The Appearance of Lipid Cells in Freeze-Etched Preparations

Morphological studies on adipocytes from obese rats - scanning and freeze-fracturing electron microscopy.

“…Similar lamellar figures have been observed in phospholipid granules in yeast cells (20) and lung (4), and a lipid-water system in vitro (13,14). Daikoku et al (12) observed that the cleared surface of rat adipose tissue had a granular appearance showing lamellar structures and that the lamellae were less distinct in the center of lipid accumulations. In starving rats, these structures were not observed , but canalicular or cylindrical structures were seen arranged at right angles to the limiting membrane.…”

“…However, these experiments did not provide any information on the accumulation of fat in the central lipid inclusion of adipocytes. The application of the freeze-fracturing technique to adipocytes makes it possible to study the mechanism of fat storage in the cells (12) Male Wistar strain rats of 27 weeks old and young adult rats of 7 weeks old were used as controls. For studies on adipocytes in obesity, hypothalamic obesity was induced b y bilateral electrolytic lesions of the ventromedial hypothalamus of young adult rats (16) .…”

Freeze‐replica study of lipid droplets in the ito cells of rat liver

“…There is a limitation in the investigation of lipid droplets by conventional thin-section electron microscopy as a result of the extraction of lipids by organic solvents during dehydration and embedding (Korn and Weisman, 1966;Collet, 1979). The freeze-replica method avoids this specific problem, because it does not use organic solvents in the preparation of specimens (Daikoku et al, 1973;Williams, 1978). Nevertheless, it is not easy to identify lipid droplets of the It0 cells in freeze-replica images, since Ito cells are relatively small in size, constitute only 1.4% of parenchymal volume of the liver (Blouin et al, 19771, and have relatively few lipid droplets in their cytoplasm in the normal state (Wake, 1971;Kobayashi et al, 1973).…”