title: Pharmacodynamic studies with a specific alpha 2-adrenoceptor agonist (BHT-933) in man.
abstract: We conducted pharmacodynamic studies in man with a specific alpha 2-adrenoceptor agonist BHT-933. The study involved nine male normotensive volunteers each of whom received BHT-933 5 mg or placebo in random order. BHT-933 significantly lowered systolic and diastolic blood pressure (BP) in supine and standing positions, the greatest effect occurring 3-4 h following drug administration. Supine values: placebo 116/73; BHT-933 99/64. Standing values: placebo 114/79; BHT-933 92/67. Heart rate was uninfluenced by BHT-933 even at the time of maximum fall in BP. Plasma noradrenaline concentration in the supine position was significantly reduced: placebo 2.5 +/- 0.8 nmol/L; BHT-933 1.7 +/- 0.6. The haemodynamic changes accompanying Valsalva's manoeuvre and cold pressor test were uninfluenced by BHT-933. All subjects experienced sedation and dry mouth following BHT-933 with a time course similar to that of the fall in BP. These results are consistent with an effect of BHT-933 on BP control through an action on alpha 2-receptors at the level of the brainstem.
mesh_terms: D000316:Adrenergic alpha-Agonists / Q000494:pharmacology*; D000328:Adult; D001143:Arousal / Q000187:drug effects*; D001381:Azepines / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D006439:Hemodynamics / Q000187:drug effects*; D006801:Humans; D006993:Hypnotics and Sedatives; D008297:Male; D009638:Norepinephrine / Q000097:blood; D012472:Salivation / Q000187:drug effects*; D013997:Time Factors
chemical_list: D000316:Adrenergic alpha-Agonists; D001381:Azepines; D006993:Hypnotics and Sedatives; C015603:azepexole; D009638:Norepinephrine