The effects of (-)-delta9-tetrahydrocannabinol on reserpine-induced hypothermia in rats.
1. An intravenous injection into rats of 1 mg/kg (-)-Delta(9)-tetrahydrocannabinol Delta(9)-THC) had no effect on rectal temperature and produced in the subcellular fractions of the brain a shift of 5-hydroxytryptamine (5-HT) from the particulate or ;bound' 5-HT to the supernatant or ;free' fraction, whereas the noradrenaline (NA) decreased in both fractions.2. Pretreatment of rats by an intravenous injection of 1 mg/kg Delta(9)-THC three times a week for four weeks, prevented the hypothermia and the reduction in brain 5-HT produced by an intraperitoneal injection of 15 mg/kg reserpine given 24 h after the last Delta(9)-THC injection.3. Pretreatment of rats by a single intravenous injection of 1 mg/kg Delta(9)-THC prevented the hypothermia and reduction in brain 5-HT produced by an intraperitoneal injection of reserpine given 1 h before. The reduction in brain NA was not prevented except at the 18 h time interval.4. An injection of 1 mg/kg Delta(9)-THC intravenously into rats 3 h after an intraperitoneal injection of reserpine accentuated the reserpine hypothermia as well as the reduction of 5-HT but not of NA in the brain.5. The reserpine hypothermia was not prevented by a single intravenous injection of 1 mg/kg Delta(9)-THC when cinanserin, a 5-HT inhibitor, was injected 30 min before the reserpine.
D000813:Anilides / Q000494:pharmacology; D000818:Animals; D001831:Body Temperature / Q000187:drug effects*; D001833:Body Temperature Regulation / Q000187:drug effects; D001923:Brain Chemistry; D002188:Cannabis / Q000494:pharmacology*; D002934:Cinnamates / Q000494:pharmacology; D003864:Depression, Chemical; D013759:Dronabinol / Q000008:administration & dosage / Q000494:pharmacology; D008297:Male; D009638:Norepinephrine / Q000032:analysis; D051381:Rats; D012110:Reserpine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D012701:Serotonin / Q000378:metabolism; D012702:Serotonin Antagonists; D013440:Sulfides / Q000494:pharmacology; D013696:Temperature; D013997:Time Factors
D000813:Anilides; D002934:Cinnamates; D012702:Serotonin Antagonists; D013440:Sulfides; D012701:Serotonin; D013759:Dronabinol; D012110:Reserpine; D009638:Norepinephrine