The effect of intracerebroventricularly infused satietin on conditioned taste aversion and feeding in rats fasted different lengths.

Satietin is a glycoprotein (50,000-70,000 daltons MW) found in human serum (greater than 2 micrograms/ml) that is reported to be a strong anorexigenic agent when infused (10-100 micrograms/rat) intracerebroventricularly (ICV) into rats. The initial three experiments presented here explored whether satietin suppresses food intake by making the animals ill or causing them to experience malaise. A two-bottle taste aversion paradigm was used for this testing. In all experiments the rats were fitted with chronic third ventricle cannulas. After recovery from surgery the rats were trained for at least 6 days to drink their water in one hour a day, 1100-1200-hr (LD12:12-hr, lights out 12:00-hr). In Experiment 1 and 3 satietin (100 or 25 micrograms/rat) or vehicle was infused ICV 30 minutes prior to exposure to a novel neutral preference fluid flavor (banana or almond flavoring in water). Three days later the rats were given a choice of the two flavors to consume; this was repeated the next day. In both experiments satietin treated rats showed strong aversion to the flavor paired with satietin infusion, while saline infused controls showed no aversion. A similar paradigm was used during the second experiment, except satietin or vehicle infusion was paired with a highly preferred saccharin-water solution. Three days later the rats were given a choice between water and the saccharin-water solution. The satietin (50 micrograms/rat) treated rats exhibited a marked aversion to the saccharin-water solution. These data suggest that satietin may be an aversive substance.(ABSTRACT TRUNCATED AT 250 WORDS)