Effects of acute and subacute treatment with ergot drugs on the GABA system in specific brain regions
- 1 September 1981
- journal article
- research article
- Published by Oxford University Press (OUP) in Journal of Pharmacy and Pharmacology
- Vol. 33 (1) , 655-659
- https://doi.org/10.1111/j.2042-7158.1981.tb13893.x
Abstract
The effect of dihydroergotoxine and dihydroergotamine on Γ-aminobutyric acid (GABA) levels, the aminooxyacetic acid (AOAA)-induced accumulation of GABA, and the in vitro activity of L-glutamate decarboxylase (GAD) have been examined in various regions of rat brain. Dihydroergotoxine (1 mg kg−1) decreased the concentration of GABA and enhanced the AOAA-induced accumulation of GABA in the caudate nucleus and cingulate cortex. Dihydroergotoxine 10·0 mg kg−1 decreased the AOAA-induced accumulation of GABA in the substantia nigra. The repeated treatment with dihydroergotoxine, 0·05 mg kg−1 for eight days, also decreased the concentration of GABA in the cingulate cortex and diminished the AOAA-induced accumulation of GABA in the substantia nigra. The administration of 0·1 mg kg−1, but not higher doses; of dihydroergotamine, enhanced the AOAA-induced accumulation of GABA in the cingulate cortex. Dihydroergotamine (10·0 mg kg−1) decreased the concentration of GABA in the cingulate cortex and increased the AOAA-induced accumulation of GABA in the caudate nucleus. The activity of GAD in the cingulate cortex, but not in the caudate nucleus, was enhanced after a high dose of dihydroergotamine. Observed increases in the AOAA-induced accumulation of GABA indicate that dihydroergotoxine and dihydroergotamine in at least some brain areas cause an apparent increase in GABA syn-synthesis in vivo, which is presumably a compensatory phenomenon due to a diminished GABAergic transmission under the influence of these drugs.This publication has 20 references indexed in Scilit:
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