Ca2+ sparks evoked by loose-patch method

    SHEN Jianª²Xin, WANG Shiª²Qiang, CHENG Heª²Ping, HAN Taiª²Zhen

    1Department of Physiology, Medical College, Xi¬ðan Jiaotong University, Xi¬ðan 710061, China, 2Department of Physiology, Medical College, Shantou University, Shantou 515041, China, 3National Laboratory of Biomembrane & Membrane Biotechnology, College of Life Science, Peking University, Beijing 100871, China

    ¡¾Abstract¡¿ AIM: To investigate the main characteristics of cardiac Ca2+ sparks evoked by loose-patch method. METHODS: Loose-seal patch-clamp combined with confocal microscopic Ca2+ imaging (Loose-patch Method) was used. RESULTS: The probability for the Loose-patch Method to evoke in-focus Ca2+ sparks was 72.2%, which was much higher than the activation of spontaneous Ca2+ sparks. The amplitude for the averaged Ca2+ sparks evoked by Loose-patch Method was (1.07¡À0.06) (in ¦¤F/F0, the normalized fluorescence, where F0 denotes the resting fluorescence) and the averaged spatial width was (1.44¡À0.03) ¦Ìm (n=124). CONCLUSION: Loose-patch Method, while maintaining the normal signaling coupling between L-type Ca2+ channel and ryanodine receptors, can evoke Ca2+ sparks and the characteristics of Ca2+ sparks by activating Ca2+ release locally and in-focus can be recorded by confocal microscope. ......