Osteoclasts, highly differentiated bone-resorbing cells of hematopoietic origin, have two conflicting tendencies: a lower capacity to survive and a higher capacity to execute energy-consuming activities such as bone resorption. Here, we report that when compared with their precursors, mature mitochondria-rich osteoclasts have lower levels of intracellular ATP, which is associated with receptor ...

Pocock, T. M., B. Williams, F. E. Curry, and D. O. Bates. VEGF and ATP act by different mechanisms to increase microvascular permeability and endothelial [Ca]i. Am J Physiol Heart Circ Physiol 279: H1625–H1634, 2000.—Vascular endothelial growth factor (VEGF) increases hydraulic conductivity (Lp) by stimulating Ca 21 influx into endothelial cells. To determine whether VEGF-mediated Ca influx is ...

To probe the mechanism by which intracellular ATP, Na+, and Cl- influence the activity of the NaK2Cl cotransporter, we measured bumetanide-sensitive (BS) 86Rb fluxes in the osteosarcoma cell line UMR-106-01. Under physiological gradients of Na+, K+, and Cl-, depleting cellular ATP by incubation with deoxyglucose and antimycin A (DOG/AA) for 20 min at 37 degrees C reduced BS 86Rb uptake from 6 t...

The skeletal muscle ATP-sensitive K+ (KATP) channel is crucial in preventing fiber damage and contractile dysfunction, possibly by preventing damaging ATP depletion. The objective of this study was to investigate changes in energy metabolism during fatigue in wild-type and inwardly rectifying K+ channel (Kir6.2)-deficient (Kir6.2-/-) flexor digitorum brevis (FDB), a muscle that lacks functional...

Nucleophosmin/B23, a major nucleolar phosphoprotein, is overexpressed in actively proliferating cells. In this study, we demonstrate that B23 exclusively localizes in the nucleolus, whereas ATP depletion results in the redistribution of B23 throughout the whole nucleus and destabilizes B23 via caspase-3 mediated cleavage. Interestingly, ATP binding precedes PI(3,4,5)P(3) binding at lysine 263 a...

BACKGROUND Ischaemia is the most frequent cause of acute renal failure. It has been previously demonstrated that ischaemia is connected with signs of necrosis and apoptosis. Apoptosis is an energy-dependent process. During ischaemia intercellular energy levels decline rapidly. Therefore, the goal of the investigation was to reveal the time dependency of cell death mechanisms during ischaemia le...

BACKGROUND Adenosine, a physiological coronary vasodilator, has been proposed to regulate coronary circulation according to myocardial oxygen demand. In the present study, we investigated the mechanisms of adenosine formation and utilization in isolated rabbit cardiomyocytes and, in particular, the existence and the role of substrate cycling between AMP and adenosine in the regulation of its co...

Purinergic receptors are present in the lateral parabrachial nucleus (LPBN), a pontine structure involved in the control of sodium intake. In the present study, we investigated the effects of α,β-methyleneadenosine 5'-triphosphate (α,β-methylene ATP, selective P2X purinergic agonist) alone or combined with pyridoxalphosphate-6-azophenyl-2',4'-disulfonic acid (PPADS, P2X purinergic antagonist) o...

The ATP content of disks of storage tissue of red beet is reduced under N(2) atmosphere to between 10 and 25% of its value in air. Plasmalemma fluxes of K(+) and Cl(-) are inhibited within 1 minute or less following removal of O(2), and the extent of this inhibition is entirely attributable to the depletion of ATP. The ATP content remains approximately constant or decreases slightly for up to 1...