Intestinal aspects of lipid absorption: in review

Abstract

The rapidly evolving field of lipid absorption is reviewed with the thrust of new knowledge focused on the interpendency of the luminal and cellular phases of absorption. To date little attention has been paid to factors that regulate the phospholipid biosynthesis in the enterocyte. The availability of 20:4 omega 6 may be the rate-limiting factor for phospholipid synthesis. The source of 20:4 omega 6 is unknown, whether it be synthesized de novo the enterocyte or entirely originating from degradation of bile phospholipid. It has been established that dietary fat can modulate the enterocyte membrane lipid composition and transport properties. Specified fats such as as fish oils rich in 20:5 omega 3 and 22:6 omega 3 have been implicated as protective against hypercholesterolemia. However, the effects of these dietary fats on the transport of nutrients across the enterocyte are not yet known, nor are the mechanisms responsible for the adaptive responses of the brush border identified.

Solubility and micelle-water partitioning of polychlorinated biphenyls in solutions of bile salt micelles

“…To each vial 3 mL of bile salt solution was added, with concentrations ranging from 0.0 mM to 20.0 mM TC and from 0.0 mM to 10 mM TDC. These bile salt concentrations are in accordance with reported luminal concentrations [11,24]. At the given experimental conditions bile salt critical micellar concentrations are considered to be 1.7 mM and 2.7 mM for TDC and TC respectively [18].…”

Using primary murine intestinal enteroids to study dietary TAG absorption, lipoprotein synthesis, and the role of apoC-III in the intestine

“…Dietary TAG is absorbed from a proximal-to-distal gradient along the length of the small intestine (29)(30)(31)(32). Correspondingly, there is a gradient of terminally differentiated enterocytes responsible for TAG absorption, as well as a gradient of apolipoprotein expression.…”

The metabolism and availability of essential fatty acids in animal and human tissues

“…The processes of lipid digestion and absorption have been reviewed several times in the last few years (B6zard and Bugaut, 1986;Bernard and Carlier, 1989;Thomson et al, 1989;Carlier ef al, 1991 (Lawson and Hughes, 1988b). However, hydrolysis takes place, probably less rapidly but completely.…”