Electrophysiological aspects of the effect of creatine phosphate on myocardial cellular activity in the normal state and in ischemia
Rozenshtraukh, L.V.; Witt, R.; Rozanski, G.
Kardiologiia 30(11): 97-101
1990
ISSN/ISBN: 0022-9040 PMID: 2087047 Document Number: 352719
The electrophysiologic effects of phosphocreatine were assessed in isolated, superfused guinea pig ventricular tissues to gain an insight into its purported antiarrhythmic properties. Under normal conditions, 10 mM phosphocreatine significantly increased effective refractory period by 14.0 +/- 0.4%, but under ischemic-like conditions (hypoxia, hyperkalemia, acidosis) it showed no significant effect. Moreover, phosphocreatine reduced free [Ca2+]0 by nearly 20% and the changes induced by this compound in control tissues could be largely reproduced with an altered Tyrode's solution containing less than 0.6 mM Ca2+. The experiments suggest that phosphocreatine may act in a similar manner as class III antiarrhythmic agents on non-ischemic, normal tissue by mechanisms related in part to changes in extracellular Ca2+ composition.