Brush border membrane non-esterified fatty acids. Physiological levels and significance for mucosal iron uptake in mouse proximal intestine
✍ Scribed by Robert J. Simpson; S. Venkatesan; Timothy J. Peters
- Publisher
- John Wiley and Sons
- Year
- 1989
- Tongue
- English
- Weight
- 548 KB
- Volume
- 7
- Category
- Article
- ISSN
- 0263-6484
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✦ Synopsis
Brush border membrane vesicles prepared using divalent cation precipitation methods can contain unphysiological levels of non-esterified fatty acids. Fatty acid production from endogenous lipid during brush border membrane vesicle preparation is effectively prevented by the lipase inhibitor diethyl 4-nitrophenylphosphate plus cooling. Vesicles prepared using this procedure have variable levels of non-esterified fatty acids (range 22-193 nmol mg-' protein). Changes in non-esterified fatty acid levels in brush border membrane vesicles parallel Fe uptake by vesicles from Fe/ascorbate solutions. Brush border membrane vesicle fatty acids appear to be derived from the diet but hypoxic mice are able to maintain high brush border membrane non-esterified fatty acid levels despite reduced dietary intake. Non-esterified fatty acids in brush border membrane may thus provide a physiological mechanism of mucosal Fe uptake. KEY woizm-lron absorption; hypoxia. AReREV1aTroNs-HEPE~-(2-hydroxyethyl)-I-piperazine-ethanesulphonic acid; NTA-nitrilotriacctic acid.