title: Opioids in the nucleus of the solitary tract are involved in feeding in the rat.
abstract: We evaluated the effect of selective opioid peptides and naltrexone on feeding when injected into the nucleus of the solitary tract (NTS). Doses of 0, 1, 2, 4, and 8 nmol of [D-Ala2,N-Me-Phe4,Gly5-ol]enkephalin (DAMGO, mu-agonist), dynorphin A-(1-17) (DynA-(1-17), kappa-agonist), and [D-Ser2]leucine enkephalin-thr, (delta-agonist) were injected into the NTS in satiated male rats, and food intake was measured at 1, 2, and 4 h. Only DAMGO significantly increased feeding above control levels at doses of 2, 4, and 8 nmol. Doses of 10 and 50 microg naltrexone in the NTS significantly decreased 18-h deprivation-induced feeding. These data suggest that NTS opioid receptors (primarily mu) may be involved in the regulation of feeding.
authors.affiliation: Department of Food Science and Nutrition, University of Minnesota, St. Paul 55108, USA.
authors.forename: C M
authors.initials: CM
authors.lastname: Kotz
authors.forename: C J
authors.initials: CJ
authors.lastname: Billington
authors.forename: A S
authors.initials: AS
authors.lastname: Levine
mesh_terms: D000700:Analgesics / Q000008:administration & dosage / Q000494:pharmacology; D000818:Animals; D004305:Dose-Response Relationship, Drug; D004399:Dynorphins / Q000008:administration & dosage / Q000494:pharmacology*; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004743:Enkephalin, Leucine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004745:Enkephalins / Q000008:administration & dosage / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D008297:Male; D008845:Microinjections; D009271:Naltrexone / Q000008:administration & dosage / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D017552:Solitary Nucleus / Q000187:drug effects / Q000502:physiology*
chemical_list: D000700:Analgesics; D004745:Enkephalins; D020875:Enkephalin, Ala(2)-MePhe(4)-Gly(5)-; D004743:Enkephalin, Leucine; D009271:Naltrexone; D004399:Dynorphins; C034318:enkephalin, Ser(2), Leu(5), Thr(6)-