Right Ventricular Myocardial Stiffness in Experimental Pulmonary Arterial Hypertension : Relative Contribution of Fibrosis and Myofibril Stiffness

© 2016 The Authors..

BACKGROUND: The purpose of this study was to determine the relative contribution of fibrosis-mediated and myofibril-mediated stiffness in rats with mild and severe right ventricular (RV) dysfunction.

METHODS AND RESULTS: By performing pulmonary artery banding of different diameters for 7 weeks, mild RV dysfunction (Ø=0.6 mm) and severe RV dysfunction (Ø=0.5 mm) were induced in rats. The relative contribution of fibrosis- and myofibril-mediated RV stiffness was determined in RV trabecular strips. Total myocardial stiffness was increased in trabeculae from both mild and severe RV dysfunction in comparison to controls. In severe RV dysfunction, increased RV myocardial stiffness was explained by both increased fibrosis-mediated stiffness and increased myofibril-mediated stiffness, whereas in mild RV dysfunction, only myofibril-mediated stiffness was increased in comparison to control. Histological analyses revealed that RV fibrosis gradually increased with severity of RV dysfunction, whereas the ratio of collagen I/III expression was only elevated in severe RV dysfunction. Stiffness measurements in single membrane-permeabilized RV cardiomyocytes demonstrated a gradual increase in RV myofibril stiffness, which was partially restored by protein kinase A in both mild and severe RV dysfunction. Increased expression of compliant titin isoforms was observed only in mild RV dysfunction, whereas titin phosphorylation was reduced in both mild and severe RV dysfunction.

CONCLUSIONS: RV myocardial stiffness is increased in rats with mild and severe RV dysfunction. In mild RV dysfunction, stiffness is mainly determined by increased myofibril stiffness. In severe RV dysfunction, both myofibril- and fibrosis-mediated stiffness contribute to increased RV myocardial stiffness.

Medienart:

E-Artikel

Erscheinungsjahr:

2016

Erschienen:

2016

Enthalten in:

Zur Gesamtaufnahme - volume:9

Enthalten in:

Circulation. Heart failure - 9(2016), 7 vom: 02. Juli

Sprache:

Englisch

Beteiligte Personen:

Rain, Silvia [VerfasserIn]
Andersen, Stine [VerfasserIn]
Najafi, Aref [VerfasserIn]
Gammelgaard Schultz, Jacob [VerfasserIn]
da Silva Gonçalves Bós, Denielli [VerfasserIn]
Handoko, M Louis [VerfasserIn]
Bogaard, Harm-Jan [VerfasserIn]
Vonk-Noordegraaf, Anton [VerfasserIn]
Andersen, Asger [VerfasserIn]
van der Velden, Jolanda [VerfasserIn]
Ottenheijm, Coen A C [VerfasserIn]
de Man, Frances S [VerfasserIn]

Links:

Volltext

Themen:

Collagen
Collagen Type I
Collagen Type III
Comparative Study
Connectin
Cyclic AMP-Dependent Protein Kinases
EC 2.7.11.11
Fibrosis
Heart failure
Hypertension
Journal Article
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
Right ventricular dysfunction
Ttn protein, rat

Anmerkungen:

Date Completed 03.07.2017

Date Revised 13.11.2018

published: Print

Citation Status MEDLINE

doi:

10.1161/CIRCHEARTFAILURE.115.002636

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM261980351