Evidence for an effect of receptor density on ligand occupancy and agonist EC₅₀.

ABSTRACT: Drug-receptor interaction theory predicts that proportional receptor occupancy is a function of ligand concentration as defined by a ligand-receptor affinity constant, and is independent of receptor density. However, we previously observed that the EC₅₀ of 5-HT reduced as the density of 5-HT₃ receptors increased, suggesting an effect of receptor density on occupancy. The current study was designed to maximise variability in experimentally observed currents and confirm this apparent contradiction prospectively. Xenopus oocytes were injected with RNA encoding 5-HT₃A receptors under conditions designed to achieve varying receptor expression levels and 5-HT-evoked currents measured using two electrode voltage clamp. Results from 99 oocytes showed that as the ma

SUBMITTER: Jarvis GE 

PROVIDER: S-EPMC6910986 | biostudies-literature | 2019 Dec

REPOSITORIES: biostudies-literature