Pain threshold and morphine activity in vitamin D-deficient rats.
In rats, vitamin D-deficiency increases basal pain threshold and the analgesic effect of morphine (hot plate test). Cholecalciferol (1000 I.U./Kg/day s.c.x 5 days) restores pain sensitivity in vitamin D-deficient rats and brings the analgesic effect of morphine back to normal. On the other hand, tolerance to morphine develops faster in vitamin D-deficient rats, this effect too being prevented by cholecalciferol treatment. These data suggest a role for vitamin D status in pain sensitivity and opiate activity.
D000818:Animals; D002118:Calcium / Q000502:physiology; D002762:Cholecalciferol / Q000494:pharmacology; D004361:Drug Tolerance; D009020:Morphine / Q000494:pharmacology*; D010146:Pain / Q000503:physiopathology*; D051381:Rats; D011919:Rats, Inbred Strains; D012684:Sensory Thresholds / Q000502:physiology; D014808:Vitamin D Deficiency / Q000503:physiopathology*
D002762:Cholecalciferol; D009020:Morphine; D002118:Calcium