Permeability of the blood-brain barrier for atenolol studied by positron emission tomography

The permeability of the blood-brain barrier for atenolol, a hydrophilic beta-adrenergic blocking agent, has been assessed in dogs, by studying the distribution of [11C]atenolol in brain tissue with positron emission tomography. The passage of atenolol into the brain was very limited, but a measurable small net influx into the brain tissues did occur. Osmotic opening of the blood-brain barrier resulted in a marked increase of the atenolol concentrations in brain tissue. The approach described, with sequential non-invasive measurements in brain tissue, is applicable to pharmacokinetic studies of atenolol in man.