5‐HT4 Receptors: Cloning and Expression of New Splice Variants

Abstract
On the basis of differences in the potencies and intrinsic activity of 5‐HT4 receptor agonists in different biological models it has been suggested that there is heterogeneity among 5‐HT4 receptors. Here, we report the molecular cloning of several 5‐HT4 receptor splice variants in mouse, rat, and human brain. Our data suggest that the differences in efficacy of 5‐HT4 ligands on 5‐HT4 receptor‐mediated responses in several tissues is due to differences in coupling efficiency rather than to the presence of different 5‐HT4 receptor isoforms.