Treherne J M, Stern J S, Flack W J, Young J M
Department of Pharmacology, University of Cambridge, U.K.
Agents Actions Suppl. 1991;33:271-6. doi: 10.1007/978-3-0348-7309-3_17.
The binding of the quaternary radioligand [3H] QMDP to the histamine H1-receptor was inhibited by a series of mono- and di-valent cations. The order of potency was Hg2+ greater than Cd2+ greater than Zn2+ greater than Ni2+ greater than Co2+ greater than Mn2+ greater than Ca2+ greater than Mg2+ greater than Li+ = Na+ greater than K+ greater than Cs+. The binding of [3H] mepyramine, a tertiary amine, was inhibited by the divalent cations to a similar extent as the binding of [3H] QMDP. Li+ also had a similar potency against the two ligands, but Na+ was a much more potent inhibitor of the binding of [3H] QMDP than that of [3H] mepyramine.
季铵放射性配体[3H]QMDP与组胺H1受体的结合受到一系列单价和二价阳离子的抑制。其效力顺序为Hg2+＞Cd2+＞Zn2+＞Ni2+＞Co2+＞Mn2+＞Ca2+＞Mg2+＞Li+ = Na+＞K+＞Cs+。叔胺[3H]美吡拉敏的结合受到二价阳离子的抑制，其程度与[3H]QMDP的结合相似。Li+对这两种配体也具有相似的效力，但Na+对[3H]QMDP结合的抑制作用比对[3H]美吡拉敏的抑制作用要强得多。
