Implantation of Sinoatrial Node Cells into Canine Right Ventricle: Biological Pacing Appears Limited by the Substrate
| Autor: | David H. Lau, Richard B. Robinson, Hao Zhang, Ira S. Cohen, Iryna N. Shlapakova, Xin Zhao, Zhiyun Xu, Peter Danilo, Dan Qu, Michael R. Rosen |
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| Rok vydání: | 2011 |
| Předmět: |
Male
Pathology medicine.medical_specialty Patch-Clamp Techniques Epinephrine Heart block Heart Ventricles Biomedical Engineering Action Potentials lcsh:Medicine Inflammation Biology Transplantation Autologous Umbilical cord Article Electrocardiography Pacemaker potential Dogs Biological Clocks medicine Animals Cells Cultured Sinoatrial Node Transplantation Sinoatrial node lcsh:R Mesenchymal stem cell Cell Biology respiratory system medicine.disease respiratory tract diseases Surgery Heart Block medicine.anatomical_structure Ventricle medicine.symptom |
| Zdroj: | Cell Transplantation, Vol 20 (2011) |
| ISSN: | 1555-3892 0963-6897 |
| Popis: | 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 (If) 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. |
| Databáze: | OpenAIRE |
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