The effect of chronic antidepressant administration on β-adrenoceptor function of the rat pineal

1 The β-adrenoceptor agonist, isoprenaline (1.5-3.0 mg kg-1 intravenously), produced a dose-related increase in rat pineal melatonin content. This increase was prevented by pretreatment with the selective β1-adrenoceptor antagonist, atenolol (2 mg kg-1), but not by the β2-adrenoceptor antagonist, butoxamine (2 mg kg-1). The β2-adrenoceptor agonist, terbutaline (5.0 mg kg-1), produced a moderate increase in pineal melatonin content