Functional, endogenously expressed 5‐hydroxytryptamine 5‐ht7 receptors in human vascular smooth muscle cells

Publisher Website
Google Scholar
Abstract
Human uterine artery smooth muscle cells in culture were shown to express constitutively both 5‐ht7 receptor mRNA and 5‐ht7‐like receptors functionally linked to cyclic AMP formation. 5‐Carboxamidotryptamine (5‐CT) and 5‐HT enhanced forskolin‐stimulated cyclic AMP accumulation in these cells, with pEC50 values of 7.12 and 6.25, sumatriptan being very weakly active. Both methiothepin (0.1 μm) and clozapine (1 μm), but not the 5‐HT4‐receptor antagonist, SDZ 205–557 (10 μm) antagonized the effects of 5‐CT. In reverse transcriptase‐polymerase chain reaction analysis, the mRNA for 5‐ht7, but not for 5‐HT4 or 5‐ht6 receptors was found to be strongly expressed in the same cells. These findings represent a further step toward the recognition of 5‐ht7 receptors as real, functional receptors.