Effects of pH on Nifekalant-Induced Electrophysiological Change Assessed in the Langendorff Heart Model of Guinea Pigs

• Kazusa Katsuyuki

  Department of Pharmacology, Faculty of Medicine, Toho University, Japan

• Nakamura Yuji

  Department of Pharmacology, Faculty of Medicine, Toho University, Japan

• Watanabe Yudai

  Department of Pharmacology, Faculty of Medicine, Toho University, Japan

• Ando Kentaro

  Department of Pharmacology, Faculty of Medicine, Toho University, Japan

• Sugiyama Atsushi

  Department of Pharmacology, Faculty of Medicine, Toho University, Japan

抄録

Since information regarding the effects of pH on the extent of nifekalant-induced repolarization delay and torsades de pointes remains limited, we assessed it with a Langendorff heart model of guinea pigs. First, we investigated the effects of pH change from 7.4 to 6.4 on the bipolar electrogram simulating surface lead II ECG, monophasic action potential (MAP), effective refractory period (ERP), and terminal repolarization period (TRP) and found that acidic condition transiently enhanced the ventricular repolarization. Next, we investigated the effects of pH change from 6.4 to 7.4 in the presence of nifekalant (10 μM) on the ECG, MAP, ERP, TRP, and short-term variability (STV) of MAP₉₀ and found that the normalization of pH prolonged the MAP₉₀ and ERP while the TRP remained unchanged, suggesting the increase in electrical vulnerability of the ventricle. Meanwhile, the STV of MAP₉₀ was the largest at pH 6.4 in the presence of nifekalant, indicating the increase in temporal dispersion of repolarization, which gradually decreased with the return of pH to 7.4.Thus, a recovery period from acidosis might be more dangerous than during the acidosis, because electrical vulnerability may significantly increase for this period while temporal dispersion of repolarization remained increased.

収録刊行物

• Journal of Pharmacological Sciences

  Journal of Pharmacological Sciences 124 (2), 153-159, 2014

  公益社団法人 日本薬理学会

キーワード

• nifekalant
• acidosis
• Langendorff
• torsades de pointes
• monophasic action potential

詳細情報

• CRID: 1390282680155871232
• NII論文ID: 130003391474
• NII書誌ID: AA11806667
• DOI: 10.1254/jphs.13127fp
• COI: 1:CAS:528:DC%2BC2cXkt1egtrc%3D
• ISSN: 13478648
• ISSN: 13478613
• NDL書誌ID: 025296125
• PubMed: 24451996
• Web Site: https://ndlsearch.ndl.go.jp/books/R000000004-I025296125
• Web Site: https://www.jstage.jst.go.jp/article/jphs/124/2/124_13127FP/_pdf
• Web Site: https://search.jamas.or.jp/link/ui/2014299887
• 本文言語コード: en
• データソース種別:
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  • NDL
  • Crossref
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