Pflügers Archiv

, Volume 423, Issue 1, pp 133–139

Temperature dependence of gap junction properties in neonatal rat heart cells

Authors

  • Feliksas F. Bukauskas
    • Kaunas Medical Academy
  • Robert Weingart
    • Department of Physiology
Excitable Tissues and Central Nervous Physiology

DOI: 10.1007/BF00374970

Cite this article as:
Bukauskas, F.F. & Weingart, R. Pflugers Arch. (1993) 423: 133. doi:10.1007/BF00374970

Abstract

Cell pairs of neonatal rat hearts were used to study the influence of temperature on the electrical properties of gap junctions. A dual voltage-clamp method was adopted, which allowed the voltage gradient between the cells to be controlled and the intercellular current flow to be measured. Cell pairs with normal coupling revealed a positive correlation between the conductance of the junctional membranes, g j, and temperature. Cooling from 37° C to 14° C led to a steeper decrease in g j, cooling from 14° C to -2° C to a shallower decrease (37° C: g j=48.3 nS; 14° C: g j=21.4 nS;-2°C: g j=17.5 nS), corresponding to a temperature coefficient, Q 10, of 1.43 and 1.14 respectively. The existence of two Q 10 values implies that g j may be controlled by enzymatic reactions. When g j was low, i. e. below 5 nS (conditions: low temperature; treatment with 3 mM heptanol), it showed voltage-dependent gating. This property was not visible when g j was large, i. e. 20–70 nS (conditions: high temperature; normal saline), presumably because of series resistances (pipette resistance). Cell pairs with weak intrinsic coupling and normally coupled cell pairs treated with 3 mM heptanol revealed a positive correlation between the conductance of single gap-junction channels, γ j, and temperature (37° C: 75.6 pS; -2°C: 19.6 pS), corresponding to a Q 10 of 1.41.

Key words

Neonatal rat heart Cardiac cells Gap junctions Electrical coupling Temperature

Copyright information

© Springer-Verlag 1993