Relationship between postextrasystolic potentiation and slow-phase force-frequency response in guinea-pig ventricular myocardium.
Relationship between postextrasystolic potentiation and slow-phase force-frequency response in guinea-pig ventricular myocardium. Acta physiol. pol. 1985, 36 (2): 175-184. We investigated relationship between postextrasystolic potentiation (PESP) and a form of slow-phase force-frequency relation, namely the post-rest recovery of contractile force (CF). We found that although the degree of post-rest recovery of CF determines CF of the potentiated beats, PESP does not affect the time-course of post-rest recovery, even if it is sustained by means of paired stimulation. Moreover, PESP may be completely or almost completely inhibited by caffeine in 10 mmolar concentration, whereas post-rest recovery is not significantly affected by this drug. We conclude, that PESP and slow force-frequency relations are based on separate cellular mechanisms.
D000200:Action Potentials; D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D006168:Guinea Pigs; D006321:Heart / Q000502:physiology*; D006352:Heart Ventricles / Q000187:drug effects; D066298:In Vitro Techniques; D009200:Myocardial Contraction / Q000187:drug effects; D013599:Systole; D016276:Ventricular Function
D002110:Caffeine