Evidence map›Paper›PMID 1380380›Full record

ArticleBritish journal of pharmacology1992

Kinetic modulation of guinea-pig cardiac L-type calcium channels by fendiline and reversal of the effects of Bay K 8644.

W Schreibmayer, O Tripathi, H A Tritthart

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Article in British journal of pharmacology, 1992. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers.

0numbers the graph read from it
0cells of the map it votes in
3citing papers in PubMed
0.4field-weighted citation impact, top 42% of its field
1 · What the graph read from it

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.

2 · The registry

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.

3 · Its place in the literature

Who cites it

3 citing papers in PubMed, 14 citations in OpenAlex.

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4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

3 authors at 2 institutions in 2 countries.

W SchreibmayerInstitute of Medical Physics and Biophysics, Karl-Franzens University, Graz, Austria.
O Tripathi
H A Tritthart
University of Graz · ATCentral Drug Research Institute · IN

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

1. The modulation of L-type calcium channel current (ICa) by fendiline, a diphenylalkylamine type of calcium channel blocker was investigated on guinea-pig ventricular myocytes by use of the whole-cell patch-clamp technique. 2. Fendiline-induced block of ICa is accompanied by modulation of the channel kinetics in a complex manner. The time course of ICa inactivation is significantly faster and the channel availability (f infinity) curve is shifted considerably to more negative potentials by fendiline. These findings can be interpreted qualitatively in terms of a modulated receptor. 3. When the 1,4-dihydropyridine agonist (4R, 4S)-Bay K 8644 was added in presence of 30 microM fendiline a further reduction of ICa instead of the expected stimulatory effect was observed. 4. A similar 'paradoxical' inhibition of ICa was produced by the pure agonist enantiomer (4S)-Bay K 8644. Thus this novel effect of Bay K 8644 cannot be attributed to changes in affinity of the 1,4-dihydropyridine receptor site for (4R)-Bay K 8644 during fendiline action. 5. The IC50 for fendiline was reduced to 3.0 +/- 0.1 microM (control value: 17.0 +/- 2.4 microM) and the Hill slope in its presence was increased to 1.90 +/- 0.1 (control value: 1.39 +/- 0.23) by 1 microM (4R, 4S)-Bay K 8644. 6. (4R,4S)-Bay K 8644 caused the expected stimulation of ICa in the presence of verapamil, diltiazem and nifedipine, overcoming the inhibitory effect of these calcium channel blockers. 7. The 'paradoxical' inhibitory effect of the agonist Bay K 8644 can be explained in terms of an allosteric interaction between fendiline and the dihydropyridine agonist.

Indexed as

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl esterAnimalsCalcium Channel BlockersCalcium ChannelsCells, CulturedDrug InteractionsFendilineGuinea PigsHeartMyocardium3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethyl-5-nitro-4-(2-(trifluoromethyl)phenyl)-, Methyl esterCalcium Channel BlockersCalcium ChannelsFendiline

Identifiers

PMID1380380
PMCPMC1907436
OpenAlexW2016642319

What OpenQuestion holds

Textmetadata
Read underepoch 390

Registered trials

None linked

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.