title: Restraint stress has no effect on morphine-induced inhibition of gastrointestinal transit in the rat.
abstract: Stress in the rat has been reported to enhance the analgesic and thermic effects of opioids, drug effects that are mediated centrally. We examined whether this stress-induced enhancement of response to opioids could also be demonstrated for a drug effect mediated largely in the periphery, morphine-induced inhibition of gastrointestinal transit. Restrained (stressed) and unrestrained (unstressed) rats were injected with saline or morphine and then administered orally a charcoal suspension; after sacrifice, the distance the charcoal traveled through the intestine was determined. After the administration of saline, restrained rats had significantly lower gastrointestinal transit than did unstressed rats; however, both groups were comparably sensitive to inhibition of gastrointestinal transit by morphine.
mesh_terms: D000818:Animals; D005769:Gastrointestinal Motility; D008297:Male; D009020:Morphine; D051381:Rats; D011919:Rats, Inbred Strains; D013312:Stress, Physiological / Q000503:physiopathology*
chemical_list: D009020:Morphine