Evidence that [³H]‐α,β‐methylene ATP may label an endothelial‐derived cell line 5′‐nucleotidase with high affinity

Characterization of P2x1 purinoreceptors on rat platelets: effect of clopidogrel

“…[ 3 H]a,b-Me-ATP, a selective ligand of the P2x1 receptors. Only one site was observed, its affinity being in the same order of magnitude compared to that reported for ATP receptors in rat bladder (Bo et al, 1994), rat vas deferens (Bo et al, 1992) and WEC cells (Michel et al, 1995). Moreover, the affinity for various analogues was also in the same range compared to those previously described for P2x1 receptors present in various tissues (Bo et al, 1994;Michel et al, 1995).…”

Distribution of P2X₁ and P2X₃ Receptors in the Rat and Human Urinary Bladder

“…However, this radioligand also binds to 5)-nucleotidase in endothelial cells [27] and therefore results obtained with it cannot be conclusive evidence for the presence or absence of P2X receptors.…”

The binding characteristics of a human bladder recombinant P2X purinoceptor, labelled with [3H]‐αβmeATP, [35S]‐ATPγS or 33[P]‐ATP

“…Secondly, the binding characteristics of [3H]-apmeATP have proved to be complex. Thus, recent evidence suggests that the high affinity [3H]-a(fmeATP binding sites in rat brain and rat vas deferens differ, possibly reflecting the presence of P2X purinoceptor subtypes , while high affinity binding of [3H]-apmeATP to a 5'-nucleotidase has been demonstrated in an endothelial-derived cell line (Michel et al, 1995). In addition, low affinity sites for [3H]-afmeATP are present in all tissues studied and these sites, which presumably represent labelling of membrane bound ATPases and ATPdependent proteins, can complicate the study of the high affinity binding sites for [3H]-ameATP in those tissues possessing an appreciable proportion of the low affinity sites (Michel & Humphrey, 1993).…”