Protective Effect of Benidipine Against the Abnormal Elictrical Activity in Single Ventricular Myocytes of the Guinea Pig Under Simulated Ischemic Conditions and Reperfusion

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Author(s)

Abstract

Induction of electrical abnormalities(EAs)under simulated ischemic conditions and after reperfusion was measured from single cardiac myocytes isolated from guinea pig ventricle using whole-cell voltage or current clamp with perforated patch variation.Conditions of simulated ischemia were produced by the exchange of medium from the standard one oxygenated with 95%O<SUB>2</SUB>−5%CO<SUB>2</SUB> gas(pH7.4)to the modified one, which contained no glucose, 8mM K<SUP>+</SUP> and 30mM sodium-D, L-lactate and was gassed with 90% argon −10%CO<SUB>2</SUB>(pH6.6).Under the simulated ischemia for 20min, EAs such as delayed afterdepolarization, early afterdepolarization, automatic activity or transient inward current were observed in about 37% of myocytes driven electrically at 1Hz.Irreversible hypercontracture occurred in myocytes of 10% or less.Upon reperfusion with the standard solution, EAs and hypercontracture were oberved in about 43% and 22% of cells, respectively.Glibenclamide-sensitive current was detected during ischemia, but tended to be enhanced during reperfusion.Amplitude of Ca<SUP>2+</SUP> current and ATP-sensitive K<SUP>+</SUP> current after reperfusion varied widely with time and from cell to cell.When myocytes were pretreated for 10min with 10nM benidipine, a 1, 4-dihydropyridine derivative Ca<SUP>2+</SUP> blocker, the incidence of EAs and hypercontracture was markedly reduced, suggesting the protective effect of benidipine against cardiac cell injury during ischemia and reperfusion.

Journal

  • The Japanese Journal of Pharmacology

    The Japanese Journal of Pharmacology 82(3), 199-209, 2000-03-01

    The Japanese Pharmacological Society

References:  38

Cited by:  2

Codes

  • NII Article ID (NAID)
    10008183423
  • NII NACSIS-CAT ID (NCID)
    AA00691188
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    00215198
  • NDL Article ID
    5320979
  • NDL Source Classification
    ZS51(科学技術--薬学)
  • NDL Call No.
    Z53-D199
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
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