Module 3: Figure smooth muscle cell Ca2+ sparks

Effect of deleting the β1 subunit of the large-conducatance (BK) channel on spark frequency in smooth muscle cells.

a. Images of a smooth muscle cell from a β1 knockout mouse (β1-KO) taken every 8.33 ms to show the generation and recovery of a Ca2+ spark. b. Simultaneous measurements of large-conducatance (BK) currents (shown in blue) and Ca2+ sparks (red) in a control cell and a β1−/− (β1-KO) cell, which had two spark sites (red and black). Note how the sparks in the β1-KO cell had very little effect on the BK current in comparison with the control cells, where each spark produced a large current response. Reproduced by permission from Macmillan Publishers Ltd: Nature, Brenner, R., Peréz, G.J., Bonev, A.D., Eckman, D.M., Kosek, J.C., Wiler, S.W., Patterson, A.J., Nelson, M.T. and Aldrich, R.W. (2000) Vasoregulation by the β1 subunit of the calcium-activated potassium channel. Vol. 407, pp. 870–876. Copyright (2000);; Brenner et al. 2000.