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.

The cellular basis of contraction in human detrusor smooth muscle from patients with stable and unstable bladders / 医学研究生学报

Considerable advances have been made in the understanding of the cellular processes that result in contraction and relaxation of detrusor smooth muscle recently,particularly in the role and modulation of calcium.Several changes in these cellular mechanisms that impair normal function have been observed in detrusor muscle from patients with unstable bladders.Whether these changes represent primary causes of bladder dysfunction or whether they are secondary to bladder dysfunction remains to be determined.Nevertheless,the identification of specific cellular lesions in bladder dysfunction presents a novel approach to identification of drug targets and potential treatment modalities.