Evidence for opiate receptor involvement in the consumption of a high palatability diet in nondeprived rats.
Nondeprived adult rats were familiarized with a highly palatable diet (powdered small animal diet mixed with sweetened condensed milk and water). The palatability of food was such that it induced vigorous feeding responses, 15-20 g food consumed within the first 30 min of access. In partially-satiated male rats, the kappa receptor agonists EKC and U-50,488 (subcutaneously administered) produced large increases in food consumption in the first 30 min of access, post-injection. In experiments with naloxone and WIN 44,441-3, we found that the effects of naloxone (0.01-10 mg/kg; S.C.) were crucially dependent on the sex and dietary history of the animals. Male, obese rats were most sensitive to naloxone's anorectic effect. Lean females were completely insensitive. WIN 44,441-3 (0.01-10 mg/kg, S.C.) had no effect on food intake in any group of animals.
Cooper
S J
SJ
Jackson
A
A
Morgan
R
R
Carter
R
R
D000818:Animals; D001067:Appetite Depressants; D001392:Azocines / Q000494:pharmacology*; D004032:Diet; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology*; D005260:Female; D008297:Male; D009270:Naloxone / Q000494:pharmacology*; D009765:Obesity / Q000188:drug therapy; D051381:Rats; D011957:Receptors, Opioid / Q000502:physiology*; D017473:Receptors, Opioid, kappa; D012737:Sex Factors
D001067:Appetite Depressants; D001392:Azocines; D011957:Receptors, Opioid; D017473:Receptors, Opioid, kappa; D009270:Naloxone; C035969:quadazocine