The main objective of the proposed research is to determine which internal signals are involved in the control of daily food intake and energy expenditure. The long-term objective is to understand the internal control of energy balance well enough to develop a medical treatment for obesity. Obesity is a risk factor for several debilitating diseases, including diabetes, hypertension, stroke and heart disease. A medical treatment for obesity would greatly reduce human suffering and would decrease the societal cost of health care. The first specific aim is to assess the effect of intravenous infusions of glucose and amino acids and of medical fat emulsions on voluntary food intake and metabolic rate. Pilot studies have shown that the rats respond to these nutrients in very different ways: they reduce their food intake following glucose infusions but not following fat infusions.
The second aim i s to determine whether the effect of glucose infusions are different during the night when neural and hormonal signals from the digestive tract are present or during the day when these signals are absent. The third specific aim is to determine whether the failure of the rats to respond to intravenous fats was due to the non-physiological form of the infused fats.
The fourth aim i s to investigate the relative importance of blood metabolites, intestinal hormones and intestinal nerves in the control of energy balance. This will be done by transplanting a supernumerary intestine into the peritoneal cavity of another rat and infusing fat into either the rat's natural intestine, into the denervated transplant or into the bloodstream. The final specific aim is to infuse promising gut peptides directly into the bloodstream in such a way as to mimic the normal blood levels of the hormones after a meal. Analogs of the hormones may provide a medical treatment for obesity.
| Walls, E K; Koopmans, H S (1992) Differential effects of intravenous glucose, amino acids, and lipid on daily food intake in rats. Am J Physiol 262:R225-34 |
| Walls, E K; Koopmans, H S (1992) Increased food intake following carotid and systemic insulin infusions. Int J Obes Relat Metab Disord 16:153-60 |
| Walls, E K; Willing, A E; Koopmans, H S (1991) Intravenous nutrient-induced satiety depends on feeding-related gut signals. Am J Physiol 261:R313-22 |
| Willing, A E; Walls, E K; Koopmans, H S (1990) Insulin infusion stimulates daily food intake and body weight gain in diabetic rats. Physiol Behav 48:893-8 |
