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.
Eisenberg
M S
MS
Department of Pharmacology, Massachusetts College of Pharmacy and Allied Health Sciences, Boston 02115.
Maher
T J
TJ
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