Evidence map›Paper›PMID 14742733›Full record

ArticleThe Journal of physiology2004

The effect of tropomyosin on force and elementary steps of the cross-bridge cycle in reconstituted bovine myocardium.

Hideaki Fujita, Xiaoying Lu, Madoka Suzuki, Shin'ichi Ishiwata, Masataka Kawai

Open access · bronzeAbstract read
In one paragraph

Article in The Journal of physiology, 2004. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 17 papers.

0numbers the graph read from it
0cells of the map it votes in
17citing papers in PubMed
0.8field-weighted citation impact, top 27% 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

17 citing papers in PubMed, 31 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

5 authors at 2 institutions in 2 countries.

Hideaki FujitaDepartment of Anatomy and Cell Biology, College of Medicine, The University of Iowa, Iowa City, IA 52242, USA.
Xiaoying Lu
Madoka Suzuki
Shin'ichi Ishiwata
Masataka Kawai
University of Iowa · USWaseda University · JP

Funding

Role of actin domains in force generation in myocardiumR01HL070041 · NHLBI · UNIVERSITY OF IOWA · PI KAWAI, MASATAKA · 2002 to 2011
$2.5M
NHLBI NIH HHS HL70041NHLBI NIH HHS R01 HL070041
6 · The paper itself

Abstract

The role of tropomyosin (Tm) in the elementary steps of the cross-bridge cycle in bovine myocardium was investigated. The thin filament was selectively removed using gelsolin (thin filament severing protein), and the actin filament was reconstituted from G-actin. Tm was further reconstituted without troponin (Tn), and the kinetic constants of the elementary steps of the cross-bridge cycle were deduced using sinusoidal analysis at pCa </= 4.66, pH 7.00, and 25 degrees C. The association constant of MgATP to cross-bridges (K(1)) after reconstitution of Tm was 20.7 +/- 2.3 mm(-1), which was about 2 x the control (untreated) myocardium (9.1 +/- 1.3 mm(-1)). Following reconstitution of Tm, the equilibrium constant of the cross-bridge detachment step (K(2)), the phosphate (P(i)) association constant (K(5)) and the equilibrium constant of the force-generation step (K(4)), which significantly changed in the actin filament-reconstituted myocardium, recovered to those of the control myocardium. Active tension after reconstitution of Tm was 0.69 x the control myocardium, a value between the control (1.00 x) and the actin filament-reconstituted myocardium (0.59 x). Tm-reconstituted myocardium was further reconstituted with Tn, and the effect of MgATP on the rate constants (K(1), K(2)) was studied. Following reconstitution with Tn, the myocardium regained the Ca(2+)-sensitivity and the active tension became 0.83 x the control myocardium. In addition, K(1) recovered to the value of the control myocardium with Tn reconstitution. These results indicate that both Tm and Tn enhance the force generated by each cross-bridge, and that Tm is primarily responsible for the change in the kinetic constants of the elementary steps of the cross-bridge cycle.

Indexed as

Actin CytoskeletonAdenosine TriphosphateAnimalsCattleHeartIn Vitro TechniquesMyocardial ContractionTropomyosinTroponinAdenosine TriphosphateTropomyosinTroponin

Identifiers

PMID14742733
PMCPMC1664932
OpenAlexW1578606251

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.