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Using Caco-2 Cells to Study Lipid Transport by the Intestine
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Using Caco-2 Cells to Study Lipid Transport by the Intestine

Published on: August 20, 2015

Electron microscopic study of the role of lipid micelles in intestinal fat absorption

C T Ashworth, J F Lawrence

    Journal of Lipid Research
    |July 1, 1966
    PubMed

    Insights

    Electron microscopy revealed small osmiophilic particles in fat absorption studies. These particles are proposed to be micellar particles involved in fat absorption by entering cells via diffusion or incorporation into spherules.

    Area of Science:

    • Cell Biology
    • Gastroenterology
    • Biochemistry

    Background:

    • Dietary fat absorption is a complex process involving the digestion and transport of lipids.
    • Micellar solutions, containing bile salts and fatty acids, are crucial for solubilizing dietary fats.
    • The precise mechanism of micelle uptake by intestinal cells remains an area of investigation.

    Purpose of the Study:

    • To investigate the ultrastructural characteristics of micellar solutions and their role in fat absorption.
    • To identify the physical form of lipids during intestinal fat absorption at the electron microscopic level.

    Main Methods:

    • Electron microscopy was used to examine in vitro micellar solutions (oleic acid, monoolein, sodium taurocholate).
    • Intestinal contents from rats during unsaturated fat absorption were analyzed.
    • Osmium and lead staining techniques were employed to visualize cellular structures and particles.

    Main Results:

    • Osmiophilic particles (30-200A) were observed in vitro and in rat intestinal contents.
    • Similar particles were found associated with microvilli and within the terminal web during fat absorption.
    • Larger emulsion droplets were present in the lumen, distinct from the smaller particles.
    • Spherules (approx. 1000A) in the terminal web increased in size and number during fat absorption.

    Conclusions:

    • The observed small particles are likely micellar particles involved in fat absorption.
    • These particles may enter absorptive cells via molecular diffusion or incorporation into spherules.
    • Spherules in the terminal web may play a role in the transport of absorbed lipids into the cell.

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