Delta-9-tetrahydrocannabinol accumulation, metabolism and cell-type-specific adverse effects in aggregating brain cell cultures.
Despite the widespread use of Cannabis as recreational drug or as medicine, little is known about its toxicity. The accumulation, metabolism and toxicity of THC were analyzed 10 days after a single treatment, and after repeated exposures during 10 days. Mixed-cell aggregate cultures of fetal rat telencephalon were used as in vitro model, as well as aggregates enriched either in neurons or in glial cells. It was found that THC accumulated preferentially in neurons, and that glia-neuron interactions decreased THC accumulation. The quantification of 11-OH-THC and of THC-COOH showed that brain aggregates were capable of THC metabolism. No cell-type difference was found for the metabolite 11-OH-THC, whereas the THC-COOH content was higher in mixed-cell cultures. No cell death was found at THC concentrations of 2 microM in single treatment and of 1 microM and 2 microM in repeated treatments. Neurons, and particularly GABAergic neurons, were most sensitive to THC. Only the GABAergic marker was affected after the single treatment, whereas the GABAergic, cholinergic and astrocytic markers were decreased after the repeated treatments. JWH 015, a CB2 receptor agonist, showed effects similar to THC, whereas ACEA, a CB1 receptor agonist, had no effect. The expression of the cytokine IL-6 was upregulated 48 h after the single treatment with 5 microM of THC or JWH 015, whereas the expression of TNF-alpha remained unchanged. These results suggest that the adverse effects of THC were related either to THC accumulation or to cannabinoid receptor activation and associated with IL-6 upregulation.
Monnet-Tschudi
Florianne
F
Department of Physiology, University of Lausanne, 7, rue du Bugnon CH-1005 Lausanne, Switzerland. Florianne.Tschudi-Monnet@unil.ch
Hazekamp
Arno
A
Perret
Nicolas
N
Zurich
Marie-Gabrielle
MG
Mangin
Patrice
P
Giroud
Christian
C
Honegger
Paul
P
D000818:Animals; D001921:Brain / Q000166:cytology / Q000473:pathology*; D002186:Cannabinoids / Q000378:metabolism; D002449:Cell Aggregation / Q000187:drug effects; D002478:Cells, Cultured; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D013759:Dronabinol / Q000032:analysis / Q000378:metabolism* / Q000633:toxicity*; D005260:Female; D020558:GTP Phosphohydrolases / Q000378:metabolism; D005968:Glutamate Decarboxylase / Q000378:metabolism; D015850:Interleukin-6 / Q000096:biosynthesis; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D013058:Mass Spectrometry; D009457:Neuroglia / Q000187:drug effects; D009474:Neurons / Q000187:drug effects; D011247:Pregnancy; D051381:Rats; D043884:Receptor, Cannabinoid, CB1 / Q000819:agonists; D043885:Receptor, Cannabinoid, CB2 / Q000819:agonists; D012015:Reference Standards; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012997:Solvents; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis
D002186:Cannabinoids; D015850:Interleukin-6; D043884:Receptor, Cannabinoid, CB1; D043885:Receptor, Cannabinoid, CB2; D012997:Solvents; D014409:Tumor Necrosis Factor-alpha; D013759:Dronabinol; D007770:L-Lactate Dehydrogenase; D002795:Choline O-Acetyltransferase; D020558:GTP Phosphohydrolases; D005968:Glutamate Decarboxylase