Radioautography was used to detect the synthesis of labeled glycerides in intestinal absorptive cells following injections of fatty chyme and glucose-6-H3 into ligated segments of upper jejunum of fasting rats. Absorption intervals ranged from 2 to 20 min. Labeling is evident throughout the cells in as short a time as 2 min. Most grains are present over droplets of absorbed fat beginning with those in the endoplasmic reticulum immediately subjacent to the terminal web. With longer absorption periods, frequent grains are present over accumulations of fat droplets in the Golgi cisternae and intercellular spaces. A similar pattern of grains is seen following absorption of either linoleic acid or safflower oil. By comparison, considerably less label is present in the cells when the fat is extracted with alcohol prior to radioautographic procedures, or when labeled glucose alone is absorbed. A significant incorporation of glucose label into newly synthesized glycerides is indicated and confirmed by scintillation counts on saponified lipid extracts. The grain distribution implies an involvement of the extreme apical endoplasmic reticulum in this synthesis.
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Article| December 01 1966
A RADIOAUTOGRAPHIC STUDY OF GLYCERIDE SYNTHESIS IN VIVO DURING INTESTINAL ABSORPTION OF FATS AND LABELED GLUCOSE
Ralph A. Jersild, Jr.
From the Department of Anatomy, Indiana University Medical Center, Indianapolis
Received: May 18 1966
Online ISSN: 1540-8140
Print ISSN: 0021-9525
Copyright © 1966 by The Rockefeller University Press
Ralph A. Jersild; A RADIOAUTOGRAPHIC STUDY OF GLYCERIDE SYNTHESIS IN VIVO DURING INTESTINAL ABSORPTION OF FATS AND LABELED GLUCOSE . J Cell Biol 1 December 1966; 31 (3): 413–427. doi: https://doi.org/10.1083/jcb.31.3.413
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