In Vivo Lipogenesis in the Domestic Chicken

Abstract

Growing crossbred chicks (490-635 g) were given glucose-U-14C or acetate-l-14C intraperitoneally and killed after 30 or 60 min. The radioactivity in plasma, liver and adipose tissue fatty acids and non-saponifiable lipids was determined. Total lipid-14C was also determined in chicks given glucose-U-14C; the difference between total lipid radioactivity and that in fatty acids and non-saponifiable lipids was taken to represent glyceride-glycerol-14C. Both substrates studied were readily utilized for fatty acid and non-saponifiable lipid synthesis. Glucose-U-14C was also utilized for glycerlde-glycerol formation. The relative importance of liver and adipose tissue as sites of fatty acid synthesis was estimated from the radioactivity, total liver weight, and body fat data. Liver was the major site of fatty acid synthesis in the chick, accounting for at least 70% of total fatty acid production. Adipose tissue makes much less of a contribution to fatty acid synthesis in the chick than in mammalian species where this tissue is responsible for 50-95% of total fatty acid synthesis.