自動能についての研究 (III)

洞結節細胞で作動する二つの Electrogenic pump

抄録

Pacemaker cells of the isolated sinus node of the rabbit were exposed to the K-free and ouabain Krebs solution. Potentials recorded by means of a conventional microelectrode technique showed two types of electrogenic pump.
One of the pump was evidenced by the hyperpolarization which was activated by K⁺, Rb⁺ and Cs⁺ after applying of the K-free solution. The another was the fluctuation potential which was evoked by the K-free and ouabain solution. The former was inhibited with applying of ouabain while the latter was voltage- and Ca-dependent.
It was dicussed that the K-activated hyperpolarizatization was caused from K-cleft, and the fluctuation from the slow inward current of Ca⁺⁺.