Search results for " calcium"
showing 10 items of 342 documents
Increased calcium influx is responsible for the sustained mechanical tone in colon from dystrophic (mdx) mice
2001
Abstract Background & Aims: Proximal colon from dystrophic mice develops spontaneous tone increment, but the mechanisms involved in its development have not been investigated. This study examined whether alterations in the properties of cell membrane calcium channels and/or sarcoplasmic reticular (SR) Ca 2+ -adenosine triphosphatase (ATPase) contribute to tone development. Methods: Effects of calcium-free solution, nifedipine, pinaverium (calcium channel blockers), and cyclopiazonic acid (CPA; SR Ca 2+ -ATPase inhibitor) on the contractile activity of colon from mdx and control mice were determined. Results Calcium-free solution abolished spontaneous contractions in both preparations, but d…
Differential effects of calcium channel antagonists (omega-conotoxin GVIA, nifedipine, verapamil) on the electrically-evoked release of [3H]acetylcho…
1990
Electrically-evoked release of [3H]acetylcholine from autonomic neurons (myenteric plexus), motoneurons (phrenic nerve) and the central nervous system (neocortex) was investigated in the presence and absence of the calcium channel antagonists omega-conotoxin GVIA, nifedipine and verapamil, whereby the same species (rat) was used in all experiments. Release of [3H]acetylcholine was measured after incubation of the tissue with [3H]choline. omega-Conotoxin GVIA markedly reduced (70%) the evoked release of [3H]acetylcholine from the myenteric plexus of the small intestine (IC50: 0.7 nmol/l) with a similar potency at 3 and 10 Hz stimulation. An increase in the extracellular calcium concentration…
Impact of coronary calcium score on diagnostic accuracy for the detection of significant coronary stenosis with multislice computed tomography angiog…
2005
One hundred twenty patients in sinus rhythm with suspected coronary artery disease who underwent multislice computed tomography of the heart and conventional coronary angiography were retrospectively selected. The population was divided into 2 groups depending on their calcium score (CS) (e.g., low CS and high CS). The diagnostic accuracy of multislice computed tomographic scans for detecting significant lesions (>50% lumen reduction) in both groups was compared with quantitative coronary angiography. The sensitivity and specificity of multislice computed tomography were 90% and 92%, and 97% and 91% for low and high CS groups, respectively.
Efficacy and safety of ezetimibe added to atorvastatin versus atorvastatin uptitration or switching to rosuvastatin in patients with primary hypercho…
2013
Hypercholesterolemic patients (n = 1,547) at high atherosclerotic cardiovascular disease risk with low-density lipoprotein cholesterol (LDL-C) levels ≥100 and ≤160 mg/dl while treated with atorvastatin 10 mg/day entered a multicenter, randomized, double-blind, active-controlled, clinical trial using two 6-week study periods. Period I compared the efficacy/safety of (1) adding ezetimibe 10 mg (ezetimibe) to stable atorvastatin 10 mg, (2) doubling atorvastatin to 20 mg, or (3) switching to rosuvastatin 10 mg. Subjects in the latter 2 groups who persisted with elevated LDL-C levels (≥100 and ≤160 mg/dl) after period I, entered period II; subjects on atorvastatin 20 mg had ezetimibe added to th…
Dietary (n-3) polyunsaturated fatty acids exert antihypertensive effects by modulating calcium signaling in T cells of rats.
