Role of Ca~(2+) signaling in overexpression of detrusor smooth muscle cell connexin 43 by cyclic stretch in vitro / 第三军医大学学报

Objective To investigate the role of Ca 2+ signaling in the overexpression of detrusor smooth muscle cell connexin 43 by cyclic stretch in vitro. Methods The detrusor smooth muscle cells (DSMC) grown on collagen-coated silicone membranes were subjected to cyclic stretch-relaxation. The Cx43 mRNA in DSMC were detected with RT-PCR, and the concentration of intracellular free Ca 2+ in DSMC was measured by confocal microscopy in conjunction with the calcium indicator, Fura-3 (Molecular Probes). Results The overexpression of Cx43 mRNA induced by cyclic stretch was significantly inhibited by EGTA.The increase of intracellular free Ca 2+ induced by stretch was also inhibited completely by EGTA, 61.95% by GdCl3, 29.98% by Nifedipine, 87.98% by Ryanodine and Thapsigargin. Conclusion The stretch-induced Ca 2+ entry, via the Ca 2+-induced Ca 2+ release mechanism, may play an important role in DSMC connexin 43 overexpression induced by cyclic stretch.