Search results for "vasodilator"
showing 10 items of 128 documents
Diabetes potentiates acetylcholine-induced relaxation in rabbit renal arteries.
2001
Abstract The response of rabbit renal arteries to acetylcholine and its endothelial modulation in diabetes were investigated. Acetylcholine induced concentration-related endothelium-dependent relaxation of renal arteries that was significantly more potent in diabetic rabbits than in control rabbits. Pretreatment with NG-nitro- l -arginine ( l -NOArg), indomethacin, or l -NOArg plus indomethacin induced partial inhibition of acetylcholine-induced relaxation. Inhibition induced by l -NOArg plus indomethacin was significantly higher in arteries from diabetic rabbits than in arteries from control rabbits. In renal arteries depolarised with KCl 30 mM and incubated with l -NOArg plus indomethacin…
Cholinergic Responses of Ophthalmic Arteries in M3and M5Muscarinic Acetylcholine Receptor Knockout Mice
2009
PURPOSE. To determine the functional role of M 3 and M 5 muscarinic acetylcholine receptor subtypes in ophthalmic arteries using gene-targeted mice. METHODS. Muscarinic receptor gene expression was quantified in murine ophthalmic arteries using real-time PCR. To test the functional relevance of M 3 and M 5 receptors, ophthalmic arteries from mice deficient in either subtype (M3R -/- , M5R -/- , respectively) and wild-type controls were isolated, cannulated with micropipettes, and pressurized. Changes in luminal vessel diameter in response to muscarinic and nonmuscarinic receptor agonists were measured by video microscopy. RESULTS. With the use of real-time PCR, all five muscarinic receptor …
Nitric oxide is involved in non-adrenergic, non-cholinergic inhibitory neurotransmission in rat duodenum
1995
1. In rat duodenum, electrical field stimulation (EFS) induced a relaxation due to activation of non-adrenergic, non-cholinergic (NANC) inhibitory intramural neurones. 2. Nitric oxide synthase (NOS) inhibitors, N omega-nitro-L-arginine (L-NNA) and N omega-nitro-L-arginine methyl ester (L-NAME), caused a dose-dependent reduction in amplitude of the NANC relaxation. Responses to low frequencies of stimulation were more sensitive to NOS inhibitors than those to high frequencies. 3. Effects induced by NOS inhibitors were stereospecific since D-NNA and D-NAME did not affect NANC relaxation. L-arginine, but not D-arginine, partially prevented the effects induced by NOS inhibitors on NANC relaxati…
Contribution of nitric oxide synthase isoforms to cholinergic vasodilation in murine retinal arterioles.
2013
Abstract Nitric oxide synthases (NOSs) are critically involved in regulation of ocular perfusion. However, the contribution of the individual NOS isoforms to vascular responses is unknown in the retina. Because some previous findings suggested an involvement of inducible nitric oxide synthase (iNOS) in the regulation of retinal vascular tone, a major goal of the present study was to examine the hypothesis that iNOS is involved in mediating cholinergic vasodilation responses of murine retinal arterioles. Another subject of this study was to test the contribution of the other two NOS isoforms, neuronal (nNOS) and endothelial NOS (eNOS), to cholinergic retinal arteriole responses. Expression o…
Role of M1, M3, and M5 muscarinic acetylcholine receptors in cholinergic dilation of small arteries studied with gene-targeted mice
2011
Acetylcholine regulates perfusion of numerous organs via changes in local blood flow involving muscarinic receptor-induced release of vasorelaxing agents from the endothelium. The purpose of the present study was to determine the role of M1, M3, and M5 muscarinic acetylcholine receptors in vasodilation of small arteries using gene-targeted mice deficient in either of the three receptor subtypes (M1R−/−, M3R−/−, or M5R−/− mice, respectively). Muscarinic receptor gene expression was determined in murine cutaneous, skeletal muscle, and renal interlobar arteries using real-time PCR. Moreover, respective arteries from M1R−/−, M3R−/−, M5R−/−, and wild-type mice were isolated, cannulated with mic…
Ca2+-activated K+ channels mediate relaxation of forearm veins in chronic renal failure
2003
In arteries, agonists such as acetylcholine release an endothelium-derived hyperpolarizing factor (EDHF) that is neither nitric oxide nor prostacyclin.To examine the responses to acetylcholine in segments of forearm veins from patients with chronic renal failure who either had never received dialysis or had undergone long-term dialysis, and to determine the contribution of nitric oxide and EDHF to endothelium-dependent relaxation in veins from patients with chronic renal failure.Isometric tension was recorded in rings of forearm vein from 34 non-dialysed patients, 27 dialysed patients and 14 multiorgan donors (controls).Relaxation in response to acetylcholine was reduced in veins of non-dia…
Comparative relaxant effects of the NO donors sodium nitroprusside, DEA/NO and SPER/NO in rabbit carotid arteries.
