Implantation of sinoatrial node cells into canine right ventricle: biological pacing appears limited by the substrate.
Cell Transplant
; 20(11-12): 1907-14, 2011.
Article
em En
| MEDLINE
| ID: mdl-21429290
ABSTRACT
Biological pacing has been proposed as a physiologic counterpart to electronic pacing, and the sinoatrial node (SAN) is the general standard for biological pacemakers. We tested the expression of SAN pacemaker cell activity when implanted autologously in the right ventricle (RV). We induced complete heart block and implanted electronic pacemakers in the RV of adult mongrel dogs. Autologous SAN cells isolated enzymatically were studied by patch clamp to confirm SAN identity. SAN cells (400,000) were injected into the RV subepicardial free wall and dogs were monitored for 2 weeks. Pacemaker function was assessed by overdrive pacing and IV epinephrine challenge. SAN cells expressed a time-dependent inward current (I(f)) activating on hyperpolarization density = 4.3 ± 0.6 pA/pF at -105 mV. Four of the six dogs demonstrated >50% of beats originating from the implant site at 24 h. Biological pacemaker rates on days 7-14 = 45-55 bpm and post-overdrive escape times = 1.5-2.5 s. Brisk catecholamine responsiveness occurred. Dogs implanted with autologous SAN cells manifest biological pacing properties dissimilar from those of the anatomic SAN. This highlights the importance of cell and substrate interaction in generating biological pacemaker function.
Texto completo:
1
Bases de dados:
MEDLINE
Assunto principal:
Nó Sinoatrial
/
Relógios Biológicos
Limite:
Animals
Idioma:
En
Revista:
Cell Transplant
Assunto da revista:
TRANSPLANTE
Ano de publicação:
2011
Tipo de documento:
Article
País de afiliação:
China