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showing 10 items of 10618 documents
Therapeutic considerations in cerebellopontine angle lipomas inducing hemifacial spasm.
2000
Lipoma is a very rare tumour at the cerebellopontine angle. We report a case of incomplete hemifacial spasm, associated with a lipoma involving and compressing both facial and acoustic nerves at their origin in the brainstem. The patient was treated with medical therapy (botulinum toxin A) and surgery. We present a review of the last ten years of the literature, with particular regard to management.
Baseline data from a prospective international disease registry for Niemann-Pick disease type C
2011
Differential blockade by nifedipine and ω-conotoxin GVIA of α1- and β1-adrenoceptor-controlled calcium channels on motor nerve terminals of the rat
1990
Electrically evoked release of [3H]acetylcholine ([3H]ACh) from the rat phrenic nerve and its facilitation by stimulation of presynaptic alpha 1- and beta 1-adrenoceptors were investigated in the absence and presence of nifedipine and omega-conotoxin GVIA. Both calcium channel antagonists did not modify electrically evoked [3H]ACh release, but selectively blocked the effect triggered by both facilitatory adrenergic receptors. The increase in [3H]ACh release mediated via beta 1-adrenoceptor activation was abolished by low concentrations (1 nM) of omega-conotoxin GVIA, whereas nifedipine (100 nM) abolished the facilitatory effect mediated via alpha 1-adrenoceptor stimulation. Therefore, the b…
NADPH Oxidase Accounts for Enhanced Superoxide Production and Impaired Endothelium-Dependent Smooth Muscle Relaxation in BKβ1 −/− Mice
2006
Objective— Nitric oxide (NO)-induced vasorelaxation involves activation of large conductance Ca 2+ -activated K + channels (BK). A regulatory BKβ1 subunit confers Ca 2+ , voltage, and NO/cGMP sensitivity to the BK channel. We investigated whether endothelial function and NO/cGMP signaling is affected by a deletion of the β1-subunit. Methods and Results— Vascular superoxide in BKβ1 −/− was measured using the fluorescent dye hydroethidine and lucigenin-enhanced chemiluminescence. Vascular NO formation was analyzed using electron paramagnetic resonance (EPR), expression of NADPH oxidase subunits, the endothelial NO synthase (eNOS), the soluble guanylyl cyclase (sGC), as well as the activity a…
Nitric oxide synthases: regulation and function
2011
Nitric oxide (NO), the smallest signalling molecule known, is produced by three isoforms of NO synthase (NOS; EC 1.14.13.39). They all utilize l-arginine and molecular oxygen as substrates and require the cofactors reduced nicotinamide-adenine-dinucleotide phosphate (NADPH), flavin adenine dinucleotide (FAD), flavin mononucleotide (FMN), and (6R-)5,6,7,8-tetrahydrobiopterin (BH(4)). All NOS bind calmodulin and contain haem. Neuronal NOS (nNOS, NOS I) is constitutively expressed in central and peripheral neurons and some other cell types. Its functions include synaptic plasticity in the central nervous system (CNS), central regulation of blood pressure, smooth muscle relaxation, and vasodila…
Nitric oxide in the pathogenesis of vascular disease
2000
Nitric oxide (NO) is synthesized by at least three distinct isoforms of NO synthase (NOS). Their substrate and cofactor requirements are very similar. All three isoforms have some implications, physiological or pathophysiological, in the cardiovascular system. The endothelial NOS III is physiologically important for vascular homeostasis, keeping the vasculature dilated, protecting the intima from platelet aggregates and leukocyte adhesion, and preventing smooth muscle proliferation. Central and peripheral neuronal NOS I may also contribute to blood pressure regulation. Vascular disease associated with hypercholesterolaemia, diabetes, and hypertension is characterized by endothelial dysfunct…
eNOS Uncoupling in Cardiovascular Diseases - the Role of Oxidative Stress and Inflammation
2013
Many cardiovascular diseases and drug-induced complications are associated with - or even based on - an imbalance between the formation of reactive oxygen and nitrogen species (RONS) and antioxidant enzymes catalyzing the break-down of these harmful oxidants. According to the “kindling radical” hypothesis, the formation of RONS may trigger in certain conditions the activation of additional sources of RONS. According to recent reports, vascular dysfunction in general and cardiovascular complications such as hypertension, atherosclerosis and coronary artery diseases may be connected to inflammatory processes. The present review is focusing on the uncoupling of endothelial nitric oxide synthas…
Dexamethasone suppresses eNOS and CAT-1 and induces oxidative stress in mouse resistance arterioles
2004
Long-term treatment with glucocorticoids is associated with mild to moderate hypertension. We reported previously that downregulation of endothelial NO synthase (eNOS) expression and activity is likely to contribute to this increase in blood pressure. In the present study, we tested the effects of dexamethasone on the vasodilation of microvascular arterioles using implanted dorsal skin-fold chambers in anesthetized C57BL/6J mice. Experiments were performed on control mice or on mice treated with dexamethasone (0.1–3 mg/kg of body wt). Endothelium-dependent vasodilation in response to ACh (0.1–10 μM) was reduced by dexamethasone in a dose-dependent fashion. Comparable inhibition was seen in …
PPARγ as an indicator of vascular function in an experimental model of metabolic syndrome in rabbits
2021
Abstract Background and aims Underlying mechanisms associated with vascular dysfunction in metabolic syndrome (MetS) remain unclear and can even vary from one vascular bed to another. Methods In this study, MetS was induced by a high-fat, high-sucrose diet, and after 28 weeks, aorta and renal arteries were removed and used for isometric recording of tension in organ baths, protein expression by Western blot, and histological analysis to assess the presence of atherosclerosis. Results MetS induced a mild hypertension, pre-diabetes, central obesity and dyslipidaemia. Our results indicated that MetS did not change the contractile response in either the aorta or renal artery. Conversely, vasodi…