RT Journal Article SR Electronic T1 Structure activity relationships of a series of buspirone analogs at alpha-1 adrenoceptors: further evidence that rat aorta alpha-1 adrenoceptors are of the alpha-1D-subtype. JF Journal of Pharmacology and Experimental Therapeutics JO J Pharmacol Exp Ther FD American Society for Pharmacology and Experimental Therapeutics SP 136 OP 144 VO 278 IS 1 A1 Saussy, D L A1 Goetz, A S A1 Queen, K L A1 King, H K A1 Lutz, M W A1 Rimele, T J YR 1996 UL http://jpet.aspetjournals.org/content/278/1/136.abstract AB The activity of a series of busprione analogs at recombinant and rat thoracic aorta alpha-1 adrenoceptors was investigated. Compound affinity for recombinant alpha-1A, alpha-1B and alpha-1D adrenoceptors from human and animal sources was determined by radioligand binding assays using membranes prepared from rat-1 fibroblasts expressing recombinant receptors with ( +/- )-[125l]iodo-4-hydroxyphenyl)-ethyl-aminomethyl-tetralone as the radioligand. Compound affinity and functional activity at rat aortic alpha-1 adrenoceptors were determined using endothelium denuded rings contracted with phenylephrine. BMY 7378 ¿8-(2-[4-(2-methoxyphenyl)-1-piperazinyl]-ehtyl)-8-azaspiro [4,5]decane-7,9-dione dihydrochloride¿ and MDL 73005EF ¿8-[2-(1,4-benzodioxan-2-ylmethylamino) ethyl]-8-azaspiro[4,5]decane-7,9-dione hydrochloride¿ were found to have significant selectivity for the alpha-1D-subtype and were high affinity antagonists of the alpha-1 adrenoceptors in the rat aorta. Leverage plot analysis of affinities of the buspirone analogs and a series of structurally diverse alpha-1 antagonists for recombinant alpha-1 adrenoceptors and rat aorta alpha-1 adrenoceptors demonstrate that the alpha-1 adrenoceptors in the rat aorta are predominantly of the alpha-1D subtype.