ATP-binding cassette transporter A1 is significantly involved in the intestinal absorption of - and -tocopherol but not in that of retinyl palmitate in mice  

Oleh:

Reboul, Emmanuelle ; Trompier, Doriane ; Moussa, Myriam ; Klein, Alexis ; Landrier, Jean-Francois

Jenis: Article from Journal - ilmiah internasional
Dalam koleksi: The American Journal of Clinical Nutrition vol. 89 no. 01 (Jan. 2009), page 177.
Topik: Vitamins; minerals; and phytochemicals

Ketersediaan

Perpustakaan FK Nomor Panggil: A07.K.2009.01 Non-tandon: 1 (dapat dipinjam: 0) Tandon: tidak ada

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Isi artikel

Background: It has long been assumed that newly absorbed vitamin A and E enter the body only via enterocyte-produced chylomicrons. However, recent results in cell cultures have shown that a fraction of -tocopherol is secreted with intestinal HDL. Objectives: The aims of this study were to identify this transporter and to assess whether it is significantly implicated in the in vivo intestinal absorption of the 2 main dietary forms of vitamin E (ie, - and -tocopherol) and in that of retinyl palmitate (vitamin A). Design: Having performed preliminary experiments in the Caco-2 cell model, we compared fasting and postprandial plasma concentrations of vitamins A and E in mice deficient in ATP-binding cassette A1 (ABCA1) transporter and in wild-type mice. Results: A substantial efflux of - and -tocopherol, but not of retinyl esters, was induced by the presence of apolipoprotein A-I at the basolateral side of Caco-2 monolayers. The efflux of - and -tocopherol was also impaired by glyburide and 4,4'-diisothiocyanostilbene-2,2'-disulfonic acid. The postprandial response of plasma -tocopherol was 4-fold lower in ABCA1–/– mice (P = 0.025) than in wild-type mice, whereas no significant difference was observed for retinyl esters. Fasting plasma -tocopherol, but not vitamin A, concentrations were lower in mice bearing the genetic deletion. Conclusions: ABCA1 is the transporter responsible for the in vivo secretion of - and -tocopherol with intestinal HDL, and this pathway is significantly implicated in the intestinal absorption and plasma status of vitamin E but not of vitamin A.

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