Genetic Determinants of Response to Beta Blockade

Inclusion Criteria:

• Subject must be willing to give written informed consent and be able to adhere to diet and study schedules.
• Subjects must be free of any clinically significant disease that requires a physician's care and/or would interfere with the study evaluations.
• Subjects must have a clinically acceptable physical examination and ECG.
• Laboratory tests (CBC, blood chemistries, and urinalysis) must be within clinically acceptable limits.

Exclusion Criteria:

• Any subject who has taken any prescription or over-the-counter drugs, other than oral contraception if female, within one week prior to study drug administration.
• Subjects who are presently, or were formerly, narcotic addicts or alcoholics.
• Active smokers.
• Subjects who have a clinically significant allergy/intolerance to atenolol.
• Females with a positive serum/urine pregnancy test at screening.
• Females who are nursing.
• Subjects with complete heart block/ any other significant cardiovascular disease.
• Subjects with a history of asthma symptoms or medication for it within last 10 years.
• Subjects who have a systolic blood pressure < 90 mm Hg or diastolic blood pressure < 50 mm Hg or heart rate < 50/min at the screening visit or on the baseline pre drug values on the study day.