2000/11/01 by Patricia J. Cooper, Ming Lei, Longxian Cheng +1 · 4 citations
Medicine · Neuroscience · Biochemistry, Genetics and Molecular Biology · #Cardiac electrophysiology and arrhythmias #Neuroscience and Neural Engineering #Ion channel regulation and function
paper · doi:10.1152/jappl.2000.89.5.2099
openalex publication_date 2000/11/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
Isolated, spontaneously beating rabbit sinoatrial node cells were subjected to longitudinal stretch, using carbon fibers attached to both ends of the cell. Their electrical behavior was studied simultaneously in current-clamp or voltage-clamp mode using the perforated patch configuration. Moderate stretch ( approximately 7%) caused an increase in spontaneous beating rate (by approximately 5%) and a reduction in maximum diastolic and systolic potentials (by approximately 2.5%), as seen in multicellular preparations. Mathematical modeling of the stretch intervention showed the experimental results to be compatible with stretch activation of cation nonselective ion channels, similar to those found in other cardiac cell populations. Voltage-clamp experiments validated the presence of a stretch-induced current component with a reversal potential near -11 mV. These data confirm, for the first time, that the positive chronotropic response of the heart to stretch is, at least in part, encoded on the level of individual sinoatrial node pacemaker cells; all reported data are in agreement with a major contribution of stretch-activated cation nonselective channels to this response.