Study of the Response of Human Small Blood Vessels

You may be eligible if

• Patients (men and nonpregnant women) with systemic hypertension, patients with hypercholesterolemia, and normal volunteers.
• All blood pressure recordings must be consistently elevated.
• No renovascular hypertension or other etiologies for elevated blood pressure.
• No definite evidence of accelerated or malignant hypertension (diastolic pressures above 115 mmHg, with associated encephalopathic changes, papilledema, progressive renal failure, or congestive heart failure), or serious intercurrent illness.
• Patients in whom withdrawal of antihypertensive medications is considered hazardous are ineligible.
• Patients in whom the blood pressure remains at normal levels 2 weeks after withdrawal of antihypertensive treatment will be closely monitored until they become hypertensive, at which time they will undergo the study. Patients in whom blood pressure does not increase after 2 months of discontinuation of therapy will be excluded from the study.
• Patients with coexistent hypertension and hypercholesterolemia are ineligible.
• Normal volunteers who are not taking any kind of medication are eligible.
• No history of diabetes, peripheral vascular disease, coagulopathy, or any other disease predisposing to vasculitis or Raynaud's phenomenon.
• No history of keloid formation.
• All patients must be capable of giving informed consent for all procedures.