Modulation of deprivation-induced food intake by D-phenylalanine.
D-phenylalanine has been shown to possess opiate-like effects upon pain perception. The present study examined whether it would have similar opiate-like effects upon food intake in deprived rats. The first experiment demonstrated that food intake of rats deprived for 24 h prior to injection was significantly reduced for 2 h following a 250 mg/kg dose of D-phenylalanine. However, intake over a 24 h period following injection was significantly increased following a 125 mg/kg dose of D-phenylalanine. The second experiment revealed that 0.3, 1.0, 3.0 and 10.0 mg/kg doses of naloxone dose-dependently reduced intake for 2 h in deprived rats when paired with a vehicle injection. However, the inhibitory actions of the two lower naloxone doses were significantly attenuated when paired with an injection of a 250 mg/kg dose of D-phenylalanine. These results are discussed in terms of whether D-phenylalanine possesses direct or indirect opiate-like effects upon ingestion.
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005260:Female; D005508:Food Deprivation; D006815:Hunger / Q000187:drug effects*; D009270:Naloxone / Q000494:pharmacology; D010649:Phenylalanine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011957:Receptors, Opioid / Q000187:drug effects
D011957:Receptors, Opioid; D009270:Naloxone; D010649:Phenylalanine