Study of the Relation Between In Vivo and In Vitro Response of Human Small Vessels
investigate the relationship between in vivo and in vitro vascular responses
Enfermedades Cardiovasculares+5
+ Hiperlipidemias
+ Enfermedades metabólicas
Estudio de Tratamiento
Resumen
Fecha de inicio: 1 de marzo de 1997
Fecha en la que se inscribió al primer participante.Over the last ten years, we have been interested in the investigation of endothelial function in patients with essential hypertension and patients with hypercholesterolemia. We have performed intra-arterial infusion of endothelium-dependent and endothelium-independent drugs into the brachial artery with noninvasive measurement of the response of the forearm vasculature by means of strain gauge plethysmography. Those studies have allowed us to: a) demonstrate the presence of endothelial dysfunction in patients with essential hypertension and in patients with hypercholesterolemia; and b) identify an abnormality in the endothelium-derived nitric oxide system that is responsible for endothelial dysfunction in these patients. Further studies to more precisely determine the intracellular processes that mediate this abnormality in endothelial function in these patients are limited by the inherent shortcomings of the in vivo technique. An alternative possibility is the study of human small vessels in vitro; however, the relationship between in vivo and in vitro vascular responses to endothelium-dependent and -independent agonists has not been established. In the present study, we propose to investigate this relationship in normal volunteers, patients with essential hypertension, and patients with hypercholesterolemia.
Protocolo
Esta sección proporciona detalles del plan del estudio, incluyendo cómo está diseñado y qué se está evaluando.Se reclutarán 87 pacientes
Número total de participantes que el ensayo clínico espera reclutar.Estudio de Tratamiento
Elegibilidad
Los investigadores buscan pacientes que cumplan ciertos criterios, conocidos como criterios de elegibilidad: estado general de salud o tratamientos previos.Cualquier sexo
Sexo biológico de los participantes elegibles para inscribirse.Voluntarios sanos permitidos
Indica si personas sanas, sin la condición que se estudia, pueden participar.Condiciones
Patología
Criterios
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.
Centros del Estudio
Estos son los hospitales, clínicas o centros de investigación donde se lleva a cabo el estudio. Puedes encontrar la ubicación más cercana a ti y su estado de reclutamiento.Este estudio tiene una ubicación
National Heart, Lung and Blood Institute (NHLBI)
Bethesda, United StatesAbrir National Heart, Lung and Blood Institute (NHLBI) en Google Maps