Endothelial dysfunction: Possible mechanisms and ways of correction.

Background: Endothelial function is impaired in atherosclerosis, hypertension, diabetes and aging, and this may be associated with an attenuated ability of endothelial cells to generate nitric oxide (NO).

Objectives: To evaluate possible alterations in endothelium-dependent relaxation in rat aortic rings, the activity of constitutive NO synthase and endothelial electrical responses to acetylcholine (Ach) in rat aorta, and the effect of one month of treatment with the angiotensin-converting enzyme inhibitor enalapril on endothelial function.

Methods: Endothelial membrane potential was measured in excised rat aorta using the perforated patch-clamp technique.

Fos and nitric oxide synthase in rat brain with chronic mesostriatal dopamine deficiency: effects of nitroglycerin and hypoxia.

We found sustained proto-oncogene c-fos expression in neurons of the lateral and medial neostriatum and suppression of this expression in nitric oxide synthase (NOS)-containing cells within the islands of Calleja after lesions of the dopaminergic mesostriatal system induced by 6-hydroxydopamine. Systemic administration of nitroglycerin (NTG) or mild hypoxia resulted in a decreased of c-fos expression in the dorsolateral part of the denervated neostriatum. However, in other brain structures NTG or mild hypoxia evoked sustained c-fos expression in NOS-containing neurons and in the sources catecholaminergic projections involved in the control of cardiovascular function.

Phospholipid vesicles (liposomes) restore endothelium-dependent cholinergic relaxation in thoracic aorta from spontaneously hypertensive rats.

Objective: The present study was designed to examine, using isolated preparations of thoracic aorta, the effects of artificial phosphatidylcholine vesicles (liposomes) on vascular endothelium-dependent responses in spontaneously hypertensive rats (SHR) compared with those in Wistar-Kyoto (WKY) normotensive rats.

Design: Phosphatidylcholine liposomes, which possess the ability to repair the plasma membrane of living cells, were used in these experiments.

Methods: Liposomes were prepared from egg phosphatidylcholine.

Involvement of endothelium in vasodilating effects of vintoperol.

Experiments were performed on vessels of the femoral vascular bed of anesthetized dogs and on isolated rings of the rat pulmonary artery, vena cava, and thoracic aorta. Vintoperol was administered intra-arterially (0.01, 0.