Purification of the anorectic agent satietin from bovine serum

Purification and properties of an endogenous anorexigenic substance extracted from the bovine serum has recently been reported. The semipurified and HPLC-purified substances have shown similar biological effect in ad lib-fed or fasted rats, as was found in the case of human satietin. This substance purified from bovine serum or plasma suppressed food intake following intracerebroventricular (ICV) or peripheral administration in rats. A similar purification procedure as was used for the preparation of human serum satietin resulted in semipurified bovine material. This preparation was further purified by HPLC reversed-phase column and yielded two peaks (peak 1 and peak 2). The retention time of peak 2 revealed by HPLC (peak addition method) and the molecular weight measurements carried out by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS-PAGE) and high performance size-exclusion chromatography (SE-HPLC) proved that peak 2 contains bovine serum albumin mostly. Rats were injected with 20 micrograms/rat of peak 1 and peak 2. Peak 1 can be considered as a putative satiety agent. Preliminary chemical and biochemical studies showed that the semipurified active agent contained 20-22% protein, 28-30% lipids, and an undetermined amount of carbohydrate. The molecular size of anorectic bovine serum preparation was 38-40 kDa, determined by means of SE-HPLC and SDS-PAGE. Based upon the similarity of chemical and biological nature to human serum satietin we named this new material bovine serum satietin (BS-SAT).