ArticleNaunyn-Schmiedeberg's archives of pharmacology2013
Inhibition of cardiac Kv1.5 and Kv4.3 potassium channels by the class Ia anti-arrhythmic ajmaline: mode of action.
Article in Naunyn-Schmiedeberg's archives of pharmacology, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 11 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
11 citing papers in PubMed, 22 citations in OpenAlex.
- Screening an In-House Isoquinoline Alkaloids Library for New Blockers of Voltage-Gated NaMolecules (Basel, Switzerland) · 2022Article
- Calcium/calmodulin-dependent protein kinase II associates with the KFrontiers in neuroanatomy · 2022Article
- The Mechanism of Ajmaline and Thus Brugada Syndrome: Not Only the Sodium Channel!Frontiers in cardiovascular medicine · 2021Review
- Challenges Faced with Small Molecular Modulators of Potassium Current Channel Isoform Kv1.5.Biomolecules · 2019Review
- Effects of ajmaline on contraction patterns of isolated rat gastric antrum and portal vein smooth muscle strips and on neurogenic relaxations of gastric fundus.Pflugers Archiv : European journal of physiology · 2019Article
- Cardiovascular pharmacology of KNaunyn-Schmiedeberg's archives of pharmacology · 2018Article
- Ajmaline blocks IStem cell research · 2017Article
- Sarpagine and Related Alkaloids.The Alkaloids. Chemistry and biology · 2016Review
- Effects of neferine on Kv4.3 channels expressed in HEK293 cells and ex vivo electrophysiology of rabbit hearts.Acta pharmacologica Sinica · 2015Article
- Anesthetic drug midazolam inhibits cardiac human ether-à-go-go-related gene channels: mode of action.Drug design, development and therapy · 2015Article
- Inhibition of cardiac Kv1.5 potassium current by the anesthetic midazolam: mode of action.Drug design, development and therapy · 2014Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 2 institutions in 1 country.
Funding
No grant is acknowledged in the PubMed record.
Abstract
Ajmaline is a class Ia anti-arrhythmic compound that is widely used for the diagnosis of Brugada syndrome and the acute treatment of atrial or ventricular tachycardia. For ajmaline, inhibitory effects on a variety of cardiac K(+) channels have been observed, including cardiac Kv1 and Kv4 channels. However, the exact pharmacological properties of channel blockade have not yet been addressed adequately. Using two different expression systems, we analysed pharmacological effects of ajmaline on the potassium channels Kv1.5 and Kv4.3 underlying cardiac I Kur and I to current, respectively. When expressed in a mammalian cell line, we find that ajmaline inhibits Kv1.5 and Kv4.3 with an IC50 of 1.70 and 2.66 μM, respectively. Pharmacological properties were further analysed using the Xenopus expression system. We find that ajmaline is an open channel inhibitor of cardiac Kv1.5 and Kv4.3 channels. Whereas ajmaline results in a mild leftward shift of Kv1.5 activation curve, no significant effect on Kv4.3 channel activation could be observed. Ajmaline did not significantly affect channel inactivation kinetics. Onset of block was fast. For Kv4.3 channels, no significant effect on recovery from inactivation or channel deactivation could be observed. Furthermore, there was no use-dependence of block. Taken together, we show that ajmaline inhibits cardiac Kv1.5 and Kv4.3 channels at therapeutic concentrations. These data add to the current understanding of the electrophysiological basis of anti-arrhythmic action of ajmaline.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.