Effects of rat- prolactin 0n ingestive behavior and leptin levels in adult male rats

Previous studies have indicated that ovine- or bovine-prolactin stimulates ingestive behavior in female, but not in male rats; i.e., that prolactin has sex-specific effects on ingestive behavior. The question addressed here was whether ingestivebehavior in male rats would be induced by rat-prolactin. In a preliminary test male rats were allowed to ingest a 1 M solution of sucrose from a drinking spout. After daily intake of sucrose became stabilized, the males received rat-prolactin by pituitary grafting. The results showed that pituitary grafling both stimulates ingestive behavior and increases serum leptin levels in male rats. These findings coupled with previous findings suggest that proinctin has species-specific effects on ingestivc behavior