Search results for "Constriction"

Ceramide Mediates Acute Oxygen Sensing in Vascular Tissues

2014

AbstractAims: A variety of vessels, such as resistance pulmonary arteries (PA) and fetoplacental arteries and the ductus arteriosus (DA) are specialized in sensing and responding to changes in oxygen tension. Despite opposite stimuli, normoxic DA contraction and hypoxic fetoplacental and PA vasoconstriction share some mechanistic features. Activation of neutral sphingomyelinase (nSMase) and subsequent ceramide production has been involved in hypoxic pulmonary vasoconstriction (HPV). Herein we aimed to study the possible role of nSMase-derived ceramide as a common factor in the acute oxygen-sensing function of specialized vascular tissues. Results: The nSMase inhibitor GW4869 and an anticera…

Comparative Analysis of the Vascular Actions of Diterpenes Isolated from Euphorbia canariensis

1998

Abstract We have analysed the effects of 2,3-diepiingol 7,12-diacetate-8-isobutyrate (compound 1), ingenol-3-angelate-17-benzoate (compound 2), ingenol-3-angelate-17-benzoate-20-acetate (compound 3) and 3,5,7,8,9,15-hexahydroxyjatropha-6(17),11-dien-14-one-5,8-bis(2-methylbutyrate)-7-(2-methylpropionate) (compound 4), four diterpenes isolated from E. canariensis, on the isometric tension developed by isolated rabbit basilar and carotid arteries. Concentration-response curves to these compounds were obtained cumulatively in both arteries at resting tension and active tone (KCl, 50 mM). At resting tension a concentration-dependent contraction was induced by the four compounds. In the basilar …

Interpretation of epicardial mapping by means of computer simulations: Applications to calcium, lidocaine and to BRL 34915

1992

The aim of this work was to compare experimental investigations on effects of lidocaine, calcium and, BRL 34915 on reentries to simulated data obtained by use of a model of propagation based on the Huygens' construction method already described in previous works. Calcium and lidocaine effects are investigated on anisotropic conduction conditions. In both cases, reduction in conduction velocities are observed. In lidocaine case, a refractory area is located along the longitudinal axis. In agreement with experimental electrical mapping, the simulations show that the stabilization of reentrant excitation is mainly due to the existence of this refractory area around which the reentrant circuit …

Effects of exercise training and montelukast in children with mild asthma

2008

Data from the general population suggest that habitual exercise decreases bronchial responsiveness, but the possible role of exercise in asthmatics is undefined. The leukotriene receptor antagonist montelukast decreases bronchial responsiveness and exercise-induced symptoms in asthmatic children. This randomized study in children with mild asthma evaluated the combined effects of aerobic training for 12 wk and montelukast or placebo on bronchial responsiveness (BHR) to methacholine, exercise-induced bronchoconstriction (EIB), inflammatory markers in exhaled breath condensate (EBC), and asthma exacerbations.Fifty children (mean age +/- SD: 10.2 +/- 2.4 yr) with mild stable asthma were random…

In vitro and in vivo characterization of a new organic nitrate hybrid drug covalently bound to pioglitazone.

2014

<b><i>Background/Aims:</i></b> Organic nitrates represent a group of nitrovasodilators that are clinically used for the treatment of ischemic heart disease. The new compound CLC-3000 is an aminoethyl nitrate (AEN) derivative of pioglitazone, a thiazolidinedione antidiabetic agent combining the peroxisome proliferator-activated receptor γ agonist activity of pioglitazone with the NO-donating activity of the nitrate moiety. <b><i>Methods:</i></b> In vitro and in vivo characterization was performed by isometric tension recording, platelet function, bleeding time and detection of oxidative stress. <b><i>Results:</i></…

Modifications in FVC during AMP Induced Bronchoconstriction in Asthma: Relationship with the Response to Methacholine and Influence of Inhaled Cortic…

2009

Potential Functional Significance of Brain-Type and Muscle-Type Nitric Oxide Synthase I Expressed in Adventitia and Media of Rat Aorta

1999

Abstract —Skeletal muscle and myocardium express μNOS I, an elongated splice variant of neuronal-type nitric oxide (NO) synthase (NOS I), and NOS III, endothelial-type NO synthase, respectively. This study was designed to elucidate whether vascular smooth muscle also contains a constitutively expressed NO synthase isoform. In the rat, μNOS I contains an insert of 102 nucleotides after nucleotide 2865 of the cDNA, yielding a protein of 164 kd. Reverse transcription-polymerase chain reaction with primers flanking this insert and with insert-specific primers indicated that endothelium-denuded rat aorta expresses both brain-type NOS I and μNOS I. RNase protection analyses with an antisense RNA…

Role of cyclic nucleotide phosphodiesterase isoenzymes in contractile responses of denuded rat aorta related to various Ca 2+ sources

2001

We have examined the cyclic nucleotide phosphodiesterase isoforms (PDE) involved in the contractile response of rat aorta to different agonists and different experimental procedures for use in functional studies. The inhibitory effect of AAL 05 on the different PDEs isolated from bovine aortic smooth muscle was examined. Compound AAL 05 appeared to be a selective PDE3 inhibitor. We analyzed the ability of the non-selective inhibitor IBMX (3-isobutyl-1-methylxanthine) and the isoenzyme selective inhibitors nimodipine (type 1), AAL 05 (6-(N-methyl-N-cyclohexyl butyl carboxamide) quinolin-2-one) and SKF 94120 (5-(4-acetamidophenyl) pyrazin-2(1H)-one; type3), rolipram (type4) and zaprinast (typ…

Effects of the exercise in the cerebral blood flow and metabolism: A review

2015

In recent years it has been shown that cerebral blood flow is affected by intense exercise, what may even lead to a reduction in the cognitive capacity. This statement is contrary to the traditional belief that cerebral blood flood remains constant and unaltered even when exercise is performed. During physical exercise of moderate intensity, cerebral blood flow increases in the cerebral areas responsible for movement. Moreover, recent studies have observed that cerebral blood flow decreases during high-intensity exercise as a consequence of a local hyperventilation and vasoconstriction of the areas with lower cerebral activity. Traditionally, the glucose has been considered as the main and …

DNA Methylation and Non-Coding RNAs during Tissue-Injury Associated Pain.

2022

While about half of the population experience persistent pain associated with tissue damages during their lifetime, current symptom-based approaches often fail to reduce such pain to a satisfactory level. To provide better patient care, mechanism-based analgesic approaches must be developed, which necessitates a comprehensive understanding of the nociceptive mechanism leading to tissue injury-associated persistent pain. Epigenetic events leading the altered transcription in the nervous system are pivotal in the maintenance of pain in tissue injury. However, the mechanisms through which those events contribute to the persistence of pain are not fully understood. This review provides a summar…