Effect of tetrahydrocannabinols on 3H-acetylcholine biosynthesis in various rat brain slices.
The effects of delta8- and delta9-tetrahydrocannabinol on the biosynthesis of 3H-acetylcholine (ACh) from 3H-choline in cortical, hypothalamic and striatal rat brain slices were examined. The two cannabinols were found to inhibit the synthesis of 3H-ACh in the three brain regions. Treatment with cannabidiol did not alter ACh synthesis. Delta8-tetrahydrocannabinol was approximately twice as effective as the delta9-isomer. This effect was not associated with alterations in striatal and cortical choline acetyltransferase or with an impaired high-affinity uptake system for choline in the striatum. Treatment with delta8- and delta9-cannabinols, likewise, did not change striatal choline and ACh levels. Antagonism of the ACh biosynthesis inhibition occurred when slices from treated animals were incubated in depolarizing concentration of K+ ion. These results suggest that the inhibition of ACh synthesis observed in tetrahydrocannabinol-treated rats may be related to interference with the propagated action potential or with the depolarization process in cholinergic neurons.
D000818:Animals; D001921:Brain / Q000201:enzymology / Q000378:metabolism* / Q000648:ultrastructure; D002188:Cannabis / Q000494:pharmacology*; D002794:Choline / Q000378:metabolism; D002795:Choline O-Acetyltransferase / Q000378:metabolism; D003342:Corpus Striatum / Q000378:metabolism; D007700:Kinetics; D008297:Male; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D013268:Stimulation, Chemical; D013574:Synaptosomes / Q000378:metabolism; D013997:Time Factors
D002795:Choline O-Acetyltransferase; D002794:Choline; D011188:Potassium