Characterization of myocardial extracellular ATP receptors by photoaffinity labelling and functional assays

Giannattasio, Bartolo; Powers, Kit; Scarpa, Antonio

doi:10.1016/0014-5793(92)81305-6

Cited by 7 publications

(2 citation statements)

References 10 publications

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“…ATp is the consequence of an internal acidosis, with ,$-methylene-ATP, P,y-methylene-ATP and ,y-imido-ATP being less potent but as efficient as ATP in inducing acidosis (Puc6at et al, 1991b (Giannattasio et al, 1992). Second, both types of effects are mediated by a common P2y-purinoceptor, but the effector involved in IATp is blocked by the non-hydrolysable analogues.…”

Section: Discussionmentioning

confidence: 99%

Pharmacological profile of the ATP‐mediated increase in L‐type calcium current amplitude and activation of a non‐specific cationic current in rat ventricular cells

Scamps

Vassort

1994

British J Pharmacology

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1 The pharmacological profile of the ATP-induced increase in Ica amplitude and of ATP activation of a non-specific cationic current, IATp, was investigated in rat ventricular cells.2 The EC50 values for Ic, increase and IATp activation were 0.36 pM and 0.76 FtM respectively. Suramin (1O tM) and cibacron blue (1 gM) competitively antagonized both effects of ATP. 3 The rank order of efficacy and potency of ATP analogues in increasing IC, amplitude was 2-methylthio-ATP ftATPtATPyS. The derivatives j-methylene-ATP, P,'y-methylene-ATP and 0,yimido-ATP up to 500 LM had no significant effects. 4 The rank order of efficacy of ATP analogues in activating a non-specific cationic current, IATp, was 2-methylthio-ATP >ATP >>ATPyS. The rank order of potency was 2-methylthio-ATPtATP. The EC" of ATPyS could not be determined owing to its very low efficacy. 5 The ATP analogues ,-methylene-ATP, ,'y-methylene-ATP and P,y-imido-ATP at 500 AM did not activate IATP but acted as antagonists of activation of IATP by ATP.6 The results suggest that the increase in Ic. amplitude induced by external ATP is due to activation of P2y-purinoceptors. 7 The mechanism of IATP activation remains to be determined before the receptor subtype involved can be deduced.

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Section: Discussionmentioning

confidence: 99%

Pharmacological profile of the ATP‐mediated increase in L‐type calcium current amplitude and activation of a non‐specific cationic current in rat ventricular cells

Scamps

Vassort

1994

British J Pharmacology

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“…value for the ATP-mediated increase in Ca# + current is 0.36 µM, with a rank order of potency of 2-MeSATP l ATP l adenosine 5h-[γ-thio] triphosphate [132]. Under photoaffinity labelling conditions, radioactive 8-azido-ATP specifically labelled a species of 45-48 kDa on an SDS\polyacrylamide gel, and UV-photolysed 8-azido-ATP irreversibly and specifically inhibited the ATPinduced cytosolic Ca# + currents [133].…”

Section: Figure 3 Atp-mediated Signal Transduction Pathways In Cardiamentioning

confidence: 99%

P2 receptor subtypes in the cardiovascular system

Kunapuli

Daniel

1998

Biochemical Journal

229

192

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Extracellular nucleotides have been implicated in a number of physiological functions. Nucleotides act on cell-surface receptors known as P2 receptors, of which several subtypes have been cloned. Both ATP and ADP are stored in platelets and are released upon platelet activation. Furthermore, nucleotides are also released from damaged or broken cells. Thus during vascular injury nucleotides play an important role in haemostasis through activation of platelets, modulation of vascular tone, recruitment of neutrophils and monocytes to the site of injury, and facilitation of adhesion of leucocytes to the endothelium. Nucleotides also moderate these functions by generating nitric oxide and prostaglandin I2 through activation of endothelial cells, and by activating different receptor subtypes on vascular smooth muscle cells. In the heart, P2 receptors regulate contractility through modulation of L-type Ca2+ channels, although the molecular mechanisms involved are still under investigation. Classical pharmacological studies have identified several P2 receptor subtypes in the cardiovascular system. Molecular pharmacological studies have clarified the nature of some of these receptors, but have complicated the picture with others. In platelets, the classical P2T receptor has now been resolved into three P2 receptor subtypes: the P2Y1, P2X1 and P2TAC receptors (the last of these, which is coupled to the inhibition of adenylate cyclase, is yet to be cloned). In peripheral blood leucocytes, endothelial cells, vascular smooth muscle cells and cardiomyocytes, the effects of classical P2X, P2Y and P2U receptors have been found to be mediated by more than one P2 receptor subtype. However, the exact functions of these multiple receptor subtypes remain to be understood, as P2-receptor-selective agonists and antagonists are still under development.

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Purification and recognition of recombinant mouse P2X1 receptors expressed in a baculovirus system

et al. 2000

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Characterization of myocardial extracellular ATP receptors by photoaffinity labelling and functional assays

Cited by 7 publications

References 10 publications

Pharmacological profile of the ATP‐mediated increase in L‐type calcium current amplitude and activation of a non‐specific cationic current in rat ventricular cells

Pharmacological profile of the ATP‐mediated increase in L‐type calcium current amplitude and activation of a non‐specific cationic current in rat ventricular cells

P2 receptor subtypes in the cardiovascular system

Purification and recognition of recombinant mouse P2X1 receptors expressed in a baculovirus system

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