Enantiomers of phenylpropanolamine suppress food intake in hyperphagic rats.
Phenylpropanolamine (PPA, d,l-norephedrine), available in many over-the-counter nasal decongestants and appetite suppressants, is a racemic mixture of the enantiomers d- and l-norephedrine. The present study evaluates the effects of the individual PPA enantiomers on a variety of nondrug (food deprivation) and drug-induced hyperphagias (2-deoxyglucose and insulin). Racemic PPA has been shown to significantly suppress food intake in these hyperphagic models. Both l-norephedrine (5-50 mg/kg) and d-norephedrine (5-150 mg/kg), administered intraperitoneally, significantly suppressed feeding after a 4-hr fast during the dark cycle. During the light period, l-norephedrine (7.5, 10, 15 mg/kg) and d-norephedrine (75, 100, 150 mg/kg) significantly reduced food intake at the 1-hr and 3-hr time intervals in the 24-hr food deprivation-, insulin- and 2-deoxyglucose-induced hyperphagic models. Only 7.5 mg/kg l-norephedrine in the insulin-induced hyperphagia at 3 hr failed to significantly suppress feeding. These results indicate that each individual PPA enantiomer possesses the ability to suppress food intake in rats made hyperphagic by various stimuli.
Department of Pharmacology, Massachusetts College of Pharmacy and Allied Health Sciences, Boston 02115.
M S
MS
Eisenberg
T J
TJ
Maher
D000818:Animals; D003847:Deoxyglucose / Q000494:pharmacology; D004435:Eating / Q000187:drug effects*; D005508:Food Deprivation; D006963:Hyperphagia / Q000503:physiopathology*; D007328:Insulin / Q000494:pharmacology; D008297:Male; D010665:Phenylpropanolamine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
D007328:Insulin; D010665:Phenylpropanolamine; D003847:Deoxyglucose