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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
10
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pubmed:dateCreated |
1992-2-18
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pubmed:abstractText |
The tryptophan-load test for vitamin B-6 nutritional status was administered to adult female Long-Evans rats fed graded levels of pyridoxine hydrochloride (PN.HCl) in two experiments, and its sensitivity to marginal vitamin B-6 intake was evaluated. In Experiment 1, rats were 4-h meal-fed an AIN-76A (20% casein) diet devoid of PN.HCl for 3 wk, then repleted (n = 12) for 6 wk with 4-h pair-fed meals of either 0.25, 0.5, 1.0 or 7.0 (control) mg PN.HCl/kg diet. In Experiment 2, rats (n = 16) were pair-fed for 10 wk either 0.0, 0.5, 1.0 or 7.0 (control) mg PN.HCl/kg diet, with 24-h access to food. Vitamin B-6 nutritional status was assessed at the end of each experiment. Except in rats fed 0 mg PN.HCl/kg diet, mean body weights were not significantly different among diet groups of either experiment. Plasma pyridoxal phosphate (PLP), pyridoxal and total vitamin B-6 concentrations, determined by HPLC, were very sensitive to gradations in dietary PN.HCl concentrations (P less than 0.05). Red blood cell endogenous and PLP-stimulated alanine and aspartate aminotransferase activity did not statistically differentiate all levels of dietary vitamin B-6, although the calculated activity coefficient for each enzyme (stimulated/endogenous activity) did. Urinary xanthurenic acid excretion following a tryptophan load [24.5 mumol (5 mg) L-tryptophan/100 g body weight, injected intraperitoneally] was significantly (P less than 0.05) elevated compared with controls only in the group fed 0 mg PN/HCl/kg diet. At the tryptophan dose used here, the tryptophan-load test was not useful in detecting marginal vitamin B-6 intake in rats.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Oct
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pubmed:issn |
0022-3166
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
121
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1627-34
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pubmed:dateRevised |
2003-11-14
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pubmed:meshHeading |
pubmed-meshheading:1765828-Administration, Oral,
pubmed-meshheading:1765828-Animals,
pubmed-meshheading:1765828-Body Weight,
pubmed-meshheading:1765828-Dose-Response Relationship, Drug,
pubmed-meshheading:1765828-Female,
pubmed-meshheading:1765828-Pyridoxine,
pubmed-meshheading:1765828-Rats,
pubmed-meshheading:1765828-Tryptophan,
pubmed-meshheading:1765828-Xanthurenates
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pubmed:year |
1991
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pubmed:articleTitle |
Insensitivity of the tryptophan-load test to marginal vitamin B-6 intake in rats.
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pubmed:affiliation |
U.S. Department of Agriculture, Western Human Nutrition Research Center, San Francisco, CA 94129.
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pubmed:publicationType |
Journal Article
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