BACKGROUND Hypertension is associated with functional and morphological alterations of the endothelium, which disturbs delicate balance of endothelium-derived factors resulting in endothelial dysfunction. The endothelial dysfunction could then facilitate the maintenance of elevated peripheral resistance, which would favor the occurrence of atherosclerosis. AIMS AND OBJECTIVES The aim of the p...

Normal endothelial cells synthesize and release biologically active substances. These substances maintain homeostasis through adequate blood flow, delivery of nutrients, activation and inhibition of coagulation proteins, prevention of thrombosis and diapedesis of leukocyte. Endothelial dysfunction implies failure of vascular endothelium to perform its normal functions of vasodilatation and vaso...

A comparison of identified sympathetic neurons in the isolated intact superior cervical ganglion revealed that secretomotor, pilomotor, and vasoconstrictor cells differ in their action potential mechanisms and in their postsynaptic alpha(2)-adrenergic responses to 10 microM norepinephrine (NE). In normal saline, the half-width of the spike afterhyperpolarization (AHP) in secretomotor neurons (1...

To clarify the effects of active vitamin D3 on pressor and vascular responses to vasoconstrictor substances, we studied pressor responses to the intravenous injection of norepinephrine or angiotensin II (Ang II) and vasoconstrictor responses to norepinephrine. Sprague-Dawley rats were given 1,25 -dihydroxyvitamin D3 subcutaneously (200 ng/kg per day) for 14 days. The administration of 1,25-dihy...

Objective. To evaluate the impact of oxidative stress on vascular reactivity to vasoconstrictors and on nitric oxide (NO) bioavailability in saphenous vein (SV) graft with endothelial dysfunction from hypertensive patients (HT). Methods. Endothelial function, vascular reactivity, oxidative state, nitrites and NO release were studied in isolated SV rings from HT and normotensive patients (NT). O...

BACKGROUND Recent studies have shown that endothelial nitric oxide (NO) is involved in modulating the vascular response to vasoconstrictors in portal-systemic collaterals of portal hypertensive rats. This study investigated which isoform of NO synthase is involved in the collateral circulation of portal hypertensive rats. METHODS The relaxation response to acetylcholine (10(-8) M, 10(-7) M an...

Resistance arteries exist in a maintained contracted state from which they can dilate or constrict depending on need. In many cases, these arteries constrict to membrane depolarization and dilate to membrane hyperpolarization and Ca-channel blockers. We discuss recent information on the regulation of arterial smooth muscle voltage-dependent Ca channels by membrane potential and vasoconstrictors...

PURPOSE OF REVIEW Anaphylactic cardiovascular collapse can be resistant to treatment with epinephrine (adrenaline) and, in some cases, diagnostic uncertainty compromises follow-up care. The purpose of this review is to examine recent studies relevant to the management and diagnosis of this condition. RECENT FINDINGS Nausea, vomiting, incontinence, diaphoresis, dyspnoea, hypoxia, dizziness and...