Search results for "Calcium"
showing 10 items of 1740 documents
Serum alkaline phosphatase negatively affects endothelium-dependent vasodilation in naïve hypertensive patients.
2015
Tissue nonspecific alkaline phosphatase, promoting arterial calcification in experimental models, is a powerful predictor of total and cardiovascular mortality in general population and in patients with renal or cardiovascular diseases. For this study, to evaluate a possible correlation between serum alkaline phosphatase levels and endothelial function, assessed by strain gauge plethysmography, we enrolled 500 naïve hypertensives divided into increasing tertiles of alkaline phosphatase. The maximal response to acetylcholine was inversely related to alkaline phosphatase ( r =−0.55; P <0.001), and this association was independent ( r =−0.61; P <0.001) of demographic and classical risk …
Modulation of cytosolic free calcium concentration by ?1-adrenoceptors in rat atrial cells
1992
The effects of α1-adrenoceptor stimulation by phenylephrine (PE) and β-adrenoceptor stimulation by isoprenaline (ISO) on Ca2+ current (ICa) and free intracellular Ca2+ concentration ([Ca2+]i) were studied in isolated atrial myocytes from rat hearts. PE did not significantly affect the magnitude of ICa, whereas large increases of peak ICa were observed in response to ISO. In electrically driven cells, PE evoked a concentration-dependent, gradual increase in diastolic [Ca2+]i and, initially, an increase in the height of peak [Ca2+]i transients. When the diastolic [Ca2+]i was increased to a greater extent, the amplitude of [Ca2+]i transients was decreased. Simultaneous measurements of [Ca2+]i …
Effects of calcium channel blockers on gastric emptying and acid secretion of the rat in vivo.
1986
Abstract Experiments were designed to evaluate the effects of three calcium channel blockers (verapamil, diltiazem and cinnarizine) on gastric emptying and secretion in the rat. Pretreatment with the calcium blockers delayed gastric emptying of phenol red in a dose-dependent manner. Verapamil was the most effective of the agents tested. Verapamil and diltiazem inhibited gastric acid secretion in the pylorus-ligated rat without affecting pepsin output. Cinnarizine was ineffective in this model. When the perfused lumen of the anaesthetized rat was used, verapamil was found to inhibit responses to carbachol or histamine more than those to pentagastrin. Further, we found a greater sensitivity t…
Fetuin-A is Associated to Serum Calcium and AHSG T256S Genotype but Not to Coronary Artery Calcification
2015
Vascular calcification has been recently associated to an increased cardiovascular risk and mortality. In few studies, Fetuin-A showed an association to coronary artery calcification (CAC), although the physiopathological mechanism underlying this association has not been fully established yet. Seventy-four patients with one or more cardiovascular risk factor and asymptomatic for coronary vasculopathy were included in the study. CAC was evaluated by Agatston score. Serum Fetuin-A levels were determined by ELISA. Molecular analysis of AHSG T256S gene variant (rs4918) was performed by PCR-RFLP. Serum Fetuin-A was correlated to serum calcium (r = 0,321; P = 0,018), but not to serum phosphorous…
Non-specific Hyperreactivity to Pharmacological Stimuli in Tracheal and Lung Parenchymal Strips of Actively Sensitized Guinea-pigs
1989
Abstract The responsiveness of tracheal and lung parenchymal strips isolated from actively sensitized guinea-pigs to CaCl2 (in K+-depolarized tissue), KCl, acetylcholine and histamine was compared with that of strips from unsensitized animals. The concentration-response curves to the mentioned agonists exhibited, in the sensitized group, a left upward displacement (greater maximal effect, lesser effective concentration 50% and a steeper slope) compared with those obtained in the unsensitized group. These results indicate the existence of a non-specific increase in responsiveness in the airway smooth muscle from sensitized animals.
Muscarinic inhibition of acetylcholine release from a novel in vitro preparation of the guinea-pig trachea
1990
An isolated preparation of the guinea-pig trachea is described which allows the simultaneous measurement of acetylcholine release and smooth muscle contraction. Incubation of the epithelium-free preparation with [3H]choline resulted in the formation of [3H]acetylcholine. Electrical stimulation caused the release of [3H]acetylcholine and a contractile response. Tetrodotoxin and omission of calcium from the medium abolished both the evoked release and contractions. The muscarinic agonists oxotremorine, carbachol and pilocarpine concentration-dependently inhibited the electrically evoked acetylcholine release and contracted the tracheal smooth muscle. Pre- and postsynaptic EC50 values for a gi…
Effect of theophylline on calcium exchangeability in ventricular myocardium.
1976
The effects of theophylline on contractile force and myocardial calcium exchangeability were studied in isolated, electrically driven Langendorff perfused guinea-pig hearts. Following a 30-min exposure to 45Ca, total cellular calcium and 45Ca activity were measured in right ventricular samples. "Nontoxic" theophylline concentrations (5 x 10(-5) -10(-3) g/ml) which augmented contractile force without producing arrhythmias or contractures had no effect on total tissue calcium and did not alter the size of the fraction of cellular calcium exchangeable under steady-state conditions. A "toxic" concentration of theophylline (2 x 10(-3) g/ml) induced contractures and increased the amount of exchan…
Chronic pharmacological treatment in takotsubo cardiomyopathy.
2008
Abstract Background Takotsubo cardiomyopathy is a disorder that has been appreciated only recently. In most of reported cases, this syndrome mimes an acute myocardial infarction. Till this moment no data are available from literature about the treatment in the acute phase of this disease. Aim of the study In our multicentric experience we have retrospectively looked at the benefits of a treatment with ACE-inhibitors, beta-blockers, Aspirin and calcium channels blockers, started until the early phases of the disease and continued for 30 days, in 36 patients affected by Takotsubo cardiomyopathy. We chose as endpoint of the study the efficacy of the used drug in improving left ventricular myoc…
A new heterozygous mutation (L338N) in the human Gsalpha (GNAS1) gene as a cause for congenital hypothyroidism in Albright's hereditary osteodystroph…
2003
OBJECTIVE: To identify the molecular defect by which psychomotor retardation is caused in two brothers with congenital hypothyroidism who received adequate treatment with l-thyroxine. CASE REPORT: A six-year-old boy presented with psychomotor retardation and congenital primary hypothyroidism (CH). The patient had a normal blood thyrotrophin (TSH) level on neonatal screening, but low total serum thyroxine and triiodothyronine concentrations prompting thyroid hormone substitution shortly after birth. Nevertheless, psychomotor development was retarded and the patient underwent further investigation. Typical features of Albright's hereditary osteodystrophy (AHO) such as round face, obesity, and…
Evidence for the neuronal origin of immunoreactive interleukin-1 beta released by rat hypothalamic explants.
1996
In this study, we have investigated the release of immunoreactive interleukin-1 beta (irIL-1 beta) from the rat hypothalamus in vitro. It was found that (1) tissue explants release sizable amounts of irIL-1 beta (ranging from 0.43 to 0.52 pg/mg of wet tissue) in 20 min incubations; (2) basal release in significantly increased by depolarization induced with 56 mM KCl; (3) K(+)-induced irIL-1 beta release is inhibited by the specific blocker of N-type calcium channels, omega-conotoxin, and by verapamil, but not by nifedipine; (4) K(+)-induced release is also inhibited by the Na+ channel blockers tetrodotoxin and lidocaine; (5) irIL-1 beta release is significantly increased by noradrenalin; su…