Refeeding varying fatty acid and cholesterol diets alters phospholipids in rat intestinal brush border membrane

Abstract

Refeeding a diet initially given shortly after weaning results in a different adaptive change in the in vitro intestinal uptake of sugars and lipids than if the diet is given for the first time at a later age. This study was undertaken in rats to test the hypothesis that changes in nutrient uptake associated with refeeding diets containing beef tallow (S), beef tallow plus 1% cholesterol (Sc), fish oil (F), or fish oil plus cholesterol (Fc) are associated with changes in the brush border membrane (BBM) phospholipids and phospholipid fatty acids. Weanling Sprague-Dawley rats were fed ad libitum one of the four diets. At 35 d of age (about 2 wk after weaning), the rats were maintained on either the same diet used at weaning, or were switched to one of the other semisynthetic diets which were then fed for a further 7 wk. At week nine (2 + 7) the rats were either continued on the same diet or were switched back to the original diet for 2 wk (2 + 7 + 2). The groups of animals which were compared included SSSc vs. ScSSc; ScScS vs. SScS; FFFc vs. FcFFc; and FcFcF vs. FFcF. Refeeding S, Sc, F, or Fc had no effect on food consumption or on body weight gain. Refeeding Fc resulted in increased ileal BBM total phospholipids, whereas rechallenge with F resulted in a decline in the jejunal BBM ratio of phospho-lipid/cholesterol. Refeeding Sc resulted in a decrease in the ileal BBM phosphatidylcholine (PC). In rats rechallenged with Fc, there was increased ileal BBM sphingomyelin (SM), increased ileal BBM phosphatidylethanolamine (PE), decreased ileal BBM PC/PE, and an increased ileal BBM SM/PC. Refeeding had no effect on the fatty acyl constituents of the jejunal of ileal BBM PC or PE. These results suggest that there are late effects of the early introduction of dietary cholesterol on intestinal BBM phospholipid content and composition that may contribute to the previously reported changes in intestinal nutrient absorption.

Effect of fatty Amazon fish consumption on lipid metabolism

“…Other studies have reported that rats kept with diets enriched with polyunsaturated and saturated fish oil did not vary their food intake 22 . Interestingly, in past decades, this dietary practice of feeding high-fat diet was used as strategy to control obesity, but with little success, since in general this type of diet has high energy content leading to body weight gain 21 .…”

A Solid-State NMR Study of Phospholipid-Cholesterol Interactions: Sphingomyelin-Cholesterol Binary Systems

“…In addition, increased Chol levels and SM/PC ratios in membranes, coupled with increased chain ordering in phospholipids, have been correlated with aging of cells and organs (Levi et al, 1989;Prisco et al, 1986;Lewin and Timiras, 1984;Aureli et al, 2000). Feeding Chol-enriched diets to rats resulted in an increased SM/PC ratio in the ileal brush border membrane (Keelan and Clandinin, 1997). In the human skin fibroblast, depletion of Chol activates the de novo synthesis of SM (Leppimäki et al, 1998), which potentiates recruitment of new Chol molecules into the membrane bilayers.…”

Cholesterol and short-chain fatty acids in diets for Atlantic salmonSalmo salar(L.): effects on growth, organ indices, macronutrient digestibility, and fatty acid composition

“…This may influence the intestinal absorption of different fatty acids ( Keelan et al . 1994 , 1997) and other nutrients ( Thomson et al . 1988 ).…”

“…CHOL uptake by intestinal cells is a time-, temperature-, dosedependent and saturable process (Sviridov et al 1993;Safonova et al 1994); the feeding of a high CHOL diet may alter fatty acid desaturase activity of the intestinal enterocytes and thus the esteri®cation pattern of brush-border membrane phospholipids . This may in¯uence the intestinal absorption of dierent fatty acids (Keelan et al , 1997 and other nutrients (Thomson et al 1988). The fatty acid elongation and desaturation system is aected by several physiological and nutritional factors, as well as fatty acid composition (reviewed by Cinti et al 1992) and dietary CHOL (Garg et al 1986).…”