High efficiency activation of L-type Ca2+ current by 5-HT in human atrial myocytes.
In human atrial myocytes, serotonin rather than sympathetic, stimulation is more frequently associated with atrial fibrillation. So does the arrhythmogenic effect of serotonin result from the mechanism of action of the receptor or the context of its action upon cardiac myocytes? The capacity of agonists to produce cAMP followed the sequence 5-HT < Iso < Forskolin to increase ICaL with 5-HT = Iso = Forskolin. The simultaneous application of threshold concentrations of 5-HT and Iso maximally increased ICaL. We will show that the effect of 5-HT upon human atrial myocytes is an imbalance between low production of cAMP and maximal activation of ICaL.
CNRS UMR 6542, Faculté des Sciences, Université de Tours, France.
Emmanuella
E
Di Scala
Ian
I
Findlay
Stephanie
S
Rose
Michel
M
Aupart
Jorge
J
Argibay
Pierre
P
Cosnay
Veronique
V
Bozon
D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001281:Atrial Fibrillation; D002118:Calcium / Q000378:metabolism; D020746:Calcium Channels, L-Type / Q000378:metabolism*; D002478:Cells, Cultured; D005576:Colforsin / Q000737:chemistry; D000242:Cyclic AMP / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004594:Electrophysiology; D005260:Female; D006325:Heart Atria / Q000187:drug effects* / Q000473:pathology*; D006801:Humans; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008875:Middle Aged; D032342:Muscle Cells / Q000378:metabolism; D009206:Myocardium / Q000473:pathology; D012701:Serotonin / Q000494:pharmacology*; D013997:Time Factors
D000319:Adrenergic beta-Antagonists; D020746:Calcium Channels, L-Type; D005576:Colforsin; D012701:Serotonin; D000242:Cyclic AMP; D007545:Isoproterenol; D002118:Calcium