An anorectic agent from adipose tissue of overfed rats: effects on feeding behavior

Parabiosis and blood-transfer studies with rodents suggest the existence of humoral factors capable of affecting energy balance. The nature and origin of these factors is undetermined. Aqueous extracts of adipose tissue from overfed rats significantly reduce food intake when administered intraperitoneally (IP) or intracerebroventricularly (ICV). We term the agent(s) responsible for this effect adipose satiety factor (ASF). A single IP dose of ASF, equivalent to 44 mg crude protein, suppresses cumulative food intake for over 12 h. ASF, prepared using a combination of adipose tissue from obese Zucker rats and overfed rats, is more potent per unit of protein than ASF prepared exclusively using adipose tissue from overfed rats. A single ICV dose of this hybrid preparation, equivalent to 14.6 micrograms of crude protein, suppresses cumulative food intake by 40% for up to 48 h. By ultrafiltration, the molecular weight associated with maximal ASF activity is between 30 and 100 kilodaltons (kDa). The behavioral specificity of ASF-induced anorexia is demonstrated using meal pattern, taste aversion, and differential starvation paradigms.