Sympathetic Mechanisms in Obesity-Crossover Design

Inclusion Criteria: * Males and females of all races between 18 and 65 years of age * Hypertension defined by two or more properly measured seated blood pressure readings \>130/85 mmHg or currently on antihypertensive medication. * Obesity will be defined as having a body mass index (BMI) ≥ 30 kg/m2. * Able and willing to provide informed consent. Exclusion Criteria: * Pregnancy or breast feeding * Current smokers or history of heavy smoking (\>2 packs/day) * History of alcohol or drug abuse * Previous allergic reaction to study medications * Type I diabetes. * Cardiovascular disease other than hypertension such as myocardial infarction within 6 months prior to enrollment, presence of angina pectoris, significant arrhythmia, congestive heart failure (LV hypertrophy acceptable), deep vein thrombosis, pulmonary embolism, second or third degree heart block, mitral valve stenosis, aortic stenosis, or hypertrophic cardiomyopathy * History of serious cerebrovascular disease such as cerebral hemorrhage, stroke, or transient ischemic attack * History or presence of immunological or hematological disorders * Impaired renal function * Treatment with chronic systemic glucocorticoid therapy (more than 7 consecutive days in 1 month) * Treatment with any investigational drug in the 1 month preceding the study * Inability to give, or withdraw, informed consent * Other factors which in the investigator's opinion would prevent the subject from completing the protocol (i.e., clinically significant abnormalities on clinical, mental examination or laboratory testing or inability to comply with protocol, inability to find IV access)