title: Cell-to-cell coupling studied in isolated ventricular cell pairs.
abstract: Cell pairs isolated from adult rat and guinea pig ventricles were used to study the electrical properties of the nexal membrane. Each cell of a pair was connected to a voltage-clamp system so as to enable whole-cell, tight-seal recording. The current-voltage relationship of the nexal membrane was found to be linear, revealing a resistance rn of 2-4 M omega. rn was insensitive to the sarcolemmal membrane potential (range: -90 to +30 mV), and exerted no time-dependent gating behavior (range: 0.1 to 10 s). Lowering pHi yielded a small increase in rn. Vigorous elevations in [Ca2+]i gave rise to an increase in rn which was associated with a cell shortening. Uncoupling caused by aliphatic alcohols or halothane did not produce cell shortening. Cell pairs were also used to study action potential transfer.
mesh_terms: D000200:Action Potentials; D000818:Animals; D002118:Calcium / Q000378:metabolism; D002450:Cell Communication; D002462:Cell Membrane / Q000502:physiology; D004553:Electric Conductivity; D006168:Guinea Pigs; D006321:Heart / Q000502:physiology*; D007473:Ion Channels / Q000502:physiology; D008564:Membrane Potentials; D011188:Potassium / Q000378:metabolism; D051381:Rats; D016276:Ventricular Function
chemical_list: D007473:Ion Channels; D011188:Potassium; D002118:Calcium