Urinary excretion of 5-L-oxoproline (pyroglutamic acid) is increased during recovery from severe childhood malnutrition and responds to supplemental glycine.
We hypothesized that a limitation in the endogenous formation of glycine might constrain catch-up growth during recovery from severe childhood malnutrition. The urinary excretion of 5-L-oxoproline is increased when the glycine available for glutathione synthesis is limited. Urinary excretion of 5-L-oxoproline was measured throughout recovery in 12 children (aged 16 +/- 6 mo) with severe malnutrition. Urinary 5-L-oxoproline was similar at admission and after recovery, but was increased significantly during rapid catch-up growth. There was a significant relationship between the rate of weight gain and 5-L-oxoproline excretion in urine. In nine children (aged 15 +/- 5 mo), the effect of oral supplementation with glycine, [1.7 mmol/(kg x d) for 48 h] during rapid catch-up growth on 5-L-oxoprolinuria and blood glutathione concentration was determined. In seven of the nine children weight gain was less than 17 g/(kg x d) and following oral glycine supplements 5-L-oxoproline excretion was reduced up to 64% and blood glutathione concentration increased up to 100%. In the two children who were gaining weight at a rate > 17 g/(kg x d), glycine supplementation was associated with a further increase in 5-L-oxoproline excretion and a decrease in blood glutathione. If 5-L-oxoproline is an index of the relative availability of glycine, then the data indicate that glycine may be limiting during rapid catch-up growth. This would have important implications for repletion of muscle and gain in height.
Institute of Human Nutrition, University of Southampton, Bassett Crescent, United Kingdom.
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Persaud
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Forrester
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Jackson
D000375:Aging / Q000502:physiology; D001835:Body Weight / Q000187:drug effects / Q000502:physiology; D002675:Child, Preschool; D005260:Female; D005527:Food, Fortified; D005978:Glutathione / Q000097:blood; D005998:Glycine / Q000008:administration & dosage / Q000494:pharmacology*; D006128:Growth / Q000187:drug effects / Q000502:physiology; D006801:Humans; D007223:Infant; D008297:Male; D009748:Nutrition Disorders / Q000652:urine*; D011761:Pyrrolidonecarboxylic Acid / Q000652:urine*; D015430:Weight Gain / Q000187:drug effects / Q000502:physiology
D005978:Glutathione; D011761:Pyrrolidonecarboxylic Acid; D005998:Glycine