Valdeolmillos M, O'Neill S C, Smith G L, Eisner D A
Department of Physiology, University College London, Great Britain.
Pflugers Arch. 1989 Apr;413(6):676-8. doi: 10.1007/BF00581820.
The "caged" calcium chelator Nitr-5 was incorporated into isolated rat ventricular myocytes. Brief illumination with ultra-violet light made the cell twitch. The light-induced twitch was inhibited by ryanodine (1-10/microM) suggesting that it resulted from calcium-induced release of calcium from the sarcoplasmic reticulum. Inhibition of the Ca current (Ni, 10 mM) abolished the electrically stimulated twitch but did not inhibit the light-induced twitch. These results provide direct evidence for the importance of Ca-induced Ca release in excitation-contraction coupling in the heart.
