Radioactive adenosine triphosphate was synthesized transiently from adenosine diphosphate and radioactive inorganic phosphate by sodium and potassium adenosine triphosphatase from guinea pig kidney. In a first step, K+-sensitive phosphoenzyme was formed from radioactive inorganic phosphate in the presence of magnesium ion and 16 mM sodium ion. In a second step the addition to the phosphoenzyme ...

A carboxylated adenosine analog (C-Ado−) has been synthesized and probed via time-resolved photoelectron spectroscopy in order to induce intra-molecular charge transfer from the carboxylic acid moiety nucleobase. Intra-molecular can be exploited as starting point probe low-energy electron (LEE) damage DNA its derivatives. Time-dependent density functional theory (TD-DFT) calculations at B3LYP-6...

Adenosine receptors (nomenclature as agreed by the NC-IUPHAR Subcommittee on Receptors [110]) are activated endogenous ligand adenosine (potentially inosine also at A3 receptors). Crystal structures for antagonist-bound [153, 313, 221, 61], agonist-bound [375, 203, 204] and G protein-bound A2A [49] have been described. The of an A1 receptor [128] adenosine-bound receptor-Gi complex [86] resolve...

objective: it has been suggested that low frequency stimulation (lfs) exerts its inhibitory effect on epileptogenesis through adenosine receptors activation. in the present study, effect of different lfs frequencies on a1 and a2a receptors gene expression was investigated in perforant path kindled seizures. materials and methods: animals were kindled by perforant path stimulation. afterdischarg...

OBJECTIVES We studied whether an increase in adenosine dose overcomes caffeine antagonism on adenosine-mediated coronary vasodilation. BACKGROUND Caffeine is a competitive antagonist at the adenosine receptors, but it is unclear whether caffeine in coffee alters the actions of exogenous adenosine, and whether the antagonism can be surmounted by increasing the adenosine dose. METHODS Myocard...

PURPOSE To investigate the effect of adenosine on the contractile tone of cultured bovine retinal pericytes. METHODS Changes in the contractile tone were quantified as the changes in the summed length of wrinkles induced by pericytes on the silicone surface on which the cells were grown. RESULTS Adenosine at 10(-9) M had no effect. In the range of 10(-8) to 10(-4) M, adenosine caused relaxa...

introduction:adenosine as a potent vasodilator has physiological role in regulation of regional cerebral blood flow (rcbf). metod: laser-dِoppler flowmetry technique was used to study pial vessels blood flow responses to adenosine receptors agonists and antagonist. male sprague dawley rats (250-350g) that were housed in standard conditions, were anesthetized with urethane (1.5g/kg). adenosine (g...

abstract background: the aims of this study were to assay the activity of adenosine deaminase (ada) in estrogen receptor positive (mcf-7) and negative (mda-mb468) breast cancer cell lines. methods: mda-mb468 and mcf-7 breast cancer cell lines were cultured in complete medium, striped serum with and without 0.0 1~-lm diethylstilbestrol (des), complete medium in the presence and absence of 111m t...

The effects of adenosine on the human His-Purkinje system (HPS) were studied in nine patients with complete atrioventricular (AV) block. Adenosine had minimal effect on the control HPS cycle length, but in the presence of isoproterenol increased it from 906 +/- 183 to 1,449 +/- 350 ms, P less than 0.001. Aminophylline, a competitive adenosine antagonist, completely abolished this antiadrenergic...

Altered nucleoside levels may be linked to pathogenic signaling through adenosine receptors. We hypothesized that adenosine dysregulation contributes to fibrosis in diabetic kidney disease. Our findings indicate that high glucose levels and experimental diabetes decreased uptake activity through the equilibrative nucleoside transporter 1 (ENT1) in proximal tubule cells. In addition, a correlati...