title: The analgesia produced by food deprivation in 4-month old, 14-month old, and 24-month old rats.
abstract: The analgesia produced by 24 hr of food deprivation was examined in 4-mo, 14-mo, and 24-mo old rats. To assess opioid and hormonal involvement in food deprivation induced analgesia, different groups of rats from each age group were injected with naltrexone (7 mg/kg), dexamethasone (0.4 mg/kg), or equivolume saline. Results revealed that food deprivation produced an equivalent analgesic response in each saline-treated age group. Also, naltrexone and dexamethasone were equally potent in blocking food deprivation induced analgesia in each age group. These results demonstrated that food deprivation activates an endogenous opioid-mediated analgesic system that involves hormonal factors and that this system does not change in function with increasing age.
mesh_terms: D000375:Aging; D000698:Analgesia; D000818:Animals; D003907:Dexamethasone / Q000494:pharmacology; D004723:Endorphins / Q000502:physiology; D005508:Food Deprivation / Q000502:physiology*; D006728:Hormones / Q000502:physiology; D008297:Male; D009271:Naltrexone / Q000494:pharmacology; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D004723:Endorphins; D006728:Hormones; D009271:Naltrexone; D003907:Dexamethasone