title: Increased plasma free dopamine after treatment with atenolol and oxprenolol in essential hypertension.
abstract: In 19 men aged 50 with essential hypertension, 18 weeks' treatment with atenolol (n = 9) or oxprenolol (n = 10) increased supine plasma free dopamine concentrations by 78% (p less than 0.05) and 121% (p less than 0.001) respectively. Increments in plasma dopamine were observed in all patients except for one treated with atenolol. Supine peripheral venous adrenaline and noradrenaline concentrations were not influenced by beta-blockade. The mechanism and significance of the present elevation of plasma free dopamine by beta-blockade are unknown. However, increased plasma free dopamine may be involved in the hypotensive effect of chronic beta-adrenergic blockade, both beta-1 selective and non-selective, and may lend further support to decreased dopaminergic activity in essential hypertension.
mesh_terms: D001262:Atenolol / Q000627:therapeutic use*; D004298:Dopamine / Q000097:blood*; D004837:Epinephrine / Q000097:blood; D006439:Hemodynamics / Q000187:drug effects; D006801:Humans; D006973:Hypertension / Q000097:blood / Q000188:drug therapy*; D008297:Male; D008875:Middle Aged; D009638:Norepinephrine / Q000097:blood; D010096:Oxprenolol / Q000627:therapeutic use*; D011187:Posture
chemical_list: D001262:Atenolol; D010096:Oxprenolol; D004298:Dopamine; D009638:Norepinephrine; D004837:Epinephrine