1999
1. Sodium nitroprusside (SNP, 10(-9)-3x10(-4) M), diethylamine/NO complex (DEA/NO, 10(-9)-10(-4) M) and spermine/NO complex (SPER/NO, 10(-8)-3x10(-4) M) induced concentration-dependent relaxation of isolated rabbit carotid arteries precontracted with KCl (50 mM) or with histamine (3x10(-6) M). 2. In KCl-precontracted arteries the order of potency was SNP=DEA/NO>SPER/NO, and in histamine-precontracted arteries the order of potency was SNP>DEA/NO>SPER/NO. Relaxations to the three NO donors were significantly higher in histamine-precontracted arteries than in KCl-precontracted arteries. 3. The guanylyl cyclase inhibitor methylene blue (10(-5) M) significantly inhibited relaxations to the three…
First Evidence for a Crosstalk Between Mitochondrial and NADPH Oxidase-Derived Reactive Oxygen Species in Nitroglycerin-Triggered Vascular Dysfunction
2008
Chronic nitroglycerin treatment results in development of nitrate tolerance associated with endothelial dysfunction (ED). We sought to clarify how mitochondria- and NADPH oxidase (Nox)-derived reactive oxygen species (ROS) contribute to nitrate tolerance and nitroglycerin-induced ED. Nitrate tolerance was induced by nitroglycerin infusion in male Wistar rats (100 microg/h/4 day) and in C57/Bl6, p47(phox/) and gp91(phox/) mice (50 microg/h/4 day). Protein and mRNA expression of Nox subunits were unaltered by chronic nitroglycerin treatment. Oxidative stress was determined in vascular rings and mitochondrial fractions of nitroglycerin-treated animals by L-012 enhanced chemiluminescence, revea…
Vascular effects of sildenafil in patients with pulmonary fibrosis and pulmonary hypertension: an ex vivo/in vitro study
2015
Sildenafil improves the 6-min walking distance in patients with idiopathic pulmonary fibrosis (IPF) and right-sided ventricular systolic dysfunction.We analysed the previously unexplored role of sildenafil on vasoconstriction and remodelling of pulmonary arteries from patients with IPF and pulmonary hypertension (PH) ex vivo. Pulmonary arteries from 18 donors without lung disease, nine IPF, eight PH+IPF and four PH patients were isolated to measure vasodilator and anti-contractile effects of sildenafil in isometric organ bath. Ventilation/perfusion was explored in an animal model of bleomycin lung fibrosis.Sildenafil relaxed serotonin (5-HT) pre-contracted pulmonary arteries in healthy dono…
Pharmacological treatment of patients with chronic critical limb ischemia: L-propionyl-carnitine enhances the short-term effects of PGE-1.
2009
Purpose. To evaluate the therapeutic effects of L-propionyl-carnitine (LPC) in patients with critical limb ischemia (CLI), as defined by the TASC guidelines. Methods. The study, double-blinded, randomised, assessed intravenous infusion of LPC 1.2 g/day in combination with PGE-1, 60 mg/day (LPC group: 37 patients), or PGE-1 only (control group: 38 patients) in a total of 75 patients suffering from CLI. Treatment duration was 20 days. We evaluated rest pain, maximum walking distance (MWD) and skin ulcer size. Results. In both groups we observed a significant reduction in pain score and ulcer size and an increase in MWD. In the patients treated with the combination, the improvement was greater…