Maintaining and monitoring the nutritional status of patients is an integral part of nursing practice. However, illness induced anorexia presents a clinical paradox food appetite is depressed at a time when metabolic energy needs are increased. Previous work by this author and others suggest that anorexia is part of the acute phase response and mediated in part by interleukin-1 (IL-1) and tumor necrosis factor (TNF). The long term objectives of this project are to explore the physiological mechanisms and biological role of illness induced anorexia in the host response to infection of tumor growth. The specific aims of this project are to determine 1) whether immunoregulatory peptides are involved in loss of food appetite with tumor growth and what cells secrete them: 2) whether suppression of food intake with tumor-growth or infection is associated with changes in gastric motility or plasma levels of glucoregulatory hormones, and 3) whether nutritional supplements affect nutritional status, immune cell function or tumor growth in the infected or tumor-bearing host. The studies will be conducted using male Wistar rats in whom the metabolic, immunological and nutritional responses to infection or tumor growth will be monitored. Serum and cell-derived culture fluids from tumor-bearing rats and patients will be bioassayed for anorexigenic and immunoregulatory activity. Measurement of the metabolic and nutritional effects of tumor growth and nutritional supplementation will be in collaboration with the Clinical Nutrition Research Unit. Data will be analyzed using statistical software packages for ANOVA and repeat measures ANOVA. The principle investigator has extensive training in small animal surgery, tissue culture, and measurement of IL-1 activity. She has established an independent laboratory in the School of Nursing which is adjacent to the Clinical Cancer Center at the University of Wisconsin- Madison Clinical Sciences Center.