Effects of ryanodine receptor channels on the spontaneous contractions of detrusor in rats of detrusor instability
- VernacularTitle:逼尿肌不稳定大鼠中RyR通道对自发性收缩影响的实验研究
- Author:
Haihong JIANG
;
Gensheng LU
;
Qianjun WEN
;
Bo SONG
- Publication Type:Journal Article
- Keywords:
detrusor instability;
ryanodine receptor channels;
spontaneous contraction;
sarcoplasmic reticulum
- From:Journal of Third Military Medical University
2003;0(08):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To explore the myogenic basis of the increased excitability and contractile activity in detrusor instability (DI) and investigate the differences of spontaneous contractions by ryanodine receptor (RyR) channels regulation in sarcoplasmic reticulum (SR) between DI and normal bladder muscle and of the RyR channels protein expression. Methods DI model was confirmed by filling cystometry from rats that underwent partial bladder outlet obstruction (BOO) about 8 weeks ago. Muscle strips were dissected from fresh bladder under microscope and the isometric tension in DI and normal strips were detected. The contractions were recorded in these strips exposed to some agents. SR microsome protein was obtained from DI and normal bladder muscle preparations and was used for Western blot analysis to determinate RyR channels expression. Results Treated with RyR channels blocker ryanodine , the contractile frequence significantly increased in normal strips, but not in DI muscle. Western blot analysis showed that RyR channels expression in DI muscle was significantly less than that in normal preparations. Conclusion RyR channels act a negative role in spontaneous contractile activity and the presumed mechanism may involve in Ca 2+ release of RyR channels which causes activation of Ca 2+ -dependent K + channels to decrease contractility. But this crosstalk mechanism is weaken in DI muscle, which provides a chance for spontaneous contractile overactivity.
