Modulation of myocardial stiffness by β-adrenergic stimulation - its role in normal and failing heart

Title:

Modulation of myocardial stiffness by β-adrenergic stimulation - its role in normal and failing heart

Creator:

Falcãa-Pires, I., Fontes-Sousa, A. P., Lopes-Conceiçaão, Brás-Silva, C., and Leite-Moreira, A. F.

Identifier:

https://cdk.lib.cas.cz/client/handle/uuid:2b76972c-6d45-47a3-98de-2be3ae9158af
uuid:2b76972c-6d45-47a3-98de-2be3ae9158af

Subject:

Fyziologie člověka a srovnávací fyziologie, srdeční selhání, heart failure, β-adrenergic stimulation, diastolic function, myocardial stiffness, 14, and 612

Type:

article, články, model:article, and TEXT

Format:

print

Description:

The acute effects of β-adrenergic stimulation on myocardial stiffness were evaluated. New-Ze aland white rabbits were treated with saline (control group) or do xorubicin to induce heart failure (HF) (DOXO-HF group). Effects of isoprenaline (10-10-10-5 M), a non-selective β-adrenergic agonist, were tested in papillary muscles from both groups. In the control group, the effects of isoprenaline were also evaluate d in the presence of a damaged endocardial endothelium, atenolol (β1-adrenoceptor antagonist), ICI-118551 (β2-adrenoceptor antagonist), KT-5720 (PKA inhibitor), L-NNA (NO-synthase inhibitor), or indomethacin (cyclooxygenase inhibitor). Passive length-tension relations were constructed before and after adding isoprenaline (10-5 M). In the control group, isoprenaline increased resting muscle length up to 1.017±0.006 L/Lmax. Correction of resting muscle length to its initial value resulted in a 28.5±3.1 % decrease of resting tension, indicating decreased muscle stiffness, as confirmed by the isoprenaline-induced right-downwa rd shift of the passive length- tension relation. These effects were modulated by β1- and β2-adrenoceptors and PKA. In DOXO-HF group, the effect on myocardial stiffness was significantly decreased. We conclude that β -adrenergic stimulation is a relevant mechanism of acute neurohumoral modulation of the diastolic function. Furthermore, this study clarifies the mechanisms by which myocardial stiffness is decreased., I. Falcão-Pires ... [et al.]., and Obsahuje bibliografii a bibliografické odkazy

Language:

English

Rights:

http://creativecommons.org/licenses/by-nc-sa/4.0/
policy:public

Source:

Physiological research | 2011 Volume:60 | Number:4

Harvested from:

CDK

Metadata only:

false