Selectivity and activity of adenine dinucleotides at recombinant P2x<sub>2</sub> and P2Y<sub>1</sub> purinoceptors

Pintor, Jesús; King, Brian F.; Miras-Portugal, Marı́a Teresa; Burnstock, Geoffrey

doi:10.1111/j.1476-5381.1996.tb15771.x

Cited by 66 publications

(61 citation statements)

References 48 publications

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“…Diadenosine polyphosphates were also found to be potent and full agonists in cells overexpressing the human P2Y 2 receptor (Lazarowski et al, 1995). Also, the avian P2Y 1 receptor is sensitive to Ap 4 A, presenting EC 50 values in the nanomolar range (Pintor et al, 1996). Important differences have been observed on native P2Y 1 receptors, where diadenosine tetraphosphate behaved as an antagonist in clear contrast to the behavior of this dinucleotide in cloned P2Y 1 receptors (Vigne et al, 2000).…”

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confidence: 92%

Effects of Diadenosine Polyphosphates on Tear Secretion in New Zealand White Rabbits

Pintor¹,

Peral²,

Hoyle³

et al. 2002

J Pharmacol Exp Ther

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Extracellular diadenosine polyphosphates play important signaling functions in a number of physiological responses. Here we show that diadenosine polyphosphates are normal constituents of tear fluid and are potent stimulators of tear secretion through their interaction with P2Y receptors. Diadenosine tetraphosphate (Ap 4 A) and Ap 5 A were found in rabbit tears under basal conditions at concentrations of 2.92 and 0.58 M, respectively. Single applications of UTP, ATP, and Ap 4 A increased tear secretion to 160 Ϯ 8% (n ϭ 16) (P Ͻ 0.001), 131 Ϯ 6% (P Ͻ 0.05), and 162 Ϯ 11% (P Ͻ 0.05) of placebo values, respectively. Ap 4 A, Ap 5 A, and Ap 6 A, but not Ap 2 A and Ap 3 A, were able to stimulate tear secretion in a dose-dependent manner. Concentration-response studies produced pD 2 values of 5.56 Ϯ 0.03, 5.75 Ϯ 0.12, and 5.50 Ϯ 0.09 for Ap 4 A, Ap 5 A, and Ap 6 A, respectively, with Ap 4 A showing the greatest efficacy. Diadenosine polyphosphates also stimulated P2Y 1 and P2Y 2 receptors expressed in 1321N1 cells with no apparent effect on the other P2Y receptors tested. Nonselective P2 antagonists did not modify the tear secretion induced by UTP or Ap 4 A in rabbit eyes in vivo or in cloned receptors, except for a weak but significant reduction in stimulated tear secretion by reactive blue 2. These results suggest that diadenosine polyphosphates stimulate tear secretion via a P2Y receptormediated mechanism. Comparing the effects of diadenosine polyphosphates applied to the rabbit eye and to cloned P2Y receptors, it appears that the P2Y 2 receptor subtype is responsible for the prosecretory effects of these compounds.

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confidence: 92%

Effects of Diadenosine Polyphosphates on Tear Secretion in New Zealand White Rabbits

Pintor¹,

Peral²,

Hoyle³

et al. 2002

J Pharmacol Exp Ther

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“…For example, receptors that are activated by Ap 4 A but not other diadenosine nucleosides have been described in recombinant rat P2X 2 receptors, expressed in Xenopus laevis oocytes. This receptor is activated by Ap 4 A, but not Ap 2 A, Ap 3 A, or Ap 5 A (Pintor et al, 1996;Wildman et al, 1999). The MM39 cell line, derived from human tracheal gland epithelium, possesses a native receptor that is also sensitive to Ap 4 A but not Ap 3 A or Ap 5 A (Saleh et al, 1999).…”

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confidence: 99%

“…In particular diadenosine triphosphate (Ap 3 A), diadenosine tetraphosphate (Ap 4 A), diadenosine pentaphosphate (Ap 5 A), Ap 6 A, and Ap 7 A are found in exocytotic vesicles, such as those in nerve terminals, adrenal medullary chromaffin cells, and platelets (Flodgaard and Klenow, 1982;Rodriguez del Castillo et al, 1988;Pintor et al, 1992aPintor et al, ,b,c, 1997Schlü tter et al, 1994;Pintor and Miras-Portugal, 1995;Jankowski et al, 1999), and diadenosine pyrophosphate (Ap 2 A) has recently been identified in secretory granules of cardiac myocytes (Luo et al, 1999). They have diverse actions in peripheral and central tissues because of their roles as extracellular signal molecules (Hoyle, 1990;Pintor et al, 1996;Kisselev et al, 1998;Hoyle et al, 2001).…”

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confidence: 99%

Presence of Diadenosine Polyphosphates in the Aqueous Humor: Their Effect on Intraocular Pressure

Pintor¹,

Peral²,

Peláez³

et al. 2003

J Pharmacol Exp Ther

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Adenine dinucleotides are present in many biological systems and may serve as physiological regulators of processes such as neurotransmitter release, vascular tone or corneal hydration. The presence of diadenosine polyphosphates was investigated in New Zealand White rabbit aqueous humor. , pyridoxal phosphate-6-azophenyl-2Ј,4Ј-disulfonic acid (PPADS), suramin, and reactive blue 2 (RB-2) alone had no effect on intraocular pressure but attenuated responses to diadenosine polyphosphates by approximately 80%. It is concluded that Ap 2 A, Ap 3 A, and Ap 5 A increase intraocular pressure, and Ap 4 A decreases intraocular pressure via mechanisms that involve P2 receptors, and that Ap 4 A present in aqueous humor may serve to regulate intraocular pressure. Furthermore, we suggest that topical application of Ap 4 A to the cornea has therapeutic potential for lowering intraocular pressure, a major risk factor for glaucoma.

