title: Pain sensitivity in dietary-induced obese rats.
abstract: Previous literature indicates possible interrelationships between the endogenous opioids or endorphins, pain response, and obesity or eating behaviour. The pain response was, therefore, examined in a rat model of obesity induced by palatable food high in unsaturated fats. Pellet-fed control and energy-dense obese and nonobese rats were tested for latency of response to a thermal stimulus using the tail flick test. Obese rats exhibited a statistically significant increase in tail flick latency compared to controls. In addition, the observed latencies were significantly correlated to the body weight of the rats (r = 0.52, p < 0.01). These data suggest that dietary-induced obese rats are similar to obese humans in being less sensitive to painful stimuli, consistent with an increase in endogenous opioids in obesity.
authors.affiliation: Department of Pharmacy, University of Sydney, Australia.
authors.forename: I
authors.initials: I
authors.lastname: Ramzan
authors.forename: B K
authors.initials: BK
authors.lastname: Wong
authors.forename: G B
authors.initials: GB
authors.lastname: Corcoran
mesh_terms: D000818:Animals; D001835:Body Weight / Q000502:physiology; D004041:Dietary Fats / Q000378:metabolism; D004723:Endorphins / Q000502:physiology*; D005247:Feeding Behavior / Q000502:physiology*; D008297:Male; D009619:Nociceptors / Q000502:physiology; D009765:Obesity / Q000503:physiopathology*; D017288:Pain Threshold / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011930:Reaction Time / Q000502:physiology
chemical_list: D004041:Dietary Fats; D004723:Endorphins