ISSN:
1474-8673
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Chemistry and Pharmacology
,
Medicine
Notes:
1 Sibenadet (Viozan®), a dual dopamine D2/β2-adrenoceptor agonist, suppresses histamine-induced tachypnoea in the dog by activating dopamine D2 receptors. We here compare the effects of sibenadet and formoterol, a selective β2-adrenoceptor agonist, on histamine-induced tachypnoea in the rhesus monkey. 2 Anaesthetized, spontaneously breathing, rhesus monkeys were set up for measuring airways resistance, respiratory rate, blood pressure and heart rate. 3 Both sibenadet and formoterol administered by aerosol, induced inhibition of the bronchoconstrictor response to aerosolized methacholine accompanied by tachycardia. Sibenadet, but not formoterol, also reduced blood pressure. 4 Administration of histamine by inhalation induced tachypnoea which was accompanied by bronchoconstriction. Tachypnoea to histamine was suppressed by both sibenadet and formoterol at doses which manifest anti-bronchoconstrictor activity. These effects and the accompanying tachycardia but not the hypotension induced by sibenadet were abolished by pretreatment with propranolol. 5 The dopamine D2 receptor agonist, quinagolide, did not suppress tachypnoea to histamine despite inducing a fall in blood pressure indicating activation of dopamine D2 receptors. 6 Thus, both sibenadet and formoterol suppress histamine-evoked tachypnoea in the rhesus monkey. The effect arises exclusively through activation of β2-adrenoceptors and probably reflects the anti-bronchoconstrictor effects of these agents. The results reveal a fundamental difference in the role of dopamine receptors in the airways of dog and rhesus monkey.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1474-8673.2004.00306.x
