Alterations of the β-adrenergic signalling, structural remodelling, and electrical failure of T-tubules are hallmarks of heart failure (HF). Here, we assess the effect of β-adrenoceptor activation on local Ca2+ release in electrically coupled and uncoupled T-tubules in ventricular myocytes from HF rats. We employ an ultrafast random access multi-photon (RAMP) microscope to simultaneously record action potentials and Ca2+ transients from multiple T-tubules in ventricular cardiomyocytes from a HF rat model of coronary ligation compared to sham-operated rats as a control. We confirmed that β-adrenergic stimulation increases the frequency of Ca2+ sparks, reduces Ca2+ transient variability, and hastens the decay of Ca2+ transients: all these effects are similarly exerted by β-adrenergic stimulation in control and HF cardiomyocytes. Conversely, β-adrenergic stimulation in HF cells accelerates a Ca2+ rise exclusively in the proximity of T-tubules that regularly conduct the action potential. The delayed Ca2+ rise found at T-tubules that fail to conduct the action potential is instead not affected by β-adrenergic signalling. Taken together, these findings indicate that HF cells globally respond to β-adrenergic stimulation, except at T-tubules that fail to conduct action potentials, where the blunted effect of the β-adrenergic signalling may be directly caused by the lack of electrical activity.
T-Tubular Electrical Defects Contribute to Blunted β-Adrenergic Response in Heart Failure / Crocini, C; Coppini, R; Ferrantini, C; Yan, P; Loew, Lm; Poggesi, C; Cerbai, E; Pavone, Fs; Sacconi, L.. - In: INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES. - ISSN 1422-0067. - ELETTRONICO. - 17:(2016), pp. 0-0. [10.3390/ijms17091471]
T-Tubular Electrical Defects Contribute to Blunted β-Adrenergic Response in Heart Failure.
CROCINI, CLAUDIA;COPPINI, RAFFAELE;FERRANTINI, CECILIA;POGGESI, CORRADO;CERBAI, ELISABETTA;PAVONE, FRANCESCO SAVERIO;SACCONI, LEONARDO
2016
Abstract
Alterations of the β-adrenergic signalling, structural remodelling, and electrical failure of T-tubules are hallmarks of heart failure (HF). Here, we assess the effect of β-adrenoceptor activation on local Ca2+ release in electrically coupled and uncoupled T-tubules in ventricular myocytes from HF rats. We employ an ultrafast random access multi-photon (RAMP) microscope to simultaneously record action potentials and Ca2+ transients from multiple T-tubules in ventricular cardiomyocytes from a HF rat model of coronary ligation compared to sham-operated rats as a control. We confirmed that β-adrenergic stimulation increases the frequency of Ca2+ sparks, reduces Ca2+ transient variability, and hastens the decay of Ca2+ transients: all these effects are similarly exerted by β-adrenergic stimulation in control and HF cardiomyocytes. Conversely, β-adrenergic stimulation in HF cells accelerates a Ca2+ rise exclusively in the proximity of T-tubules that regularly conduct the action potential. The delayed Ca2+ rise found at T-tubules that fail to conduct the action potential is instead not affected by β-adrenergic signalling. Taken together, these findings indicate that HF cells globally respond to β-adrenergic stimulation, except at T-tubules that fail to conduct action potentials, where the blunted effect of the β-adrenergic signalling may be directly caused by the lack of electrical activity.File | Dimensione | Formato | |
---|---|---|---|
Crocini et al IJMS2016.pdf
accesso aperto
Descrizione: Articolo principale
Tipologia:
Pdf editoriale (Version of record)
Licenza:
Open Access
Dimensione
1.07 MB
Formato
Adobe PDF
|
1.07 MB | Adobe PDF |
I documenti in FLORE sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.