2001
After 10 wk of feeding an experimental diet enriched with (n-3) polyunsaturated fatty acids (PUFA), i.e., eicosapentaenoic acid [EPA, 20:5(n-3)] and [DHA, 22:6(n-3)] (EPAX), blood pressure in spontaneously hypertensive rats (SHR), but not in normotensive Wistar-Kyoto (WKY) rats was reduced relative to rats fed an unsupplemented control diet. Concanavalin A-stimulated T-cell proliferation was diminished in both strains of rats fed the PUFA/EPAX diet. The experimental diet lowered secretion of interleukin-2 in SHR, but not in WKY rats compared with rats fed the control diet. To determine whether there was a defect in calcium homeostasis in T cells during hypertension, we employed the followin…
Identification of calcium sensing receptor (CaSR) mRNA-expressing cells in normal and injured rat brain
2009
Calcium sensing receptor (CaSR), isolated for the first time from bovine and human parathyroid, is a G-protein-coupled receptors that has been involved in diverse physiological functions. At present a complete in vivo work on the identification of CaSR mRNA-expressing cells in the adult brain lacks and this investigation was undertaken in order to acquire more information on cell type expressing CaSR mRNA in the rat brain and to analyse for the first time its expression in different experimental models of brain injury. The expression of CaSR mRNAs was found mainly in scattered cells throughout almost all the brain regions. A double labeling analysis showed a colocalization of CaSR mRNA expr…
Contractile hyporesponsiveness to norepinephrine of forearm veins in chronic renal failure.
2006
Background We recently reported that endothelium-dependent relaxation is impaired in forearm veins from patients with chronic renal failure. However, assessment of responses to norepinephrine remains controversial. We examined the contractile response to norepinephrine in forearm veins from patients on chronic hemodialysis and the role of nitric oxide (NO), prostanoids, and Ca 2+ -activated K + channels in this response. Methods Isometric contraction curves were obtained in rings of forearm vein from 21 dialyzed patients and 12 multiorgan donors in response to norepinephrine (1 nmol/L to 10 μmol/L) or KCl (5 to 100 mmol/L). Results Veins from uremic patients were markedly less responsive to…
Functional evidence for different roles of GABAA and GABAB receptors in modulating mouse gastric tone
2010
Abstract The aims of the present study were to investigate, using mouse whole stomach in vitro , the effects of γ-aminobutyric acid (GABA) and GABA receptor agonists on the spontaneous gastric tone, to examine the subtypes of GABA receptors involved in the responses and to determine the possible site(s) of action. GABA induced gastric relaxation, which was antagonized by the GABA A -receptor antagonist, bicuculline, potentiated by phaclofen, GABA B -receptor antagonist, but not affected by 1,2,5,6-Tetrahydropyridin-4-yl methylphosphinic acid hydrate (TPMPA), GABA C -receptor antagonist. Muscimol, GABA A -receptor agonist, mimicked GABA effects inducing relaxation, which was significantly re…
Calcium-enriched bread for treatment of uremic hyperphosphatemia
2004
Abstract Objective To assess phosphate-binding efficacy of a new food product, bread with unusually high calcium content (Ca-bread). Design and setting A randomized parallel group trial in the university hospital outpatient dialysis unit. Patients Fifty-three randomly selected uremic patients who met the following inclusion criteria: (1) required maintenance hemodialysis treatment, (2) were not to receive vitamin D throughout the study, (3) were nondiabetic, and (4) were diagnosed with hyperphosphatemia. Intervention Fifty-three patients were randomized into 2 groups: control group (n = 26), which received calcium acetate as a phosphate binder throughout the study, and Ca-bread group (n = 2…
The association between the 4G/5G polymorphism in the promoter of the plasminogen activator inhibitor-1 gene and extension of postsurgical calf vein …
2013
The objective of this study was to evaluate whether the presence of a plasminogen activator inhibitor type 1 (PAI-1) promoter polymorphism 4G/5G could significantly influence the proximal extension of vein thrombosis in spite of anticoagulant treatment in patients with calf vein thrombosis (CVT) following orthopaedic, urological and abdominal surgery. We studied 168 patients with CVT, who had undergone orthopaedic, urological and abdominal surgery, subdivided as follows: first, 50 patients with thrombosis progression; second, 118 patients without thrombosis progression. The 4G/5G polymorphism of the plasminogen activator inhibitor 1 was evaluated in all patients and in 70 healthy matched co…