The role of α_1D‐adrenoceptors in the vasculature of spontaneously hypertensive (SHR) and normotensive Wistar Kyoto rats (WKY), of different ages was assessed in pithed rats by the use of the selective α_1D‐adrenoceptor antagonist BMY 7378 (8‐[2‐[4‐(2‐methoxyphenyl)‐1‐piperazinyl]‐ethyl]‐8‐azaspiro [4.5]decane‐7,9‐dione dihydrochloride). BMY 7378 displaced the pressor effect of phenylephrine in young pre‐hypertensive pithed SHR rats, but produced no effect in young WKY rats (dose ratio of 3.4 and 1.6, respectively), while in adult rats BMY 7378 produced a greater shift in the phenylephrine response curve than in younger animals (dose ratio of 3.2 and 6.2 in WKY and SHR, respectively). The presence of α_1D‐adrenoceptors in the vasculature of pre‐hypertensive rats, suggests its role in the pathogenesis/maintenance of increased blood pressure.

British Journal of Pharmacology (1999) 126, 1534–1536; doi:10.1038/sj.bjp.0702468