Retained inhibition of the beta receptor by propranolol after preincubation and washout.
Mouse thymus cells possess a B2-adrenergic receptor and, when centrifuged through a solution of propanolol at 5 degrees and washed three times, will produce reduced amounts of cyclic AMP during a 5 minute challenge with isoproterenol at room temperature. Depending on the concentration and nature of the antagonist, the retained inhibition may be greater or less than that seen when it is added with the agonist. This retained inhibition is readily reversed at 37 degrees even in the absence of the agonist. These effects can also be demonstrated with rat erythrocytes and with their subsequently prepared ghosts making it most likely that they result from the specific and tight binding of the antagonist to the beta receptor.
Retained inhibition of the beta receptor by propranolol after preincubation and washout. Mouse thymus cells possess a B2-adrenergic receptor and, when centrifuged through a solution of propanolol at 5 degrees and washed three times, will produce reduced amounts of cyclic AMP during a 5 minute challenge with isoproterenol at room temperature. Depending on the concentration and nature of the antagonist, the retained inhibition may be greater or less than that seen when it is added with the agonist. This retained inhibition is readily reversed at 37 degrees even in the absence of the agonist. These effects can also be demonstrated with rat erythrocytes and with their subsequently prepared ghosts making it most likely that they result from the specific and tight binding of the antagonist to the beta receptor.