Extracellular ATP as a signaling molecule for epithelial cells

ATP, an extracellular signaling molecule in red blood cells: a messenger for malaria?

Adenosine 5' triphosphate (ATP), discovered in 1929 by Karl Lohmannest, is described as an essential energy source for cells. In the biochemistry of all living organisms, ATP hydrolysis provides the energy required for the chemical reactions of metabolism. It is the precursor of a number of essential enzyme cofactors, such as nicotinamide adenine dinucleotide (NAD + ) and coenzyme A [NAD + , fl...

UTP as an extracellular signaling molecule.

In addition to their central role in many biochemical processes, uridine nucleotides are important extracellular signaling molecules that regulate a broad spectrum of cell functions via activation of P2Y2, P2Y4, and P2Y6 receptors. Cellular release of UTP provides a mechanism for autocrine control of calcium- or protein kinase C-dependent processes.

ATP as a signaling molecule: the exocrine focus.

Why and how do cells release ATP? It is not spilled energy. ATP becomes an extracellular regulator. Various cellular responses are initiated by purinergic receptors and signaling processes and are terminated by breakdown of ATP by ectonucleotidases. In epithelia, ATP regulates salt and water transport; other effects may be longer lasting.

Intercellular Ca2+ signaling in alveolar epithelial cells through gap junctions and by extracellular ATP.

Inter- and extracellular-mediated changes in intracellular Ca2+ concentration ([Ca2+]i) can ensure coordinated tissue function in the lung. Cultured rat alveolar epithelial cells (AECs) have been shown to respond to secretagogues with increases in [Ca2+]i and have been shown to be gap junctionally coupled. However, communication of [Ca2+]i changes in AECs is not well defined. Monolayers of AECs...

Extracellular ATP as a Regulator of Intracellular Signaling in Thyroid FRTL-5 Cells