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“…We performed similar experiments with PC12 cells, which possess P2X2 and P2Y2 receptors but not the P2X7 receptor. In PC12 cells, 100 mM UTP induces [Ca 2+ ]i elevation via the P2Y 2 receptor (18,19) and subsequent application of 100 mM ATP in the presence of UTP induces [Ca 2+ ]i elevation via the P2X2 receptor (14,20 Kaiho et al (3) reported that anions inhibit ATP-binding to the receptor and that the order of inhibition correlates with the hydration energy of each anion. ATP 4-has been reported to be the effective agonist form of ATP for the P2X7 receptor (21).…”

Section: Replacing External CLmentioning

confidence: 99%

Effects of Anions on ATP-Induced [Ca2+]i Increase in NG108-15 Cells

Watano

Matsuoka

Ogawa

et al. 2002

Japanese Journal of Pharmacology

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ABSTRACT-We investigated the effects of anions on different P2 receptors by measuring ATP-induced increase in intracellular Ca2+ concentration ([Ca 2+ ]i) in fura-2-loaded NG108-15 and PC12 cells. In NG108-15 cells, ATP at 100 mM and 1 mM induced a transient and a sustained [Ca 2+ ]i increase, respectively. The former, but not the latter, was inhibited by U-73122, indicating that the former was via the P2Y2 receptor and the latter via the P2X7 receptor. When external Cl -was replaced by other anions, the [Ca 2+ ]i increase mediated by the P2Y2 receptor was not changed, but that mediated by the P2X7 receptor varied in the order of aspartate]i increases mediated by the P2Y2 and P2X2 receptors were not affected by various anions. These results suggest that modulation by anions is unique to the P2X7 receptor and does not occur in P2Y2 and P2X2 receptors. This may be because the mechanism of ATP binding to the P2X7 receptor may be different than that to other P2 receptors.Keywords: ATP, P2X7 receptor, Anion, NG108-15 cell, PC12 cell NG108-15 cells are hybrids of mouse neuroblastoma N18TG-2 and rat glioma C6Bu-1 cells. NG108-15 cells possess two types of functional P2 receptors, P2X7 and P2Y 2 (1 -7). P2X 7 receptors are nonselective cation channels, which cause influx of extracellular Ca 2+ (2 -4, 8, 9). P2Y2 receptors are G-protein coupled receptors that are involved in the production of inositol-1,4,5-trisphosphate (IP3) via activation of phospolipase C (PLC) and induce Ca 2+ release from IP3-sensitive intracellular Ca 2+ stores (1). Using the whole-cell voltage clamp, Kaiho et al. (3) found that the current through the P2X7 receptor was enhanced in NG108-15 cells when extracellular ] i ) via P2X 7 and P2Y 2 receptors (1 -7) in NG108-15 cells. Ca 2+ signals by these two receptors can be distinguished from each other because the P2Y2 receptor is activated by a low concentration of ATP (100 m M), while the P2X7 receptor requires a higher concentration of ATP (>0.3 mM) for activation. In the present study, using fura-2-loaded cells, we investigated whether anions modulate Ca 2+ permeability through the P2X 7 receptors by monitoring ATP-induced [Ca 2+ ]i elevation. We also investigated whether the effects of anions were unique to the P2X7 receptor by comparing them with the effects on P2Y 2 and P2X2 receptors in NG108-15 and PC12 cells. MATERIALS AND METHODS Cell cultureNG108-15 cells were grown in high-glucose Dulbecco's modified Eagle's medium supplemented with 7% (v /v) fetal bovine serum, 100 mM hypoxanthine, 0.4 m M aminopterin and 16 mM thymidine (7). Cells were maintained in 100-mm tissue culture dishes and incubated at 37°C in a humidified atmosphere of 10% CO2 and 90% air.PC12 cells were grown in Dulbecco's modified Eagle's medium supplemented with 5% (v /v) fetal bovine serum, 5% (v /v) heat-inactivated horse serum, and 2 mM Lglutamine (10). Cells were maintained in 100-mm tissue culture dishes and incubated at 37°C in a humidified atmosphere of 5% CO2 and 95% air. Solutions and drugsThe standard Cl ...

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Selectivity and activity of adenine dinucleotides at recombinant P2x₂ and P2Y₁ purinoceptors

Cited by 66 publications

References 48 publications

Effects of Diadenosine Polyphosphates on Tear Secretion in New Zealand White Rabbits

Effects of Diadenosine Polyphosphates on Tear Secretion in New Zealand White Rabbits

Presence of Diadenosine Polyphosphates in the Aqueous Humor: Their Effect on Intraocular Pressure

Effects of Anions on ATP-Induced [Ca2+]i Increase in NG108-15 Cells

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Selectivity and activity of adenine dinucleotides at recombinant P2x2 and P2Y1 purinoceptors

Cited by 66 publications

References 48 publications

Effects of Diadenosine Polyphosphates on Tear Secretion in New Zealand White Rabbits

Effects of Diadenosine Polyphosphates on Tear Secretion in New Zealand White Rabbits

Presence of Diadenosine Polyphosphates in the Aqueous Humor: Their Effect on Intraocular Pressure

Effects of Anions on ATP-Induced [Ca2+]i Increase in NG108-15 Cells

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Selectivity and activity of adenine dinucleotides at recombinant P2x₂ and P2Y₁ purinoceptors