Search results for "Enos"
showing 10 items of 1576 documents
Adenosine negatively regulates duodenal motility in mice: role of A1 and A2A receptors
2011
BACKGROUND AND PURPOSE Adenosine is considered to be an important modulator of intestinal motility. This study was undertaken to investigate the role of adenosine in the modulation of contractility in the mouse duodenum and to characterize the adenosine receptor subtypes involved. EXPERIMENTAL APPROACH RT-PCR was used to investigate the expression of mRNA encoding for A1, A2A, A2B and A3 receptors. Contractile activity was examined in vitro as changes in isometric tension. KEY RESULTS In mouse duodenum, all four classes of adenosine receptors were expressed, with the A2B receptor subtype being confined to the mucosal layer. Adenosine caused relaxation of mouse longitudinal duodenal muscle; …
Control of oxidative metabolism in volume-overloaded rat hearts: effects of different lipid substrates.
1994
The relationship between intracellular energy parameters and myocardial O2 consumption (VO2) was studied in control and volume-overloaded hearts perfused with different lipid substrates and over a range of left ventricular work loads. In control hearts, a unique linear relationship between log of cytosolic [ATP]/[ADPf].[Pi] (where [ADPf] is concentration of free ADP) and myocardial VO2 was observed between low and high work loads for both fatty acids studied. In volume-overloaded hearts perfused in the presence of exogenous palmitate, the slope of the relationship between log [ATP]/[ADPf].[Pi] and myocardial VO2 was considerably depressed. It would seem that, under these conditions, much o…
The metalloproteinase-disintegrin ADAM10 is exclusively expressed by type I muscle fibers.
2008
ADAM10 (Kuzbanian) is a member of a recently discovered family of membrane-anchored metalloproteinases with a complex and conserved domain structure. In part, these metalloproteinases have been implicated in muscle formation. Herein the expression pattern of ADAM10 in human skeletal muscle was studied. ADAM10 was found to be present in human myoblasts and to be exclusively expressed in type I fibers, suggesting that it may be critical in muscle fiber differentiation.
Left Ventricle Biomechanics of Low-Flow, Low-Gradient Aortic Stenosis: A Patient-Specific Computational Model
2022
This study aimed to create an imaging-derived patient-specific computational model of low-flow, low-gradient (LFLG) aortic stenosis (AS) to obtain biomechanics data about the left ventricle. LFLG AS is now a commonly recognized sub-type of aortic stenosis. There remains much controversy over its management, and investigation into ventricular biomechanics may elucidate pathophysiology and better identify patients for valve replacement. ECG-gated cardiac computed tomography images from a patient with LFLG AS were obtained to provide patient-specific geometry for the computational model. Surfaces of the left atrium, left ventricle (LV), and outflow track were segmented. A previously validated …
ATP distribution and localization of mitochondria in Suberites domuncula (Olivi 1792) tissue
2011
SUMMARY The metabolic energy state of sponge tissue in vivo is largely unknown. Quantitative bioluminescence-based imaging was used to analyze the ATP distribution of Suberites domuncula (Olivi 1792) tissue, in relation to differences between the cortex and the medulla. This method provides a quantitative picture of the ATP distribution closely reflecting the in vivo situation. The obtained data suggest that the highest ATP content occurs around channels in the sponge medulla. HPLC reverse-phase C-18, used for measurement of ATP content, established a value of 1.62 μmol ATP g–1 dry mass in sponge medulla, as opposed to 0.04 μmol ATP g–1 dry mass in the cortex, thus indicating a specific and…
Gill ATPase activity in Procambarus clarkii as an indicator of heavy metal pollution.
1989
Lake Albufera and the surrounding rice field waters are subjected to very heavy loads of sewage and toxic industrial residues, including heavy metals, from the many urban and waste waters of this area. The American red crayfish, Procambarus clarkii have a high resistance to toxic effects of heavy metals. The sublethal effects of heavy metals on gills of fish and aquatic invertebrates have been extensively studied. Some metabolic disturbances and histologic damages have been reported, as well as osmoregulation alterations. However, little work has been done about the effect of heavy metals on Na,K and Mg-ATPases of freshwater invertebrate gills. Na,K-ATPase is the prime mediator of ion trans…
Presence of phosphorylatedO-ribosyl-adenosine In T-ψ-stem of yeast methlonine initiator tRNA
1989
We report in this paper on isolation and characterization of two unknown nucleosides G* and [A*] located in the T-psi-stem of yeast methionine initiator tRNA, using the combined means of HPLC protocols, real time UV-absorption spectrum, and post-run mass spectrometry by electron impact or fast atom bombardment. The G* nucleoside in position 65 was identified as unmodified guanosine. The structure of the unknown [A*] in position 64 was characterized as an isomeric form of O-ribosyl-adenosine by comparison of its chromatographic, UV-spectral and mass spectrometric properties with those of authentic O-alpha-ribofuranosyl-(1"----2')-adenosine isolated from biosynthetic poly(adenosine diphosphat…
Poly-ADP-Ribose (PAR) as an epigenetic flag
2009
Epigenetics is the study of hereditable chromatin modifications, such as DNA methylation, histone modifications, and nucleosome-remodelling, which occur without alterations to the DNA sequence. The establishment of different epigenetic states in eukaryotes depends on regulatory mechanisms that induce structural changes in chromatin in response to environmental and cellular cues. Two classes of enzymes modulate chromatin accessibility: chromatin-covalent modifiers and ATP-dependent chromatin remodelling complexes. The first class of enzymes catalyzes covalent modifications of DNA as well as the amino- and carboxy-terminal tails of histones, while the second uses the energy of ATP hydrolysis …
The nucleosome-remodeling ATPase ISWI is regulated by poly-ADP-ribosylation.
2008
ATP-dependent nucleosome-remodeling enzymes and covalent modifiers of chromatin set the functional state of chromatin. However, how these enzymatic activities are coordinated in the nucleus is largely unknown. We found that the evolutionary conserved nucleosome-remodeling ATPase ISWI and the poly-ADP-ribose polymerase PARP genetically interact. We present evidence showing that ISWI is target of poly-ADP-ribosylation. Poly-ADP-ribosylation counteracts ISWI function in vitro and in vivo. Our work suggests that ISWI is a physiological target of PARP and that poly-ADP-ribosylation can be a new, important post-translational modification regulating the activity of ATP-dependent nucleosome remodel…
Alteration of poly (ADP-Rib) synthesis during progesterone- caused gene expression in oviducts of quails.
1976
Summary The biological model of the selective induction of RNA synthesis in oviducts of estrogen stimulated immature quails by progesterone has been used to clarify whether poly (ADP-Rib) is involved in DNA transcription. The chromatin-bound as well as the soluble poly (ADP-Rib) polymerase has been isolated from oviducts and the optimal reaction conditions have been determined. The activities, as measured by the incorporation rates of NAD + into poly (ADP-Rib), of both, chromatin-bound « endogenouspolymerase (in the absence of « exogenousDNA and histones) and soluble enzyme (native DNA - lysine-rich histone ratio: 4.3) from progesterone treated quail oviducts, have been determined to be onl…