title: The opioid system majorly contributes to preference for fat emulsions but not sucrose solutions in mice.
abstract: Rodents show a stronger preference for fat than sucrose, even if their diet is isocaloric. This implies that the preference mechanisms for fat and sucrose differ. To compare the contribution of the opioid system to the preference of fat and sucrose, we examined the effects of mu-, delta-, kappa-, and non-selective opioid receptor antagonists on the preference of sucrose and fat, assessed by a two-bottle choice test and a licking test, in mice naïve to sucrose and fat ingestion. Administration of non-selective and mu-selective opioid receptor antagonists more strongly inhibited the preference of fat than sucrose. While the preference of fat was reduced to the same level as water by the antagonist administration that of sucrose was still greater than water. Our results suggest that the preference of fat relies strongly on the opioid system, while that of sucrose is regulated by other mechanisms in addition to the opioid system.
authors.affiliation: a Laboratory of Nutrition Chemistry, Division of Food Science and Biotechnology, Graduate School of Agriculture , Kyoto University , Kyoto , Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Sakamoto
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Okahashi
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Matsumura
authors.forename: Yoko
authors.initials: Y
authors.lastname: Okafuji
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Adachi
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsuzuki
authors.forename: Kazuo
authors.initials: K
authors.lastname: Inoue
authors.forename: Tohru
authors.initials: T
authors.lastname: Fushiki
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D002755:Choice Behavior / Q000187:drug effects / Q000502:physiology; D004041:Dietary Fats / Q000008:administration & dosage; D004435:Eating / Q000187:drug effects / Q000502:physiology; D004655:Emulsions / Q000008:administration & dosage; D005518:Food Preferences / Q000187:drug effects / Q000502:physiology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D009270:Naloxone / Q000031:analogs & derivatives / Q000494:pharmacology; D009271:Naltrexone / Q000031:analogs & derivatives / Q000494:pharmacology; D009292:Narcotic Antagonists / Q000494:pharmacology; D010743:Phospholipids / Q000008:administration & dosage*; D017465:Receptors, Opioid, delta / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017473:Receptors, Opioid, kappa / Q000037:antagonists & inhibitors / Q000378:metabolism*; D017450:Receptors, Opioid, mu / Q000037:antagonists & inhibitors / Q000378:metabolism*; D013024:Soybean Oil / Q000008:administration & dosage*; D013395:Sucrose / Q000008:administration & dosage*
chemical_list: D004041:Dietary Fats; D004655:Emulsions; D009292:Narcotic Antagonists; D010743:Phospholipids; D017465:Receptors, Opioid, delta; D017473:Receptors, Opioid, kappa; D017450:Receptors, Opioid, mu; C545823:soybean oil, phospholipid emulsion; D009270:Naloxone; C051844:norbinaltorphimine; D013395:Sucrose; D009271:Naltrexone; D013024:Soybean Oil; C034643:naloxonazine; C055382:naltrindole
keywords: dietary fat; naltrexone; opioid system; preference; sucrose