The proposed studies address the basic question of the nature of the metabolic signals that control food intake. Preliminary studies suggest that a biochemical event in liver common to the metabolism of glucose and fatty acids provides an integrated signal for meal initiation. ATP, which could potentially provide such a signal, has been suggested as a stimulus for the control of feeding, but this hypothesis has not been tested directly. Preliminary experiments utilizing the fructose analogue, 2,5-anhydro-D-mannitol (2,5-AM), implicate a decrease in liver ATP levels as a signal for meal initiation. The proposed experiments will examine the role of adenosine triphosphate (ATP) and its metabolites in the control of feeding behavior in rats. Behavioral measurements, along with 31p nuclear magnetic resonance spectroscopy and high pressure liquid chromatography, will be used to (1) Assess the role of decreased hepatic ATP level in the elicitation of eating induced by administration of metabolic inhibitors; (2) Assess the relationship between hepatic phosphate and ATP levels and the eating response to 2,5-AM; (3) Determine the role of hepatic sodium-phosphate co-transport in the eating response to 2,5-AM; (4) Determine the relationship between hepatic ATP levels and the hyperphagia in chronic experimental diabetes; and (5) Determine the relationship between hepatic ATP levels and food intake in response to fasting. These studies will help to elucidate the metabolic control of food intake and therefore will contribute to a fuller understanding of the etiology of anorexia, overeating and obesity, and to the development of appropriate strategies for their prevention and treatment.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
9R01DK053109-04
Application #
2420009
Study Section
Psychobiology, Behavior, and Neuroscience Review Committee (PBN)
Project Start
1997-05-15
Project End
1997-12-14
Budget Start
1997-05-15
Budget End
1997-12-14
Support Year
4
Fiscal Year
1997
Total Cost
Indirect Cost
Name
Monell Chemical Senses Center
Department
Type
DUNS #
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Ji, H; Friedman, M I (2008) Reduced hepatocyte fatty acid oxidation in outbred rats prescreened for susceptibility to diet-induced obesity. Int J Obes (Lond) 32:1331-4
Ji, Hong; Friedman, Mark I (2007) Reduced capacity for fatty acid oxidation in rats with inherited susceptibility to diet-induced obesity. Metabolism 56:1124-30
Friedman, Mark I (2007) Obesity and the hepatic control of feeding behavior. Drug News Perspect 20:573-8
Stefan, M; Ji, H; Simmons, R A et al. (2005) Hormonal and metabolic defects in a prader-willi syndrome mouse model with neonatal failure to thrive. Endocrinology 146:4377-85
Ji, Hong; Outterbridge, Lisa V; Friedman, Mark I (2005) Phenotype-based treatment of dietary obesity: differential effects of fenofibrate in obesity-prone and obesity-resistant rats. Metabolism 54:421-9
Friedman, Mark I; Graczyk-Millbrandt, Grazyna; Ji, Hong et al. (2003) 2,5-Anhydro-D-mannitol increases hepatocyte sodium: transduction of a hepatic hunger stimulus? Biochim Biophys Acta 1642:53-8
Ji, Hong; Friedman, Mark I (2003) Fasting plasma triglyceride levels and fat oxidation predict dietary obesity in rats. Physiol Behav 78:767-72
Rawson, Nancy E; Ji, Hong; Friedman, Mark I (2003) 2,5-Anhydro-D-mannitol increases hepatocyte calcium: implications for a hepatic hunger stimulus. Biochim Biophys Acta 1642:59-66
Friedman, Mark I; Koch, James E; Graczyk-Milbrandt, Grazyna et al. (2002) High-fat diet prevents eating response and attenuates liver ATP decline in rats given 2,5-anhydro-D-mannitol. Am J Physiol Regul Integr Comp Physiol 282:R710-4
Ji, Hong; Graczyk-Milbrandt, Grazyna; Osbakken, Mary D et al. (2002) Interactions of dietary fat and 2,5-anhydro-D-mannitol on energy metabolism in isolated rat hepatocytes. Am J Physiol Regul Integr Comp Physiol 282:R715-20

Showing the most recent 10 out of 17 publications