Key result
[3H]WEB 2086 binds to identical sites as [3H]PAF in human platelets with a Kd of 6.1 nM, making it a suitable antagonist radioligand for labelling PAF receptors.
[3H]WEB 2086 is a suitable antagonist radioligand for labelling PAF receptors in human platelets.
Offers new tool for PAF receptor studies in platelets; leaves open clinical translation.
Two new antagonists of platelet-activating factor (PAF), the pyrrolothiazole derivative 52770 RP and the triazolodiazepine WEB 2086, have been studied as radioligands in intact human platelets. [3H]52770 RP and [3H]WEB 2086 bound specifically to high-affinity sites with dissociation constants (Kd) of 14.8 and 6.1 nM, respectively. The maximal number of sites for [3H]52770 RP binding was approx. 15-fold higher than for [3H]PAF and [3H]WEB 2086. In addition, C16-PAF, lyso-PAF, WEB 2086 and 52770 RP had Ki values which were nearly identical for both [3H]PAF and [3H]WEB 2086, whereas only 52770 RP competed for [3H]52770 RP-binding sites. These results demonstrate that in human platelets the sites of [3H]WEB 2086 binding are identical to [3H]PAF-binding sites, whereas those of [3H]52770 RP are not. [3H]WEB 2086 appears, therefore, to be a suitable antagonist radioligand for labelling PAF receptors.
No takes yet. Share an insight, caveat, or question.
Ukena et al. (1988) studied Intact human platelets. [3H]52770 RP and [3H]WEB 2086 vs. [3H]PAF was evaluated on Radioligand binding to high-affinity sites (Kd and Ki values). [3H]WEB 2086 binds to identical sites as [3H]PAF in human platelets with a Kd of 6.1 nM, making it a suitable antagonist radioligand for labelling PAF receptors.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: