title: Brush border membrane non-esterified fatty acids. Physiological levels and significance for mucosal iron uptake in mouse proximal intestine.
abstract: 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-1 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.
authors: Department of Clinical Biochemistry, King's College School of Medicine and Dentistry, London, U.K.
authors: R J
authors: RJ
authors: Simpson
authors: S
authors: S
authors: Venkatesan
authors: T J
authors: TJ
authors: Peters
mesh_terms: D000818:Animals; D005230:Fatty Acids, Nonesterified / Q000096:biosynthesis / Q000378:metabolism*; D007408:Intestinal Absorption / Q000187:drug effects; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D007501:Iron / Q000378:metabolism*; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D008871:Microvilli / Q000187:drug effects / Q000378:metabolism; D009596:Nitrophenols / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000494:pharmacology
chemical_list: D005230:Fatty Acids, Nonesterified; D009596:Nitrophenols; D009943:Organophosphorus Compounds; C008644:nitrophenylphosphate; D007501:Iron