The demonstration of intercellular coupling between cells of the canine distal AV bundle using lucifer yellow-CH and histological sections.
To determine whether iontophoresed lucifer yellow and histological paraffin sections could be utilized to evaluate electrical coupling in the canine heart, the negatively charged vital dye was injected into cells of the distal AV bundle (DAVB) in superfused atrial preparations by applying a hyperpolarizing 35 to 100 nA current. Dye injection periods ranged from minutes to over an hour in some cells. Following diffusion periods of 1 to 19 h, fluorescence was found to be restricted to fascicular compartments over a distance of 0.06 to 3.0 mm. Since the fascicles contained eight to nine fibers, and the cells have an estimated length of 0.1 mm, dye had diffused into as many as 200 cells. The results produced novel findings concerning the apparent electrical isolation of fascicles within the DAVB and it is suggested that the method may possibly be useful in tracing intercellularly coupled pathways.
Racker
D K
DK
Department of Biophysics and Physiology, Chicago Medical School, North Chicago 60064.
D000818:Animals; D002036:Bundle of His / Q000502:physiology*; D002450:Cell Communication; D004058:Diffusion; D004285:Dogs; D004594:Electrophysiology; D005456:Fluorescent Dyes; D006329:Heart Conduction System / Q000502:physiology*; D006339:Heart Rate; D006652:Histological Techniques; D007478:Iontophoresis; D007546:Isoquinolines / Q000032:analysis; D013997:Time Factors
D005456:Fluorescent Dyes; D007546:Isoquinolines; C017475:lucifer yellow