Functional, endogenously expressed 5-hydroxytryptamine 5-ht7 receptors in human vascular smooth muscle cells.
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 microM) and clozapine (1 microM), but not the 5-HT4-receptor antagonist, SDZ 205-557 (10 microM) 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.
Schoeffter
P
P
Preclinical Research, 386/744, Sandoz Pharma Ltd, Basel, Switzerland.
Ullmer
C
C
Bobirnac
I
I
Gabbiani
G
G
Lübbert
H
H
D002478:Cells, Cultured; D000242:Cyclic AMP / Q000096:biosynthesis*; D004587:Electrophoresis, Agar Gel; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism; D011985:Receptors, Serotonin / Q000187:drug effects / Q000378:metabolism*; D012701:Serotonin / Q000031:analogs & derivatives / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology
D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; D012701:Serotonin; C047087:5-carboxamidotryptamine; D000242:Cyclic AMP