The Effects of a Beta-2 Selective Adrenergic Receptor Antagonist

We examined the interaction between isoproterenol and ery- changes in heart rate, but effects on diastolic blood pressure thro-dI-1-(7-methylindan-4-yloxy)-3-isopropylaminobutan-2-ol and twitch tension were inhibited competitively. The data con-(ICI 1 1 8,551), a beta-2 selective adrenergic receptor antago- firm the beta-2 nature of the skeletal muscle adrenergic recep-nist, with respect to heart rate, diastolic blood pressure and tor and suggest that it may be slightly more sensitive than that twitch tension (soleus muscle) in anesthetized cats. Dose-re- in blood vessels. Because depression of twitch tension is sponse curves to isoproterenol (0.025-1.0 tg/kg iv.) were known to correlate with essential tremor, the data are consist-generated for each parameter and then repeated successively ent with clinical reports demonstrating control of tremor by after three doses of lCl 1 1 8,551 (1 0, 25 and 1 00 tg/kg i.v.). nonselective beta adrenergic receptor antagonists. ICI 1 1 8,-ICI 1 1 8,551 did not significantly alter isoproterenol-induced 551 may be efficacious in controlling tremor in man. IC! 1 18,551 [erythro-dt-1-(7-methylindan-4-yloxy)-3-isopro-pylaminobutan-2-olJ is a beta adrenergic antagonist with marked selectivity toward beta-2 receptors as demonstrated with respect to the heart, peripheral circulation and uterus (Bilski et al., 1980, 1982; O’Donnell and Wanstall, 1980). Bet