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Ionic currents and action potentials in rabbit, rat, and guinea pig ventricular myocytes.
Basic Res Cardiol. 1993 Mar-Apr; 88(2):93-102.BR

Abstract

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.

Authors+Show Affiliations

Department of Pharmacology, Szent-Györgyi Albert Medical University, Szeged, Hungary.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Comparative Study
Journal Article
Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, P.H.S.

Language

eng

PubMed ID

8389123

Citation

Varró, A, et al. "Ionic Currents and Action Potentials in Rabbit, Rat, and Guinea Pig Ventricular Myocytes." Basic Research in Cardiology, vol. 88, no. 2, 1993, pp. 93-102.
Varró A, Lathrop DA, Hester SB, et al. Ionic currents and action potentials in rabbit, rat, and guinea pig ventricular myocytes. Basic Res Cardiol. 1993;88(2):93-102.
Varró, A., Lathrop, D. A., Hester, S. B., Nánási, P. P., & Papp, J. G. (1993). Ionic currents and action potentials in rabbit, rat, and guinea pig ventricular myocytes. Basic Research in Cardiology, 88(2), 93-102.
Varró A, et al. Ionic Currents and Action Potentials in Rabbit, Rat, and Guinea Pig Ventricular Myocytes. Basic Res Cardiol. 1993 Mar-Apr;88(2):93-102. PubMed PMID: 8389123.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Ionic currents and action potentials in rabbit, rat, and guinea pig ventricular myocytes. AU - Varró,A, AU - Lathrop,D A, AU - Hester,S B, AU - Nánási,P P, AU - Papp,J G, PY - 1993/3/1/pubmed PY - 1993/3/1/medline PY - 1993/3/1/entrez SP - 93 EP - 102 JF - Basic research in cardiology JO - Basic Res Cardiol VL - 88 IS - 2 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. SN - 0300-8428 UR - https://www.unboundmedicine.com/medline/citation/8389123/Ionic_currents_and_action_potentials_in_rabbit_rat_and_guinea_pig_ventricular_myocytes_ DB - PRIME DP - Unbound Medicine ER -