Module 12: Figure CSQ-induced hypertrophy
Comparison of Ca2+ release patterns in control (A, C and E) and hypertrophic (B, D and F) cardiac myocytes overexpressing calsequestrin (CSQ).
The distribution of Ca2+ at rest (−70 mV; A and B) and after stimulation (depolarization to 0 mV; C and D) clearly shows that the control cells display Ca2+ sparks at rest (A) and a large global signal upon stimulation (C). By contrast, the hypertrophic myocyte displayed no sparks (B), and the signal following activation was much smaller and had a blotchy appearance (D). Note that the Ca2+ current (ICa) that flows into the cell is larger and inactivates quicker (E, *) than that in the hypertrophic cell (F, **). The lower traces indicate that the Ca2+ transient in control cells is larger and sharper than that recorded in hypertrophic cells. Reproduced, with permission, from Jones, L.R., Suzuki, Y.S., Wang, W., Kobayshi, V.R., Ramesh, V., Franzini-Armstrong, C., Cleeman, L. and Morad, M. (1998) Regulation of Ca2+ signaling in transgenic mouse cardiac myocytes overexpressing calsequestrin. J. Clin. Invest. 101:1385–1393; see Jones et al. 1998.