逼尿肌不稳定与肾上腺能β受体关系的研究

Correlation between β-adrenoceptor and detrusor instability

目的 :研究 β肾上腺素受体 ( β -AR)在膀胱出口梗阻 (BOO)型逼尿肌不稳定中的作用。 方法 :建立大鼠BOO型逼尿肌不稳定动物模型 ,离体逼尿肌条拉力实验观察逼尿肌不稳定时异丙肾上腺素 (IsoprenalineISO)对逼尿肌舒张功能的影响 ,采用放射配基结合法侧定BOO型逼尿肌不稳定和稳定组及正常对照组大鼠逼尿肌 β受体最大结合容量 (Bmax)和平衡解离常数 (Kd)。结果 :ISO对逼尿肌的松弛作用呈浓度依赖性 ,对不稳定膀胱组的作用强度明显低于正常对照组及梗阻后稳定组 ,P <0 0 5 ,对逼尿肌的松弛作用呈浓度依赖性 ,对不稳定膀胱组的作用强度明显低于正常对照组及梗阻后稳定组 ,P <0 0 5 ,梗阻后不稳定组 β-AR密度 (Bmax)较正常对照组及梗阻后稳定组明显降低 ,结果分别是 ( 6 6 2 3± 6 39)fmol/mg蛋白、 ( 85 85± 7 5 3)fmol/mg蛋白和 ( 81 36± 6 72 )fmol/mg蛋白 ,三组动物之间β -AR的Kd无明显差异 ,P >0 0 5。结论 :逼尿肌不稳定时 β -AR激动剂松弛逼尿肌的作用减弱 ,β -AR密度变化可能参与大鼠BOO后逼尿肌不稳定的发生 ,选择性 β-AR激动剂可以用于不稳定膀胱治疗。

Objective:To explore the effect of β-adrenoceptor(β-AR)on detrusor instability in rats with bladder outflow obstruction(BOO).Methods:The animal model of detrusor instability with BOO was established.Detrusor strip dynamic experiment in vitro was used to observe the effect of isoprenaline (ISO)on the relaxation function of the detrusor when it was unstable.Radioigandbinding assay was employed to detect the maximum binding capacity of β-AR(β max )and its equilibrium dissociation constant(kd)in rats.Results:The effect of ISO on the relaxation of detrusor that depended on the concentration in instability group was much weaker than that in normal group and stable group(P<0 05).The density of β-AR in instability group decreased significantly compared with that in normal group and instability group,which was (66 23±6 39)fmol/mg,(85 85±7 53)fmol/mg and (81 36±6 39)fmol/mg,respectively.No significant difference of the kd among 3 groups was observed (P>0 05)?Conclusion:The relaxant effect of β-AR agonist on the detrusor decreased when it was unstable.The change of the β-AR density may play a role in detrusor instability and selective β-AR agonist might be useful in the treatment of unstable bladder.