(±)-Atenolol-d7 is intended for use as an internal standard for the quantification of (±)-atenolol (Item No. 17250) by GC- or LC-MS. (±)-Atenolol is an antagonist of the B1-adrenergic receptor (B1-AR; Ki = 1.14 uM).{28226} It is selective for B1-ARs over B2-ARs (Ki = 48.7 uM). (±)-Atenolol (200 mg/kg per day) delays the onset of hypertension in spontaneously hypertensive rats.{49503} Formulations containing atenolol have been used in the treatment of high blood pressure.