The use of 5-L-oxoproline excretion in urine as an index of glycine insufficiency
The use of 5-L-oxoproline excretion in urine as an index of glycine insufficiency
It has been shown that in normal adults there is a low excretion of 5-oxoproline (208 μmol/day, 95% CI 189 to 277) which varies among and between individuals. Vegetarians were found to excrete increased levels of urinary 5-oxoproline (336 μmol/day, 95% CI 278 to 392, p<.01 compared to omnivores) compared with those on a mixed diet which included animal protein. When the dietary nitrogen intake of normal adults was controlled there was a significant increase in urinary 5-oxoproline (510 μmol/day, 95% CI 318 to 710, p<.001 compared to adequate protein intake) on the fifth day on a low protein diet. The excretion in the vegetarians was the same as that predicted from the response to that of controlled low protein intake.
Further it was shown that when there is an unbalanced demand for glycine during growth (pregnancy, infancy, childhood and adolesence) there was an increase in urinary 5-oxoproline. In pregnancy and early infancy there was a wide variability between individuals and the rate of excretion could reach very high values. The basis of these differences is not clear, but there was a suggestion that maturity or difference in rates of growth might be important associates. When children recovering from severe malnutrition were given dietary supplementation of glycine for a short period of time there was evidence of benefit, although this was not clear cut. The appearance was that in the children who were growing most rapidly the supplement was not sufficient to satisfy all the demands associated with the most rapid weight gain.
These data provide supporting evidences that glycine should be considered a conditionally essential amino acid during growth and marginal intake, when the demands for glycine are greater than the supply.
University of Southampton
Persaud, Chandarika
a61532b0-9a23-46f5-9713-e73e0428e2dc
1994
Persaud, Chandarika
a61532b0-9a23-46f5-9713-e73e0428e2dc
Persaud, Chandarika
(1994)
The use of 5-L-oxoproline excretion in urine as an index of glycine insufficiency.
University of Southampton, Doctoral Thesis.
Record type:
Thesis
(Doctoral)
Abstract
It has been shown that in normal adults there is a low excretion of 5-oxoproline (208 μmol/day, 95% CI 189 to 277) which varies among and between individuals. Vegetarians were found to excrete increased levels of urinary 5-oxoproline (336 μmol/day, 95% CI 278 to 392, p<.01 compared to omnivores) compared with those on a mixed diet which included animal protein. When the dietary nitrogen intake of normal adults was controlled there was a significant increase in urinary 5-oxoproline (510 μmol/day, 95% CI 318 to 710, p<.001 compared to adequate protein intake) on the fifth day on a low protein diet. The excretion in the vegetarians was the same as that predicted from the response to that of controlled low protein intake.
Further it was shown that when there is an unbalanced demand for glycine during growth (pregnancy, infancy, childhood and adolesence) there was an increase in urinary 5-oxoproline. In pregnancy and early infancy there was a wide variability between individuals and the rate of excretion could reach very high values. The basis of these differences is not clear, but there was a suggestion that maturity or difference in rates of growth might be important associates. When children recovering from severe malnutrition were given dietary supplementation of glycine for a short period of time there was evidence of benefit, although this was not clear cut. The appearance was that in the children who were growing most rapidly the supplement was not sufficient to satisfy all the demands associated with the most rapid weight gain.
These data provide supporting evidences that glycine should be considered a conditionally essential amino acid during growth and marginal intake, when the demands for glycine are greater than the supply.
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Published date: 1994
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Local EPrints ID: 458518
URI: http://eprints.soton.ac.uk/id/eprint/458518
PURE UUID: 2c8f4aab-7eb3-499d-9d84-aea29f2377a4
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Date deposited: 04 Jul 2022 16:50
Last modified: 23 Jul 2022 00:21
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Author:
Chandarika Persaud
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