Search results for "Vasoconstriction"
showing 10 items of 134 documents
Intravital Microscopy in the Cremaster Muscle Microcirculation for Endothelial Dysfunction Studies
2015
The intravital microscopy in the mouse cremaster muscle microcirculation is a method widely used to visualize in vivo blood cells interacting with the endothelium and within the vessels. Therefore, it is a suitable technique to study leukocyte-endothelial cell interactions along every stage of the canonical leukocyte recruitment cascade: rolling, adhesion, intravascular crawling, and migration both in postcapillary venules and arterioles of the mouse cremasteric microcirculation. This technique also enables to assess vessel functionality, since hemodynamic parameters such as shear stress, flow rate, and vasodilatation/vasoconstriction, among other vascular events, can be additionally determ…
Efficacy of intra-arterial lidocaine infusion in the treatment of cerulein-induced acute pancreatitis
2020
Background Disturbances in pancreatic microcirculation, beginning with vasoconstriction, are crucial in early pancreatitis and progression to necrotizing pancreatitis. Thus, vascular-targeted treatment aiming to restore a sufficient level of microcirculation through vasodilation would possibly reduce the severity of pancreatitis. Lidocaine is an anti-arrhythmic and local anesthetic drug, which also acts as a vasodilator at higher concentrations. Objectives To evaluate the efficacy of intra-arterial infusion of lidocaine into the celiac trunk in treatment of cerulein-induced acute pancreatitis. Material and methods Wistar rats (n = 20) were randomly divided into 2 equal groups: the control g…
Glycyrrhetinic Acid Reverses the Lipopolysaccharide-Induced Hypocontractility to Noradrenaline in Rat Aorta: Implications to Septic Shock
2014
Abstract.: Septic shock and associated vascular hyporeactivity to vasoconstrictor agonists remain a major problem of critical care medicine. Here we report that glycyrrhetinic acid (GA), the active component of licorice, effectively restores vascular contractility in the model of lipopolysaccharide (LPS)-treated rat aorta. GA was as effective as the NO synthase inhibitor NG-nitroarginine methylester. GA did not affect the vascular NO levels (measured by EPR spin trapping) and relaxations to l-arginine in LPS-treated rings as well as relaxation to S-nitroso-Nacetylpenicillamine in control rings. Thus, GA may represent an interesting alternative to NO synthase inhibitors in sepsis-associated …
Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis
2016
AIM. To evaluate the effects of asymmetric dimethylarginine (ADMA) in renal arteries from portal hypertensive and cirrhotic rats. METHODS. Rat renal arteries from Sham (n = 15), pre-hepatic portal hypertension (PPVL; n = 15) and bile duct ligation and excision-induced cirrhosis (BDL; n = 15) were precontracted with norepinephrine, and additional contractions were induced with ADMA (10-6-10-3 mol/L), an endogenous inhibitor of nitric oxide (NO) synthase. Concentration-response curves to acetylcholine (1 × 10-9-3 × 10-6 mol/L) were determined in precontracted renal artery segments with norepinephrine in the absence and in the presence of ADMA. Kidneys were collected to determine the protein e…
Accumulation of Symmetric Dimethylarginine in Hepatorenal Syndrome
2005
In patients with cirrhosis, nitric oxide (NO), asymmetric dimethylarginine (ADMA), and possibly symmetric dimethylarginine (SDMA) have been linked to the severity of the disease. We investigated whether plasma levels of dimethylarginines and NO are elevated in patients with hepatorenal syndrome (HRS), compared with patients with cirrhosis without renal failure (no-HRS). Plasma levels of NO, ADMA, SDMA, and l-arginine were measured in 11 patients with HRS, seven patients with no-HRS, and six healthy volunteers. SDMA concentration in HRS was higher than in no-HRS and healthy subjects (1.47 ± 0.25 vs. 0.38 ± 0.06 and 0.29 ± 0.04 μM, respectively; P < 0.05). ADMA and NOx concentrations were…
