食用ガエル心房筋の興奮収縮連関過程におよぼすpHの効果

DOI Web Site Web Site

書誌事項

タイトル別名
  • Effects of pH on the Processes of Excitation-Contraction Coupling of Bullfrog Atrium
  • ショクヨウ ガエル シンボウ キン ノ コウフン シュウシュク レンカン カテ

この論文をさがす

抄録

It has long been demonstrated that in cardiac muscle alterations in the extracellular pH exhibit a remarkable inotropic effect, whereas the precise mechanism is not fully clarified yet in spite of many associated thories. In recent years, however, abundant informations about the processes of excitation-contraction coupling (E-C coupling) of cardiac muscle have been obtained. Accordingly, the mechanisms of inotropic actions of pH on cardiac muscle must also be reexamined on the basis of these lately developed theories of E-C coupling. In the present experiment, therefore, we attempted to elucidate the fundamental mechanism of actions of pH upon several processes of E-C coupling using the bullfrog atrium whose processes of E-C coupling have been fairly well known. The preparation used in the present experiments were the atrial muscle bundles isolated from the bullfrog (Rana cathesbiana). The effects of changes in the external pH on action potential (AP), twitch tension and potassium contracture were observed in one series of experiments, in which AP was developed by means of double glycerol gap method and potassium contracture, by replacing a Ringer solution with a contracture solution containing 100 mM KCl. In the second series, the membrane potential was depolarized to the required levels in order to observe the effects of pH on the membrane currents and contraction. The voltage clamp appratus for the experiment was the same to those used by New and Trautwein (1972a). The pH was set to required values by bubbling with adequately mixtured gases (100% O2 and 100% CO2), or by adding the appropriate amount of NaOH to the Ringer solution containing 2 mM each of a acetylglycine, maleic acid and Tris (hydroxymethyl)-aminonethane.

収録刊行物

キーワード

詳細情報 詳細情報について

問題の指摘

ページトップへ