Summary
In situ fatty acid synthesis has been measured with 3H2O in anaesthetised lean and obese Zucker (fa/fa) rats. The accumulation of fatty acids was increased in both the liver and adipose tissue of young fa/fa rats as a result of both an increased rate of lipogenesis and an increase in tissue mass. Whereas total hepatic lipogenesis increased with age, total adipose tissue lipogenesis decreased in older fa/fa rats. Experiments with hepatectomized rats showed that the liver was the major site of the excess fatty acid synthesis in fa/fa rats. The enhanced rate of lipogenesis in fa/fa rats was abolished by either pairfeeding or streptozotocin treatment. The results suggest that the increased fatty acid synthesis in fa/fa rats is secondary to the hyperphagia, hpyerinsulinaemia, and increased mass of hepatic and adipose tissues.
Article PDF
Similar content being viewed by others
References
Zucker, T.F., Zucker, L.M.: Fat accretion and growth in the rat. J. Nutr. 80, 6–19 (1963)
Bray, G.A., York, D.A.: Genetically transmitted obesity in rodents. Physiol. Rev. 51, 598–646 (1971)
Bray, G.A., Barry, W.S., Mothon, S.: Lipogenesis in adipose tissue from genetically obese rats. Metabolism 19, 839–848 (1970)
Taketomi, S., Ishikawa, E., Iwatsuka, H.: Lipogenic enzymes in two types of genetically obese animals, fatty rats and yellow KK mice. Horm. Metab. Res. 7, 242–246 (1975)
Deb, S., Martin, R.J.: Effects of exercise and of food restriction on the development of spontaneous obesity in rats. J. Nutr. 105, 543–549 (1975)
Martin, R.J.: In vivo lipogenesis and enzyme levels in adipose and liver tissues from pair-fed genetically obese and lean rats. Life Sci. 14, 1447–1453 (1974)
York, D.A., Bray, G.A.: Adipose tissue metabolism in six week old fatty rats. Horm. Metab. Res. 5, 355–360 (1973)
York, D.A., Bray, G.A.: Genetic obesity in rats. II. The effect of food restriction on the metabolism of adipose tissue. Metabolism 22 443–453 (1973)
Schonfeld, Y., Pfleger B.: Overproduction of very low density lipoproteins by livers of genetically obese rats Am. J. Physiol. 226 1178–1184 (1971)
Bloxham, D.P., York, D.A.: Metabolic flux through phosphofructokinase and fructose 1,6-Diphosphatase and its relation to lipogenesis in genetically obese rats. Biochem. Soc. Trans. 4, 989–993 (1977)
Bloxham, D.P., Fitzsimons, S., York, D.A.: Lipogenesis in hepatocytes of genetically obese rats. Horm. Metab. Res. 9, 304–309 (1977)
Hems, D.A., Rath, E.A., Verinder, T.R.: Fatty acid synthesis in liver and adipose tissue of normal and genetically obese (ob/ ob) mice during the 24 hr cycle. Biochem. J. 150, 167–173 (1975)
Loten, E., Rabinovitch, A., Jeanrenaud, B.: In vivo studies on lipogenesis in obese hyperglycemie (ob/ob) mice. Possible role of hyperinsulinemia. Diabetologia 10, 45–52 (1974)
Lowenstein, J.M.: Effect of hydroxycitrate on fatty acid synthesis by rat liver in vivo. J. Biol. Chem. 246, 629–632 (1971)
Folch, J., Lees, M., Sloane-Stanley, Y.N.: A simple method for the isolation and purification of total lipids from animal tissues. J. Biol. Chem. 226, 497–509 (1957)
Windmeuller, H., Spaeth, A.E.: Perfusion in situ with tritium oxide to measure hepatic lipogenesis and lipid secretion. J. Biol. Chem. 241, 2891–2899 (1966)
Windmeuller, H., Spaeth, A.E.: De novo synthesis of fatty acid in perfused rat liver as a determinant of plasma lipoprotein production. Arch. Biochem. Biophys. 122, 362–369 (1967)
Brunengraber, H., Boutry, M., Lowenstein, J.: Fatty acid and 3-α-hydroxysterol synthesis in the perfused rat liver. J. Biol. Chem. 248, 2656–2659 (1973)
Clark, D., Rongstad, R., Katz, J.: Lipogenesis in rat hepatocytes. J. Biol. Chem. 269, 2028–2036 (1974)
Lemmonier, D., Aubert, R., Suquet, J.-P., Rosselin, G.: Metabolism of genetically obese rats on normal or high fat diet. Diabetologia 10, 697–701 (1974)
Schonfeld, Y., Felski, C., Howald, M.: Characterization of the plasma lipoproteins of the genetically obese-hyperlipo-proteinemic Zucker fatty rat. J. Lipid Res. 15, 457–464 (1974)
Martin, R.J., Lamprey, P.: Early development of adipose cell lipogenesis and glycerol utilization in Zucker obese rats. Proc. Soc. Exp. Biol. Med. 149, 35–39 (1975)
Zucker, L.M., Antoniades, H.N.: Insulin and obesity in the Zucker genetically obese rat ‘fatty’. Endocrinology 90, 1320–1330 (1972)
Zucker, L.M.: Efficiency of energy utilization by Zucker hereditarily obese rat ‘fatty’. Proc. Soc. Exp. Biol. Med. 148, 498–500 (1975)
York, D.A., Steinke, J., Bray, G.A.: Hyperinsulinemia and insulin resistance in genetically obese rats. Metabolism 21, 277–284 (1972)
Dilettsuo, B., Wangsness, P.: Effect of age on hyperphagia of genetically obese Zucker rat. Proc. Soc. Exp. Biol. Med. 154, 1–5 (1977)
Stern, J.S., Johnson, P.R.: Spontaneous activity and adipose cellularity in the genetically obese Zucker rat (fa/fa). Metabolism 26, 371–380 (1977)
Author information
Authors and Affiliations
Additional information
The authors are grateful to the M. R. C. for award of a project grant.
Rights and permissions
About this article
Cite this article
Godbole, V., York, D.A. Lipogenesis in situ in the genetically obese Zucker fatty rat (fa/fa): Role of hyperphagia and hyperinsulinaemia. Diabetologia 14, 191–197 (1978). https://doi.org/10.1007/BF00429780
Received:
Revised:
Issue Date:
DOI: https://doi.org/10.1007/BF00429780