The effects of the diterpene sclareol glycol on seizures do not depend on central benzodiazepine receptors.
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Abstrakt
Using pentylenetetrazol (PTZ) in subconvulsant doses, it was found that the semisynthetic diterpene sclareol glycol (SG) from the labdane family of diterpenes at a dose well below the lethal dose, although not being convulsant, had a proconvulsant action in mice. This action is indicated by the number of mice undergoing convulsions and the reduction of latency. Specific binding of [3H]-diazepam in vitro to whole homogenate fractions prepared from hippocampus of rats was not inhibited by SG. At the same time comparatively investigated Ro 15-1788 inhibited [3H]-diazepam binding. It is suggested that the proconvulsant effect of SG is realized not through interactions with central benzodiazepine receptors as Ro 15-1788 does, but perhaps through interactions with adenylate cyclase (stimulating its catalytic subunit and thus increasing brain 3',5'-AMP availability). Other brain neurotransmitter systems (e.g., GABA) should also participate in realization of the proconvulsant effect of SG.