Pharmacodynamic interaction of clonidine and muscimol in hypertension.

The effect of the GABA agonist muscimol on the hypotensive action of clonidine in SHR was investigated. Muscimol administered before clonidine significantly (p < 0.01) intensified clonidine-induced reduction of blood pressure. This effect was achieved at muscimol doses which themselves had no influence on blood pressure. Muscimol injected after clonidine was ineffective. Our data suggest that the muscimol-clonidine interaction occurs at the level of GABAergic neurotransmission since both agents have been proved to activate the function of GABAergic neurons.