Aging and day-night rhythms in feeding in mice: effects of the putative sigma opiate agonist, N-allylnormetazocine (SKF-10,047).
Day-night rhythms in feeding behavior and response to the putative sigma opiate agonist, N-allylnormetazocine (+/- SKF-10,047, 0.10-10 mg/kg), were measured in young (1-2 months), mature (8-12 months) and old (24-30 months) male CF-1 mice. The mice consumed more food at night than in the day-time, though this nocturnal peak was markedly reduced in the mature and old animals. The young mice also displayed a significant nocturnal enhancement in SKF-10,047 (0.10-1.0 mg/kg) stimulated feeding, that could, in part, be suppressed by the opiate antagonist naloxone (1.0 mg/kg). The day-night rhythm in ingestive responses to SKF-10,047 (0.10-1.0 mg/kg) was reduced in the mature animals and absent in the old animals. The old mice failed to show any significant increase in ingestive response following opiate administration. A higher dose of SKF-10,047 (10 mg/kg) had no significant ingestive effects in any of the age groups of mice; the excitatory, psychotomimetic-related effects, being also reduced in the old animals.
D000375:Aging; D000818:Animals; D001921:Brain / Q000502:physiology; D002940:Circadian Rhythm / Q000187:drug effects*; D004723:Endorphins / Q000502:physiology; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D009270:Naloxone / Q000494:pharmacology; D010620:Phenazocine / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011957:Receptors, Opioid / Q000187:drug effects*; D017480:Receptors, sigma
D004723:Endorphins; D011957:Receptors, Opioid; D017480:Receptors, sigma; D009270:Naloxone; C012134:SK&F 10047; D010620:Phenazocine