Endothelial and neural factors functionally involved in the modulation of noradrenergic vasoconstriction in healthy pig internal mammary artery
2011
The role of endothelial and neural factors as modulators of neurogenic- and noradrenaline-induced vasoconstriction was examined in healthy pig internal mammary artery (IMA). Tetrodotoxin-, guanethidine-sensitive electrical field stimulation (EFS)-, and noradrenaline-elicited contractions were significantly diminished by prazosin (n=8, P0.001) and less so by rauwolscine, indicating functional α₁- and α₂-adrenoceptor-mediated noradrenergic innervation of the IMA. Endothelium removal reduced neurogenic (n=8, P0.01) but augmented noradrenaline responses (n=8, P0.01), suggesting the release of two endothelium-dependent factors with opposite effects. In the presence of endothelium, neurogenic and…
Arginine Vasopressin Enhances Sympathetic Constriction Through the V 1 Vasopressin Receptor in Human Saphenous Vein
1998
Background —Arginine vasopressin (AVP) not only acts directly on blood vessels through V 1 receptor stimulation but also may modulate adrenergic-mediated responses in animal experiments in vivo and in vitro. The aim of the present study was to investigate whether AVP can contribute to an abnormal adrenergic constrictor response of human saphenous veins. Methods and Results —Saphenous vein rings were obtained from 32 patients undergoing coronary artery bypass surgery. The vein rings were suspended in organ bath chambers for isometric recording of tension. AVP (3×10 −9 mol/L) enhanced the contractions elicited by electrical field stimulation at 1, 2, and 4 Hz (by 80%, 70%, and 60%, respectiv…
Functional Role of α1-Adrenoceptor Subtypes in Murine Ophthalmic Arteries
2011
PURPOSE To identify the α(1)-adrenoceptor (α(1)-AR) subtypes mediating vascular adrenergic responses in murine ophthalmic arteries. METHODS Expression of mRNA was quantified for individual α(1)-AR subtypes in murine ophthalmic arteries using real-time PCR. To assess the functional relevance of α(1)-ARs for mediating vascular responses, ophthalmic arteries from mice deficient in one of the three α(1)-AR subtypes (α(1A)-AR(-/-), α(1B)-AR(-/-), and α(1D)-AR(-/-), respectively) and wild-type controls were isolated, cannulated with micropipettes, and pressurized. Changes in luminal artery diameter in response to the α(1)-AR agonist phenylephrine, the sympathetic transmitter noradrenaline, and to…
Riociguat versus sildenafil on hypoxic pulmonary vasoconstriction and ventilation/perfusion matching
2017
Introduction Current treatment with vasodilators for pulmonary hypertension associated with respiratory diseases is limited by their inhibitory effect on hypoxic pulmonary vasoconstriction (HPV) and uncoupling effects on ventilation-perfusion (V'/Q'). Hypoxia is also a well-known modulator of the nitric oxide (NO) pathway, and may therefore differentially affect the responses to phosphodiesterase 5 (PDE5) inhibitors and soluble guanylyl cyclase (sGC) stimulators. So far, the effects of the sGC stimulator riociguat on HPV have been poorly characterized. Materials and methods Contraction was recorded in pulmonary arteries (PA) in a wire myograph. Anesthetized rats were catheterized to record …
Antihypertensive properties of lactoferricin B-derived peptides.
2010
A set of eight lactoferricin B (LfcinB)-derived peptides was examined for inhibitory effects on angiotensin I-converting enzyme (ACE) activity and ACE-dependent vasoconstriction, and their hypotensive effect in spontaneously hypertensive rats (SHR). Peptides were derived from different elongations both at the C-terminal and N-terminal ends of the representative peptide LfcinB(20-25), which is known as the LfcinB antimicrobial core. All of the eight LfcinB-derived peptides showed in vitro inhibitory effects on ACE activity with different IC(50) values. Moreover, seven of them showed ex vivo inhibitory effects on ACE-dependent vasoconstriction. No clear correlation between in vitro and ex viv…