early life in term and preterm infants
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DOI：
10.1136/fn.76.3.f152
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发表时间：
1997-05-01
影响因子：
4.4
通讯作者：
Rutter, N
中科院分区：
文献类型：
--
作者：
Jackson, AA;Persaud, C;Rutter, N
尿5-L-氧代脯氨酸测定足月和早产儿从出生后不久，直到6周的出生后年龄，以确定他们的能力，合成甘氨酸。在足月婴儿中，肌酐的排泄量是正常成人的5 ~ 10倍，从出生后72小时的105 μ mol/mmol肌酐增加到6周龄的170 μ mol/mmol肌酐。5-L-氧脯氨酸排泄量与妊娠时间、出生体重呈显著的线性负相关。到6周龄时，足月儿和早产儿之间的5-L-氧代脯氨酸不再有显著差异。在男孩和女孩之间，或者在母乳喂养或人工配方奶喂养的婴儿之间，5-L-氧代脯氨酸的排泄没有差异。如果5-L-氧代脯氨酸排泄的变化部分取决于甘氨酸的内源性形成的程度，那么甘氨酸的形成在生命早期可能是边缘性的，早产儿比足月儿更是如此，提供了甘氨酸是新生儿中条件必需氨基酸的额外证据。
Urinary 5-L-oxoproline was measured in term and preterm infants from shortly after birth until 6 weeks of postnatal age to determine their ability to synthesise glycine. In term infants the excretion was five to 10 times that seen in normal adults, increasing from 105 mu mol/mmol creatinine in the first 72 hours after birth to 170 mu mol/mmol creatinine at 6 weeks of age. There was a significant inverse Linear correlation between the excretion of 5-L-oxoproline and length of gestation or birthweight. By 6 weeks of age there was no longer a significant difference in 5-L-oxoproline between term and preterm infants. There was no difference in the excretion of 5-L-oxoproline between boys and girls, or between infants fed on human milk or an artificial formula.If, in part, variability in the excretion of 5-L-oxoproline is determined by the extent to which the endogenous formation of glycine is adequate, then glycine formation may be marginal during early life, more so in preterm than in term infants, providing additional evidence that glycine is a conditionally essential amino acid in the neonate.