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Titolo:
beta-carotene 15,15 '-dioxygenase activity in human tissues and cells: evidence of an iron dependency
Autore:
During, A; Smith, MK; Piper, JB; Smith, JC;
Indirizzi:
ARS, USDA, Beltsville Human Nutr Res Ctr, Phytonutrients Lab, Beltsville, MD 20705 USA ARS Beltsville MD USA 20705 Phytonutrients Lab, Beltsville, MD 20705 USA Westchester Cty Med Ctr, Dept Surg, Valhalla, NY 10595 USA Westchester CtyMed Ctr Valhalla NY USA 10595 urg, Valhalla, NY 10595 USA
Titolo Testata:
JOURNAL OF NUTRITIONAL BIOCHEMISTRY
fascicolo: 11, volume: 12, anno: 2001,
pagine: 640 - 647
SICI:
0955-2863(200111)12:11<640:B1'AIH>2.0.ZU;2-R
Fonte:
ISI
Lingua:
ENG
Soggetto:
VITAMIN-A; DIOXYGENASE ACTIVITY; INTESTINAL-MUCOSA; RAT INTESTINE; CACO-2 CELLS; LINE CACO-2; CONVERSION; ENZYME; EXPRESSION; COPPER;
Keywords:
beta-carotene; cleavage; intestine; liver; desferrioxamine; human;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Life Sciences
Citazioni:
31
Recensione:
Indirizzi per estratti:
Indirizzo: During, A ARS, USDA, Beltsville Human Nutr Res Ctr, Phytonutrients Lab, Beltsville, MD 20705 USA ARS Beltsville MD USA 20705 ients Lab, Beltsville, MD 20705 USA
Citazione:
A. During et al., "beta-carotene 15,15 '-dioxygenase activity in human tissues and cells: evidence of an iron dependency", J NUTR BIOC, 12(11), 2001, pp. 640-647

Abstract

The two objectives of this study were to investigate beta -carotene 15,15'-dioxygenase activity in human tissues and to determine the effect of desferrioxamine on the dioxygenase activity. Two human in vitro models were used: the TC7 clone of the intestinal cell line Caco-2 and small intestinal mucosa preparations. beta -Carotene 15,15'-dioxygenase activity in the small intestinal mucosa was (mean +/- SD) 97.4 +/- 39.8 pmol/h.mg protein for fiveadults (44-89 y) and 20 pmol/h.mg for an infant (17 months). No activity was detected in adult stomach tissue. We report for the first time the dioxygenase activity in human liver: 62 pmol/h.mg for a normal adult liver and 7pmol/h.mg for a liver exhibiting gross pathology. The maximum capacity of beta -carotene cleavage in an adult was estimated to be 12 mg/day (one fifth by small intestine and four fifths by liver), assuming an optimal beta -carotene/retinal cleavage ratio of 1:2. The dioxygenase activity was decreased up to 80% with increasing desferrioxamine concentrations in the two in vitro models. Desferrioxamine was characterized as a noncompetitive inhibitor. In TC7 cells, the inhibitory effect of desferrioxamine was reversed by iron addition, suggesting that this effect was related to the ability of desferrioxamine to chelate iron, purported to be an obligate cofactor of the enzyme. In conclusion, these data report the presence of beta -carotene 15,15'-dioxygenase activity in human small intestine and liver and demonstrate that desferrioxamine efficiently inhibits intestinal beta -carotene cleavage in human tissues and cells. (C) 2001 Elsevier Science Inc. All rights reserved.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 29/03/20 alle ore 14:34:10