TY  - JOUR
JF  - BASIC RESEARCH IN CARDIOLOGY
VL  - 88
SN  - 0300-8428
EP  - 102
N1  - Department of Pharmacology, Szent-Györgyi Albert Medical University, Dóm tér 12, Szeged, H-6701, Hungary            
Department of Veterinary Preclinical Sciences, University of Liverpool, United Kingdom            
Department of Medical Physiology, Institute of Medical Biology, University of Tromsř, Norway            
Department of Physiology, University Medical School of Debrecen, Hungary
            CODEN: BRCAB            
Correspondence Address: Varró, A.; Department of Pharmacology, Szent-Györgyi Albert Medical University, Dóm tér 12, Szeged, H-6701, Hungary            
            Chemicals/CAS: Calcium Channels; Calcium, 7440-70-2; Potassium Channels; Potassium, 7440-09-7
AV  - restricted
UR  - https://doi.org/10.1007/BF00798257
Y1  - 1993///
ID  - publicatio32183
IS  - 2
SP  - 93
TI  - Ionic currents and action potentials in rabbit, rat, and guinea pig ventricular myocytes
A1  -  Varró András
A1  -  Lathrop David A
A1  -  Hester SB
A1  -  Nánási Péter Pál
A1  -  Papp Gyula
N2  - Distinct differences exist in action potentials and ionic currents between rabbit, rat, and guinea pig ventricular myocytes. Data obtained at room temperature indicate that about half of the rabbit myocytes show prominent phase 1 repolarization and transient outward current.
Action potentials in guinea pig ventricular myocytes resemble those from rabbit myocytes not exhibiting phase 1 repolarization; and guinea pig myocytes do not develop transient outward current. Rat ventricular action potentials are significantly shorter than those from rabbit and guinea pig ventricular myocytes. Unlike rabbit and guinea pig myocytes,
rat ventricular myocytes also exhibit a prominent phase 1 and lack a well defined plateau phase during repolarization. All rat ventricular myocytes exhibit a transient outward current which can be best fitted by a double exponential relation. There are no significant differences between the amplitude, voltage dependence and inactivation kinetics of the inward calcium currents observed in rabbit, rat and guinea pig. The steady-state current-voltage relations between -120 mV and -20 mV, which mostly represent the inward rectifier potassium current are similar in rabbit and guinea pig. The amplitude of this current is significantly less in rat ventricular myocytes. The outward currents activated upon depolarization to between -10 and +50 mV are different in the three species. Only a negligible, or absent, delayed rectifier outward current has been observed in rabbit and rat; however, a relatively large delayed rectifier current has been found in guinea pig. These large interspecies variations in outward membrane currents help explain the differences in action potential configurations observed in rabbit, rat, and guinea pig.
ER  -