Objective: Under physiologic conditions in animals and pathologic conditions in humans, purinergic mechanisms contribute significantly to detrusor contractions. Although the activation of P2X1 receptors (P2X1R) accounts for the largest portion of bladder smooth muscle (BSM) responses to ATP, previous reports have shown that P2X1R antagonists do not completely abolish the purinergic component of...

P2X4 receptors are adenosine triphosphate (ATP)-gated cation channels present on the plasma membrane (PM) and also within intracellular compartments such as vesicles, vacuoles, lamellar bodies (LBs), and lysosomes. P2X4 receptors in microglia are up-regulated in epilepsy and in neuropathic pain; that is to say, their total and/or PM expression levels increase. However, the mechanisms underlying...

Interleukin‑1β (IL‑1β) has a significant role in osteoarthritis (OA). The purinergic receptor, P2X4, has previously been implicated in IL‑1β secretion. The NLRP1 inflammasome mediates the production of IL‑1β in inflammatory disorders. However, it is unknown whether P2X4 modulates NLRP1‑mediated IL‑1β release. In the present study, the correlation between the P2X4 receptor and NLRP1 was investig...

The P2X4 receptor is a newly identified receptor expressed in the heart cell. Its function was elucidated with cardiac transgenic (TG) expression of the receptor by using the myocardium-specific a-myosin heavy chain promoter. The presence of the transgene was determined by polymerase chain reaction by using primers specific to the receptor and the vector linker region, by Southern blotting of t...

The essence of neuronal function is to generate outputs in response to synaptic potentials. Synaptic integration at postsynaptic sites determines neuronal outputs in the CNS. Using immunohistochemical and electrophysiological approaches, we first reveal that steroidogenic factor 1 (SF-1) green fluorescent protein (GFP)-positive neurons in the ventromedial nucleus of the hypothalamus express P2X...

P2X4 and P2X7 are members of the P2X receptor family, comprising seven isoforms (P2X1-P2X7) that form homo- and heterotrimeric non-specific cation channels gated by extracellular ATP. P2X4 and P2X7 are widely coexpressed, particularly in secretory epithelial cells and immune and inflammatory cells, and regulate inflammation and nociception. Although functional heteromerization has been establis...

ATP-gated purinergic P2X4 receptors (P2X4Rs) are expressed in the central nervous system and are sensitive to ethanol at intoxicating concentrations. P2XRs are trimeric; each subunit consists of two transmembrane (TM) alpha-helical segments, a large extracellular domain, and intracellular amino and carboxyl terminals. Recent work indicates that position 336 (Met336) in the TM2 segment is critic...

P2X receptors (P2XRs) are ion channels gated by synaptically released ATP. The P2X4 is the most abundant P2XR subtype expressed in the central nervous system and to date is the most ethanol-sensitive. In addition, genomic findings suggest that P2X4Rs may play a role in alcohol intake/preference. However, little is known regarding how ethanol causes the inhibition of ATP-gated currents in P2X4Rs...

P2X4 receptors (P2X4Rs) are ligand-gated ion channels capable of conducting cations such as Na(+). Endogenous cardiac P2X4R can mediate ATP-activated current in adult murine cardiomyocytes. In the present study, we tested the hypothesis that cardiac P2X receptors can induce Na(+) entry and modulate Na(+) handling. We further determined whether P2X receptor-induced stimulation of the Na(+)/Ca(2+...

The binding of ATP to trimeric P2X receptors (P2XR) causes an enlargement of the receptor extracellular vestibule, leading to opening of the cation-selective transmembrane pore, but specific roles of vestibule amino acid residues in receptor activation have not been evaluated systematically. In this study, alanine or cysteine scanning mutagenesis of V47-V61 and F324-N338 sequences of rat P2X4R ...