62] Cultured avian liver explants for studies of lipogenic enzymes

Abstract

Publisher Summary This chapter describes the cultured avian liver explants for the studies of lipogenic enzymes. Most primary liver cell culture systems for the study of lipid metabolism involve disassociated hepatocytes and utilize serum that contains many hormones, unknown growth factors, and lipids, and thus makes it difficult to evaluate the role of hormones and lipids in the regulation of lipogenic enzymes. The characterization of an embryonic avian liver explant culture system maintained in a chemically defined culture medium, not containing serum, has made it possible to probe into the mechanism of hormonal induction of lipogenic enzymes, such as fatty acid synthase, stearoyl-CoA desaturase, and malic enzyme. The explants cultured in control medium lacking hormones maintained their initial specific activities of [U- 14 C]glucose oxidation to CO 2 , [ 3 H]uridine incorporation into RNA, and [ 3 H]leucine incorporation into cellular proteins. These results indicate that the functional viability of the liver can be maintained in explant culture for at least 120 h. The liver explant culture system is well suited for the investigation of mechanism by which insulin induces lipogenic enzymes.