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. Author manuscript; available in PMC: 2021 Jan 11.
Published in final edited form as: J Biol Chem. 2003 Jun 4;278(35):33501–33518. doi: 10.1074/jbc.M303591200

Fig. 5. Accumulation of lipid in PITPα−/− duodenal epithelium.

Fig. 5.

A, intracellular lipid in enterocytes of PITPα−/− duodenum. Sections (5 μm thick) of duodenum from PITPα+/+ and PITPα−/− P5 siblings were stained with osmium and counterstained with toluidine blue O. Black granules identify lipid. Relevant genotypes are given. B, electron micrographs of duodenal epithelium from PITPα+/+ (left) and PITPα−/− (right) P8 mice are shown. Bars are 5 μm. C, electron micrographs of enterocytes from PITPα+/+ and PITPα−/− mice as indicated. Bars are 2 μm. D, electron micrographs of lipid bodies from PITPα+/+ (left panels) and PITPα−/− enterocytes (right panels) as indicated. Dimensions of the lipid bodies aside, the general morphologies of these structures exhibit many similarities in wild-type versus mutant enterocytes, and most are membrane-enclosed. Boundary membranes are indicated by arrows. A cytoplasmic lipid droplet (L) with a fuzzy border is shown for contrast. Bars are 0.2 μm. E, distribution histogram of vesicle perimeters in PITPα+/+ (solid symbols) and PITPα−/− mice (open symbols). Perimeter measurements were made for 428 and 398 lipid bodies from PITPα+/+ and PITPα−/− enterocytes, respectively. F, enlargement of smooth ER in PITPα−/− duodenal enterocytes as revealed by electron microscopy. Lipid-engorged regions are identified by arrows. These smooth ER luminal regions are contiguous with the lumen of adjacent rough ER that is easily recognized by the associated ribosomes (not shown). Bar is 0.4 μm. G, PITPα−/− mice exhibit reduced brain α-tocopherol and post-prandial TG levels. Parameters are indicated. Measurements were made from nine PITPα+/+ and nine PITPα−/− mice. Averages ± S.D. are given.