Centrally induced hypotension by 2-(2,6-dichlorophenyl)-5,6-dihydroimidazo (2,1-b)-thiazole fumarate (compound...

The experimental compound 44-549 = 2-(2,6-dichlorophenyl)-5,6-dihydroimidazo (2,1-b)-thiazole fumarate was tested in chloralose-anaesthetized cats. Low doses of compound 44-549 showed a much more pronounced hypotensive effect when injected into the left vertebral artery than upon intravenous administration. The compound possesses central hypotensive activity, which could be blocked by yohimbine, administered via the vertebral artery. Central alpha-adrenoreceptors are probably involved. Compound 44-549 resembles clonidine both pharmacologically and chemically. It is somewhat less potent.