The effect of delta9-tetrahydrocannabinol on body temperature and brain amine concentrations in the rat at differnt ambient temperatures.
1. Rats were injected intravenously with 2 mg/kg (-)-trans-delta9-tetrahydrocannabinol (delta9-THC) at ambient temperatures of 4 degrees, 21 degrees, 31 degrees and 37 degrees C. 2. The general behavior exhibited by rats treated with delta9-THC was similar at all four ambient temperatures. 3. Body temperatures were recorded continuously before and after drug administration. At 4 degrees and 21 degrees C, delta9-THC caused hypothermia whereas no change in body temperature occurred at 31 degrees and 37 degrees C. 4. The concentrations in the whole brain of noradrenaline (NA), dopamine, 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) were determined spectrophotofluorimetrically 1 h after drug administration. At 4 degrees C delta9-THC caused an increase of 5-HT, at 21 degrees C an increase of 5-HIAA, at 21 degrees C an increase of 5-HIAA AND A decrease of NA, and at 37 degrees C an increase of 5-HT and 5-HIAA. 5. At all ambient temperatures, delta9-THC increased the brain levels of 5-HT and/or 5-HIAA. A correlation between the delta9-THC-induced hypothermic response and the possible alteration of brain 5-HT metabolism cannot be excluded.
D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects; D001679:Biogenic Amines / Q000378:metabolism*; D001831:Body Temperature / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D013759:Dronabinol / Q000494:pharmacology*; D008297:Male; D051381:Rats; D013696:Temperature; D013997:Time Factors
D001679:Biogenic Amines; D013759:Dronabinol