Dietary modifications of phospholipid composition and biophysical properties of the brush border membrane along the trout intestine.
Brush border membranes (BBM) are isolated from middle and posterior intestine of trout fed either an essential fatty acid-rich diet or a saturated one. The different phospholipid classes are separated, and their fatty acid composition is determined. Fluorescence anisotropy studies are performed using two lipid fluorophores, namely diphenylhexatriene (DPH) and trimethylamino-diphenylhexatriene (TMA-DPH). The results indicate that the usual parameters affecting the lipid fluidity such as the phospholipid:protein (PL:PROT), cholesterol:phospholipid (CHOL:PL), and sphingomyelin:phosphatidylcholine (SP:PC) ratios and the unsaturation of the acyl chains are sufficient to explain the fluidity values determined using DPH, but not those obtained with TMA-DPH as a probe. This fluorophore is assessed to be localized only in the external leaflet of the membrane. Hence, it will be affected by the composition of the major phospholipids of this leaflet, sphingomyelin and phosphatidylcholine.
Centre de Neurochimie du CNRS, Strasbourg, France.
X
X
Pelletier
G
G
Duportail
C
C
Leray
D000818:Animals; D004041:Dietary Fats / Q000378:metabolism*; D005227:Fatty Acids / Q000008:administration & dosage* / Q000378:metabolism; D005228:Fatty Acids, Essential / Q000008:administration & dosage / Q000378:metabolism; D005454:Fluorescence Polarization; D005456:Fluorescent Dyes; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism* / Q000648:ultrastructure; D008871:Microvilli / Q000378:metabolism; D010743:Phospholipids / Q000378:metabolism*; D012487:Salmonidae / Q000378:metabolism*; D014337:Trout / Q000378:metabolism*
D004041:Dietary Fats; D005227:Fatty Acids; D005228:Fatty Acids, Essential; D005456:Fluorescent Dyes; D010743:Phospholipids